Abstract:The realtime accurate position update technology of agricultural machinery was one of the most important studies in agricultural machinery automatic navigation system, and it has a very important significance to improve the efficiency of intelligent agricultural production. However, in the field operation of agricultural machinery automatic navigation system, the situations that the number of satellite was unstable, the GPS signal was blocked, and data transmission was wrong would cause low location precision and poor stability. In order to solve the above problems, a two dimensional kinematic model of agricultural machinery was built, and an adaptive extended Kalman filtering algorithm which adjusted the system’s state covariance was carried out based on the integrated navigation system of GNSS/MIMU/DR. The algorithm was used to compute the difference of present estimate and predictive value. When the difference became greater, it showed that the system state had changed greatly, so as to make appropriate adjustments to the system state covariance matrix for better filtering. The algorithm was verified by static test and linear guide rail test to accurately evaluate the accuracy of the integrated navigation and positioning system. The tests indicated that: in static state, the average value deviation of heading was 0.0014°, the maximum deviation was 0.0998°, the standard deviation was 0.0474°, and the position average deviation was 0.0037m, the maximum deviation was 0.0081m, the standard deviation was 0.0010m; in straight rail state, the average value deviation of heading was 0.0245°, the maximum deviation was 0.4324°, the standard deviation was 0.2511°, and the position average deviation was 0.0076m, the maximum deviation was 0.0186m, the standard deviation was 0.0044m. All the different evaluations proved that the adjusted filtering was superior to the traditional filtering, which indicated the necessity and superiority of the proposed algorithm. At the same time, it is proved that the method can satisfy the accuracy and stability requirements of the agricultural machinery navigation and positioning system.

Abstract:Aiming at reducing the influence caused by uneven fields to the working quality of precision agricultural equipment, lots of agricultural machinery were designed with special mechanisms to profile the farm surface, while the working efficiency is still limited to the response rate of servo and control system. For above reasons, a kind of ARMA (Autoregressive and moving average) algorithm was put forward and then be applied to predict vehicle attitudes so as to realize compensation control for tractor implement. The theory and applicability of ARMA were analyzed in detail before modelling using roll angle data collected from a working rice transplanter by the Inertia and GNSS measurement system. Finally, a 90slength data set was acquired of which the first 60s data was used to model, while the last 30s data was designed to make comparison with predicted values. In order to reduce the amount of calculation, the 100Hz raw data at frequency of 2Hz, 5Hz and 10Hz was output and then predicted the future roll angle of the three sets of data in 1~2 s respectively. First of all, the different method was deployed to make angle series stationary; secondly, a combining method of box ordersearch solution and the MLE (Maximum likelihood estimation) was adopted to build models; at last, with the aid of AIC (Akaike information criterion), the final best model was identified after confirming the AIC. For better following of the dynamic trend of rice transplanter attitude and eliminating the negative influence brought by the increasing amount of sample data, the online modelling method that older sample data was substituted constantly by new observational values in the modeling process was needed. By using three groups of sample data, prediction of rice transplanter attitude in future 1~2s was conducted utilizing Matlab, meanwhile, the whole predicting time was 30s. The results showed that: the validity of ARMA model in predicting attitude trend of farm vehicles was proven; for all the three sets of angle samples, 2s predicting error shows larger than 1s predicting error; the 5Hz roll angle series showed the best predicting effect, with 1s RMSE (root mean square error) and std (Standard deviation) of 0.6567°and 0.6565°, and 2s RMSE and std of 0.6712° and 0.6769° respectively.

Abstract:GNSScontrolled land leveling system is complicated to operate and farmland measuring is timeconsuming, in order to solve these problems, this paper aimed at developing a fast GNSScontrolled land leveling system. The system including the core processing platform, GNSS signal receiving device and hydraulic. The system can achieve the fast farmland reference design, graphic land leveling, slope land leveling; the farmland reference design meant realtime correction calculation of the reference plane prior operation and in operation without farmland measuring, which increased the accuracy; the algorithm of slope land design was optimized based on the early stage of the system algorithm，and the slope land leveling algorithm applied to the fast GNSScontrolled land leveling system was proposed. Since this system can work without farmland measuring, it can be applied to the paddy field leveling which couldnt be measured. After slope leveling, it can achieve the fast irrigation water and the uniform water coverage, reduce the amount of cutting and filling soil as well as improve the leveling speed. Longterm experiment was done to test the system and results showed that after the graphic leveling, the maximum elevation difference was decreased from 18.9cm to 8.1cm, elevation standard deviation was decreased from 11.2cm to 5.5cm, the average land leveling measuring point error was less than 5cm, and the cumulative percentage rose from 75.693% to 90.674%.After slope leveling, the actual farmland slope was similar to the designed slope, leveling speed was fast and leveling effect was good.

Abstract:In order to improve the efficiency of GNSS (global navigation satellite system) controlled land leveling system, the feasibility of automatic GNSScontrolled land leveling system was discussed. A path planning algorithm for automatic GNSScontrolled land leveling system was proposed. Firstly the hardware design on early foundation was improved and the tension acquisition module was designed as well as correcting it, which provided data for later path planning. In this method, the global path planning and local realtime path planning were combined to forkliftload or full load the shortest and the longest effective operation of the optimal evaluation, integration and density mean Kmeans clustering farmland grid; then according to the design of low forklift excavation high filling method and local search strategy to give ground path global planning and the actual work was carried out in accordance with local adjustment and planning tension sensor. Farmland automatic navigation ground experiment showed that the maximum elevation difference after the plane leveling went down from 22.8cm to 2.7cm and the height standard deviation of elevation dropped from 12.6cm to 1.5cm; the cumulative percentage, of which the accuracy errors were less than 5cm, was increased from 81% to 97% after the land leveling. This method can achieve better route planning and efficient working of tractors. The full loaded rate and unloaded rate of forklift, the sum of which was about 20%, were less than those of the other methods, increasing the effective working time and providing technical support for automatic GNSScontrolled land leveling system.

Abstract:In order to accurately evaluate the performance of the tractor and the technical level of the operator, the CAN bus data analysis and storage system were used to acquire work parameter information of John Deere 7830 type tractor in certain operating width with returning cultivation method. ARCGIS, Matlab and Excel were used to visualize and analyze the data. The results showed that GPS receiver acquisition of latitude and longitude can be changed into plane coordinates with Gauss projection algorithm that can be more accurate to calculate the effective work area (1856hm2);reasonable coefficient of tractor torque was 27.01% of total output torque；engine load rate and fuel economy were relatively low and manual operation technology need to be improved; the actual speed of the tractor was 1700r/min which was 1600r/min more than rated speed at engine full load and power match was good. Based on the speed, torque and fuel consumption, the engine idling state and the effective operation time (2.75h) could be calculated.

Abstract:An automatic navigation control system based on controller area network was designed on Dongfanghong X-804 tractor, which includes the navigation controller, GPS system, steering system and CAN communication system. The navigation controller, which used ARM processor AT91SAM9261 embedded CPU, was used to realize automatic navigation control based on double closedloop PID algorithm, and the CAN interface circuit was designed by using a control chip transceiver SN65HVD1050D. The function nodes realized steering control, speed control, brake control, and machine lift control respectively. Then, a communication protocol of CAN2.0 was presented for distributed control network. Finally, CAN communication experiment and field test were carried out based on Dongfanghong X-804 tractor. Experimental results demonstrated that the CAN bus system was able to transfer data well, and the double closedloop control solved the control overshoot well and the average error was 0.41°, with 1.32s tracking time. The field test result showed that the average lateral tracking error of positioning was 0.021m in line tracking and 0.016m in headland turning.

Abstract:Along with the further subsoiling operations, the precise detection of subsoiling quality and subsoiling area became a new problem and new demand. Existing subsoiling and landpreparation machine have no monitor devices. So the subsoiling quality and effective area were measured by hand. The process was inefficient and the result was easily affected by manmade factors. Based on the Beidou navigation system and the network information technology, a subsoiler scheme which could implement remote collecting, transmission, and monitoring information was presented. The subsoiler operation information was transmitted reliably by using mobile communication technology and internet technology. In the monitoring terminal, the Web technology and the Browser/Server network structure were used to apply the integration of bottom control network and Internet. Then the remote management system of subsoiler was established. Data communication service program used the multithreading technology and ActiveMQ message queue technology to do the highly concurrent data processing and optimize the processing capacity of database. System frontend page program used the realtime data query cache technology and Memcached memory object caching system, effectively reduced the database load and ensured the data real time requirements. System mainly included subsoiling depth detection sensor, vehicle terminal, monitor server and application service. The main functions of the system included basic data management, subsoiling machine orientation regulation, subsoiling quality regulation, subsoiling machine information maintenance, etc. The subsoiling operation quality testing equipments were installed in October 2015 in Jilin province. System ran continuously for two months. During these two months, the data transmission was accurate, stable and no packet loss. The maximum transmission delay time was just 35 s. Users can visit the web site of the system to get the realtime condition information and work area; also can carry on the statistical analysis of effective work area. The experiment results showed that the system can satisfy the actual requirement of the remote monitoring and management for subsoiler.

Abstract:The furrow sowing with whole plasticfilm mulching on double ridges had been widely used in the arid region of Northwest China, because it could resist drought and increase production. The mechanical sowing with film was an inevitable trend in farming. The working performance of operation machine for direct insert hillseeder based on mechanism with approximate constant speed for corn whole plasticfilm mulching on double ridges was studied, and the best working parameters of prototype, which avoided phenomenon of dislocation of soil hole and mechanical damage of daylighting mulch, were obtained. The Plackett-Burman test was performed to screen the significant parameters from the eight selected parameters (proportion of amplification mechanism, transmission ratio of the mechanism with approximate constant speed, opening displacement of holeformer, angle of holeformer, rotation speed of crank, forward speed of machine, rotation speed of driving lever and planting depth of holeformer). It was found that the rotation speed of crank, forward speed of machine and rotation speed of driving lever had significant effects on dislocation of soil hole rate and mechanical damage rate of daylighting mulch while the other five parameters’ influence was negligible. The steepest ascent test was used to determine the best region of significant parameters. Based on the result of Box-Behnken test, the quadratic polynomial model for dislocation of soil hole rate and mechanical damage rate of daylighting mulch with the three significant parameters were created, the effect of single factor and interaction factors on different response values was explored, and the Optimization-Numerical calculation method was combined to optimize and test the work parameters of direct insert hillseeder in the fields.The test results showed that the operation performance of prototype was in accordance with requirements of national standard, the effects orders of three parameters on dislocation of soil hole rate were as follows: forward speed of machine, rotation speed of crank and rotation speed of driving lever. The effects orders of three parameters on mechanical damage rate of daylighting mulch were as follows: forward speed of machine, rotation speed of driving lever and rotation speed of crank. The optimal working parameters were machine forward speed of 0.52m/s, crank rotation speed of 72r/min and driving lever rotation speed of 140r/min. Confirmatory tests showed that the average value of dislocation of soil hole rate was 1.23% and mechanical damage rate of daylighting mulch was 9.56%, which were dropped significantly compared with before optimization of dislocation of soil hole rate (1.56%~5.87%) and mechanical damage rate of daylighting mulch (10.63%~73.37%). With the optimized working parameters, the threw speed could achieve zero and the problems of picking and tore films and holes with seedlings dislocation were solved, and the mechanical damage of daylighting mulch was also avoided. Meanwhile, it proved that the established regression model was reliable.

Abstract:In order to realize precision seeding for super rice and other crops in the seedling tray, the ration of quantitative seed supply is one of the important indicators to measure the performance of precision seed meter. Due to the uneven feeding of existing fluted roller seed meter, it needs to discuss quantitative seed supply technology deeply from the theory to test. A quantitative seed supply device with electromagnetic vibration scoop shape fluted roller was designed, including a detail structure design for scoop shape fluted roller, vibrating board and rubber sheet, etc. The theoretical model for quantitative seed supply was built with structure characteristics of the device, and the actual seed supply quantity was tested under the condition that electromagnetic vibration frequency was always constant. It was obtained that the influence rules of actual seed supply quantity were electromagnetic vibrator amplitude and fluted roller rotational speed. The test results showed that the actual seed supply quantity was close to theoretical model, the relative error of quantitative seed supply was less than 4%, when the seed rotational speed of metering wheel was 0.8~6.6r/min and above 6.6r/min, the electromagnetic vibrator amplitude was selected as 10μm and 15μm, respectively. The research results can provide a reference for digital design of precision seed meter.

Abstract:The current corn sowing depth is controlled by limit wheels and profiling mechanism that can only achieve the consistency of ditch depth and can not achieve the consistency of sowing depth. From the view of soil cover and compaction soil determining the thickness of the upper soil(sowing depth), the author developed covercompaction soil monitoring system that can achieve automatic control of planting depth, ensure the consistency of corn planting depth, and establish the basement of the neat, complement, sturdy of the seedling. The system took MSP430 microcontroller as control center, expert system shaped from compaction strength by field experiment as standard, result from pressure transmitter of compaction soil system as a means, to realize the results from transmitter contrasting with the expert system. Then the machine can constantly adjust the cover soil system and the amount of overburden soil to ensure the stability and consistency of sowing depth and compaction strength. The working principle of covercompaction soil control system is that when machine worked the pressure transmitter which was arranged on compaction wheel, it can constantly detect the pressure of the wheel, then the pressure data was imported to microcontroller memory and compared with the threshold which was arranged in expert system. If the data was within the range of the threshold, the sowing depth will be normal and the system will maintain the status quo. If the data was higher than the threshold,the sowing depth and compaction strength would be too large, it meant that the machine should reduce the sowing depth, then the microcontroller will send message to shorten the electric cylinder’s length until the data under the standard value in order to reduce the amount of the overburden soil and vice versa. The author conducted response time experiment and the result indicated that the response time of the system was 0.58s and the actual response time was less than the experiment. Field experiment results showed that when machine’s sowing speed reached from 3km/h to 8km/h, the qualified rate of sowing depth was higher than 90% and the sowing quality was better than that of profiling mechanism device, so the system effectively improved the consistency of sowing depth.

Abstract:The performance monitoring system of a portable seedmetering device was developed, which took a programmable logic controller (PLC) and a touchable screen as the core, to improve the convenience, flexibility and high precision of seedmetering monitoring. The monitoring system applied programming software, named Delta WPLSoft V237, to customize the PLC ladder diagram program and configuration software, named DOPSoft 20004, to achieve the development of human computer interaction interface. The performance monitoring system of seedmetering device was mainly composed of detection system, control system and monitoring system. Detection system used two rectangular fiber area sensors, which were installed on the top and bottom of monitored area to detect qualified number, replay number, leakage number and seeding rate. The interval between seeds was detected by sensor to determine seed spacing. Closed loop control system was composed of PLC, servo driver, servo motor and pulse encoder, servo motor and seedmetering shaft was directly connected, the working speed of planter was simulated through controlling the speed of servo motor. It was used to control the seedmetering device of rotating shaft work speed, realize precision stepless regulation and ensure the seedmetering device of rotating shaft according to the set speed stable operation. Monitoring system was mainly controlled by the touch screen, which can display sowing device performance with various technique indexes and the running situation of the control system. It can set seedmetering relevant parameters on the human computer interaction interface to realtimely monitor the performance indicators of seedmetering device, including qualification rate, seedmissing rate, seedrepeating rate, coefficient of variation and breaking rate. The test results on monitoring system accuracy showed that the test accuracy of sensor 1 was above 95.42% and 1.77%~4.58% of test error was caused by the situation that two seeds may fall into the same monitoring zone at the same time during seedmetering process. The error was decided by metering performance of the device and the reseeding caused by situation that two seeds fell into the same monitoring zone can be tested by sensor 2 which was under the seed sprout. The test error rate was between 1.77% and 4. 58%, while the combination of sensor 1 and sensor 2 can get the accuracy rate range from 97.90% to 99.22%. Two tests of quadratic orthogonal regression on the rotation speed of planting plate and the interval of two seeds’ falling time demonstrated that the performance of the chosen spoontyped seed metering device was the best with rotation speed of 32.29r/min, seed spacing of 28.44cm and machine moving speed of 4.25km/h. The parameter information from the test, including row spacing, qualification rate, seedmissing rate and seedrepeating rate, etc., can provide scientific basis for seedmetering device to achieve its best performance at appropriate speed. It can solve the bulkiness and intricacies shortage of seedmetering testbed which was used indoors to imitate field working environment in China. Meanwhile, the results can provide technical reference for precisely seeding of corn notillage planter.

Abstract:Spoonchain metering is the most widely used metering device in small and mediumsized potato planter at present because of its high reliability, low cost and adjustable plant spacing. Its performance is closely related with the planting quality. However, spoonchain metering still encounters loss sowing problem, which can be reduced by optimizing structure and parameters of metering device. Nevertheless, the rate of loss sowing is still around 7%. Artificial assistance metering can resolve these problems effectively but with increased labor intensity and hidden danger. In order to solve this problem, a loss sowing detection method based on capacitance value precision measurement technology was proposed in this paper, and an automatic reseeding system was designed which was mainly composed of control system, capacitance sensor and reseedmetering device. In order to test performance of the automatic compensation system, a performance test was carried out using selfmade device. Spoonchain was driven by a servo motor and its speed was adjusted by servo driver. Reseedingchain was driven by a servo motor and its speed was controlled by PLC controller. Micro potatoes, with diameter of 25~30mm, were used in main metering system and reseeding system. The metering speed was set as 0.3, 0.4, 0.5, 0.6, 0.7m/s, and the number of theoretical seed metering was 600 at different speeds. By mounting a laser sensor on seed discharge hole, the number of normal seeding and reseeding were recorded by PLC automatically. Total seeding, loss sowing, normal seeding, theoretical seeding, reseeding rate, original rate and final rate of loss sowing can be calculated. The tests showed that, with the metering speed increasing from 0.3m/s to 0.7m/s, the original rate of loss sowing, the final rate of loss sowing, the metering row spacing error and the reseeding row spacing error were increased from 7% to 11.3%, 1.1% to 1.75%, 3.3% to 9.1% and 7.6% to 16.9%; with the increasing of chain speed, changes of reseeding rate were relatively small, and the final rate of loss sowing was less than 1.75%, and rate of reseeding was around 84.6%. The performance of the designed compensation system is stable, and the loss sowing problem of potato spoon-chain metering device can be solved well.

Abstract:In order to solve the problem of Ethiopia tef mechanized seeding, a fertilization seeder for tef based on PLC was designed. The tef seeder mainly included seedmetering device, furrow opener, PLC control system and so on. Sowing speed was measured by speed sensor, and corresponding relationship between sowing speed and servo motor speed was established, which can be used to control servo motor speed to achieve the same seeding rate per unit area at different sowing speeds. A small seedmetering device and singledisc opener were designed to solve the problem of poor uniformity and low stability. The PLC control system was designed for sowing, which can assure the tef seeder worked well in clay soil. It would be easy to adjust seeding rate and fertilizer rate through humancomputer interaction interface. Seedmetering device performance experiment was carried out at different seeding rates of 4kg/hm2, 5kg/hm2 and 6kg/hm2 and sowing speeds of 3km/h, 4km/h and 5km/h. The results showed that the consistency variability coefficient of row seeding quantity was decreased with the increase of seeding rate and sowing speed, and the stability variability coefficient of full seeding quantity was decreased with the increase of seeding rate, which was firstly increased and then decreased with the increase of sowing speed. When the seeding rate was 5kg/hm2, the consistency variability coefficient of row was 5.02%, stability variability coefficient of full row seeding quantity was 0.89%, seed damaged rate was 0.1% and seed uniformity coefficient of variation was 18.9% under zero level testing condition, which can meet the standard requirements. The sowing uniformity coefficient of variation was 20.4% in field experiment, which can meet tef agronomic requirements.

Abstract:The rice planting area in China accounts for 21% of world’s planting area, but there is only 6% of water resource of the world. Water consumption of traditional rice planting was about 12000m3/hm2 〖JP〗in the whole growing period, which made a difficulty in planting rice at large scale in cold and arid region of China. In order to enlarge rice planting area and improve the level of mechanization in aerobic soil with plastic film mulching, planters were designed in different planting patterns to meet the agronomic requirements for rice cultivation with plastic film mulched drip irrigation. The parameters of key components (drumtype dibbler and covering device) were determined by dynamics and kinematics analyses. Besides, the factors that affected sowing performance were confirmed as sowing roller’s radius (R), length of duckbilled soil opener of drumtype dibbler (H) and walking speed (v), factors that affected mulching performance were diameter of mulching roller (D), lift helix angle (β) and walking speed (v) of planter. According to orthogonal test, the three factors and four levels orthogonal optimal experiments were carried out, which indicated the importance of the three factors for sowing performance were in the order as H>R>v. Meanwhile, for the mulching performance, the importance of the three factors were in the order as β>D>v. When the length of duckbilled soil opener was 28mm, radius of sowing roller was 180mm, lift helix angle was 35°, diameter of mulching roller was 360mm, and walking speed was 0.65m/s, the qualified rate of sowing depth was 92.6%, qualified rate of sowing number per hole was 94.7%, qualified rate of mulching was 91.2% and vacancy rate was 1.8%. The rice yield was 10500kg/hm2, the average spike number per hectare was 3.25 million. The performance of this planter could meet the technical requirement for rice sowing with plastic film mulched drip irrigation.

Abstract:In order to reduce working resistance and power consumption of subsoiler, and improve the applicability to different soil, 1SZ-600 selfexcited vibration subsoiler characterized by adjustable spring pretightening force was designed. The main part of the selfexcited vibrating subsoiler was tension spring, parameters of the spring were determined through subsoiler overall structure and springs location. Working resistance reduction was achieved by selfexcitation vibration unit. The pretightening force of spring was changeable according to soil mechanical properties. Field experiment was conducted in Guan County, Hebei Province. Experimental factors included working depth of 250mm, 300mm and 350mm, operating speed of 2.5km/h, 3.2km/h and 4.0km/h. Results showed that to ensure the premise of deep tillage, selecting appropriate spring preload can effectively reduce the traction resistance. 〖JP2〗The draft resistance was decreased by 19.26%, 15.43% and 22.65% at working depth of 25cm, 30cm and 35cm 〖JP〗with working speed of 2.5km/h, respectively. When the working speed was 4km/h, draft resistance was decreased by 10.3%, 13.9% and 21.4%, respectively. Traction resistance reduction was obvious with higher working speed and it was decreased by 10.30%~22.65% compared with nonvibrating subsoiler at any speeds and working depths. Variance analysis was conducted to ensure the significant influence of test factors. Results showed that working speed, tillage depth and machine structures had significant influence on the traction resistance. The increase rate of the traction resistance of vibration was less than that of non vibration with the increase of tillage depth at different operating speeds due to drag reduction of a selfexcited vibration unit.

Abstract:Surface tillage technology could weed and eliminate the soil harden and wheel ruts, but it is difficult to avoid straw blocking for current surface tillage machine. In order to achieve surface tillage and weeding with a large number of straw mulching and decrease soil disturbance under the requirements of conservation tillage, a doublevane symmetrical rotary blade with the functions of chopping and sliding cutting was designed. Edge curve and structural parameters of this surface tillage blade were determined by theoretical analysis, and the results from finite element static analysis and modal analysis by using SolidWorks software and Abaqus software, which indicated that the blades structure could meet the requirements of strength and it won’t occur resonance phenomenon. The field comparison experiments among surface tillage blade, rotary blade and topsoil shovel were conducted after corn harvest, and the results showed that the crumbling and weeding ability of doublevane symmetrical rotary blade had an advantage over topsoil shovel and the surface roughness and residue cover rate after working were also better than those of rotary blade. Therefore, the soilcrushing rate of doublevane symmetrical rotary blade was 92.2%, surface roughness was 0.6cm, weeding rate was 97.3% and residue cover rate after surface tillage was 39.5% on the condition of all remaining on the field, thus this doublevane symmetrical rotary blade could meet the operation requirements of surface tillage under conservation tillage.

Abstract:Strawchopping device with chopping and fixed knife supported slide cutting was designed, which was suitable for horizontal maize straw crushing machine. The supported slide cutting force formed by equal slidingcutting angle fixed knife and the highspeed spinning chopping knife along with the roller of device was used to crush straw. The cutting edge curve of fixed knife was logarithmic spiral curve equation. The chopping knife was made up with parallelstraightening blade and modified Lmachetes. Combined with the characteristics of corn straw, the parameters of key components were confirmed, and then the ANSYS-Workbench software was used to check the static strength finite element analysis of fixed knife, the mode of crushing roller was analyzed and a series of stress figures of the fixed knife and the first six frequencies and corresponding mode shapes of crushing roller were obtained. The result of finite element analysis showed that the maximum stress of fixed knife was occurred on its posterosuperior, the value was 13841MPa, and the materials met the requirement. The work frequency of crushing roller (23.3~30Hz) was far below its first natural frequency (102.62Hz), thus the resonance phenomenon would not occur. The field experiments showed that the straw crushing average qualified rate was 91.5%, when the strawchopping device with chopping and fixed knife was at 1600r/min of the crushing roller, the power consumption can be reduced by 17.4% compared with the device without fixed knife (1800r/min).

Abstract:Rotary tiller is a land preparing implement with great practicability, which is widely used to reduce the farming time and labor spend. The left and right wheels of tractor don’t work in the same horizontal plane in practical due to the uneven farmland. Rotary tiller and tractor are connected by the threepoint hitch, which means the rotary tiller has the same gesture as the tractor during the rotary tillage. Rotary tilling in lateral inclination gesture will not only destroy the untilled bottom of the farmland, but also affect the tillage flatness, tillage depth etc. All of this will ultimately lead to the poor rotary tilling quality and low working efficiency. To decrease the influence of rotary tiller working in lateral inclination gesture, a rotary tiller auto leveling system was designed which mainly including rotary tiller, leveling rack, hydraulic control system and the auto leveling control system. The front of leveling rack was connected to the tractor threepoint hitch while rotary tiller was hanged in the lower back of the leveling rack with two pin rolls. One end of the leveling cylinder was hinged with leveling rack while the other was hinged with the rotary tiller. Therotary tiller rotated relatively to the telescopic movement of the leveling cylinder. Auto leveling control system controlled the solenoid directional valve according to roll angle of the tractor detected by angle sensor, and drove leveling cylinder stretching out and drawing back to adjust the angle between the rotary tiller and leveling rack (namely the angle between the rotary tiller and tractor). An auto leveling closecycle control was designed to keep rotary tiller working in a desired angle by the means of combining the leveling cylinder elongation detected by the linear displacement sensor and the geometrical relationship between rotary tiller and leveling rack. Experiment was taken in ridge vegetable lands between auto leveling rotary tiller and the nonleveling rotary tiller. The data of the surface flatness of the field before and after plowing was collected by the level gauge, while the tractor roll angle and rotary tiller leaning angle were collected respectively by two attitude sensors at the same time. The tillage flatness and tillage depth of two kinds of rotary tillers and the performance of auto leveling system were analyzed. Experimental results show that the surface flatness by the auto leveling rotary tiller was improved significantly comparing to the nonleveling rotary tiller, the maximum height difference of the auto leveling rotary tiller in lateral direction was 1.9cm, while the nonleveling rotary tiller was 9.8cm; the tillage depth of auto leveling rotary tiller in lateral direction was more stable, the maximum height difference in lateral direction of the tillage depth was 1.8cm, while the nonleveling rotary tiller was 9.7cm.

Abstract:Vehicles and agricultural machinery are often trapped caused by slipping and sinkage when working on soft terrain. Therefore, a superior propulsive performance is significant for the vehicle. By observation of the dactylopodites of Chinese mitten crab, three bionic soil contact parts with different cone angles were fabricated. The article focused on the drag force in the horizontal movement of soil contact parts, which were compared with cylinder sample. Experiments of walking foot were carried out in soilbin filled with fine quartz sand. The influence of motion velocity, insertion depth and cone angle to the drag force were analyzed. Results showed the drag force was increased with the square of insertion depth and the cone angle of soil contact part. When the cone angle of bionic walking foot was doubled and trebled, the drag forces were increased by 47.18% to 167.57%. And the drag force was linearly correlated with motion velocity. In the scope of velocity of experiments, the drag force was increased by 11.37% at most with the increasing velocity. A model for predicting the drag force of walking foot was created based on the estimating formula proposed by ALBERT, and was combined with the experimental results. The verification of the model showed that the residual was not higher than 3.62N and the average relative error between the model calculation values and experimental data was lower than 22.77%. Thus the model can be used for both variable section and equal section soil contract part, and it was accurate enough in the prediction of the drag force. The research results provided theoretical basis for predicting the performance of propulsion of the soil contact part and the development of legged mechanisms on soft terrain.

Abstract:An intelligent facilities seedling machine was put forward and designed with the analysis of modern factory seedling technology. PLC programmable control was adopted in this machine. Human machine interface, sensor technology and frequency control of asynchronous motors were integrated into the control system to realize the accurate seeding operation. Selecting suction hole diameter, vacuum degree, seed box moving speed as experiment factors, an orthogonal experiment on suction performance was carried out with cabbage seeds as test object. The experiment result showed that the optimal parameter combination of factors were vacuum pressure of 7kPa, suction hole diameter of 0.8mm, seed box moving speed of 0.03m/s, and under the optimal parameter combination of factors, the singleseeding rate was 93.82%, missseeding rate was 3.71%, and reseeding rate was 2.47%. Furthermore, under the above conditions, a seeding performance test was carried out. The test showed that the singleseeding rate can reach 92.63% with seeding efficiency of 400 tray per hour, which can meet the requirements of precision seeding agronomic for vegetables.

Abstract:Plastic film cultivation technology, which was hailed as “the second revolution of agricultural production”, had the effects of increasing temperature, conserving soil moisture, suppressing weed and boosting crop yield. However, the major ingredients of agricultural plastic mulching film are polyolefin compounds which are degradationresistant. The mechanization of residual film recycling is an effective approach for solving pollution of residual films. The major operation procedures of residual film recycling include releasing film, collecting film and removing film, and unloading and releasing film operations are the crucial link of recycling residual films. Concerning existing releasing equipment of residual film collector had the problem of low reliability and film releasing rate, a runnertype film releasing equipment was designed. Through analysis on the film releasing mechanism of this equipment, its structural characteristics and dimension parameter were determined. Taking the space between film releasing shovels, forward speed and penetrating angle as influence factors and film releasing rate as response value, the influence of each factors on film releasing rate was calculated based on the regression analysis and response surface analysis with Design-Expert 8.0.2 software. The contribution of each factor to the influence on film releasing rate from big to small were penetrating angle, space between film releasing shovels and forward speed. Three-factor quadratic regression models between film releasing rate and penetrating angle of film releasing shovels, forward speed and space between film releasing shovels were established. Optimizing calculation of structure and working parameters of film releasing shovels was conducted through calculation method of nonlinear optimization. The results showed that when the space between film releasing shovels was 220mm, forward speed was 1.0m/s and penetrating angle was 30°, the theoretical maximal film releasing was 93.8%. Proof test indicated that the film releasing rate with these parameters was 91.3% and the error between theoretical value and trial value was 2.5%, which verified the correctness of regression model.

Abstract:To improve the automation and efficiency of plug seedling transplanter, a fullrowalternatepickup and dispersealternatedropping automatic seedling transplanting machine was designed, which was applicable for transplanting from plug trays to plug trays or to flowerpots with high location accuracy. The working process and principle of transplanting machine were introduced. The optimal transplanting strategy was selected and mechanism structure of the whole machine and disperse component for endeffectors was designed based on the fullrowalternatepickup and dispersealternatedropping requirement. To improve location accuracy affected by motion of transplanting platform and synchronous belt flexible deformation, the rigidflexible coupling model of transplanting platform was established and simulated in ADAMS under the transplanting horizontal motion of constant acceleration and deceleration, cubic polynomial and quintic polynomial. The results indicated that the location accuracies under three motions were all higher than 99.7% and the one with quintic polynomial was the highest. The location accuracy experiment of transplanting platform and the whole transplanting performance experiment were conducted under different transplanting efficiencies. The results showed that the designed mechanism was reliable with a success transplanting rate of 90.23% at speed of 120 seedlings/min and the location accuracy was 0.15~1.22mm.

Abstract:In order to study the internal unsteady flow characteristics in the mixedflow pump caused by flow rate conditions, the external characteristic of mixedflow pump was predicted based on the standard k-ε twoequation model by using ANSYS CFX software. The influences of flow rate on internal pressure distribution, streamlines and turbulence kinetic energy distribution were further analyzed. The time domain and frequency domain responses at different monitor positions under various flow rate conditions were compared with each other. The results showed that the trend of external characteristic curve of mixedflow pump acquired by numerical simulation or experiment test was basically the same, the deviations of head and efficiency compared with numerical prediction and experimental measurement were 3.29% and 0.27%, respectively, which indicated that the numerical calculation was equipped with high accuracy. When it was operated under part loading conditions, the high pressure gradient between blade pressure surface and blade suction surface could lead to blade tip leakage flow, which had a great impact on mainstream in the impeller. Meanwhile, affected by the rotorstator interaction, more energy loss and higher turbulent kinetic energy dissipation were appeared in the impeller outlet and flow passages of guide vanes. With the increase of flow rate, the tip leakage flow was decreased gradually, the rotorstator interaction became weaker and the flow field in the impeller tended to be steady. Under different flow rate conditions, the pressure fluctuations at different monitoring positions had obvious periodic property, the time domain curve of pressure fluctuation contained four peak values and four valley values within a spin cycle of the impeller, and also the blade passing frequency always played the dominant role. Moreover, the influence of flow rate condition on impeller inlet and guide vane middle section was the most obvious and the amplitude value of pressure pulsation coefficient under part loading condition was the most dramatically changed. With the increase of flow rate, the amplitude value of pressure fluctuation in the frequency domain was decreased. This research provided a reference for expanding the operation range of mixedflow pump and optimization design of impeller and guide vanes in mixedflow pump.

Abstract:Layered fertilization technology has broad prospect for its less time requirement, labor saving and high utilization efficiency. A layered fertilization device which consists of adjustable instrument, one fixed fertilization mouths and two adjustable fertilization mouths was designed. The adjustable instrument consists of removable working piece, groove ear and guiding groove. Based on the discrete element method (EDEM), simulation tests were conducted to investigate the trend of fertilizer distribution ratio for different lift angles α and working length of fertilizationpiece L. The simulation model of fertilizer and layered fertilizing device was built. The results showed that larger lift angle led more fertilizer particle flowing into the up two fertilization mouths. And increasing the working length of fertilizationpiece is helpful for obtaining more fertilizer by making more particles colliding with the tube. In order to determine the suitable working parameters of layered fertilization device, four kinds of fertilizers commonly used for maize, were selected for laboratory tests. According to relatively references, the desirable fertilizing ratio was determined as 1〖DK〗∶6〖DK〗∶3. Test results showed that these kinds of fertilizers were influenced by the lift angle of device, working length of fertilizationpiece samely, which was consistent with simulation results. When the lift angle was at 30°~40°, fertilizing proportion amplification of up mouth was 10% and middle mouth was 3%, which proved that the increase of lift angle was in favor of improving up layer fertilizing ratio. Simultaneously, working parameters of layered fertilization device were determined as α of 36° and L of 13~16mm. To explore the working performance of this device, field experiments were conducted at speed of 1.36~7.58km/h. Three types fertilizing devices, adjustable and nonadjustable layered device, common layered device, were used and soil crosssection area after fertilizing were obtained to compare the distribution of fertilizer. Results showed that the adjustable layered fertilization device could layer fertilize into three layers and middle layer gained the most, second was bottom layer, which met the corn requirement for fertilizer.

Abstract:In view of the problems of traffic ability and the precise control of fertilizer application of the additional fertilizer machinery, the variable rate fertilization system of triwheel high frame operation vehicle was designed. It was composed of mechanical fertilization system, hydraulic system and electronic speed control system. Its trafficable height was 1.2m, and could apply fertilizer to four lines of corn at the same time. During operation, the hydraulic system powered hydraulic motor to drive the outer groove wheel type fertilizers. The control of fertilizer application was realized by electronic speed control system adjusting the rotational speed of fertilizer shaft, using closedloop control and the microprocessor STM32F103R8T6 core, combining the setting parameters such as dose rate and the speed signals being detected to calculate the advancing velocity of high frame operation vehicle and the theoretical rotational speed rotational and the actual rotational speed of fertilizer shaft and displaying them, adopting the incremental PID algorithm to control electrohydraulic proportional flow valve. The laboratory test showed that average coefficient of variation of the fertilizer amount was minimum when fertilizer trough work length was 30 mm. The fitting equation of fertilizing amount and rotational speed was determined. PID parameters was set as proportional coefficient of 1.2, the integral coefficient of 0.02, and the differential coefficient of 0.4. The field experiment showed that the average deviation of fertilizer application was 0.84%, the average coefficient of variation was 1.852%, realizing mechanized and precise additional fertilizer for corn.

Abstract:The widelyused online mixing system has a small range of mixture ratio and a detection problem at small flow ratio of pesticide. This paper developed an onlinemixing system, which mixed pesticide into carrier directly. A spiral porous mixer, which included lefthand type and righthand type of the spiral plates, was designed and assembled alternatively. A diskshaped mixer was proposed to promote the uniformity of the concentration from the spiral porous mixer. This system consisted of a precise plunger pump to deliver the pesticide, an embedded controller based on STM32 to detect the water level in the tank, a diskshaped mixer, and an electromagnetic switch valve to provide a certain outflow of water. The water and pesticide were mixed in the spiral porous mixer, then flowed into the discshaped mixer, and sprayed on the crops by the spray pump. The pressure sensor was calibrated with the water level in the water tank, the flowmeter was calibrated with the pressure sensor, and used to test the error. The pulse frequency driving the plunger pump was calibrated with the rotate speed, and used to test the outflow error of pesticide. In the range of the work flow, the flow of the water and the flow of the pesticide were measured at the same time. Using chlorpyrifos as the target pesticide, the sampling points of the mixture concentration were measured by a liquid mass spectra. The actual density of the sampling points was obtained, and a comparison experiment with the artificial full mixing of the pesticide and the water was carried out. The experiment results showed that working at the mixture ratio of 150∶1 ~ 1000∶1, the average flow error of water was 1.35%, the maximum error was 7.15%; the average flow error of pesticide was 2%; the maximum error was 3%; the maximum error of the mixture ratio was 6.75%. After a test of mixing using chlorpyrifos, the average error of the mixture concentrations was 11.7%.

Abstract:Lightweight high clearance boom sprayer with airassisted system was designed to develop efficient pesticide application technologies for soybean at middle and later growing stages. The sprayer wheel tread can be adjusted from 1600mm to 1750mm, ground clearance was 800mm, wheel base was 2000mm, spray span was 8000mm. Various soybean field experiments were conducted to measure the performance of airassisted spraying system on lightweight high clearance boom sprayer. The experiment results showed that when the operating speed was 4km/h, droplet coverage rate of the positive soybean leaves surface was increased by 19.0 percentage points in upper canopy and 17.0 percentage points in middle canopy, while that in lower canopy was increased by less than 5.0 percentage points through improving the spray pressure. Droplet coverage rate of back soybean leaves surface was increased by 5.5 percentage points in upper canopy and 2.3 percentage points in middle canopy, and that in lower canopy was increased by less than 1.0 percentage points. Droplet coverage rate by using ST110-05 nozzle was improved by 21.0 percentage points, 26.0 percentage points and 10.0 percentage points compared with that by using ST110-03 nozzle on the positive soybean leaves surface in upper, middle and lower canopies, respectively. Droplet coverage rate by using ST110-05 nozzle was increased by 5.0 percentage points and 1.0 percentage points in comparison with that by using ST110-03 nozzle on the back soybean leaves surface in upper and middle canopies, respectively, and no significant influence on lower canopy. When the air speed of curtain was 11.5m/s, the airassisted system could make the droplet coverage rate of positive soybean leaves surface increase by 26.8 percentage points and 22.0 percentage points in middle and lower canopies, respectively. The droplet coverage rate of back soybean leaves surface was increased by 23.1 percentage points, 18.1 percentage points and 8.4 percentage points in upper, middle and lower canopies, respectively. The assisted air flow had strong penetrability which was shown in the droplet coverage rate on positive and back leaves surfaces, and improved the distribution uniformity in soybean canopies. However, the droplet loss rate on the ground was increased.

Abstract:To improve the quantity of droplets deposition and reduce the quantity of pesticide in the orchard on small fruit tree or sparse orchard, a track selfpropelled orchard sprayer was designed by combining the air-blast spray with internet of things technology. The machine was composed of mechanical frame, control system, power, walking system, transmission system and airblast spray system. The control system was made up of ultrasonic sensors, microcomputer control layer, WiFi wireless transport layer and mobile phone. The mobile phone can show some spray reference and send instructions to microcomputer. Experiment result showed that the quantity of droplets deposition was increased by 34.57% when the airassisted sprayer was used, the variation coefficient was reduced by 13.39 percent points, and compared with continuous spray, automatic target spray could save pesticide by more than 30%. The fan driving airflow of airblast sprayer improved droplets adhesion ratio on target and droplet distribution uniformity. The intermittent spraying was realized by ultrasonic sensors detection of effective target and control system processing spraying status parameters on-line, pesticide utilization was saved and residues were reduced. The machine had advantages of small size, convenient operation and good passing ability, which satisfied the need of plant protection work of low and short orchard.

Abstract:Mechanization of seed industry is a precondition of seed industry’s modernization, and in order to improve the efficiency and quality of crop breeding, speeding up the development of breeding mechanization is the inevitable trend. For further promoting performance of the team developed cropland plot wheat seeds harvester, also reducing and improving the sample generation harvester which used stripping header to cause the big grain spatter loss, and the threshing unit feeding mouth and its cover internal easily remained and blocked issues, so the 4GX-100 type cropland plot wheat seeds harvester was improved designed. By combining prototype transmission system solutions, the double harvest header and conical threshing unit with telescoping lever were designed, and determined the structural parameter of conical threshing unit(length of feeding section and threshing section, big small section size). Meanwhile, the threshing component structure parameters were designed and calculated, including 〖JP3〗quantity and the circumferential distribution completely. Analyzed of conical roller speed between 406r/min and 610r/min, the length of telescoping lever was 172.5mm and the eccentricity was 40mm. In order to reduce the seed remain rate, the threshing material particle model (wheat grain and short stalks) was established by EDEM software, and carried out simulation analysis of the movement migration process of threshing material in conical threshing unit body. Field performance experiment of the improvement harvester showed that when the prototype feed quantity was 0.52kg/s, the total loss rate was 1.18%, the seed broken rate was 0.13%, the impurity rate was 0.64% and the seed remain rate was 0.02%, and the productivity could reach 0.18hm2/h, which taking only a brief idling could rapidly clear the machine. The machine was in smooth operation, which was no blocking phenomenon in threshing unit feeding mouth and cover internal. The conical threshing unit with telescoping lever could grab, thresh and convey the feeding material, which had strong adaptability, also met the demands of the design and the stipulation of the correlation technique. This study can provide a reference for the development of the cropland plot wheat seeds harvester, and will have a promising prospect of application and spreading in the seed industry mechanization equipment in China.

Abstract:To solve the present stage combine monitor system lack of remote network interconnection and remote monitoring ability of operating data and fault information, this paper developed an information monitoring system for main parts working condition of combine harvester based on Android mobile phone.On the basis of combine local monitoring system, we can achieve effective monitoring and fault information processing for revolution speed of threshing cylinder, a stirring dragon speed and similar parameters, and realize Android client remote operation and fault information monitoring.Mainly through the C8051F020 microprocessor connected with multi hall sensor, the key information of the main working parts, such as revolution speed of threshing cylinder, stirring dragon speed, was acquired. C8051F020 through UART0 serial interface with SIM900A module and SIM900A module sent a TCP connection request to the China mobile internet open platform server. Then the data was received by a Android smart phone based on network platform in realtime. Using the fault diagnosis method based on the instantaneous variation trend of the target signal in the single chip microcomputer for fault diagnosis, transmitted fault information of condition monitoring was used to realize realtime monitoring for combined harvester critical information and fault diagnosis. Simulation tests showed that the lower computer acquisition system, server and client performance were stable, data loss rate was controlled within (less than) 5%, information access delay time was less than 2s with alarm in time and correctly, and was able to meet the requirements of remote information acquisition and fault monitoring when combine harvesters work outdoors.

Abstract:Through the research analysis of corn harvester status at home and abroad as well as market demand of the current corn harvester，a new type of corn harvester for the stalk chopping and conveying device reaping both corn stalk and spike were designed emphatically. The advantages and disadvantages of different types of cutter were compared and analyzed, the cutting performance and function of feeding were considered, then the rotor milling cutter was adopted as the stem cutting device. To explore the power consumption influence factors of rotor milling cutter, the 3D simulation software ANSYS/LS-DYNA was used and a threefactor and threelevel orthogonal simulation test of the rotor rotating speed, thickness and the blade angle was carried out. The simulation results showed that the rotational speed and blade angle on the level of P≤0.10 had significant effects on power consumption for corn stalks cutting, and the thickness of the blade on the level of P≤0.10 had less influence however. Through the simulation, the best working parameters of rotor milling cutter was determined as the blade speed of 1400r/min, thickness of 7mm and blade angle of 20°, and on this occasion the power consumption was minimum. The single stem feeding device and double stem feeding device were compared and analyzed, and the transmissions were considered in as well, the transmissions of single stem feeding device were simpler. Then different tooth profiles and different speeds of roller conveyors were designed, and the relationship between four conveying rollers linear velocity was established by theoretical analysis, providing basis for transmission design. The different types of stem cutter were compared and analyzed, and rotary chopper was adopted. Then the drum diameter, blade installation form, dynamic location were designed and calculated, and through calculating, the theoretical length of stalk chopped was 34.6mm. Finally, the field experiment was carried out. Results showed that the feed rate was 4.06kg/s, operation speed was 1.2m/s, and the average stubble height was 9.5mm, coefficient of variation was 6.32%. The stem length curve was drawn, and the actual chopped stalks length was between 0 ~ 40mm and percent of pass was 95%. The average real chopped length was 35.2mm and had no significant difference with the theory chopped length 34.8mm in the level of P≤0.05. At the same time, the other indicators of the harvester meet the design and relevant national standards.

Abstract:In order to study the influence of relative setting position between reciprocating cutter and nip point of gripping chains and the growth direction of corn ears on corn harvesting performance, a new gripping device of corn combine harvesting of corn stalk and ears in the crampingcuttingtransporting type was designed. A rice special agricultural chain was used to replace the gathering chain and gripping chain of gripping device in original corn combine harvester. The theory of dividing, dialing and gripping corn stalk was analyzed. Recurdyn software was employed to build a rigidflexible system with corn stalk as flexible part and cuttinggrapping device as rigid element. The effect of five horizontal distances between reciprocating cutter and nip point of gripping chains and three growth directions of corn ear on motion of 〖JP3〗ear growth point were simulated. The five distances were -70mm, -35mm, 0mm, 35mm and 70mm,〖JP〗 respectively, and the three directions were separately machine forwarding direction, opposite and vertical to forward directions. The simulation results showed that both the growth direction of corn ears and relative distance had effect on motion of corn plants. When the horizontal distance was -70mm and -35mm, corn plants were cut with no cramping, they would incline to the direction of corn ear growing; when the distance was 0mm, 35mm and 70mm, corn plants were cut with cramping and they would move with gripping chains. A corn combine harvester for stalk and ears was designed and manufactured to test the performance of cutting and gripping device with horizontal distance of -70mm and -35mm in the field. Field tests were made at machine working speed of 1.2m/s and gripping chain speed of 1.39m/s. The results indicated that when the horizontal position of cutter relative to the nip point of grip chains was -70mm, the total plant loss was 36.2%, while it was 3.3% with the position of 35mm. This verified that cutting with gripping could greatly reduce the grain harvesting loss, and it proved that the simulation analysis was reasonable and reliable. This study illustrated corn combine harvester for stalk and ears in the crampingcuttingtransporting type needed to cut with gripping and provided a basis for design of corn combine in this type.

Abstract:Snapping mechanism with four knife rolls and stripper plates has the advantages of smaller kernel damage, faster capacities and higher ground speeds compared with spialribbed snapping rolls, but knife rolls are more aggressive, which can lead to more stalk breakage and more trash in the load. In order to solve this problem, a new type of fluted rolls was designed through the analysis of causes of stalk breakage. Four additional rolls of L shape were installed between each knife roll, which provided a straight pulldown of stalks. Theoretical analysis and computer simulation were made to determine structure parameters, and then an experimental prototype was made to test its performance. The experiment was carried out in existed snapping apparatus test bench, and three snapping mechanisms were chosen to do this comparison, which were traditional four blades snapping rolls and fixed snapping plate, four blade pull stalk rolls and clearance adjustable snapping plate and the new snapping rolls and clearance adjustable snapping plate. The ratio of trash in load was measured. Experiments results were analyzed by carrying out variance and significance analysis of effects assessed. Different snapping mechanisms had no significant effects on ratio of trash in load with confidence of 0.95，but different snapping knife rolls had significant effects on ratio of trash in load. The ratio of trash in load was reduced from 3.3% to 1.45% with combination of clearance adjustable snapping plate and new snapping knife rolls compared with traditional four blade snapping rolls and fixed snapping plate, wherein the contribution ratio of adjustable snapping plate and new blade rolls were 67.0% and 33.0%, respectively. The ratio of trash in load was the least with new snapping knife rolls and clearance adjustable snapping plate, which was 1.45%, and it met the requirement of national standard regulations and achieved the design purpose.

Abstract:In order to reduce the header splashing losses of rape combine harvester, an online collection method with its device was proposed based on the transverse positive pressure airflow for row depending rape harvester. The collection process was analyzed and optimized by theoretical calculation, virtual simulation and bench test. The falling height of rapeseeds and airflow velocity were selected as main studying factors by theoretical analysis firstly. Fluent-EDEM coupling simulation tests were carried out to analyze how these two selected factors affected the collection rate without rape stalks, and two counter measures, including addition of auxiliary collection screen and gridding the collecting grooves were put forward. Finally, the bench tests were conducted to verify whether the measures were effective. The results showed that rapeseeds collection rate was increased with the decrease of falling height, and gone down with the descending of airflow velocity. The falling height, airflow velocity and interaction between them influenced rapeseeds collection rate significantly. The location of auxiliary collection screen and its interactions between other factors were not significant. The best test combination was A3B3C3. It was under the condition with auxiliary collection screen installed on the fourth collection grove, falling height set as 200mm and frequency of the converter was 50Hz. With gridded collecting grooves and auxiliary collection screen, the best collection rate was 70.34%, while without them the collection rate was sharply decreased to 48.02%, which indicated that the two improving measures were effective.

Abstract:Panax notoginseng harvest is waste of time and labor in hilly areas without mechanization, thus a dieselpowered selfpropelled Panax notoginseng harvester was designed, which consisted of mining shovels, scraping soil part, elevator, compacting soil part, collection boxes and other components. Analytical mapping was used to analyze mining shovels, the angle that Panax notoginseng and soil mixture can successfully pass digging shovel blade was determined as 96°. It was obtained from analysis of elevator kinematics that when elevator was inclined 25°, Panax notoginseng harvester and soil mixture had the highest broken rate. The speed of elevators, vibration frequency of vibrating screen sieve and speed of rototiller were taken as experimental factors, and root damage rate and harvesting net rate were used to conduct second rotary orthogonal combination experiment. The results showed that the experimental factors’ influences on indexes from big to small were frequency vibration of shaker, elevating speed and speed of rototiller. When elevating speed was 0.78m/s, vibration frequency of shaker separator was 10Hz, speed of rototiller was 2.5r/s, the root damage rate and harvesting net rate were 1.6% and 96.32%, respectively. The optimal parameters of influential factors were adopted to verify the results. After the test, root damage rate and harvesting net rate were 1.6% and 96.8%，respectively, which was consistent with calculation results and in line with the harvesting index of agronomic requirements. The study provided a reference technology for development of productlevel Panax notoginseng harvester for medicinal material.

Abstract:In order to achieve localization adaptability of selfwalking type tomato harvesting machine fruit separation device, the fruit separation device performance was optimized with the method of response surface analysis. The oscillator spindle speed, the oscillator eccentric mass, roller rotation speed and tomato feeding volume were chosen as the influence factors, and the fruit separation rate, breakage rate and impurity rate were used as the response indexes, a multiple regression model was established based on the response surface analysis with Matlab software, and the credibility of the prediction model was analyzed by using the R2, P and the variance of the residual S2; the effects of experimental factors on test index were analyzed based on the response surface method and the influence factors and the best combination of level were achieved, and combined with the nonlinear optimization method, the optimization calculation of fruit separation rate, damage rate and impurity rate were carried out. The results showed that when the oscillator spindle speed was 342.86r/min, vibrator eccentric mass was 40kg, roller rotation speed was 22r/min and tomato feed quantity was 19kg/s, the fruit separation rate, broken rate and impurity rate were 98.33%, 3.37% and 4.17% respectively. By the experiment, tomato separation parameters got by response surface method were feasible; the research result offered the theoretical foundation and scientific basis for the further study of the processing tomato vibration separation technology, also for fruit vibration harvesting technology parameters optimization.

Abstract:With the aim to research the pellets discharge characteristics of flutewheel feeding machine, the Hertz-Mindlin no slip contact model was used to analyze the contact force and damping force between interacting particles, and then the translational motion and rolling motion equations for pellet feed were established. By using discrete element method, particles velocity distribution, law of particles motion and the distance from a single particle to central axis of flutewheel were simulated, and the effects of flutewheel speed on particles velocity distribution and thickness of drive layer were analyzed. Discharge characteristic experiments of four flutewheel feeding machine were done by using Linyi Yongao 700 and Yongao 997 pellets. According to the experimental results, conclusions were drawn that the filling coefficient of flutewheel was decreased with the increase of rotation speed, and the flutewheel speed had a significant impact on filling coefficient. Meanwhile, the fixed proportion and fixed weight feeding experiment of four flutewheel feeding machine was carried out, the testing result showed that the maximum measurement error of feeding was 1.13%, the minimum error was 0.56%, the average error was 0.83%, and the blend quality of pellet was good. In conclusion, four flutewheel feeding machine can meet the precise feeding, and also it can meet the automatic mixing of a variety of fine pellets. Compared with the screw conveyor feeding machine, the flutewheel feeding machine has advantages in simple mechanical structure, synchronous metering discharge, effective particles impingment mixing and high speed discharge.

Abstract:Harvest bales in the field, including process of collecting， transportation, loading and stacking bale all need to consume a lot of time and labor, thus to improve the bale harvest efficient, it was needed to design collecting wagon of rectangular bale. Its structure was mainly composed of traction device, feeding device, bale thruster, unloading device, collection tank and the electrohydraulic control system. Collecting wagon of rectangular bale was hooked up to the rear side of compression chamber of rectangular bale baler, bales were arranged to collect according to certain rules, and finally unloaded the bale group on the ground. When collection jobs of collecting wagon of rectangular bale were affected by terrain condition, bale shape, bale density and other factors, sometimes tilt of bale would happen in the process of feeding, which seriously affected the work efficiency and stability. According to problems that working stability was seriously impacted by bale tilt in the feeding process of collecting wagon of rectangular bale, ARIZ was used to analyze feeding device of critical component of collecting wagon of rectangular bale, and determine the cause of the problem. Through analyzing the system components function, it indicated that the main reason leading to bale tilt was insufficient feeding device to bale guidance function. Aiming at the problems existing in the technical system, technical contradictions, object-field analysis and other methods were used to do systematic analysis; totally 40 innovative principles, separation principle, knowledge base query and 76 standard solutions of the TRIZ were applied, and a series of innovative design was formed. By using Pro/Innovator software, the work efficiency, equipment reliability, production costs and complexity of equipment were comprehensively evaluated for the new solutions to get the optimal solution. Finally, through test of the improved machine, results showed that the improved machine had advantages of high collecting efficiency and good working stability. Bale group neat rate was 100%, and the main performance indicators all met the requirements of relevant standards. Therefore, the results can provide reference for the relevant field of ARIZ innovative design products.

Abstract:A monitoring and controlling system of drip irrigation in cotton field was designed and developed based on ZigBee wireless sensor network technology in order to save water resources and use fertilizer effectively. The system collected soil environment information in realtime through a wireless sensor network. And an adaptive weighted fusion algorithm was used to fuse soil moisture data for each node. According to the fusion data, the control commands were transmitted to the solenoid valve to perform realtime monitoring and automatic irrigation. The proportion of fertilizer injection was set based on irrigation water amount, and different requirements of fertilizer amount and fertilizer concentration at different growth stages of cotton. The flow rate of liquid fertilizer was acquired in realtime by using wireless sensor network, thereby realizing the monitoring of fertilizer amount instantly. Meanwhile, the control commands of solenoid valve were sent according to the amount of fertilizer, thus the integration of water and fertilizer irrigation was accomplished. During operation, the data collected by the sensors could be sent to the host computer through ZigBee wireless network coordinator, which was displayed and stored in realtime. Test results showed that the system could achieve automatic control and detection of irrigation and fertilization in accordance with the design requirements.

Abstract:In order to solve the problem in traditional protected agriculture, namely the inefficient use of water and fertilizer, less information collection, weak capability of data mining and implementation, an intelligent cloud irrigation system was proposed based on the technology of dualline decoding and cloud computing to integratively manage water and fertilizer for protected agriculture, which was composed of intelligent cloud irrigation control system, automatic machine of integration of water and fertilizer, water saving irrigation system with high efficient. The system via dualline decoding technology, and a variety of sensors were used to collect the parameters of crop growth environment for each individual protected agriculture in realtime. Then all kinds of collected data were timely transmitted and stored in cloud data management platform. Thereafter, the ability of calculation and analysis from cloud calculated cluster was used, water and fertilizer needs, irrigation and fertilization system in protected agriculture under different environmental conditions for crop growth were scientifically determined to achieve intelligent control of water and fertilizer integration. The system was of great importance in guiding protected agriculture to achieve high yield, high quality, ecology and safety in production. Two application examples in planting bases of protected agriculture showed that compared with the traditional irrigation methods, the intelligent cloud irrigation system based on the technology of dualline decoding and cloud computing to manage integrated water and fertilizer for protected agriculture can improve the water use efficiency by 25%~40% and fertilizer use efficiency by 15%~35%, which shortened labor time and decreased labor force sharply.

Abstract:A water and fertilizer integrated system for organic cultivation was designed. The system integrated functions of preparing and compounding organic liquid as well as automatical irrigation. Through different subroutines of the system, the aerobic fermentation of organic materials, liquid filtration, compounding and dilution of stock solution, and decision and execution of irrigation strategy can be conducted. Thus, the integration of preparation and management of nutrient solution in organic cultivation, as well as high efficiency and fine management in water and fertilizer could be achieved. In order to verify the reliability and applicability of the system, coconut chaff was selected as organic matrix and nonsoil and organic cultivation experiment of cucumber was carried out in the solar greenhouse. The results showed that the system was operated stably in preparation of organic liquid and management of water and fertilizer was good in cucumber cultivation. The mechanization and automation of organic fertilizer and water management was implemented. The yield of cucumber was up to 48165kg/hm2, the content of total soluble sugar, vitamin C and titratable acidity were 2.7%, 99.2mg/kg and 008%, respectively. The development and application of this system would break through the bottleneck that existed in water and fertilizer management in organic cultivation, and it had important realistic significances.

Abstract:A new compound suction fertilizer device based on Venturi principle was developed to improve the efficiency of fertilizer absorption. The new device was made up with one Venturi tube and a suction cavity. The size of Venturi tube was chosen according to the GB/T 2624—2006. The suction cavity was covered on the Venturi tube. The performance of new device was tested to compare with traditional equipment. The result showed that the vacuum negative pressure at throat of compound fertilizer suction device was decreased from zero to -0.71MPa with the increase of pressure difference between inlet and outlet from 0.02MPa to 0.32MPa. Moreover, the absorption flux was increased linearly with the increase of absolute value of vacuum negative pressure. When the pressure difference between inlet and outlet reached 0.28MPa, the vacuum negative pressure was dropped to the lowest value of -0.71MPa, and then the absorption flux reached its maximal value. The total amount of fertilizer could be increased by number of suction pipes, so that it can improve the efficiency by several times compared with the conventional single Venturi tube, although the single suction absorption flux of compound device was slightly reduced due to the pressure loss. In conclusion, the new compound fertilizer suction device could be precisely changed by changing the inlet pressure when inlet and outlet pressure difference was between 0.02MPa and 0.28MPa, which could be useful for precise control.

Abstract:The nitratenitrogen (NO-3N) of wet soil samples was detected through sensor fusion method. The prediction model of NO-3N was established by ionselective electrode (ISE) and soil moisture sensor. The interference of water content on fast detection of wet soil was analyzed. The statistical linear transformation between soil mass water content and volumetric water content was determined through calibration experiments. The algebra relationship among soil water content, volume of soil extractant and mass of dry material was derived. Compared with the standard spectrometric detection, the poor prediction accuracy of root mean square error (RMSE) of more than 17.00mg/L was obtained in bare ISEbased NO-3N detections. Meanwhile, the average absolute error (AE) was 3.79~44.81mg/L, which indicated a nonnegligible predicted deviation from real soil NO-3N condition. Through the sensor fusion approach, the NO-3N prediction results indicated significantly good consistency with standard spectrometric detection results. The adjusted determination coefficient (R2) of regression equation was 0.97, RMSE was less than 7.05mg/L, and AE was 0.17~17.95mg/L. The sensor fusion method obviously improved the detection accuracy of nitratenitrogen detection compared with the bare ISE detection. Meanwhile, it demonstrated the advantage of higher efficiency than that of conventional laboratory soil detections which required soil pretreatment. The method and experimental results could provide references for ISE applications to online soil macronutrient fast detections.

Abstract:In order to realize the detection of heavy metal Pb2+ in soil, the content of heavy metal Pb element in soil was detected by terahertz spectroscopy. The relationship between spectral absorption rate and Pb2+ content in soil was analyzed. A basic method for the detection of heavy metal content in soil by terahertz technology was provided. The soil samples with a certain concentration gradient (30~900mg/kg) were produced by sample holder method and pressedslice method. The spectral data of terahertz transmission soil were collected and preprocessed, including smoothing, multiple scatter correction and baseline correction. The model of heavy metal Pb2+ element in soil samples was established by using the method of full spectral, interval partial least squares and genetic algorithm, respectively. The results showed that the model established by sample box method and genetic algorithm method was the optimal one. The correlation coefficients of calibration set and prediction set were 0.86 and 0.81, root mean square errors of calibration set and prediction set were 23.55mg/kg and 39.52mg/kg, respectively. This research provided a theoretical and methodological reference for important parameters detection of farmland soil using terahertz and the preliminary applications research of terahertz.

Abstract:To improve the property of starch film and the additional value of cornstalk, this paper studied the effects of ultrafine grinding time on the composition structure of cornstalk. And 1h ultrafine grinding cornstalk was selected to prepare films with starch. Then the creep and creep-recovery behavior of starch-based films were investigated, to which different content of ball milling cornstalk was added. The results showed that after 1h ball-milling, the fiber bundle and the cell wall of cornstalk can be damaged relatively completely. Comparing with control sample, the particle size and crystallinity were decreased significantly, from 85.33μm to 9.46μm and from 39.46% to 19.29%, respectively. However, with the extension of grinding time, the reunion phenomenon was gradually increased, eventually formed larger particles aggregation. The creep and creep-recovery behavior results indicated that the creep deformation, creep compliance, and irreversible deformation were decreased with the increase of the cornstalk content untill reached 15%.When the content was up to 20%, the anticreep behavior trended to be weaken. Finally, fourcomponent Burgers model was used to fit creep strain and time data (R2>0.98).

Abstract:In order to study the influence of straw biomass pyrolysis in a rotating bed reactor under different carrier gas conditions, including no carrier gas, the tail gas and N2, biomass pyrolysis was tested based on the reactor. The biochar, biooil and syngas were collected respectively, and the yield rates were calculated. The biochar’s calorific value and elements were analyzed; biooil’s calorific value, water content and elements were analyzed; the syngas’ composition and content of organic compounds were analyzed by using gas chromatography. Passing the tail gas can reduce the generation of bio char, increase the production of bio oil, and the higher calorific value of bio char was, the higher carbon content was. The water content of bio oil was decreased, and organic matter content was increased. But when the calorific value of bio oil decreased, the content of light organic matter was the highest in syngas. The tail gas can take away pyrolysis gas more quickly or participate in the pyrolysis of twotime reaction. Biomass react was the most adequate, and tail gas can increase the activity of H; reduce water content, but no way to remove oxygen elements, so the oxygen elements retained in the bio oil. Nitrogen can reduce production of biochar, increase bio oil production and calorific value, and change a little carbon content of biochar, bio oil moisture and organic matter content, but the calorific value of the bio oil greatly increased; the light organic matter content in syngas was the least. Nitrogen can reduce twotime reaction and pyrolysis gas can quickly leave the reactor.

Abstract:The complicated fibrousnetwork structure of lignocellulose has adverse impact on the starting time of biomass dry anaerobic digestion. According to the pyrolytic properties of lignin, thermochemical pretreatment by using fluidized bed was put forward to pretreat the biomass. The present work was aim to investigate the influences of the thermochemical pretreatment technique on the biogas production via biomass dry anaerobic digestion. Experiments for the biogas production via biomass dry anaerobic digestion using the corn stalk samples treated at 150℃, 170℃, 190℃, 210℃ in a fluidized bed and untreated sample were carried out at 35℃ for 42d, respectively. Obviously, the results showed that thermochemical pretreatment could change the fibrousnetwork structure of lignocellulose. It resulted 5.98%~22.25% and 1.75%~20.99% decrease on hemicellulose and lignin, and enhanced the methane production ranging in a certain temperature. The digestion time T80 mirrored the efficiency of fermentation, 190℃ and 210℃ pretreatments got the shortest digestion time which were shorter 3d than the untreated of 30d. The highest methane yield of 30d was obtained at 190℃ pretreatment biomass sample which was 16.30% higher and the startup time was 2.10d less than the untreated. Other pretreatments also improved the methane yield by 1.67%~9.78% and resulted the startup time less than the untreated. Although 210℃ pretreatment could destroy the structure of lignocellulose more seriously, it also led methane production reduction due to the more wastage of hemicellulose and cellulose. The conclusions could be made that thermochemical pretreatment technique is one of the effective methods to improve the methane production and accelerate the startup time of dry anaerobic digestion observably.

Abstract:The burning of crop straws polluted environment due to lack of high efficient and rapid industrialization processing measures for straws in the producing area. Based on roller forming principle and theory for straw with no mold, a technical solution was put forward, including roller rolling, high pressure and cold forming. During the experiment of key performance parameters on the multiroller forming for straws, corn straws with different moisture contents from 9% to 23% and size of no more than 12mm were used to study their compression properties by an universal testing machine with neither a mold nor a closed state. The curves of compression properties were obtained. Yielding phenomenon was found during the compression procession and the compression process can be divided into four stages which were the loose stage, pressed stage, yielding stage and forming stage. Meanwhile, the compression yield limit of corn straws was decreased with the increase of moisture content. Briquette thickness test of straw with moisture content of 9% at various compression levels verified the roller forming principle, and it also provided design basis about the compression ratio for multistage roller forming device. Finally, based on the principle of roller rolling and forming and the compression properties of straws, a multistage roller forming device for straw by using feed rollers, compression rollers and forming rollers was designed, which can meet the requirements of efficient and industrial production technology in the producing area.

Abstract:A handheld and portable device for detecting meat quality parameters was designed, which was composed of hardware components including detecting probe module with multispectral light sources array, constant flow driver module, multispectral data acquisition and processing module, wireless transmission and display module, as well as application software based on Android system on terminal display platform. In addition, multispectral array contained 64 LED light sources which related to the quality parameters and it were divided into eight groups and each group incorporated eight different LED light sources of which the center wavelengths were 475, 515, 525, 575, 610, 760, 810, 910nm respectively, forming a diameter of 5cm brightness uniformity detection range for obtaining spectral data of meat samples. The dimension of this device was 175mm(L)×115mm(W)×25mm(H) and the weight was about 0.45kg. In addition, cost of device was less 2500 RMB. When using multispectral light array to detect samples, some lights were absorbed by samples and another part was reflected from samples which was called diffuse light. After obtaining diffuse light from samples, a silicon photodiode detector with spectral response range of 400~1100nm was installed to receive diffuse light from pork meat in detection zone, and then the signal from silicon photodiode detector were amplified and processed by amplifier chip and A/D converter chip, then different wavelengths spectral data were calculated for establishing meat quality prediction model. For verifying this device, 43 pork samples with different quality attributes were collected for data acquisition and three algorithms including multiple linear regression (MLR), partial least square regression (PLSR) and multiple linear regression (MLR) mathematical with stepwise method were employed to establish pork prediction models. The parameters included color parameters (L*, a*, b*) and total volatile basic nitrogen (TVB-N) content in meat respectively. The 43 samples were divided into calibration and validation sets according to the proportion of 3〖DK〗∶1 to achieve more reasonable prediction results. The results showed that the multiple linear regression (MLR) mathematical with stepwise method had the best prediction model, the correlation coefficients of prediction (Rp) for pork color (L*, a*, b*) and TVB-N content were 0.9471, 0.8504, 0.8563, 0.8027, respectively. At last, the same number of 12 pork samples from two groups of A, B at different time periods were used to verify the feasibility of this model, and the coefficient between predicted values of pork color (L*, a*, b*) and TVB-N content and their true values in each group were more than 0.80. In addition, coefficient of variation (CV) of verifying results in two groups was less than 1.1%, which indicated that this model of this device had certain stability to some extent. This experiment demonstrated that it has the potential in nondestructive detection for assessing meat freshness using this device, which not only meet the requirements of nondestructive testing but also can be widely applied for assessing meat quality in future.

Abstract:Wheat is one of the main cereal grain which was produced not only in China but also at abroad. The aim of this paper is to study the feasibility of several selected variables from short wavelength near infrared spectroscopy to quantify crude protein of the whole wheat grain. In total, 52 whole wheat grain samples were collected, including 39 samples for calibration and 13 samples for validation. On the one hand, the crude protein of these samples were analyzed by using the Chinese standard of Kjeldahl method; on the other hand, those were scanned to obtain near infrared spectra with the wavelength range of 900~1700nm by using a wheat analysis system developed by Chinese Academy of Agricultural Mechanization Sciences (CAAMS). Both of spectroscopic pretreatment method and sensitive variables were optimized, then the model was built by partial least squares regression method. The results showed the combination of multiple scattering correction and wavelet transform performed better. Competitive adaptive reweighted sampling method showed an efficient variable selection, which picking 12 variables and taking 2% of the full range spectral variables, including 1028, 1158, 1199, 1367, 1407, 1445, 1478, 1494, 1550, 1584, 1661, 1686nm. Based on the optimized pretreatment method and selected variables, the model showed that the prediction determination coefficient and prediction root mean square error were 0.961 and 0.369, respectively. Competitive adaptive reweighted sampling variable selection based short wavelength near infrared spectroscopic technique showed a potential for crude protein quantitative analysis on whole wheat grain.

Abstract:Discriminant analysis of different species of meat and bone meal (MBM) can provide necessary technical support for feed safety. A total of 20 MBM samples, including five porcine, five poultry, five bovine and five ovine samples, were chosen. All the samples were of reliable sources. Bone fragment samples were prepared using standard methods and their microscopic images were obtained by biological microscope imaging system. Five lacunas’ characterization data were extracted from each image by Matlab software including the area, perimeter, major axis and minor axis of each lacuna. Results showed that all the specific characterization data of lacunas fit the normal distribution and significant difference was found between different species. Partial least squares discriminant analysis (PLS-DA) results showed that it is feasible to classify mammalian MBM and poultry MBM based on the area and perimeter values of lacuna, while it was hard to discriminant different species of MBM samples based on the major axis and minor axis. Results of separate validation proved that successful discrimination of mammalian and poultry MBM could be performed based on the separate area, perimeter and pair combination values of bone fragments; the correct discriminant rate of established model were all 0.93, while result based on the pair combination values was better than that of separate parameter values. However, it was difficult to further discriminant ruminant and porcine MBM samples by this technique.

Abstract:Feed ingredients with high-fiber are widely available and a price competitive source of energy and nutrients for nonruminants. Rapid analysis of detergent fiber content in highfiber feed ingredients, including neutral detergent fiber (NDF) and acid detergent fiber (ADF), contributes to a fine regulation of dietary fiber levels in feed, and the exercise of its nutritional value. Classical Van Soest method for detergent fiber determination is tedious and sensitive to particle size and high cost in the consumption of filter-bag. It is not suitable for feed plant regular detection. The nearinfrared spectroscopy (NIRS) technique is nondestructive, non-pollutive, fast and relatively inexpensive. NIRS methods have been widely adapted in conventional composition analysis of feed. Feed ingredients with highfiber normally derives from a wealth of sources, like byproducts of grain plant. Single species NIRS model is hardly satisfied the demand of various ingredients in one feed plant. Researchers devoted to developing a unified NIRS model to determination of NDF and ANF for different feed ingredients with highfiber. A NIRS model for NDF and a NIRS model for ADF were built for analyzing six kinds of feed ingredients, including maize DDGS, soybean hull, wheat bran, alfalfa pellet, shotcrete corn bran, and beet pulp particles. Totally 327 samples were collected from China, including 75 maize DDGS, 48 soybean hull, 48 wheat bran, 48 alfalfa pellet, 59 shotcrete corn bran, and 49 beet pulp particles. NDF and ADF were obtained by using Van Soest methods. Fouriertransform nearinfrared spectrometer collected nearinfrared diffuse reflectance spectroscopy with spectral range of 4000~10000cm-1, at the resolution of 16cm-1 and 64 times scanning per scan. Calibration models were constructed by using partial least squares method, combined with derivative processing, multiplicative scatter correction and so on. Results showed that NDF and ADF distribution of six kinds of feed ingredients were respectively 21.20% ~ 65.28%, 6.40%~48.31%. For NDF model: determination coefficients of calibration and verification were 0.971 and 0.963 respectively; RMSEs of calibration and verification were 1.68 and 1.82 respectively; the relative percent deviation was 5.2, and optimal pretreatment method was the second derivative. For ADF model: determination coefficients of calibration and verification were 0.990 and 0.985 respectively; RMSEs of calibration and verification were 1.32 and 1.63 respectively; the relative percent deviation was 8.2 and the optimal pretreatment method was the first derivative with multiplicative scatter correction. These models are appropriate to a variety of high-fiber feed ingredients for the determination of NDF and ADF in feed plant.

Abstract:Based on the former research on heat pump drying characteristics of wolfberry, a large heat pump drying room was designed and established, and then 1000kg of wolfberry fruit was dried. The result showed that the heat pump drying room could supply abundant heat and control temperature and humidity precisely, which could meet the needs of wolfberry drying process. During the drying process, the temperature was gradually increased and humidity was decreased, it was reasonable to set 10 as a turning point at the drying stage, namely the moisture content could be detected when temperature was risen to 52℃, if the moisture content on dry basis was higher than 1.0, the set temperature should be maintained, if the moisture content was arrived at or below 1.0, the temperature could continue to be risen, the highest temperature was not higher than 64℃. The quality of dried wolfberry in different positions of heat pump drying room was measured, which showed that the total phenol content was between (5.92 ± 0.3)mg/g and (8.12 ± 0.18)mg/g, the total ketone content was between (70.99 ± 1.68)mg/g 〖JP3〗and (113.88 ± 0.26)mg/g, the total phenol content and total ketone content of the samples in the back of the room were significantly higher than those in the front. From the point of antioxidant properties, samples in the back of the room had higher ·DPPH scavenging activity and ferric ion reducing antioxidant power than those in the front. Compared with the wolfberry dried in the coal chamber, samples dried by heat pump drying room had higher overall quality (total phenol, total ketone. ·DPPH clearance, iron ion reduction ability), and the drying time was reduced by 20% and drying costs was reduced by 19%, hence heat pump drying process was reasonable and heat pump drying room could be applied to production practice.

Abstract:With the continuous development and application of transgenic crops, more and more transgenic foods were launched on the market, and people paid more and more attention to the safety of these foods. While Chinas regulation of transgenic crops and products is not optimistic, and the organization level of production enterprise is low, if the domestic enterprises copy the foreign traceability system, the problems of unclose integration in production process management will appeared. Thus, combining with the existing production flow and situations of China’s transgenic crops enterprises and taking transgenic maize as example, a full traceability system model for transgenic crops and products was built based on the basic theory of workflow net, through the analysis of important steps which affect gene characteristics and quality security in genetically modified crops production process. Eventually, with the guidance of the model, a full traceability system model for transgenic crops and products was designed and developed, which showed great theoretical and practical significance.

Abstract:Nowadays, aiming at the problems of packaging film scraping and incision deviation caused by the cutting mechanism in the fruitvegetable packaging machine, a cutting mechanism of fruitvegetable packaging machine based on the linkages and the cam mechanism was proposed. Firstly, the motion mathematical model of the cutting mechanism was established. Then, by using the virtual prototype of ADAMS, 〖JP3〗the parametric model of movement characteristics of cutting mechanism was completed according to these mathematic equations. And the influence of the main parameters of the mechanism on the movement of the mechanism were analyzed, including the link length of l1, l2, l3 and rise rotation angle β of the cam. Meanwhile, depending on the analysis method of sequential quadratic programming (SQP) algorithm, the optimal aggregative index could be obtained under the condition that l1 was 247mm, l2 was 154mm, and l4 was 1395mm. In this situation, the kinematic simulation analysis showed that the maximum value of acceleration of the lower cutter was 7.971mm/s2, and the cutting distance was 20.4mm. Finally, based on the above simulation and analysis, the prototype was processed with the optimized parameters. And the prototype test using the PVC film cutting rate as the main indexes was carried out. The results showed that the cutting rate was above 98% for the PVC film with thickness of 11μm, 12μm, 13μm, which indicated that the cutting mechanism could satisfy operation demand of the fruitvegetable packaging machine.

Abstract:Potato flakes (PF) and raw potato flour (RPF) are essential materials in potato staple food strategy. Although PF has many excellent properties, the high production cost of PF limits the exploitation of potato production. Thus, obtaining a substitute of PF is significant for potato staple food strategy. Freeze drying and hot air drying (60℃ with or without blanching) were used to dehydrate potato powder. The appearance, microstructure, functional and reconstitution properties of RPF were researched compared with PF. The results showed that the LAB values of freeze dried RPF and hot air dried RPF with blanching were close to those of PF. However, color of the hot air dried RPF without blanching turned brown seriously, whose whiteness was much lower than that of PF. In microstructure, there was a big difference between RPF and PF in cell adhesion and starch gelatinization degree. The cells of PF were arranged well without any adhesion and raw starch granule. In contrast, cell walls of RPF were adhered and raw starch granule was abounded in cell. 〖JP3〗The blue value of hot air dried RPF (309.90) was similar to that of PF (399.36). The water holding capacity (6.58g/g) and transparency (93.66%) of PF were significantly higher than those of RPF. Among the three kinds of RPF, hot air dried RPF with blanching was mostly similar to PF in values of functional properties. The water holding capacity, oil holding capacity and transparency of hot air dried RPF with blanching were 3.51g/g, 0.61g/g and 50.37%, respectively. Reconstitution properties of hot air dried PRF with blanching were similar to those of PF with reconstitution ratio of 9.68 and reconstitution stability of 95.51%. Therefore, the hot air dried RPF with blanching can be candidate PF substitutes in potato productions in the future. Further effort is needed to improve the uniformity and stability, and to solve the problem of dehydration and aging of the hot air dried RPF.

Abstract:In order to improve the current situation of lacking of agricultural video processing technologies, such as agricultural video shot detection, agricultural video annotation, the video scene detection technology, video semantic annotation and disease diagnosis algorithm for agriculture were studied, and the semantic mining oriented semantic scene detection model was constructed. Firstly, a vegetable video shot database was established by using multimodal fusion video segmentation technology. Secondly, through the study of vegetable knowledge system, a Chinese dictionary of vegetables knowledge was constructed. At last, the multimodal fusion based semantic annotation model for vegetable scene was presented though analyzing target recognition technology in multiple modals. The recognition results of semantic similarity of three modal were measured by HowNet, and video semantic scene detection model was built. The similarity of adjacent shots was measured, and the similar adjacent shots on semantic would be clustered, so that the clustered video scenes would be more suitable for contentbased video retrieval. Experiment results showed that the proposed method reached accuracy rate of 96.9% on vegetable semantic scene detection. This method can solve the ambiguity problem of existing algorithms annotating vegetable videos, and it would help to realize professional and objective semantic annotation of vegetable video scene.

Abstract:Currently, the monitoring system of ornamental fish culturing water quality has the problems such as high cost, poor flexibility and wiring difficulty. In order to solve these problems, a monitoring system was provided based on wireless sensor network. Realtime monitoring of water quality parameter was realized. When the dissolved oxygen was low, it can increase the oxygen content in time and ensure that the water quality was stayed at the best condition. The data acquisition node of this system can collect information of water quality and send the processed data information to USB gateway node and the GPRS gateway node by using wireless communication. The USB gateway node sent the data to computer by USB interface and the GPRS gateway node uploaded the data to data server, so that users can check the water quality data by visiting remote server on mobile phones. The research language of nodes was C language, which can realize collecting, processing and wireless sending of water quality parameter data. VB 60 was applied to develop upper computer software while the mobile phone application was developed by Android system. In the test phase, the communication performance of node was good and the key factor to increase reliability of the system was to choose proper radiofrequency power according to communication distance. As the deviation of the sensor was negligible in the test, this system can meet the demand of monitoring of ornamental fish culturing water quality, which made it possible to provide reliable realtime monitoring of water quality parameter in large scales.

Abstract:The varying pattern of soil moisture in crop field environment was measured, analyzed and compared. The correlation coefficients between soil moisture and precipitation amount as well as between soil moisture and temperature were closely studied. The measured soil moisture data were nonstationary time series, which were quasiperiodic. The periodicity characteristic was varied with growth stages of spring maize. Precipitation amount was one of the most important stochastic environmental factors which interfered soil moisture. Oriented to this randomness feature, soil moisture was measured in different soil depths (10cm and 30cm, represented two typical types of soil moisture’s fluctuation) at four different maize growth stages. The soil moisture data measured in 10cm soil depth represented a volatile fluctuation, while that in 30cm soil depth was relatively stable. A model group for shortterm soil moisture prediction was introduced based on the GM(1,1) method. The model group was tested by using soil moisture data acquired from field. Results showed that compared with single prediction model, the prediction precision was evidently improved by corresponding submodel of the model group. The overall mean relative error was less than 2% for the model group. Comparing results of different combinations in soil moisture prediction using the model group, the result at maize seedling stage in 10cm soil depth was the best. Moreover, considering the influence of precipitation, parameter u in model group was optimized and adjusted, which further improved the performance of the moded group for soil moisture prediction.

Abstract:The body temperature is one of the important parameters for cow health status and also is one of great significance reference for disease diagnosis and treatment. The data collection of cow body temperature by manual cant be realtiming and sometimes has errors so that brings a lot of difficulties to management. In view of development of computer technology and applications in the agriculture, based on the current mainstream of WiFi, a realtime monitoring system was applied to inspect the variation of cow body temperature. The digital temperature sensor DS18B20 was used to collect cow’s aural temperature, communicated with ESP-WROOM module that was integrated Tensilica L106, 32bit microcontroller (MCU), a 16bit RSIC with the complete system and selfcontained WiFi networking capabilities through onewire connector. At the first time ESP-WROOM module must be configured by SmartConfig protocol with APs (Access point) parameters which aiming to be slinked with AP. Once the connection was successfully established, the temperature data will be sent to MCU. After received, MCU packs data and parameters send to server through TCP protocol. And the data collected were stored in MySQL database respectively in different cows. The soft system programmed with Java language can achieve realtime acquisition, storage, display and inquiry of cows temperature data. The asynchronous communication models in view of Java NIO class were used to solve the masses of service requests delivered and the request congestion excluded. The results of experiment showed that errors of the proposed device were ±0.2℃ with the range of 30~50℃, the proper transfer distance of sensor node was 80m, and the loss rate of network passage was 4.42%. The power consumption was decreased with collecting time and sleep mode. It is proved that the characteristic of lowpower, small bulk, high precision of sample can be provided and applied practically.

Abstract:Crop spectrum characteristic analysis plays an important role in growth condition monitoring and nutrition diagnosis for precision management. It is also the theoretical basis of remote sensing data analysis. In order to predict the nutrient content of crop nondestructively and quickly, a spectrum detection system for summer corn was developed to measure the reflectance of 350~820nm. The system had three parts, i.e., optical sensor, data storage and transmission module and controller. And spectral information collection software included three modules, i. e., acquisition parameters, acquisition control and data management. Calibration experiment was carried out to test the performance of spectrum analyzing system. The correlation with ASD Field Spec Hand Held 2 was analyzed. The result showed that the average determination coefficient was 0.94. It was used to detect the chlorophyll and moisture contents of corn leaves. The relationships were analyzed based on the one and twodimensional correlations, respectively. Firstly, the chlorophyll content detecting model was established based on firstorder differential and Kvalue clustering method by using 548nm,594nm and 652nm with determination coefficients of 0.43 and 0.36. Then, the response relationships between moisture content and chlorophyll content in corn leaves were discussed and the model was revised by wavelengths at 480nm, 594nm, 652nm and 819nm. The revised chlorophyll content detecting model was established with determination coefficients of 0.47 and 0.34.

Abstract:Aiming at degeneration of UAV’s farmland aerial images in rainy or foggy weather, this article proposed an integrated method based on dark channel prior(DCP) and optimized contrast enhancement(OCE). Firstly, this method identified the existence of sky from the original image, and then segmented and feathered the original images in Gauss method with Canny edge detection algorithm. Secondly, the nonsky regions, where luminance value was low, were filled with binarized dilation and morphological erosion removed. Finally, both nonsky and sky regions within a frame were processed by dark channel and optimized contrast enhancement algorithm respectively. In this research, the effect of the proposed algorithm was evaluated by noreference quantitative assessment using 100 aerial photographing images. The experimental results showed that the possibility of Halo effect, compared to DCP, was reduced by 95% while its comprehensive evaluation average index was raised by 26%. Consequently, without obvious transition region and color cast, the proposed method filtered the fog of the aerial images well and the color reproduction was high. Meanwhile, the average processing efficiency in the proposed algorithm was up to 32% (33 frame per second) higher than classical DCP. Hence, the method could met the realtime requirements.

Abstract:Lameness in dairy cow has been reported to be a critical economic factor and a vital animalwelfare issue for the dairy industry around the world. Lameness necessitates medical treatment reduces milk production, results in decreased body condition, impairs reproduction performance, and adversely impacts the social status of animals. Economically, lameness is reported to be the third most cost problem for dairy herds following mastitis and subfertility. So it would be the best way if the early symptoms of lameness could be recognized. Based on the Walkway (pressure measurement trail) which was produced by America Tekscan Company, the photoelectric sensor was used to trigger the electric circuit, which will also trigger the start and stop measuring system. After the obtainment of data, the analysis software was used to do disposal and analysis work, compute single or multiple gait parameters, as well as catch the data tables and curves. In the preliminary experiment, with the human being as the test objects, the result showed that the gait parameters which based on extraction and analysis of the surface pressure using the pressure distribution measurement system built by Walkway, could reflect the realtime motion state of the test subjects, and the extraction work would be faster, also with a higher degree of accuracy. That means the measurement system could be used to analyze the gait parameters, which also lays a theoretical foundation of recognition for the early stage lameness afterwards, making it possible to achieve unsupervised automatic gait detection in the future. 

Abstract:Currently, the mainly used corn ear variety test are traditional artificial way and semiartificial way based on machine vision. Semiartificial variety test needs people to complete ear of corn placement, then it got the feature extraction of corn ear by using machine vision technology, and the manual collection of corn ear was needed after completing the measurement. The disadvantages of this method were shown as below: semiartificial, nonautomatic, measurement efficiency restricted by manual. To solve these problems and achieve automatic image acquisition and automatic weighing during the process of corn ear variety test traits, an automatic variety test system for corn ear was designed. It included linear vibration feeder, positioned laterally transmission mechanism, pneumatic gripping eight transfer mechanism, image acquisition platform, weighing platform, push mechanism, programmable logic controller (PLC) and computer, which realized the aim of automatic feeding corn ear, automatic sorting, automatic image acquisition and automatic weighing. This project made a prototype trial on the basic. The results of experiment showed that the prototype trial worked well, it gripped and placed corn correctly, and the camera acquired images reliably. One working period costed less than 6s and the measurement speed was up to 600ms per ear using single camera. In general, the prototype meets the requirements of test species.

Abstract:It is very important and necessary to ensure plant protection unmanned aerial vehicle (UAV) not to cross its working field border when it is performing spray job. Meanwhile, it is the key technology for farmers to keep their working UAVs safe and with high working efficiency. In order to guarantee the security and efficiency of working plant protection UAV, a highly efficient and reliable electronic fence system was designed and developed based on ray method, which could be used for detecting whether the UAV had crossed its working field’s border, and giving a warning in time when there was crossborder trend. The basic idea of the method was to generate a safety border inside the working field’s original border based on the area of field border and UAV’s flying speed. When the UAV was detected to fly inside the safety boundary, there was no need for crossborder detection; when the UAV was detected to fly between its working fields border and its safety border, it was needed to proceed detecting whether the UAV was going to cross the working field’s border, and a warning should be triggered by electronic fence system if the UAV was going to cross the border. The system would throw an exception when the UAV was out of its working field’s border. The system was tested and the results showed that the developed electronic fence system for plant protection UAV could be used to detect UAVs’ flying state in real time, and monitor whether plant protection UAVs crossed their working border and give a warning in time whenever there was any crossborder trend.

Abstract:The images of locust slices with abundant textures are often negatively impacted by external noises during image acquisition, enhancement and so on. These noises then destroyed the textures of the locust slice images and hindered the study of the locust cell structures. In the frequency domain, traditional 2D wavelet transform based on tensor, in which only have two directions, horizontal and vertical, can’t deal with high dimensional data effectively. Besides, the filter that constructed wavelet was isotropic, so the traditional denoising methods using wavelet denoising noise made image edge and texture blur. Shearlet often uses a compactly supported traditional wavelet function as its wavelet basis. Then this wavelet basis though translation, dilation and shear transform, makes shearlet express multiple directions. The shearlet filter is anisotropic. Shearlet uses the special frame structure, in which can preserve texture and edge so as it will not be noised. Shearlet transform was based on multiscale geometric analysis. Shearlet can represent image sparsely. Thus this paper proposed a Shearlet algorithm based on Meyer window function. The algorithm used Meyer wavelet as the wavelet basis function, since Meyer wavelet was symmetric and infinitely differentiate. First, Meyer wavelet function and scale function were used to construct a Meyer window function. 〖HJ〗Meyer window function was used to decompose the noisy locust slice images in frequency domain, and compute Shearlet norms in each scale and each direction. Second, the traditional hard threshold method was used to process the Shearlet coefficient. Finally, through Shearlet inverse transform, the locust slices images were restructured. In the experimental section, two groups of experiments were set up. In the first group experiment, the proposed algorithm was compared to other denoising algorithms, such as Meyer wavelet threshold denoising algorithm, partial differential equation denoising algorithm and so on. The classical image quality evaluation index was adopted to evaluate the performances of these algorithms. The adopted evaluation index included mean squared error (MSE), peak signal to noise ratio (PSNR), and structure similarity (SSIM). When the noise standard deviation was 30, the PSNR got by this paper was 2.5dB higher than that got by Meyer wavelet threshold denoising algorithm, and 2dB higher than that got by partial differential equation denoising algorithm. The second group experiment, in order to verify the retain texture with different directions, a locust cell image with much more texture was selected. The final experiment result showed that this algorithm can retain effectively. Others traditional denoising algorithm made the edge and textures blur.

Abstract:In order to solve the problems when conventional ground vehicles and wheels driving on soft terrain, such as poor trafficability，low efficiency， and big energy consumption, the transformable wheel was innovatively designed. Its design consisted of deformation mechanism, driving mechanism and wheel feet. The wheel had two extreme working statuses: unfolded wheel and folded wheel. It can realize walking and rolling. Based on classical terramechanics theory，the dynamics models of interactions between two types of working wheel status and three kinds of typical soft soils were established. Drawbar pull, driving torque and driving efficiency as well as sinkage of diametervariable wheel were analyzed under the condition of different slips, where the drawbar pull and driving torque were increased with the increase of slip rate, drawbar pull and drive torque of the unfolded wheel were up to 3990N and 2395N·m, and those of the folded wheel were up to 1435N and 1390N·m, respectively. In a certain radius of the wheel, the traction efficiency was soared to the maximum with the increase of slip rate and then it was slowly descended to zero. The maximum traction efficiency of unfolded wheel and folded wheel were 0.53 and 0.19, respectively, and the corresponding slip rate ranges were 0.1~0.2 and 0.2~0.3. The results indicated that traction trafficability indexes were limited by wheel slip and soft soil parameters．The unfold wheel can significantly improve drawbar pull，driving efficiency and soft soil traction trafficability，and reduce sinkage compared with the folded wheel. Finally, transformable wheel prototype trial production was presented, and installed on the amphibious allterrain vehicle by using the principle of submergingfloating. With the traction test, the unfolded wheel did not provide sufficient driving force when the slip rate was greater than 0.52 (that for folded wheel was 0.44), and the data was recorded six times. The difference between test results and computed results was less than 10%, which proved the applicability and validity of deformable wheel on soft terrain. 

Abstract:Wire mesh wheel has good trafficability on soft and clammy terrain; however, there were few studies on traction trafficability of wire mesh wheel on dry sand soil. The lightweight wheelssoil testing system was developed. The wheel sinkage, driving torque, drawbar pull and traction efficiency were adopted as testing indexes, and the tests on tractive trafficability of wire mesh wheel and cylindrical wheel were conducted under soft and natural soil state. The apparent sinkage of wire mesh wheel was obtained based on rut noncontact measurement. Results indicated that the real sinkages of wire mesh wheel were ranged from 13.1mm to 26.3mm (soft state) and from 8.1mm to 18.7mm (natural state), compared with those of the cylindrical wheel, the average increasing rate were 264% (soft state) and 22.7% (natural state), respectively. The apparent sinkage of wire mesh wheel was decreased with the increase of slip ratio, while the apparent sinkage of cylindrical wheel was increased firstly and then decreased. As the increase of slip ratio, both the driving torque and drawbar pull were increased, and traction efficiency was increased firstly and then decreased. The maximum driving torques of wire mesh wheel were 3.18N·m(soft state) and 3.76N·m (natural state). The driving torque of cylindrical wheel was larger than that of wire mesh wheel. The maximum drawbar pulls of wire mesh wheel were up to 8.46N (soft state) and 9.9N (natural state), the drawbar pull under natural soil state was increased by 16.7% than that on the soft soil state. The driving torque increasing ratio of cylindrical wheel was 45.2%, and the increasing average ratio was 32.3% for drawbar pull, compared with that of wire mesh wheel. The traction efficiency driving torque of wire mesh wheel was obviously larger than that of cylindrical wheel. The traction efficiency under natural soil state was increased by 17.9% than that on the soft soil state. The test conclusions indicated that the trafficability of wire mesh wheel was better than that of cylindrical wheel on dry sand soil, when comprehensively considered the effect of wheel sinkage and traction efficiency. The research results provided technical methods and basic data for development of lightweight vehicles, ground testing and traction trafficability assessment of wheel.

Abstract:To complete the field management of tobacco corn and other high stalk crops, a small high clearance tracked vehicle with remote control and full hydraulic drive was designed. The vehicle was more compact than most of the vehicles which used mechanical transmission structures and it had better passing ability in the field. A synchrovalve was used to improve the straight driving stability of the vehicle. The effect of offset barycenter and synchrovalve for the straight driving stability of the vehicle was studied. SolidWorks software was used to accurately assess the positions of the offset barycenter when the vehicle was noload and put two or four counterweights on the left frame. The quality of each counterweight was 42.6kg. Torques of left hydraulic motor were 23.19N·m, 32.79N·m and 42.41N·m.〖JP〗 Torques of right hydraulic motor were 34.28N·m,34.47N·m and 34.65N·m. Static torque values were applied to the motors and AMEsim software was used to simulate the hydraulic system. Simulation results showed that the differences between the motors were less than 1% and more than 38% relative to the total speed when the system had or didnt have synchrovalve. The driving direction of the tracked vehicle was adjusted well on the dry and hard cement floor. The direction was marked with red rope and marked the end point 50 m away in right ahead of the vehicle. The vehicle was driven forward to the end point and the offset distance was measured. Deviation rate was equal to offset distance divided by 50. Prototype tests showed that when hydraulic system had synchrovalve, the deviation rates of the vehicle were 4.12%, 4.28% and 4.62%. When hydraulic system didnt have synchrovalve, the deviation rates of the vehicle were 5.08%, 6.54% and 9.43%. Simulations and tests showed that using synchrovalves to improve the straight driving stability of the vehicle was feasible. Deviation rates of the vehicle could meet the requirements of the relevant national standards. This research could provide references for small high clearance tracked vehicles which were driven by hydraulic.