Abstract:During the vegetable transplanting for the existing vegetable semi-automatic transplanter, the plug seedlings picking and feeding are nearly dependent on manual work, so the work efficiency is very low. Aiming at this problem, a vegetable plug seedling automatic pick-up mechanism was designed. The motion and dynamic mathematical model were established. Moreover, the influences over the mechanism motion and dynamic characteristic by some important parameters were analyzed by using the parametric models. The design of optimization objective for automatic picking vegetable plug seedlings was proposed. And then, the range of mechanism parameter which met the requirements of the motion trajectory for plug seedling picking was obtained. In addition, the dynamic analysis for the pick-up mechanism was carried out based on the range. Meanwhile, taking the minimal force wave of mechanism bearing as optimization objective, the optimal parameter combination of pick-up mechanism was obtained. With these parameters, the plug seedling pick-up mechanism processed better the motion trajectory and better dynamic performance which met the demands of seedling picking.

Abstract:To improve the automation and efficiency of plug seedling transplanter, a full-row-pick-up and single-dropping seedling transplanter was designed based on the type-PVHR2 semi-automatic transplanter with rotary seedling-received cup device. The seedling pick-up end-effector system performed the removal of total number of seedlings in a row and dropped them individually into their cups. The rotary-lifting mechanism was used to help the end-effector to move down to pick the seedlings from the tray upwards, rotate at 90°to drop the seedlings into the cups, and reverse at 90° to the upside of tray. With the principle of fully picking the row seedlings and dropping them one-by-one in mind, seedling pick-up unit driven cam contours were designed to open and close the pick-up units. Based on the transplanting requirements, motion matching and timing control of the mechanism and the cams were carried out to ensure proper coordination in the transplanter. Automatic transplanting experiments for the 72-hole plug cucumber seedlings with the age of 28d showed that the designed mechanism was reliable with a success pick-up rate of 95% at pick-up speed of 3600 seedlings/h, pick-up embedded depth of 27mm, and pick-up angle of 10°.

Abstract:A kind of transplanting seedling disc conveying device and positioning control system were developed for automatic disk conveying and accurate position of pot seedling transplanter. The moving speed and distance of seedling disc could be adjusted according to the disc size, which was driven by gas-liquid damping cylinder. The PLC was used as control core and the touch screen was used as human-machine interface. Experimental results showed that the influence caused by the cylinder response lag and machining error could be eliminated by setting the compensation value. The positioning control error was less than 1mm, which met requirements of high-speed automatic transplanting machine.

Abstract:An automatic delivery mechanism of potted-seedling for vegetable transplanter based on PLC was designed. The automatic mechanism of taking potted-seedling from pot with non-damaging was designed. The ejector pin driven by high speed servo electric cylinder was used. The potted-seeding was taken from the pot with precise, high speed and non-damaging. The potted-seedling was located and transplanted precisely by the stepping motor which was controlled by the software system of PLC. The casting potted-seedling mechanism synchronously, consisted of the timing belt and gear, was designed, which realized the synchronous movement between the casting potted-seedling unit and the duckbilled-type planting shoe. The problem of non-uniform rotation velocity of duckbilled-type planting shoe driven by ground wheel was solved. The seedling accuracy was increased. At last, the device was designed, which verified the correctness of automatic delivery mechanism.

Abstract:An automatic transplanter mechanism was designed. According to the mechanism principle, the corresponding mathematical model was built. Relationship of each parameter in the proposed model was analyzed. For the different types of seedling trays, Matlab was used, which optimized the structural parameters of the model. The proposed seedling pick-up mechanism met the design demands of opening-closing in a given range and clamp for seedling substrate.

Abstract:The core of automatic transplanter is automatically and efficiently picking seedlings. Besides the mechanical structural factors, many other factors, like mechanical properties of seedlings, would affect the successful transplanting rate. Taking cucumber plug seedlings as object, the experiments of clipping and picking seedlings for measuring the picking seedlings force, and gripping seedlings for measuring pressure resistance of seedlings were carried out. The orthogonal experimental design was used to analyze the effect of filling amount, substrate composition, and moisture content on the force of picking seedlings and pressure resistance of seedlings. The experiment results showed that the above three factors all had significant effect on force of picking seedlings and pressure resistance of seedlings. The order from high to low was: filling amount, substrate composition and moisture content for force of picking seedlings, and moisture content, substrate composition and filling amount for pressure resistance of seedlings. The optimum working conditions were as follows: substrate for each cell of 33.5cm3, substrate composition with peat, vermiculitel and perlitel (volume ratio of 3∶1∶1), and moisture content of 65%. These optimum working conditions were accordance with results of comprehensive score obtained by experiment on picking seedling machine.

Abstract:The seeds always collided with the seeds tube and opener during the process of seeding. Due to the combined effect of the collision and machines forward, the landing position of the seed was random, which resulted in lower uniformity. To solve this problem, a helm-shaped no-tillage precision fertilization planter for corn was designed. It was mainly composed of crush straw and seedlings zone cleaning device and helm dipper disk type of dibber. The helm dipper disk type of dibber was integrated by the steering wheel of dibble and dipper disk seeding device. The steering wheel of dibble could take the seeds accurately and the dipper disk seeding device could throw seeds in fixed points, so that the precision sowing was realized. The fertilizer ditch was generated by the crush straw and seedlings zone cleaning device. The fertilization was completed by the outer sheave of fertilizer device. The result of field experiments showed that the average depth of sowing and fertilization were 52.1mm and 70.5mm, and the germination rate was improved to 95%. It satisfied the requirements of conservation tillage technology in the experimental area.

Abstract:The corn precision seeder with whole plastic-film mulching on double ridges in dry land was researched independently. The horizontal absolute velocity of hole-former was made zero at seeding time by using cam and crank combination mechanism to control it, which could improve the planting operation process tore film, picked film and dislocated of the soil hole with hole-former. For further study the working performance with the corn precision seeder, the Box-Behnken experimental design with four factors and three levels was performed, parameters such as seeder speed, rotation speed of crank mechanism, rotation speed of cam mechanism and angle of film cutter were selected as independent variables, which would influence dislocation of soil hole rate. The mathematical model was established. The effects of various parameters and their interactions were analyzed as well. The test results showed that effects order of four parameters on dislocation of soil hole rate were as follows: rotation speed of cam mechanism, rotation speed of crank mechanism, seeder speed and angle of film cutter. The optimal working parameters were seeder speed of 0.50m/s, rotation speed of crank mechanism of 50.2r/min, rotation speed of cam mechanism of 46.4r/min and angle of film cutter of 23.6°, then the dislocation of soil hole rate production of 1.221% was obtained. Confirmatory tests showed that the relative error was little.

Abstract:For the mechanization system of maize-wheat production in the north China plain, a basic planting specification was optimized which met the requirements of agricultural mechanized farming. The type 2BYM—12 folding and dynamic anti-blocking no-till maize planter had functions of seedling zone cleaning, dynamic anti-blocking, intelligent stepless adjustment to plant spacing, automatic testing farming quality and quantity of large scale precision seeder, adjustment to sowing depth, copying work and so on. Lightweight technology and hydraulic folding technology were adopted beneficial to agricultural machine field transfer and operation. Based on power matching calculation and load calculation, the type 2BYM—12 no-till planter was analyzed with finite element method. The calculation indicated that the stress distribution of no-till planter was similar to the actual situation, and satisfied the design requirements.

Abstract:The basic structure and work principal of the type 9BQS—3.0 pneumatic scarifying and sowing compound operation machine were introduced. The general structure, shallow scarifying device, press roller and metering device were designed and computed. The experiment results indicated that the seeder had good performance and reasonable structure. The soil broken rate was 94.5%. The bulking intensity of shallow scarifying layer was 63%. The seed broken ratio of elymus dahuricus was 1.2%. The seeder could perform the compound operation of scarifying, furrowing, seeding, covering soil and flatting simultaneously.

Abstract:Aim at avoiding seed missing and enhancing working quality of sower, based on the PIC single-chip microcomputer control technology, a monitoring system was designed and applied to monitor the pneumatic no-tillage sower’s performance. The general structure and system circuit of the pneumatic sower monitoring system were designed, and the correlation parameters were set. The fan rotational speed, walking speed, planting area, and material level of pneumatic seeder were monitored real-timely by using the monitoring system. The experimental results showed that the pneumatic sower monitoring system had high precision measurement accuracy. It could complete real-time monitoring of working process.

Abstract:When planted in one year two crop area of China, it is important to reduce energy consumption and improve planting performance, and ensure the anti-blocking performance as well. When the support cutting was carried out, the cutting force needed became smaller because some of it was got from external force. Taking support cutting device—floated support anti-blocking device as research object, the static strength finite element analysis of key components blade and support plate was conducted with ANSYS software. The load of blade came from resistance of cutting straw and soil, and the load of support plate came from holding power of straw and soil. On the basis of established finite element model, a series of stress figures were obtained after calculation. The result indicated that the stress of blade mainly focused on x>0 area of right hole heart, and the area from hole heart to turning place. The maximum of equivalent stress was 2151.2Pa. The stress of support plate mainly focused on arc plate area and flat plate area closed to the arc plate side. The maximum of equivalent stress was 3.77×105Pa. The field experiment showed that the machine had a good working performance and deformation was not found on the blade and support plate.

Abstract:During the operation ofsuction-vibration precision seeder, the seeds on the tray were reducing continuously and suction height was declined accordingly. Through the experiments, combining with physical characteristics of rice seeds, the law of quantitative change for these seeds was obtained. A control method of suction height was proposed. Moreover, the quantity and cycle of the seeds-adding device were determined and seeding tests were conducted. The results showed that the seed-suction height control method and the seeds-adding control mode could make the seeds-layer thickness range at 8~18mm, and the absorbing rate of the seeds-suction could arrive at 94% or more, which was able to meet the requirements of precision seeding seeder.

Abstract:Metering performances in a pneumatic seeder of rapeseed processed with different pre-soaking methods, including pre soaking in warm water, cold water and without pre-soaking, were investigated to estimate whether sowing mechanization could be applied into the seeds qualified to agronomic requirement of pre-soaking. The results indicated that mechanical and physical properties of rapeseed had obvious change after soaking, which could be characterized by softened seed coat and increased 1000-grain weight and plumpness. Additionally, residual modulus degraded by 40%, the cracking load decreased by 10% and the cracking deformation aggrandized by 20%. When the rotational speed of seeder was slower than 36r/min, the sowing-performance as the quality of feed index for the three kinds of seed were more than 95%, while the miss index were less than 4%. Although the mechanical properties appeared degraded, the seeder never destructed the appearance and germinating ability of seeds. The results of the research concluded that rapeseed under pre-soaking would suitable for sowing mechanization with the pneumatic metering technology employed both positive and negative pressure.

Abstract:In order to study the adaptability of different tillage treatments in annual double cropping areas in northern China， four different tillage treatments were set up, including subsoiling, rotary tillage, conventional tillage and no-till. The effects of different tillage treatments on soil water stable aggregates, soil bulk density, soil water content, soil temperature and crop growth were studied. The results showed that, no-till and subsoiling increased the content of soil water stable aggregates with a diameter larger than 0.25mm at 0～10cm and 10～30cm soil layer, respectively. While the results of no-till and conventional tillage was not obvious. The regulating effects in soil bulk density were increased with the increase of the depth of soil layer. Rotary tillage and subsoiling could reduce the content of soil bulk density at 0～10cm and 10～30cm soil layer, respectively. The soil bulk density of no-till was the biggest at 0～20cm soil layer, and there were no significant differences observed among the conventional tillage, rotary tillage and no-tillage under 20cm soil layer. The preserve soil moisture ability of subsoiling was higher than others. Compared with subsoiling, the soil moisture content of rotary tillage, plowing tillage and no-tillage was reduced by 2.5%, 1.6%, 0.4%，respectively. The range of soil temperature of plowing tillage was the greatest with the change of air temperature, while the range and daily mean soil temperature of no-till was the least. Subsoiling promoted the yield of winter wheat and the growth of crops in the initial stage, while no-till had a better result at a later stage.

Abstract:Sliding-knife-type disc opener was designed with combination structure characteristic of disc opener and slide-knife opener. The diameter, gap contour curve and quantity of sliding-knife-type disc opener were determined by calculation. The interaction of sliding-knife-type disc opener and soil were simulated by LS—DYNA module of ANSYS. The results of field trials showed that sliding-knife-type disc opener had excellent buried and broken stubble abilities.

Abstract:Aim to the problems of complicated adjustment of PID parameter, time-consuming and strongly empirical in variable rate fertilization system, genetic algorithm PID (GA-PID) tuning method was proposed to implement flexible parameter adjustment. By using Matlab/Simulink simulation, the square wave response of traditional PID and GA-PID system were compared. The results showed that GA-PID control strategy was superior to the conventional PID in response speed, overshoots, and setting time. System steady performance experiment was carried out at variable rate fertilization test bench. The results showed that GA-PID control algorithm of variable rate fertilization system was very accurate, the static error was small, and speed range linearity as good. GA-PID retrenched the process of parameter tuning and optimized the parameter tuning results.

Abstract:To investigate factors influencing the performance of mulching plastic film collector and determine the optimal working conditions, the theoretical analysis and motion simulation were carried out. By using the soil-bin trolley experiment, the orthogonal experiment with influence factors of machine operating speed, speed ratio (the ratio of spring-tooth axis speed and the speed of machine operating) and the embedded depth of the shovel for lifting film was carried out. Consistent with theoretical analysis, simulative studies demonstrated that the collection ratio of mechanism could reach the optimal when the machine operating speed was 0.7m/s, the speed ratio was 1.0, and the embedded depth of the shovel for lifting film was 110mm.

Abstract:A low self-propelled sprayer for conventional orchard was developed in order to solve the plant protection mechanization. The power distribution unit was designed by theoretical analysis and virtual prototype to realize all working parts running independently. Eight shifts were designed by main and assistant gear-box. The sprayer could switch two-wheel drive to four-wheel drive according to running condition. Its minimum trafficable height was 1600mm. In the dosage range of 0~400L, the front wheels crossed obstacles reduced from the 87mm to the 70mm, and rear wheel obstacles height was independent of dosage. The minimum turning radius was about 2000mm. The simulation result by Creo Parametric 2.0 showed the sprayer worked steadily, and the velocity was between 1.5 to 16km/h. The effects of pesticide volume on centre of gravity and stability were little.

Abstract:The jet mixing apparatus (JMA) is an important part for mixing the water with the pesticide, which has good prospect in large plant protection machinery. The parameter of area ratio, area of nozzle and distance between nozzle and mixing chamber were discussed by theoretical analysis. The standard k—εtwo-equation model was adopted to simulate the interior flow field. Combined with experiment data, the performance characteristics, the effects of structural parameters on the JMA property were discussed. Results showed that the optimum area ratio was related to working pressure, outlet pressure and jet pressure. The distance between nozzle and mixing chamber should be equal to optimum extent of free stream. The maximum relative error and average error of relative pressure at different area ratio were 0.125 and 0.051, respectively. The numerical model and simulation method were validated validate to meet the requirements of engineering. The jet flow decreased when the relative pressure greater than 0.3. The maximum relative pressure was between 0.5 and 0.6 under different available pressures. The optimum area ratio of JMA was between 1.6 and 2.0. The optimum distance between nozzle and mixing chamber was between 2.6mm and 4.6mm.

Abstract:To discover the characteristic of tip clearance flow, the large eddy simulation (LES) method with sliding mesh technique was used for analyzing the unsteady flow in a low-specific-speed axial-flow pump under five different operating conditions. The tip-leakage vortices and pressure pulsations of near-tip zone on the blades were examined. It was found that the dominant tip-leakage vortex extended to the pressure side of the neighboring blade for all five investigated flow rates. As the flow rate increased from 0.7Qd to 1.2Qd, the angle between the dominant tip-leakage vortex and the blade reduced from 20°to 14°. The results also showed that the amplitude of pressure fluctuation in the near-tip zone on the blades became higher when the flow rate was farer from the design flow rate, especially on the pressure side of the blade. At the 0.7Qd condition, the pressure fluctuation amplitude of the monitoring point PP3 (at the near-tip zone on the pressure side of the blade close to the blade leading edge) was 8.5 times of the one at design flow rate, and the high-frequency pulsation occurred due to tip-leakage vortices. When the flow rate was more than 1.0Qd, the pressure fluctuations of PP3 was dominated by the rotation frequency.

Abstract:Considering actual mounting dimension of each pipe section, the steady and unsteady total flow field was calculated based on the excellent hydraulic model of axial flow pump. Fluid domain was discretized with structured mesh and analyzed with standard turbulence model. Pressure fluctuation values of impeller inlet, impeller outlet, middle of the guide vane and guide vane outlet were monitored. It turned out that prediction results were in good agreement with the experimental results. Radial distribution of pressure fluctuation for axial flow pump at different rotation speeds was investigated, and the results showed that the distribution of RMS along the radius also changed when the rotation speed varied. In terms of frequency domain chart, at the inlet of impeller, large amplitude of sub-harmonic emerged in the middle of the passage and near the hub; while at the guide vane outlet, amplitude of sub-harmonic of the monitor point in the middle of passage was relative higher and amplitude of sub-harmonic was relative lower near the hub and passage outer edge.

Abstract:In order to study the impact of different tongue angels on the rotor-stator interaction, the internal flow of the centrifugal pump with three different tongue angels was simulated numerically by simulation of full flow field. The pump performance, internal flow characteristics, pressure pulsation characteristics and the radial force characteristic were obtained. Compared with the experiment results of pump performance, PIV test results and CFD computations, the proposed numerical methods had higher accuracy. The results showed that when tongue angel increased from 23°to 33°gradually, the head showed an increasing tendency and the high efficiency zone was widened. The maximum efficiency point was toward to the large discharge. The internal low was improved and the turbulent kinetic energy distribution was uniform with tongue angel of 33°. When tongue angel was 23°, the amplitude of the pressure fluctuation and the radial force on the impeller were significantly greater than the other two types of volute for different operating conditions. Under the low flow rate, the radial force pointed to positive Y-axis with the decreasing of tongue angels, while under the design flow rate and large flow rate, the radial force on the impeller was distributed symmetrically. Therefore, the pressure fluctuation near tongue could effectively be improved and the radial force on the impeller reduced with the increasing of tongue angels.

Abstract:In order to solve the problem existed in using of multilayer manure cleaning system carrying board which were manure accumulated at the end of multilayer manure, high demanding of large height of interlayer spacing in cage system, and poor stability of mechanical scraper, the discrete element analyses software EDEM 2.3 was used to numerically simulate the working process of multilayer manure cleaning system. The effects of the scraper vertical angle X1, the scraper longitudinal angle X2, and the inclination angle of manure carring board X3 on mechanical property of the multilayer manure cleaning scraper were analyzed. The reliability of the simulation model was verified by comparing the performance of virtual scraper and the multilayer manure cleaning scraper equipped in first generation prototype of 9LPT—3. Quadratic orthogonal rotation design with three factors was introduced by the simulation model, the width of manure deposit body after scraping process Y1, the maximum height of manure deposit body in scraping process Y2, and the stability of manure cleaning speed Y3 were selected as the indexes. The result showed that X1、X2 and X3 significantly correlated wih Y1 and Y2 (P<0.0001 and P<0.05 respectively), but didn’t correlate with Y3. It could be concluded that the most optimal mechanical property of the multilayer manure cleaning system would be obtained when x1、x2 and x3 were respectively selected as 7°, 35° and 5°.

Abstract:Combustion characteristics and kinetics of bio-tar before and after catalytic upgrading were studied on a thermogravimetric apparatus. The results showed that the combustion process was divided into four stages: light organics volatilization, volatilization content combustion, less volatilization content combustion and residue combustion. Weight loss in the first two stages of raw tar was about 75%, whereas that of tar after upgrading was about 90%. With the increasing heating rates, weight loss rate increased heavily along with significantly enhanced combustion stability. According to thermogravimetric curve calculation kinetic parameters, activation energy of upgrading tar was lowered and in agreement with that from TG analysis. The gas from combustion was analyzed by Fourier transform infrared spectroscopy method, which showed the gaseous products generated in three phases of 241~380℃, 380~500℃ and 500~600℃.

Abstract:Biomass gasification was performed on a fluidized bed reactor with steam as gasifying agent. Two-stage gasification processes in a fluidized bed were adopted. This research aimed to determine the effects of reaction temperature and steam-to-biomass ratio (u) on exergy distribution, chemical exergy, physical exergy and exergy efficiency of the product gas, and residual ratio and exergy efficiency of the unreacted carbon, etc. Over the ranges of the test conditions used, chemical exergy varied from 10832.13kJ/kg to 16510.54kJ/kg, physical exergy ranged between 685.05kJ/kg and 1146.71kJ/kg chemical exergy/physical exergy ratio varied from 13.5 to 17.7, and exergy efficiency of product gas ranged between 35.52% and 60.78%. The results showed that the top two contributions of gas component to exergy value were H2 and CO. With the increase of reaction temperature, chemical exergy, physical exergy and exergy efficiency of the product gas increased, whilst chemical exergy/physical exergy ratio, and residual ratio and exergy efficiency of the unreacted carbon decreased correspondingly. The exergy value and efficiency of the product gas first increased and then decreased with the increase in u. An optimal value of u should be chosen between 1.2 and 1.6.

Abstract:Compression modeling tests were performed by taking a 9JYK—2000A circular mold briquetting machine as testing apparatus and rice straw as the raw material. According to the experimental result, the effect rules of craft parameters on the energy consumption per ton solid biofuel of straw briquetting machine were analyzed, and the optimal parameter combination was obtained. Based on the Design-Expert 8.0.6 regression analysis method and response surface method, a mathematical model was established by taking fuel consumption per ton as response, to analyze the influence of the four factors, named the moisture content, operation temperature, clearances between rolls and die and the spindle speed. The result indicated that when the raw material had the moisture content of (23.92±3)%, operation temperature of 84.5℃, the gap of roll-die of 2.47mm and the spindle speed of 160.8r/min, the relax density mean was 1.023g/cm3, and the energy consumption per ton was 27.10kW·h/t. The order of contribution rate of every experiment factor on target index was obtained as follows: spindle speed, moisture content, clearances between rolls and die, operation temperature. The relative error between the calculated values and experimental values was 4.50%, which proved that the regression model equations could be used to predict the fuel consumption per ton of circular mold briquetting machine.

Abstract:Rice straw, whose outer surface is covered by silica, has relative higher ash content. 100% pure rice straw panel board manufactured with conventional low cost urea formaldehyde (UF) was featured by low strength, poor dimensional stability and high resin requirement. This work employed liquid hot water to pretreat rice straw, with pretreatment temperature of 160℃ and 170℃ and residence time of 2min, 4min and 6min. The pretreated rice straw was mixed with wood particle at the ratio of 1∶1 by using UF to produce rice straw-wood composite with 0.75g/cm3 density. The hot press temperature and pressure were 150℃ and 3.5MPa, respectively. The resin application level was 12%. The experimental results indicated that the panel board made with rice straw pretreated under 160℃ for 6min and 170℃ for 4min and 6min met the requirement of China national standard for particleboard GB/T 4897—2003.

Abstract:Vis/NIR spectroscopy was used to detect TVC and color of chilled pork rapidly and non-invasively. Vis/NIR scattering image in the range of 400nm to 1100nm were collected from 54 chilled pork samples. The scattering profiles were fitted accurately by four-parameter Gompertz function. The TVC and color L* prediction models were built with support vector machines (SVM) regression. The regression coefficient (Rv) of combination α, β, θ, δ and combination α, β, δ were 0.937 and 0.935, and the standard error of prediction (SEP) were 0.600\lg CFU/g and 0.702lg CFU/g, respectively. For color L*, the prediction model based on combination β and δ could give satisfactory results with Rv of 0.930 and SEP of 1.515. The results demonstrated that Vis/NIR spectroscopy combined with SVM was precise and potential for valid, rapid, non-invasive detection of chilled pork.

Abstract:In order to build a robust model for predicting water content in fresh pork based on hyperspectral imaging technology, the influence of sample set partition, spectral preprocessing and wavelengh selection on model prediction result was discussed. The pork sample set was parted by concentration gradient(CG) firstly, and then the reflectance spectra was pre-processed with multiple scattering correlation(MSC), first derivative and autoscale successively. The partial least square regression (PLSR) model was built, which had the best prediction abilities. The water content values were predicted with the cross-validation and prediction correlation coefficients (Rc and Rp) of 0.814 and 0.804, with the root mean square error (RMSECV and RMSEP) values of 0.726% and 0.686%, respectively. The feature wavelengths were identified by using competitive adaptive reweighted algorithm. The proposed PLSR model was again built by using the feature wavelengths, which had remarkable prediction abilities with Rc and Rp of 0.926 and 0.924, with RMSECV and RMSEP of 0.467% and 0.438%, respectively.

Abstract:A beef quality on-line detection and classification models by Vis/NIR reflectance spectroscopy was established. The system parameters were optimized. Signal collection and spectroscopy preprocess were carried out by Vis/NIR reflectance spectroscopy and a handheld probe device. The scanning times were set on condition that system kept proper detection accuracy and stability, which was 10 times in wavelength range of 400~700nm and 30 times in wavelength range of 700~2000nm, and acquisition time of 900ms. Spectra leverage value of beef was calculated to eliminate abnormal samples, and then different data processing methods were used to establish beef quality PLSR models which finally showed the optimal result of beef quality prediction. The results indicated that the PLSR model with SNV processing had better performance, with the correlation coefficient of 0.9068 and root mean square error of 7.1963N for validation set of beef tenderness, 0.8854 and 2.3628 for L*, 0.8362 and 2.2969 for a*, 0.8453 and 2.1054% for validation set of beef cooking loss, respectively. The correlation coefficient was above 0.8 and the tenderness classification accuracy reached to 93.5%.

Abstract:The cross section images of beef rib-eye in spectral region of 400～1000nm were collected by using a hyperspectral imaging system. With comparative analysis of the spectral curves of the fat regions and the muscle ones of beef rib-eye images, it was found that the reflection intensity of fat regions and muscles areas for beef rib eye images in different spectral bands were obviously different. Fitting the reflection intensity ratio of the fat regions and muscle regions with the wavelength, it could be concluded that, in the 534nm band, the difference between the reflection intensity of fat regions and the one of muscle regions was the maximum. The image processings such as median filtering, region growing and Otsu’s thresholding etc. were conducted on the original color beef rib-eye images and the 534nm band beef rib-eye images for the segmentation of the beef marbling, respectively. The result showed that the higher segmentation accuracy of beef marbling could be obtained by using the 534nm band beef rib-eye images compared with the original color beef rib-eye images.

Abstract:In order to meet the demand of rapid detection of microorganisms indicators for agricultural products in safety onsite monitoring, an automatic rapid detection system was developed based on computer vision and serial-communication technology. The realized functions of the proposed system included, automatic capture of the images, auto-focus of the system, analysis and processing of images, output the detection results, etc. The system adopted an auto-focus technology based on digital image processing. According to the characteristics of staining images of microorganisms in the agricultural products, rough focusing method combined with accurate focusing method were used to improve the auto-focus efficiency. The average auto-focus time of the system was 10.2s. By using this detection system, the close to real-time detection results could be obtained (detection time was less than 1h). Moreover, the system had advantages of easy operation and high automation.

Abstract:In order to fast discriminate adulterated Fenyangwang wine, taking Fenyangwang wine with 53%vol of alcohol concentration as example, BP neural network and least squares support vector machine (LS—SVM) discriminant analysis models were established based on near infrared spectroscopy combined with chemometric methods. The spectra of 180 and 120 adulterated Fenyangwang wine samples were collected. Savitzky—Golay (SG) convolution smoothing was used to pre-treat the spectral data. Seven and eleven principal component factors were extracted respectively by using principal component analysis (PCA). Then, BP neural network and LS—SVM were used in discriminant analysis of unknown samples. Results showed that the accuracy of SG—PCA—BP neural network was up to 100%. The accuracy values of SG—PCA—LS—SVM models for two experimental groups were 84.4% and 83.3%, respectively.

Abstract:A system with functions of surface defect detection and classification for cherry tomatoes based on machine vision was proposed. The system integrated image acquisition, image processing, image recognition and robotic palletizing, which could achieve image filtering, binarization, edge-detection and location identification. An edge-detection algorithm was proposed based on fractional differential and Sobel operator. The effectiveness of the proposed algorithm was tested by comparing the sorting results of seven different algorithms on the same parcel of cherry tomatoes. Experimental results showed that the algorithm could effectively detect defects and classify the cherry tomatoes. The comprehensive classification accuracy was 98.4% with a good application prospect.

Abstract:For removing the noise in the spectral data, Matlab 7.0 wavelet toolbox was used to denoise the data. In order to get the best denoising effect, the model evaluation parameters were investigated from the db2 to db9 wavelet respectively in dbN wavelet basis, and the db6 was thought to be the best wavelet according to the investigation result. Using the db6 wavelet, the optimal decomposition layer was five when changed from three to seven. For getting the best denoising method, the signal-to-noise ratio (SNR) and root mean square error (RMSE) were used to evaluate denoising effect in different thresholds, and the hard threshold value of the heuristic denoising method was observed to be the best one. The prediction model was built using the reconstruction spectrum by partial least squares (PLS) method. The correlation coefficient of the proposed model was 0.907. The root mean square error values of calibration and prediction were 0.819 and 0.905. The performance index was 88.3%. The model parameters using wavelet denoising were better than the original signal. It was showed that wavelet denoising was feasible in prediction of tomato vitamin C with NIR spectroscopy.

Abstract:The classified feasibility of pear jujube with normal, rot and disease defect fruit by using hyperspectral imaging technology was analyzed. A best mathematical model was established by treating first derivative as the best pre-processing which was compared with other different kinds of proceeding methods. The stepwise discriminant analysis and least square support vector machines (LS—SVM) were applied to build the full-wave band, approximation coefficients and principal components models, respectively. The results indicated that the stepwise discriminant analysis model was more suitable for classifying the three different kinds of pear jujube samples. The average correct recognition rate was 99.12%.

Abstract:According to the problem of location failure or large deviation probably generated on account of sensor information loss or abnormal fluctuation when the tractor worked in the complicated field environment, a multi-sensor fusion positioning system based on the weighted-confidence was designed, which composed of global position system and dead reckoning system. The corresponding sub-filter and the global filter were constructed based on the federated Kalman filtering. Then the confidence distance and confidence function of every sensor was defined to compute the confidence coefficient of each sub-filter, which was used as adaptive factor after weighted arithmetic. Finally, the adaptive factors were fused optimally in the global filter to get more accurate position estimates. The computer simulation and field test were carried out to validate the effectiveness and reliability of the designed multi-sensor fusion positioning system.

Abstract:To overcome shortages of the existing algorithms for crop rows detection, such as the noise interference and slow processing speed, an algorithm based on constraint of liner correlation coefficient was proposed for crop rows line detection. Firstly, according to the characters of farm land images, ROI area was processed to increase the speed of image processing. Secondly, crop row numbers and edge information were detected by vertical projection method. Finally, an algorithm based on constraint of liner correlation coefficient was adopted to fit the feature points of crop to realize line detection. In order to fit the feature points, the N points were removed, which were the farthest from each side of fit line, until the fitting line met the requirement of liner correlation coefficient r. By comparing with Hough transform and random detection algorithm, the results showed that the proposed algorithm had the advantages of fast detection and strong anti interference. The results of navigation tracking experiment showed that this navigation system could track the target path accurately and effectively. The maximum lateral deviation was no more than 4cm and 7cm at the speed of 0.6m/s and 1.2m/s respectively.

Abstract:To reduce the limitation of the season and place for transplanter automatically driving, the virtual test scene model of rice paddy field was studied. The fractal based rice paddy field terrain and water wave generation methods were studied. The information of terrain and topography in rice paddy field were studied with digital maps. With Multigen Creator, 3-D scene with rice seedlings, ridge belts, drains and other information were generated. Fractal based water wave simulation method was used to simulate dynamic effects on water wave while transplanter was driving in paddy field. According to the position error between crop rows and transplanter model, the transplanter model was driving along rice seedlings rows in virtual scene.

Abstract:According to the requirement of agriculture intelligent development, a multi-type fruit harvesting robot was developed, which could realize the harvesting of single fruit and a string of fruits. The software design and hardware structure of fruit harvesting robot were described. The vision identification and positioning method of litchi and citrus were researched. The behavior control method of manipulator was also researched. The work flow of harvesting robot was expounded. The harvesting experiment of litchi and citrus were designed, and the test results indicated that every modules run well. The harvesting success rate of multi-type fruit harvesting robot for litchi was 80%, and for citrus was 85%. The average execution time of a single harvest cycle for two kinds of fruit was 28s.

Abstract:In order to guide robot arm to be close to apple target accurately, and avoid complex stereo matching of machine vision, a fruit locating method based on laser vision system was presented. According to the features of the system structure, scanning and motion controlling, a coordinate system of laser vision system was established, which was used to represent 3-D spatial information of target. Three different kinds of coordinate systems were transformed for offering directional data to robot arm, which separately belonged to image, laser vision system and robot arm. The grabbing experiment in orchard showed that the accurate grabbing ratio of robot arm was 100% while recognition index RRC was more than 90%.

Abstract:In order to improve the intelligent level of grape bagging and reduce the amount of human labor, a robot system for grape bagging was developed. The hardware structure of robot system was designed based on cylindrical coordinate. A method was proposed in order to get target feature extraction and recognition method by genetic algorithm. Compared with the proposed algorithm, the segmentation method using morphology algorithm and BP neural network under the HSI color space needed more time. The result of experiments showed that when the velocity of platform was 0.3m/s, the recognition rate for grape was up to 95% and the average time-consuming was about 136ms. The grape bagging robot success rate was 85% and the average time-consuming for a cluster of grapes was 39.6s.

Abstract:The curve equation of cutter was established which could determine cutting path and mathematical model. The 3-D model of cutter was constructed. Then, the force condition when the cutter working was analyzed. The law of slip shear motion was discussed. The slip shear angle of cutting edge was deduced. The edge curve of cutter was described. With the construction of slip shear motion equation of the nonlinear motion cutter, slip shear angle of the cutter under dynamic conditions was put forward. Finally, the force and movement of cutter were built in 3-D visual simulation. The harvesting robot prototype installed with the designed cutter was performed in cutting experiments, which could snip the diameter of 1～8mm for litchi branch. Results of simulation and physical experiments showed the effectiveness of the slip shear model and movement equation of cutter. Its nonlinear motion could meet the cutting composite trajectory requirements of realizing feed movement and rotary-cutting. Meanwhile, this scheme could reduce the feed motor and transmission mechanism in X- and Y-directions and achieve the function of cutting. The maximum cutting force acquired by simulation and physical cutting tests was 600N. The proposed cutter was suit for the diameter of 1～6mm and had good performance.

Abstract:Aiming at the characteristics of various parts of mature citrus, uncertainty and variability of light and environment, various parts of citrus image data had been conducted to exploratory data analysis and identify. The characteristics of exploratory data analysis method and the principle of citrus recognition based on color channel were analyzed. The flow chart of exploratory data analysis of citrus image data was provided. The acquired citrus images were divided into three different lighting conditions: front-lighting, normal light and backlighting. The image data of citrus fruits, stems and leaves were collected. According to the image data, the sorted box-plot on color component for all parts of citrus based on six kinds of color space were designed. With data analysis about the graphics of box-plot, a vision model of recognition of different parts of citrus was given based on I2 color component of I1I2I3 color space. When the threshold value of I2 was 0.3, the branches, the leaves and the grass in complex background could be removed and thus citrus fruits and their background could be segregated. Finally, 300 differently illuminated citrus images were collected in natural circumstance as test objects, all rip citrus fruits were effectively recognized based on the vision model of I2 color feature, and the citrus fruits recognition ratio was 98.4%. Also the situation was confirmed that the fruit stems and leaves could not be distinguished only relying on color feature because of their similarity color.

Abstract:A machine vision system for detecting bruise on apple surface was developed. The system was consisted of single-channel transfer unit, image acquisition unit and classification unit. A CCD camera with a 635nm filter and two plane mirrors were used to acquire the image of overall surface of apple sample. The system was designed to rotate apple at three different positions in the conveyor running, acquiring nine images of same apple. Digital image processing method was used to analyze sample defects. Ratio between black pixels and all pixels was calculated and compared with a fit value to judge the bruise area. The detection accuracy of the system for sample was 92.5%.

Abstract:A weeding robot that could work on intra-row weeding and inter-row weeding simultaneously was proposed to improve weeding efficiency. The robot adopted suspension structure for the optimization of field adaptability. Physical prototype of the robot was developed and manufactured. According to the obstacle-crossing analysis, the suspension structure was of good adjusting function. The obstacle navigation characteristic of weeding robot was simulated by ADAMS. Its ability of crossing obstructions in convex, concave and oblique lands was researched and simulated. The results showed that the robot could move on these three typical lands with excellent adaptability.

Abstract:In order to find out an automatic monitoring method of plant insect pests, non-destructive detection software system with compatibility of PC hardware, Windows XP and Windows 2000 software environment was developed based on the information fusion of image and spectrum, which was programmed by VC++ and Matlab language. Working principal and process of the system, hardware composition and software system were introduced. The system could collect image and spectral data automatically, process data, predict the damaged degrees (DD) and display the detection results. Finally, the system was used to detect the DD of leaves. The detection results from the experiment showed that the proposed system could be used for non-invasive detection of DD of leaves with high accuracy and reliability．

Abstract:In order to improve the accuracy, efficiency and automatic degree of existing acquisition techniques of dairy cow’s conformation linear appraisal traits, a research method based on depth image was proposed reconstructed the corresponding part with dairy cow’s conformation linear appraisal traits to measure and acquire linear appraisal indexes. Xtion PRO was chosen as raw data acquisition device. The experiment acquired point cloud from dairy cow’s body random position was completed by data acquisition program compiled based on OpenNI interface, and then measured by using MeshLab. The results showed that it was feasible to use low cost RGBD equipment to acquire a range image of corresponding part with the dairy cow’s conformation linear appraisal traits. And then, according to the point cloud acquired from range image, the dairy cow’s appraisal indexes were reconstructed and acquired. The relative error was less than 9% and the error was less than 10mm.

Abstract:It is important to detect cow oestrus in time and accurately. According to the characteristics of increasing activity, shorter repose time and increasing animal heat during cow oestrus, vibrational sensor and temperature sensor were used to detect the above parameters. LVQ neural network model was built, which taking walking steps, repose time and animal heat as input, and behavior characteristics as output. The results showed that, with the proposed algorithm, the correct detection rate was up to 100%, and prediction rate for oestrus was more than 70%.

Abstract:State space model of stayed cable—magnetorheological damper vibration reduction control system was constructed based on Halmiton principle. Taking the main bridge C20 stayed-cable in Ningbo as the research object, the matrix parameters of the state space equations was analyzed and calculated by using the Rayleigh theory. Thus, based on the state space equation and stochastic control system theory, the vibration reduction control algorithm with state variance performance constrain for stayed cable—magnetorheological damper system was analyzed in detail. Simulation results showed that the given vibration reduction control algorithm could guarantee the stability of stayed cable—magnetorheological damper system and receive effective constraint of the system vibration amplitude. The vibration reduction control effect was good.

Abstract:An experimental apparatus was designed to analyze the mechanics parameter of shovel and excavationof the lunar soil. The test bed was consisted of two parts: shovel device and excavating device, which could realize linear shovel movement and rotational excavating movement. The shovel test with this experimental apparatus proved that shovel speed had very little effect on the force of shovel while different compaction status of lunar soil and angle of shovel affected a lot of force of shovel. In the excavation experiment, with the increasing of revolving speed, the peak torque would also increase. The experiment initially confirmed the parameters of properties of soil mechanics of sampling machine on the surface layer. It could supply significant reference to the study of mechanical property of the interactions between the sampler and lunar soil.

Abstract:A bionic airfoil based on a silent-fight long-eared owl wing was built by using root mean square. The flow structure around the owl wing and the related source were revealed. The unsteady flow showed that a leading-edge boundary layer was separated, and later a bubble was formed due to instability. Furthermore, a vortex detached from the bubble, drifted downstream, and immediately broke down later. A turbulent boundary layer was reattached on the upper surface. A similar evolution occurred on the lower surface, but the vortex drifted further downstream. The corresponding far-field directivities suggested dipole noise and the maximum intensity was at the trailing edge. It suggested that the scattering noise was dominant. In the spectrum, the noise was mainly concentrated in the mid frequency and the tonal characteristics also agreed with the flow structure. The noise of the bionic airfoil started to drop significantly around 1kHz, and the similar trend was also gained for the natural owl wing with decrease above 2kHz.

Abstract:In order to study the binding characteristics of cuticle and prism layer of Cyclina sinensis and apply it to improve the anti-corrosion performance of agricultural machinery, type-JSM—6700F scanning electron microscope and the revetest scratch tester of CSM instruments Revetest Xpress Plus were used to observe the surface microstructure and binding characteristics of cuticle and prism layer of Cyclina sinensis, respectively. The results showed that the binding characteristics of cuticle and prism layer was better when the spherical particles size of the back of Cyclina sinensis cuticle layer and the bore diameter of the prism layer surface were in the same range. The scratches of different parts of Cyclina sinensis cuticle surface existed a certain difference. The fluctuations of friction coefficient were large when horizontal scored and they were small when longitudinal scored. The results indicated that the binding characteristics of cuticle and prism layer was relatively better, especially the binding characteristics of cuticle and prism layer of Cyclina sinensis abdomen.