Abstract:An active fault-tolerant control strategy based on control law reconfiguration was put forward for vehicle semi-active suspension system. A 2-DOF quarter vehicle semi-active suspension system model and fault suspension model were built. Semi-active suspension fault detection and on line diagnosis of suspension actuator’s fault gain were realized by output residual error obtained from designing robust observer. Then, on the basis of LQG controller and on-line diagnosis, active fault-tolerant control was realized on fault suspension through adjusting LQG control law to design fault-tolerant controller based on control law reconfiguration. The results of simulation under Matlab/Simulink and bench experiment showed that active fault-tolerant control strategy based on control law reconfiguration could rapidly restore the comfort performance of fault suspension system to the level close to that of semi-active suspension in the absence of fault after 0.5 to 2.0 s delay, eliminate the effects caused by actuator fault, and increase the reliability of suspension control. 

Abstract:Based on inerter-spring-damper structural system, a passive realization method of ideal skyhook damping was presented by using the anti-resonance of the inerter-spring-mass system. A passive skyhook-damping suspension system was designed. The whole car model of the suspension was built to compare the performance of conventional passive, ideal skyhook-damping and passive skyhook-damping suspensions. The results showed that in contrast to conventional suspension, passive skyhook-damping suspension could suppress vertical, pitch and roll vibration of vehicle body with frequency of 1~3 Hz. The RMS values of vertical, pitch and roll acceleration reduced by 14%, 14.6% and 9.3%, respectively. The proposed suspension could improve ride comfort and achieve the main functions of ideal skyhook-damping suspension. The results also indicated that the passive realization method of ideal skyhook damping was corrective and effective. 

Abstract:Real-time measurement for automotive suspension distance based on acceleration was carried out by using virtual real-time controller. This paper set up a test system, in which the industrial embedded system CompactRIO and several C modules were employed as its hardware collector, besides typical ICP acceleration sensor, displacement sensor and GPS system were also employed. FPGA programming and controller programming using the multi-threading and FIFO method were completed in LabVIEW. The time information was contained in every sample data package, which effectively improved the speed of data transmission and the accuracy of data processing. Wavelet filter and support vector machine (SVM) model were built and embedded in CompactRIO to predict and output suspension distance (CAN, 100 Hz) in real time. The grade of seven kinds of typical roads was determined according to the RMS value of acceleration of suspension’s lower measuring point, which was employed as input element of the SVM model. The road way tests and data analyses indicated that the controller consumes less than 1 ms when completing one point’s wavelet filtering and predicting in which ε=0.01 for ε-SVR algorithm. The relationship coefficient of the suspension displacement curves of predicted by SVR model and measured in road way tests were more than 0.90 primarily. So the system could meet the requirements of accuracy and real-time control. 

Abstract:To improve torque load capacity and extend the application scope of current continuous variable transmissions (CVT), a kind of bi-metal belts CVT was designed. The transmission principle of kinematics and dynamics and transmission efficiency of the proposed CVT was derived. Mathematical model of the CVT hydraulic system was deduced and stability of the model was analyzed. The bi-metal belts CVT was simulated by AMEsim and the PID controller parameters were adjusted. The results showed that the proposed CVT could solve ratio synchronous control problem and had good ratio tracking accuracy. The bi-metal belts CVT could double the torque load capacity in contrast to typical CVT on the same clamping fore condition. Feasibility of the proposed CVT was verified preliminary.

Abstract:In order to improve the shifting quality and reduce the shift time, a shifting mechanism for automated manual transmission (AMT) direct driven by electromagnetic linear actuator was proposed. Compared with the conventional AMT (about 1.78 kg), the total mass of shifting mechanism (1.37 kg) was reduced by 23%. The shift process was divided into several stages and the feasibility of design program was verified based on detailed mathematical models of shift process and the test bench of AMT. Gear select movement did not exist in the process of gearshift and it could make upshift and downshift happened in the same time. The 3~4 gearshift time was controlled at 120 ms when the rotary speed difference was 500 r/min and the moment of inertia was 0.03 kg·m2. The shifting quality of AMT was improved and could be further improved in the future. The results showed that the shifting mechanism of automated manual transmission based on electromagnetic linear actuator could achieve the functional of automatic shift, and it had well application prospect in the field of automatic transmission.

Abstract:The key of closed-loop simulation of vehicle handling stability is to establish a driver model which could adapt to complicated path. The driver’s preview path was divided into several segments. Lateral displacement and heading angle deviation were calculated. Vehicle steering motion was controlled based on deviation of heading angle and position, therefore the vehicle could follow any complex path. In order to obtain the control parameters of driver model, different driving mode was designed. Genetic algorithm was applied to optimize these control parameters. The co-simulation results of Carsim and Simulink showed that the optimized driver model could fulfill the conditions of complicated road. 

Abstract:Most cars belong to independent suspension vehicle and their front shafts are broken, for which their steering system are more complex than non-independent suspension vehicle. The reason of the front wheels occur to oscillate is not evident which keeps shimmy control from going. It is a severe problem that needed to be solved urgently because it can lead to the tires bursting and lose manipulation stability. Therefore, many nonlinear factors and mechanism elasticity were taken into account synthetically during modeling, including clearance of steering mechanism, elasticity and clearance of redirector, nonlinear lateral force of tire, dry friction of the pin. Based on the second Lagrange method, 4-DOF high dimension nonlinear vibration model was established. Numerical analysis presented the influence rules of nonlinear parameters, structural parameters and positional parameters to vibration characteristics of the steering system, and open out the vibration specialty of the system and mutual influence relation of system parameters. The results could give the theoretical and technical support for dynamic design and mutual matching of structural parameters, and shimmy control. 

Abstract:The tyre model based on neural network was built. Inference rules of working condition were established based on the classification of electric power steering (EPS) conditions, which could lead to a correct judgment. Furthermore, according to the different working conditions of EPS, the fuzzy rules of fuzzy PID were changed to achieve active switching of multi-assist characteristics. The whole multi-body dynamic vehicle model was built. The SIMPACK-Matlab co-simulation was carried out on the snakelike road, and then compared with the car test based on dSPACE. The simulation result showed that the control strategy based on the proposed model could effectively reduce the driver’s operating torque and improve the returnability of vehicle. 

Abstract:The transplanting mechanism with planetary deformed elliptic gears was proposed and the kinematics equations of transplanting tip were established. The kinematics simulation software of this mechanism was compiled. A group of mechanical parameters were optimized and obtained by using this software and comprehensively taking into account the factors of hole shape, return trajectory of transplanting tip, pose of transplanting tip while catching and transplanting seedlings, relative velocity of transplanting tip while catching seedlings and so on. Then the test-bed of this transplanting mechanism was developed to test the kinematics parameters such as trajectory and velocity of the transplanting tip. Through the comparison between test result and kinematics analysis results, the correctness of kinematics model and analysis results were verified. Compared with the transplanting mechanism with planetary elliptic gears, the proposed transplanting mechanism had higher verticality rate of seedling and lower injury rate of seedling. 

Abstract:A planting mechanism with planetary gears of transplanting machine was put forward. Its structure and working principle were expounded and motion trajectory equation was established. The characteristic coefficient λ was introduced and planting mechanism end’s motion trajectory was obtained with the different λ. Taking a single duck mouth planting mechanism as the research object, the virtual prototype was established, which was composed of planetary gears, seedling and the surface. The planting frequency of 30 plants/min was set as the design parameter. The former and latter duck mouth ends’ motion trajectory and the duck mouth’s opening, felling seedling situations were simulated when the λ was 0.90, 1.00, 1.18, 1.24 and 1.28. The simulation results showed that when λ was 0.90 and 1.00, the latter duck mouth avoiding seedling was not in time and making the seedling moving forward even lodging. When λ was 1.18 and 1.24, the former and the latter duck mouth avoiding seedling were full and the seedling wont be interfered. When λwas 1.28, the latter duck mouth avoiding seedlings’ space was more fully, but the former duck mouth avoiding seedlings’ space was insufficient and the seedling was interfered. When the characteristic coefficient λwas 0.90, 1.00 and 1.22, the prototype experiment was carried out on cucumber seedling of 20 d in the homemade soil bin. The results showed that for λ of 1.22, the upright degree of seedling was the best. The excellent-good rate was up to 86.7%. For λ of 0.90, the upright degree of seedling was the worst and the excellent-good rate was 0. The test results and simulation results were consistent.

Abstract:According to inertial properties and surface characteristic of rice seed, Euler dynamical model was built. Matlab software was used to simulate the movement stability of the seeds. The numerical simulation results proved that rotation about x-axis and y-axis was unconditional stability, while rotation about z-axis was stable with some conditions. The effect of parameters on movement stability of rotation about z-axis, such as crank length, angular velocity, the friction coefficient between the rice seed and the guide plate, angle of vibrating board, and angle of guide plate, were analyzed. According to the results of simulation, through orthogonal experiment on fabricated device, a set of optimized parameters were obtained. Through experiments, above 89% embryo of rice seed were ordered.

Abstract:A numerical calculation model of air-assist boom spraying was established. The Fluent was used to simulate the gas-liquid two phase flow field of air-assist boom spraying when the operational parameters of influencing factors changed, including airflow velocity of air curtain, the horizontal and vertical relative position between the air curtain and the nozzle, and the spraying angle. The results showed that the influence of air curtain on gas-liquid two-phase gradually increased with the increase of airflow velocity of air curtain. The air curtain could be more useful to anti-drift performance when there was a reasonable horizontal distance between the air curtain and the nozzle. Air curtain going away from the nozzle in vertical direction was equivalent to airflow velocity of air curtain decreasing. Therefore, the anti-drift performance went weaker. With the increase of spraying angle, the kinetic energy of droplets in vertical direction decreased. More droplets were difficult to reach the sample surface because of the attenuation of kinetic energy in vertical direction, so that the anti-drift performance went weaker.

Abstract:In order to investigate the droplet deposition on hairy, waxy and rough plant leaves, a series of experiments were schemed with a combination of five droplet sizes of 138.2 μm, 176.5μm, 209.1 μm, 235.1 μm and 283.7 μm and six leaf dip angles of 0°, 15°, 30°, 45°, 60° and 75°. The orthogonal tests were used to analyze the cross influences among plant leaf surface structures, leaf surface dips and droplet sizes. The experiment results showed, under same spray volume, droplet deposition tended to decline with the increase of the droplet sizes in general. On the hairy structure leaf surface, a turning point turn up after which the deposition decrease was getting larger sharply when the droplet size was over 231.5μm. On hairy and rough surfaces, droplet deposition increased with the surface dip’s reducing. However, on the waxy leaf surfaces, a positive deposition mutation might take place as the surface dip exceeded 45°. The study concluted that leaf dips had more influence on droplet deposition than leaf surface structures while the droplet size made little effect on it. 

Abstract:An air-and-screen cleaning unit test-bed combined with centrifugal air flow cleaning and rotary screening was developed. The basic structure and working principle of cleaning unit test-bed were discussed, and the main structural and operating parameters were determined. Experiments were carried out in order to find the relationship between cleaning performance and main factors, such as centrifugal fan rotating speed, screen rotating speed, screen surface type, and screw conveyor rotating speed. An orthogonal test and the method of comprehensive analysis were carried out to find primary and secondary factors affecting the cleaning performance, which were screen rotating speed, centrifugal fan rotating speed, screen surface type, and screw conveyor rotating speed. When the centrifugal fan rotating speed was 2200 r/min, the screen rotating speed was 60 r/min, screen surface type was diamond-shaped hole mesh screen with the long diagonal of 6.7 mm, short diagonal of 4.0 mm, the screw conveyor rotating speed was 1150 r/min, the optimum operation condition was obtained. 

Abstract:The structure and working principle of two-ridges and four-lines semi-feeding self-propelled peanut type-4HBL-4 combine harvester was introduced. It could completely harvest two-ridges and four-lines peanuts in one time and accomplish digging, excavation to soil, transportation, picking, separation, cleaning, collection boxes and other operations. The suspension type with square institution which had better ground-profiling effect was adopted. Collecting-fruit equipment was used to clean twice. Throughout the test in the field, it met the requirements of design and relevant standards with the picking rate of 98.9%, the total loss rate of 3.3%, breakage rate of 0.2%, impurity rate of 3.1%, and net operating-hour productive efficiency of 0.16 hm2/h, which met the design requirements and related standards.

Abstract:A method for identifying sugar cane internodes was proposed based on Matlab. The cane internode was pre-processed by using gray processing and Sobel edge extraction. The mathematical morphology of expansion, corrosion and re-expansion was used to eliminate the edge of the sugar cane internode and unwanted small edge, so the edge of sugarcane internodes straight line was obtained. And then, the location coordinates of sugarcane internodes were got when R had its strongest value by using Radon function for straight line extraction. A theoretical basis of device of anti-bud injury in seedcane cutting was provided. The recognition accuracy was 100%, and the position accuracy was 0.1 mm. 

Abstract:In order to solve the problems of low efficiency, low accuracy and high cost in existing rear suspension testing system, a field test system of suspension tools based on virtual instrument was designed. The master and server computer model, sensor fusion and wireless transmission technology were adopted in the proposed system, which could realize suspension tools multi-parameters real-time synchronous measurement. The tractor fuel consumption, emissions, drive wheel slippage rate and agricultural tool six component forces, PTO torque and rotational speeds, etc. were tested in the field under the conditions of tractor pull test platform or suspending 2BMSF-12/6 no-till dill. The results showed that the communication of field test system was normal, and the data was reliable and accurate. It satisfied the general rear suspension tools field test requirements and could provide theoretical support for design optimization and applicability evaluation.

Abstract:To monitor grain cleaning loss of combine harvester automatically and real-timely during the working process, a grain loss monitoring sensor was developed. Modal analysis was carried out under the conditions of different thicknesses and different boundaries by using ANSYS software with 304 stainless steel plate, T6 aluminum, brass plate as sensitive plates. Grain collision tests were carried out to study the relationship between the sensitive plate vibration characteristics and detecting performance by using YT-5L piezoelectric ceramic as sensitive element. Material and structure of the sensitive plate was selected. A signal process circuit which composed of voltage amplifier, band-pass filter, precision full-wave rectification and envelope detector and a control instrument which used AT89C52 microcontroller as the core chip were developed to measure the grain impact signal. The control instrument also had the alarm and communication functions. Field experimental results showed that the instrument could discriminate grain impact signal from strong interference effectively, and the grain cleaning loss ratio could be real-timely displayed, the maximum monitoring error was 2.39%. 

Abstract:Based on the field plot experiments of four chemical N application rates (0, 65, 130 and 195kg/hm2) and two irrigation levels (52.5 and 105 mm) applied to summer maize and winter wheat growing, the NO-3-N, NH+4-N and total nitrogen migration and accumulation in the first 450 cm depth of layered soils for each treatment were studied. The results showed that the soil texture and structure had a significant effect on soil moisture, NO-3-N and total nitrogen content and distribution in soil profile, and soil structure had a significant effect on soil NH+4-N content and distribution in soil profile. Fertilization and irrigation had different influence depth on soil NO-3-N, NH+4-N and total nitrogen, and the direct influence depth was 400, 200 and 120 cm, respectively, while the indirect influence depth was 400 cm for all. Soil NO-3-N in the treatments that irrigation level was 52.5 mm and nitrogen application rate was 195 kg/hm2, and irrigation level was 105 mm and nitrogen application rate greater than or equal to 130 kg/hm2 had obvious phenomenon of migration, and the migration depth was 250 and 400 cm, respectively. For the 0~450cm layered soils that had a loam, sandy soil and loam layer from top to bottom, the average soil NO-3-N, NH+4-N and total nitrogen content were all in the following descending order: 380~450cm loam layer, 0~120 cm loam layer, and 120~380 cm sandy soil layer. The special 380~450 cm loam layer blocked the migration of water and nitrogen. It was advised to use an irrigation level of 52.5 mm and nitrogen application rate of 65 kg/hm2 at a single time in growing summer maize and winter wheat in southeast agricultural region of Beijing.

Abstract:To effectively reveal scale effect of soil attributes and provide information for sampling design, the spatial variability response rules of soil organic matter and total nitrogen to sampling grain size were identified by spatial autocorrelation, semi-variogram and fractal dimension in Loess Plateau, China. The results showed that the average content of SOM and STN were 14.79 g/kg and 0.78g/kg, respectively. With the sampling grain size increasing, the coefficient of variation of SOM had basically not changed, but that of STN showed a gradually elevated trend. In addition, the spatial autocorrelation of SOM and STN was weakened and their spatial variability from random factors became much stronger. Meanwhile, the relationship between spatial variability and sampling grain size was not linear, but a reverse “U” type changing trend. The spatial distribution of SOM and STN concentration exhibited higher in the north and lower in the south of study area. SOM content was at the mid-low level, but STN content was under the normal level which led to much more nitrogen needed in the future. 

Abstract:Mean flow velocity is one of the most important hydraulic variables in soil erosion modeling, which is normally estimated by multiplying surface velocity of flow with a correction factor (α). So a reasonable α value is imperative for precise estimation of mean flow velocity. The effects of grain resistance, transport resistance and vegetation resistance on correction factor α were investigated through indoor scouring experiment on the basis of the datasets collecting from the literature. The results showed that α decreased as grain resistance, transport resistance increased and increased as vegetation resistance increased. The effects of different resistance forms on α were mainly achieved by changing the velocity profile of overland flow. The grain resistance and transport resistance made the velocity profiles steeper, while the vegetation resistance made the velocity profiles gentler. The prediction equation of α under various forms of resistance was proposed by using stepwise regression analysis and the predicted values agreed well with the measured ones.

Abstract:Six representative winter wheat cultivars released since 1949 in central Henan province were selected to study the effects of different water treatments on chlorophyll fluorescence characters and antioxidant enzyme activities in flag leaves during flowering and milky stages. The results showed that chlorophyll content index of winter wheat cultivars increased with years which set up the basis for improving the photosynthetic functions. Chlorophyll fluorescence parameters of winter cultivars bred in 1990s and after 1990s were higher than the early cultivars. The malondialdehyde content of the modern cultivars decreased and activities of superoxide dismutase increased more quickly after flowering stage, which showed stronger capacity of scavenging oxygen free radical. Peroxidase activities of the modern cultivars improved to resist droughts under drought stress. Activities of catalase and ascorbic acid peroxidase of the modern cultivars increased quickly to scavenge oxygen free radical which was helpful to the maintenance of stronger photosynthetic capability. 

Abstract:A field experiment was conducted to test the effect of mulched drip irrigation under water deficit regulation (WDR) on leaf photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), tuber yield and potato water use in oasis irrigation region. The results showed that Pn , Tr and Gs were reduced by WDR during different potato growth stages. No obvious difference was found in Pn before and after re-watering of potato, but Tr and Gs were obviously improved. Potato yield was not decreased by low WDR during tuber initiation, but was significantly (p＜0.05) decreased in the medium WDR plots during tuber initiation and low and medium WDR plots during tuber bulking. Periodic water consumption of potato was greatly affected by WDR, and the higher soil water deficit, the less potato periodic water consumption. In addition, the total water consumption throughout the whole growing season was significantly lower in all the WDR potatoes than that in full irrigation plots (CK). The highest water use efficiency (WUE) was maintained in low WDR potato during tuber initiation, significantly improved by 36.2%, 32.4% and 14.2% than that in medium WDR plots during tuber bulking, low WDR plots during potato starch accumulation and CK, respectively. Therefore, mulched drip irrigation under WDR may reduce Pn, Tr, Gs, and periodic and total water consumption of potato, but its WUE can be greatly improved. In addition, potato yield will not be reduced by mulched drip irrigation under low WDR during tuber initiation.

Abstract:A thermal dissipation probe (TDP) was used to continuously measure the sap-flow rate of apple tree in Changwu county in loess tableland area of China from July to October, 2012. The effect of meteorological factors, soil moisture and other environment factors on sap flow was analyzed. The results showed that diurnal variation of the sap-flow rate of apple tree was a single peak curve in both sunny and rainy days. On sunny day, the sap-flow started more early and stopped more lately than on rainy day. The sap-flow rate of apple tree was positively correlated with solar radiation, vapor pressure deficit, atmospheric temperature and atmospheric relative humidity with a linear equation, and negatively correlated with air relative humidity. The dependency of sap-flow rate on various meteorological factors on the sunny day was more significant than on the rainy day. In addition, the sap-flow rate of apple tree varied distinctly in different environment conditions of soil moisture. Under the water stress condition, the sap-flow rate was significantly lower than that under the moist soil condition. The change of sap-flow rate showed a broad-peak curve, indicating that the transpiration was higher under the moist soil condition.

Abstract:In order to alleviate freshwater shortage in salinization area, use the saline water more scientifically and rationality, and improve the yield of alfalfa, taking Zhongmu No.1 as the materials and freshwater (mineralization degree of 1 g/L) as contrast, the experiments were conducted to learn the effect of saline water (mineralization degree of 3 g/L, 5 g/L and 7 g/L) on germination percentage and plant height of alfalfa. The results showed that the germination percentage and plant height had no significant difference between 3 g/L and fresh water, but it showed great difference when the mineralization degree raised to 5 g/L and 7g/L. The results indicated that, in order to ensure the germination percentage more than 80%, the mineralization degree should be controlled to less than 4.48 g/L. When the satisfied plant height was attained, the mineralization degree should less than 4.66 g/L, otherwise, the growth of alfalfa would be inhabited by long-term salt stress.

Abstract:Pig manure was mixed with wheat straw as bulking agent, the mixtures were amended with 0 or 10% additives including apple pomace, calcium superphosphate and biochar of total dry weight and composted for 46 d. Effect of three additives on composting process were studied. Additives of apple pomace and biochar could shorter the time to reach the high temperature period, electricity conductivity were 4.2, 5.4 and 2.8 mS/cm with three additives in the end, respectively. Three additives showed the abbility of nitrogen conservation. The decrease rate of N loss compared with control were 55.3%, 54.4% and 58.6%, respectively. Rate of DTPA form in total amount decreased with 3.9%, 5.8% and 5.7% for Zn, 11.0%, 12.0% and 12.3% for Cu in three additives, respectively. The differences were not significant. Analysis of Sposito forms showed that Zn was mainly in the forms of SP3 and SP4, reached to 74.5%～87.4%, while Cu in the forms of SP2 and SP4, reached to 69.0%～80.9% of the total amount. SP1 form of Zn with treatments of calcium superphosphate and biochar decreased more than apple pomace, while SP1 form of Cu with treatment of calcium superphosphate decreased the most.

Abstract:Lack of buffering capacity of fermentation substrate in anaerobic digestion may easily lead to acidification. Alkalinity is a key indicator for measuring buffering capacity of the fermentation substrate, so its online monitoring should be enhanced to keep the anaerobic fermentation process stable automatically. An online monitoring system based on joint titration of alkalinity and VFA was designed. The software system was introduced in detail. The system could determine alkalinity and VFA simultaneously, which achieved real-time curve display and pH meter calibration. Moreover, automatic analysis could be realized. The experiment results showed that the system had the ability of the rapid determination of alkalinity and VFA in the fermentation process. The relative standard deviation was less than 5%, which was lower than the manual titration and indicated a high measurement accuracy of the proposed system.

Abstract:The acid and alkali pretreatment method was employed to explore the different effect of straw pretreatment on reducing sugar component and methanogenic features of straw hydrolysate. The results indicated that xylose was the major component in the mixed reducing sugar solution in the tests with higher HCl concentration(9% and 7%), however that of glucose was slightly higher than xylose in the tests with lower Ca(OH)2 concentration(2 g/L and 4 g/L) in the early 48 h. Methanogenic features with different ratio of glucose and xylose was studied and indicated it was significantly affected by the mole fraction of glucose in mixture. The biogas yield increased with the xylose increasing, and the lowest biogas 191.75 mL/g was in the test of 100% glucose，while the highest biogas yield 633.14 mL/g and energy conversion efficiency 26.40% were both in the test of 25% glucose. There was certain biogas production delay for pure xylose test.

Abstract:Based on electromagnetic induction heating technology, a fluidized bed gasification reactor based on induction heating was manufactured. It could provide heat for the biomass gasification process from the inside, and control the gasification reaction temperature accurately. Taking rice husk as raw materials of biomass, steam and air gasification as gas agent, biomass gasification for hydrogen production experiment was carried out. The effects of reactor temperature, steam to biomass ratio (S/B), and equivalence ratio (ER) on gas composition and hydrogen yield were investigated. According to the experimental results, it was found that when the reactor temperature was 800℃, the hydrogen content increased with the increase of S/B or the decrease of ER, hydrogen yield reached its maximum at the S/B of 1.5 or at the ER of 0.22. The highest hydrogen content (35.47%) and the highest hydrogen yield (78.22g/kg), was achieved simultaneously at a reactor temperature of 950℃, ER of 0.22, and S/B of 1.5.

Abstract:A portable artificial olfaction system based on visualization sensor array was employed to characterize the flavor from three kinds of vinegar. Optimal experimental process was conducted in visualization sensor fabrication and image collection. The result showed that the stability of image gained by camera was better than scanner’s. When volatilization time was set at 15min, the stable images could be obtained, as well as the reaction between the sensor array and the vinegar achieved its maximum response value. The data was analyzed with statistical and chemometric methods, including principal component analysis and linear discriminant analysis. The recognition rate was up to 100%. 

Abstract:The physical properties and rheological properties of flax gum-agar mixed gels were researched. The effect of flax gum content on the physical properties of the mixed gels system were investigated in light transmission and freeze dried experiments. The influence in gel temperature, melting temperature and gel strength were also tested in both temperature sweep and frequency sweep. Storage modulus was regressed with power-law model in frequency sweep test. 

Abstract:Infrared radiation drying characteristics of carrot slices were studied by using infrared radiation drying device. The drying curves of carrot slices were obtained in experiments under different drying conditions. The results showed that the better drying performance appeared when the drying temperature was 70℃, the slice thickness was 5mm and the irradiation distance was 140mm. The experimental datum was simulated with different mathematical models. The results also showed that Page model was fitted to express infrared radiation drying process of carrot slices. Both the Page model and Midilli model could match with the actual value under the same condition; however, Page model was easier to build and calculate. 

Abstract:The pre-cooling process of Agaricus bisporus by using heat transfer theory was analyzed. The cooling time was predicted with the lumped parameter model, and the performance of the mathematical model was checked using experimental data. It was turned out that the model could be used to predict the temperature change during the pre-cooling process of Agaricus bisporus, and it could be used to predict different conditions on pre-cooling. At the same time, the increase in cooling air velocity beyond the above values did not affect the cooling rate significantly. The pre-cooling rate was increased with the increase of the air velocity, and fitted the power function. The equation of the fitting curves between the air velocity and central temperature was obtained.

Abstract:In order to discuss the design and computation methods of egg’s pointed end and blunt end automatic orientation, the dynamics and motion regularity were analyzed and the mechanism of axial motion which was generated by the egg on two rolling conveyer rollers was studied. Results showed that the regularity of egg axial motion accorded with the principle of alternating axis friction wheel drive. The theoretical calculation methods of axial motion displacement and the model of transmission relation between egg and rollers were built. The test methods and practical calculation methods of axial motion parameters of egg were also established. Results showed that the regularity of actual displacement for axial motion of city chicken eggs corresponded with the calculation results in theory and the correction factor was 0.55(diameter of 30mm, center distance of 57mm, convey speed of 57mm/s). It was practicable to analyze the axial motion of eggs on the supporting rollers by using the principle of alternating axis friction wheel drive which laid the theoretical foundation of design and computation of automatic orientation device of pointed end and blunt end of eggs. 

Abstract:The internet of things (IOT) in agriculture consisted three layers, including perceive, transportation and application. The perceive layer were used to acquire the information of crops, soil and environment. The transportation layer was used to establish the transportation network of IOT in agricultural by combing the techniques like GPRS, Zigbee, WIFI, Bluetooth and the intelligent networking methods. The process layer focused on the intelligent management of agriculture, including multidimensional information fusion, intelligent decision and automatic control, et al. The key problems, research emphasis and application fields of IOT in agriculture include three layers were discussed in detail and analyzed. The prospect and development trend of IOT in agricultural in modern agriculture was put forward.

Abstract:To intelligently recognize apple fruit diseases from low-resolution images taken in natural environment, a method based on compressive sensing was proposed. Three kinds of apple fruit diseases (apple ring rot, apple anthracnose and new apple ring rot) were investigated. Eight texture feature values were extracted to construct the training eigenmatrix. Then compressive sensing was used to approximate the sparse coefficient vector which was the sparse representation of the sample eigenvector on the training eigenmatrix. Thus the test sample was classified by analyzing the coefficients vector. Both the gray relation analysis and the support vector machine recognition models were constructed to compare with the proposed method. The recognition rates of three models were 86.67%, 90% and 90%, respectively. The experimental results showed that the recognition method based on compressive sensing could effectively recognize these three kinds of apple fruit diseases. 

Abstract:A segmentation method of cucumber disease image with complex background was proposed. Firstly, most of the background in color images was removed by combined method of ExG and OTSU, which retained the green part of the image as much as possible. Then, according to the red component of the disease image, the data item was created automatically. Meanwhile, the differences between the red components of adjacent pixels were set as the smooth item. The threshold-pretreatment-based graph cuts algorithm was constructed based on the above data item and smooth item. The proposed method was used to segment the color images of four kinds of cucumber diseases. The results showed that it could better segment the diseased regions from the color images of cucumber diseases. The mean accuracy of recognition was more than 90%, and the average running speed was 2.12 s. The proposed method could meet the requirement of real-time image processing. 

Abstract:The shadow is the most common interference factor of remote sensing image in mountainous and hilly area, so shadow removal is helpful to the improvement of accuracy and effectiveness for image interpretation and feature recognition. Shaded vegetation index (SVI) was constructed, and the band regression model was built for the shadow removal. The proposed method was applied in HJ-1 multi-spectral image. The results showed that SVI could increase the differences among water, shaded area and bright area. The threshold method could be used to effectively detect the shadow in the image. The correlation analysis showed that R2 of each band regression models was above 0.80. The comparison of image statistical indicators before and after the shadow removal indicated that, the band mean value increased significantly with the removal of shadow at the near-infrared band influenced by shadow and vegetations. The standard deviations of shadow-removal image were lower than those of the original image, especially at the near-infrared band. The testing results showed SVI had good detection effects for the shadow of HJ-1 image in mountainous and hilly area, and the band regression model method could effectively remove the shadow.

Abstract:The hybrid applications of biofan and micro-porous aerator were adopted. Biofan was mainly used in daytime and micro-porous aerator was mainly used usually at night or in rainy days. With the changing environmental parameters, a fuzzy neural network based on reversed error propagation was applied to maintain the stability of dissolved oxygen. Tests showed that 40.6% energy was saved. The output was increased by 31.9% and the final margin was increased by 136.1%. Zigbee network was applied in the measurement of water quality parameters. The optimized LEACH communication protocol was used to achieve the purpose of node energy conservation and loss balance. According to the actual measurement of dissolved oxygen requirements, soft and hard threshold parameters were set to reduce sending times of mode data. Tests showed that the lifetime of optimized wireless sensor network was extended by 58%.

Abstract:The station instantaneous workload bottleneck was caused by task processing time differences among different models. According to the given production schedule and considering the average workload and instantaneous load of assembly line, mixed assembly line balancing model was built with the objective of minimum station processing time variation, station’s workload smooth index and assembly line overload time. The effect of task processing time differences among different models on the assembly line balance was also taken in to account. The multi-objective optimization algorithm based on non-dominated sorting particle swarm optimization (NSPSO) was designed. The example verified that, compared with genetic algorithm, NSPSO had higher solution quality and solving efficiency in large mixed balancing problem. 

Abstract:In order to improve the ability to predict the manufacturability of complex surfaces in the design stage, the manufacturability evaluation indexes and models of complex part surfaces were studied. The factors affecting the manufacturability of the complex part surfaces were divided into two groups, the geometrical complexity (GC) and the technological complexity (TC). Considering the features in GC, the complex part surfaces were classified into several clusters according to distribution features of complex surfaces and slopes, which established the group patterns of the parts. Then the discrete and the reduction algorithms of rough set were used to calculate the weights of the feature attributes including a few attributes in TC. After that, the method of fuzzy pattern recognition and the calculation of surface similarity were used to evaluate the manufacturability of parts. A case study showed that the method could evaluate the manufacturability of the complex part surfaces accurately.

Abstract:A spherical metamorphic mechanism with parallel structure was proposed. It consisted of a moving platform, a base plate and four connecting legs between moving platform and base plate. Three of these legs had the same structure named circle legs and the other one named middle leg. Spherical metamorphic mechanism could transform to normal configuration and metamorphic configuration respectively with the change of constraint applied by middle leg. The moving platform was in possession of three revolute degrees of freedom which equivalent to spherical joint and extra translational freedom in the direction of radius. Based on screw theory, the mobility of this mechanism was analyzed firstly. Secondly, the constraint sub-matrix and actuation sub-matrix were obtained and the complete Jacobian matrix was established by integrating these two sub-matrices. In the end, the singular conditions of spherical metamorphic mechanism were analyzed by investigating the ranks of the complete Jacobian matrix and methods used to avoid the occurrence of singularities were given which were propitious to mechanical design.

Abstract:In order to improve the working frequency of electro-hydraulic exciters, an electro-hydraulic exciter based on differential hydraulic cylinder controlled by 2D valve was proposed, which could realize the change of hydraulic intrinsic frequency by controlling the volume of non-rod chamber. The scheme of electro-hydraulic exciter was analyzed and the mathematical model was set up. The simulation model was also constructed by the Simulink Toolbox of Matlab. The vibration waveform of exciter in low-frequency, middle-frequency and high-frequency were simulated. To verify the theoretical analysis and real vibration waveform of exciter, the electro-hydraulic exciter was designed and experimented. Results showed when the main part of the load constituted by the elastic force, the output waveform of exciter was prone to saturation under frequency of 5 Hz. With the increase of agitating frequency, the saturation disappeared. The resonance phenomenon would be occurred when the exciting frequency was equal to the intrinsic frequency of hydraulic system. The vibration amplitude would drop down rapidly after the resonance frequency. 

Abstract:A robust H∞ adaptive control method based on backstepping theory was proposed for position servo system of asymmetric hydraulic cylinder in the presence of parameter uncertainties and external disturbances. In the controller design process, a proper Lyapunov function of the subsystem was selected to avoid the problem caused by repeated differentiations of high-order system. The robust control method guaranteed the output tracking error satisfied the H∞ performance. Considering the uncertain parameter in front of the control input could lead to the nesting problem caused by the mutual inclusion of the control law and parameter adaptive law, the uncertain parameter in the model of the system is replaced and a proper Lyapunov function was constructed, which solved the problem. Finally, the stability of the closed loop system was proved based on Lyapunov function approach. Simulation results verified that the proposed controller enabled the output of the closed loop to track the given signal at a faster speed, to achieve smaller tracking error and better robustness to parameter variety by contrast with PID control method.

Abstract:The M-B fractal model was modified. The deformation properties of elastic stage, elastic-plastic stage and plastic stage of elastomer were analyzed. In the combination of macro and micro perspective, the fractal model of normal contact stiffness between two cylinders’ joint surfaces was established considering the influence of friction. And the influence of relevant parameters on the normal contact stiffness was revealed with the research of numerical simulation. The work had geometric characteristics and scale independence, which improved the fractal model of joint surfaces to a certain extent. Simulation works showed that normal contact stiffness increased with the increase of actual contact area and contact force, and decreased with the increase of normal load. And when the friction coefficient was less than 0.3, the normal contact stiffness showed linear attenuation with the increase of friction coefficient. When the friction coefficient was larger than 0.3, the normal contact stiffness showed exponential attenuation with the increase of friction coefficient.

Abstract:The exact analytical solutions to fractal dimension and fractal roughness were put forward through structure function. Some formulas relating to static friction coefficient in joint interface were revised. A universal Matlab program was compiled to attain the domain extension factor. The rigorous analytical expressions for the autocorrelation function, power spectrum density function and structure function were given in detail. Taking a joint interface for example in YK31320 common gear-hobbing machine according to the experimental findings about hydrostatic guideway, the theoretical solution for static friction coefficient in joint interface was quantitatively confirmed. The confirmation results showed that the absolute windage between the theoretical static friction coefficients and the experimental ones fluctuated from -0.04502 to 0.00966, while the relative error between them distributed from-30.78% to 9.762%. 

Abstract:Based on the material removal model, it was concluded that the increase of finishing pressure was a practicable method for improving the efficiency of the magnetic abrasive finishing. By adding ultrasonic vibration to the magnetic abrasive finishing process, the instantaneous pulsating finishing pressure of magnetic abrasive particles could be increased. Experiment results showed that, magnetic abrasive particles could efficiently remove the workpiece material and keep surface smooth with the combined force in rotational movement and vertical impact. The practical experiment proved that the finishing efficiency was improved by 50% or so. The surface roughness of workpiece decreased to 0.06μm. Compared with only magnetic abrasive finishing, the ultrasonic vibration-assisted magnetic abrasive finishing made the surface morphology smoother and well-distributed in digital microscope. By using X-ray interferometer detection, the stress state of workpiece surface layer after ultrasonic vibration-assisted magnetic abrasive finishing changed from residual tensile stress (+320 MPa) to compressed stress (-40 MPa), which effectively improved fatigue strength of workpiece. 