Abstract:A mathematical model of proportional lowering valve was built to meet the requirement of electro-hydraulic lifter on high-power tractors. To improve the response characteristic and control accuracy of the hydraulic system, the model of the valve was established based on state space method. Then the influence on the dynamic characteristics of the valve was analyzed with respect to the parameter varieties of the components with the simulation and 4 steps Runge—Kutta method was adopted with Matlab/Simulink edited so as to obtain the optimum combination of the valve parameters. At last, the diameter of damping hole on pilot valve was 1.0mm, the diameter of damping hole on main valve was 1.2mm, the diameter of mainvalve larger face was 20mm, and the diameter of pilot valve was 8mm.

Abstract:The automatic fuzzy algorithm for controlling tilling depth of tractor based on slip rate was simulated. Firstly, the mathematical of the system was built and simulated by using Matlab/Simulink. Secondly, the fuzzy controller was designed. Further simulated analysis of the proposed model was carried out. At the same time, PID controller and fuzzy-PID controller were also designed and simulated. And then, these three controllers performance was compared, including responsiveness, adaptability, and anti-interference performance. As a result, fuzzy-PID and fuzzy controller was more suitable for this system, but fuzzy-PID needed more variables and seemed more complex.

Abstract:Based on the engine experiment, the transmission system of multi-purpose (rotary tilling, seeding, mowing and transporting) self-propelled pasture plot operation machine was optimally matched by using optimum design software which was developed in Matlab. The best matching scheme was obtained after simulation of power performance and fuel economy of transmission system and matching calculation between engine and transmission system. The selected matching scheme of engine and transmission system was optimized further, and then the transmission parameters were obtained after optimization. The results of transmission parameters were as follows: transmission ratio of first speed was 2.0039, second speed was 1.4595, third speed was 0.9775, fourth speed was 0.6751, reverse gear was 1.9840, transmission ratio of high-gear and low-gear were 1.0478 and 3.1102, respectively, and transmission ratio of central drive was 5.3711. Power performance and fuel economy of machine were improved to some extent, and matching degree between engine and transmission system was increased by 6.29% after optimization.

Abstract:To adapt to the environment of mountain orchard road transport characteristics, according to the tracked vehicle running characteristics, its general layout requirements were put forward based on the improvement of side rollover resistant capability of the tracked vehicle for mountain orchard. After the completion of all assembly designs, in order to improve side rollover resistant capability of the tracked vehicle for mountain orchards, the general layout of the system design was completed. The vehicle’s 3-D model was established and carried on the simulation. The simulation results showed that the design met the design requirements, and shortened the period of design.

Abstract:Taking separated multeity machine as the research object, the three-point hitch linkage for the rototilling-planting combined machine was designed. The design was started with the principle of three-point hitch linkage. The effective clearance of single combined mechanism was analyzed. The capsize resistance was analyzed by the unit’s longitudinal stability coefficient and climbing stability coefficient. The maximum effective distance was 41cm. From analyzing the moving states of rotary blades, the place of clods and the muzzle velocity, the minimum effective distance was 19cm after several times of calculation and experiment.

Abstract:During the up-film transplanting for dibble-type transplanters, the mulch film could be easily dilaceraded and scraped. Aiming at this problem, a pot seedling transplanter in duck-beak style was designed while the working principle of it was expounded. The motion mathematical model of its planting mechanism was established. And then, parametric modeling for the planting mechanism based on the model was completed in ADAMS. The influences over the mechanism motion characteristic by some important parameters were analyzed by using the parametric model. In addition, the cave value which formed by the distance between two intersections points of the duck-beak trajectory and ridge line as possible as small was taken as the optimization objective, while the higher upright degree of seedling was ensured. Meanwhile, the optimal parameter combination of planting mechanism was obtained. With it, the cave value was 1.8mm and the verticality of duck-beak trajectory after transplanting seedlings was higher, and then the demands of up-film transplanting could be met, namely higher upright degree of seedling and without dilacerating films.

Abstract:Based on the movement trajectory formula of dibble-type planting device, the zero-velocity planting and the least damage of mulch-film was analyzed. The main parameters for transplanter were discussed. The proposed machine was designed and the experiment was carried out. The analysis and experiment showed that it’s better to plant seedlings during rising stage of the planting devices. Spacing can be changed by changing the transmission ratio or the number of planting devices.

Abstract:A closed loop control system for adjusting fertilizer scatters breath was developed based on the PWM technology. The module circuit, sensor installation and close-loop feedback method were designed. The relation of disc rotation speed and scatters breath was built with experiment. The breadth value could be input to system directly according to the operation needs, so the rotating disk could work under specifying speed which improved operated performance and intelligence of the machine. Experiment showed that with the different operation speed and different width scatters, the maximum error and the minimum error between actual scatters breadth and target scatters breadth was 5.50% and 2.86%, respectively. The designed system can meet the practical production requirements.

Abstract:According to requirement of stability on working status for the automatic fertigation system, the monitoring devices and monitoring methods of water supply status, fertilizer suction status, nutrient mix status and irrigation/fertilization status were designed. Intelligent controller controlled automatic fertigation systems based on the monitoring results of working status of all aspects. At last the prototype was trial-manufactured. The performance of the prototype was tested. The test results showed that the working status of automatic fertigation system was stable, and the system could satisfy the requirements of irrigation and fertilizer proportion in greenhouse. The problem of monitoring working status of automatic fertigation system was solved.

Abstract:Focusing on the problem of high missing-seeding rate of commonly used air-suction seed metering device when sowing corn seeds, especially at the edge of fields, a kind of air-suction precision metering device which used a mechanical supporting plate to assist carrying seeds was designed. There were many cells around the edge of the mechanical supporting plate which help to support and grip seeds, so the performance of attaching seeds of the air-suction seeding disc increased remarkably. The parameter of metering-device working area and main structural parameters of the supporting plate were analyzed and determined. Experiment results showed that the seeding quality of the newly designed metering device was satisfactory and the qualified index of seed spacing exceeded 91.40%, the missing-seeding rate and the reseeding rate were less than 3.82% and 4.78% respectively, and the coefficient of variation of seed spacing was less than 18.37%. All of which were obviously better than the corresponding indexes of commonly used air-suction seed metering device under the same working speed and air pressure.

Abstract:The design of quadratic regression orthogonal rotating experiment was used to test the performance of air-suction precision seed-metering device on the type JPS—12 seed metering performance testing bench. The seeding qualified index was 72.31%~98.17%. The leaking index was 0.51%~18.7%. The regression equation was received by regression analysis of the test results. 3-D figures were drawn with Matlab. Various effects on the experimental indexes by each factor could be received. The experimental factors were optimized, and then the best combination was achieved. When the relative pressure was -2.86kPa,the hole diameter was 5.2mm and the speed of seed tray was 21r/min, the seeding qualified index was 91.03% and the leaking seed index was 2.98%.

Abstract:In order to determine the optimal operation parameters, experimental study was carried out on rotate velocity and inclination angle of alfalfa seed pelleting kettle. The results showed as follows: in order to make the kettle bottom paved with alfalfa seeds, rotate speed must be increased while the inclination angle increased. When the inclination angle took a certain value, the rotate speed must be in little range to make alfalfa seed pave the kettle thoroughly. The optimal inclination angle was 36°～42°, and optimal rotate speed was 28～39r/min.

Abstract:The designed rice seeder could perform tilling, seeding, fertilizing and covering activities simultaneously. Equal distribution of the seed was completed by the structure of roller feed and hydraulic driving system. The bothway augers could prepare for the field. It was showed that the coefficient of variation for the equal distribution was 24.5%. The coefficient of variation for the even seed consumption for every ridges was 3.2%. The seed broken ratio was 0.2%.

Abstract:A 3-D multiphase computational fluid dynamics model was used to study the coupling interaction of the natural wind, the air curtain and discrete droplets in the boom sprayer application and analyze the characteristics of air-assisted spray condition parameters on the boom spraying drift. The analytic results showed that increased outlet velocity of the air-assisted flow stressed droplet movement to target and then decreased the droplet deposition rate. Small nozzle flow rate implicated obvious loss trend of droplet drift. However, when the nozzle flow was excessive, the anti-drift loss of capacity of droplets decreased significantly. Air-assisted blowing angle had no significant impact on the drift reduction.

Abstract:A multifunctional machine with functions of ditching and stalk-disposing while harvesting was developed. Field tests results showed that the mean working velocity and efficiency of the machine were about 0.8m/s and 0.27hm2/h. The ratio of stalk discharged to ditch was up to 95%. The field operation of harvesting, ditching and stalk-disposing was complete in one time.

Abstract:In order to test the performance of grain loss monitoring sensor and search for the best installed location, a calibration test-bench which composed of lifting platform, lifting driving mechanism, feeding device and the sensor installation platform was designed. Full wheat grain, blighted wheat grain and stalks with different lengths were selected as calibration materials to test the performance of grain loss monitoring sensors in different installation heights and installation angles. The laboratory tests showed that for different moisture wheat samples, the measurement error of grain loss monitoring sensor could be limited to less than 4.8%. The installed location of the grain loss monitoring sensor was determined when monitoring the separate loss according to laboratory calibration results. The field tests showed that the average separate loss monitoring error was 3.40%.

Abstract:With the aim to study the mechanical properties of wheat stalks fracture, a kind of control system for the mechanics testing of wheat stalks was developed .The test equipment mainly included control section, executive body, information collection and display module, among which the quite accurate data acquisition system was very simple to operate. The experiment results show that the system is stable and reliable ,with the deviation of collection data lower than 0.1%, which can fulfill the system requirements and test the wheat stalks feature in mechanics and physics. It provides an effective and reliable method and tool for material mechanics.

Abstract:In order to establish an accurate finite element model of header and get complete structural dynamic characteristics for combine harvester, the experimental modal analysis of type 4LZ—2.0 header was carried out. The modal parameters in each order were recognized by using ModalVIEW. Finite element model was analyzed by using UG software, and MAC value of experimental mode was calculated. The finite element model of header was validated.

Abstract:Ag Leader grainyield monitor system was introduced. The yield monitor system experiment was carried out on the domestic medium and small combine harvester. The grain yield system was mainly composed of multi-channel sensors including grain flow sensor, terminal display processor and GPS system. First, the calibration experiment of system was executed. And then, the harvesting experiment of winter wheat in the field was performed and the acquired data were processed. With the analysis of spatial autocorrelation method, yield data presented high dependence within 20m. Semi-variance analysis showed that the variation of the yield data was obvious which presented the property of aggregated distribution. The yield map based on Kriging interpolation showed the trend of patch distribution and the properties of aggregated distribution. The experimental results could provide necessary theoretical evidence for the application of precision agriculture.

Abstract:The performance simulation of a small-scale corn harvester’s divider and snapping roll for hilly area was analyzed by using ADAMS. A 3-D model of the corn harvester header was established with Pro/E. The preprocessed model was imported into the ADAMS environment to build the virtual prototype model. A performance simulation of divider and snapping roll was done. The results showed that the design of the divider shape had some defects, which lead to the result that the cornstalks cannot be normally fed. Meanwhile, it gave the best values of speed and inclination of the snapping rolls, the optimal parameters were: snapping roll speed of 800~1000r/min, and snapping roll inclination of 30°.

Abstract:The models of stripper rollers of a certain type of corn harvester and corn plants were established in Pro/E. And then, these models were led to the ADAMS environment with the interface of MECHANISM/Pro to create the virtual prototyping models including constrains and motions. The harvesting process was simulated based on the ADAMS techniques of sensor and manuscript control. The simulation data analysis was mainly focused on the case that the corn plants at the angle of 79°. Finally, the best inclination angle of plant, 89°, was derived based on the analysis of harvest time and grain hurt rate.

Abstract:The establishment of flexible corn model is a key process of the corn-harvest mechanism, which is a kind of rigid-flexible coupling multi-body system. A modal neutral file for ADAMS was created in ANSYS by meshing the stem model and defining the attach point. The model of harvest mechanism and the modal neutral file of corn stem were imported into ADAMS. The status of motion of stem was simulated by applying load, constraints, and drive. And from the simulation, the variation of location and velocity were obtained. The status of motion in the mechanism was studied.

Abstract:Various influence factors on chopping yield of maize stalk were analyzed and the conditions of better levels of influence factors were discovered, which were as follows: feeding distance position near fixed blades side, forward speed of 0.6~0.8 m/s, rotational speed of cutter head of 1576r/min. Under the conditions of better levels of each influencing factor of maize stalk chopping effect , by using high speed photography and vast experiments, three motion laws were reached, which were through the below stages, instant of contacting with cutter head, process of chopping and after chopping.

Abstract:The method of quadratic regression general rotation was used to optimize the parameters of seed cotton cleaning apparatus .The results showed that the main factors of impacting impurity rate walking were the barbed nails drum speed, serrated roller speed and cotton brush roller speed. The three factors gradation importance was the serrated roller speed, cotton brush roller speed and barbed nails drum speed. Optimal group of parameters was the serrated roller speed of 291r/min, the cotton brush roller speed of 695r/min,the barbed nails drum speed of 367r/min. In this case, the impurity was 15.10%.

Abstract:Extraction components of threshing unit for rape combine harvester are complicated, including rapeseed, stems, pod shells and light debris. To study the aerodynamic characteristics of rape extraction components, test suspension velocities of these components were conducted in type PS—20 measuring test-bed respectively. The results showed that the linear relationship between suspension velocity of rapeseed and particle size was exposed. The quadratic polynomial relationship between the suspension velocity of stem and diameter was exposed. The stem length (<100mm) revealed there was no significant effect on the suspension velocity. Suspension velocities of rapeseed and stems were observed to be closer (7~10m/s), higher than suspension velocities of pod shells and light debris (1~3m/s). Meanwhile, suspension velocities of rapeseed and pod shells both was exposed a linear increase relationship with the moisture content, while suspension velocities of stems and light debris both was exposed an exponential increase relationship with the moisture content. It’s concluded that the difference of their suspension velocities could be applied for cleaning the extraction components. The suspension velocities of light debris and pod shells were small in extraction components. The air flow cleaning method was suggested to separated them and the airflow velocity was 4~6m/s.

Abstract:A semi-feeding peanut picking test-bed was developed to carry out the studies on optimized design and experiment on the structural and motion parameters of semi-feeding peanut picking device. Based on the motion analysis of picking process, ideal position state and parameter relationship of pods cluster during the picking section were determined to ensure that all the pods cluster could pass through the best picking areas by bottom-up and gradual-orderly mode. Influencing factors of picking frequency and strength as well as the influence on the picking performance were analyzed. On the basis of picking mechanism analysis and the experimental verification, the picking roller employed six backward-curved blades. After the multi-criteria response surface experiments, the optimized combination of structural and operational parameters were obtained as follows: the roller length was 1.200mm, the included angle between chain and roller was 7.2°, the roller diameter was 152.5mm, roller overlap distance was 5mm, roller rotate speed was 371r/min, chain conveying speed was 1.025m/s.

Abstract:Based on agronomic requirements of the garlic harvest, one kind of garlic harvester for split was designed. It included garlic seedling shear and garlic mining which configured in the front and rear of the tractor. It can complete garlic stems shear, garlic mining, garlic soil separation once a time. The garlic vine and garlic stack respectively to facilitate the collection and transport. Garlic was collected with a string bag directly after drying, to avoid leakage and save time and venue. Eccentric linkage vibrated the mining shovel, reduced the traction resistance and reduced energy consumption. Eccentric institutions as well as digging shovel motion simulated and analyzed by Pro/E，so that the whole structure and motion parameters were optimized and laid the foundation for the prototype trial.

Abstract:The green-skinned sugarcane from Xiantao city in Hubei province was used as the test material. The peeling and cutting characteristics in the internode and node of the green-skinned sugarcane on the computer control electronic universal testing machine was studied with the home-made blade of 15° angle and the fixture. The test results showed that, when peeling the internode part of the sugarcane stalk, the blade load first increased and then decreased. When peeling the node part of the sugarcane stalk, the blade load first increased and then decreased, but it soon increased again and decreased after. When cutting off the internode and node parts of the sugarcane stalk, blade load showed an increasing trend.

Abstract:In order to study the walnut-cracking broken mechanism and performance of walnut-cracking device, the cracking experimental research for certain physical characteristics was done by using a walnut-cracking device based on extrusion friction mechanism. On this basic, walnut varieties, size (length of edge), the moisture content of walnut shell ,which were investigated by single-factor experiments, were tested to specify the effects of walnut cracking. The result is that the optimal scope of walnut and machine was as follows: 6°as cone basket angle of device, edge length above 28mm, thickness of the shell below 2mm and 8%~10% as moisture content of walnut.

Abstract:A test-bed was designed for cutting and rubbing straw, an experiment was carried out by cutting and rubbing corn straws with 75% moisture content. By means of orthogonal experimental analysis, the best parameters of this device were as follows: the spindle speed of 1000r/min, multiple saw cutting blade, three hammers and feeding speed of 0.88m/s. The result shows that when cutting and rubbing corn straw with 75% moisture content, the breaking rate is higher than 96%.

Abstract:An automated inspection system based on virtual instrument technology was proposed for machine quality improvement. To meet national quality standard of the combine harvester, a group of testing items were chosen and built in the developed system. To obtain better efficiency and accuracy, rapid measurement technique for different measurement parameters were evaluated. Taking brake performance test for example, a reaction type tester was constructed for brake force measurement. Customized software programmed based on LabWindows/CVI and multi-channel data acquisition device were also integrated into the inspection system for better system performance. The developed inspection system was improved for combine harvester quality inspection with high accuracy and efficiency.

Abstract:According to the national diamond theory of Michael Porter, choosing 5 species 15 indexes for evaluating the agricultural equipment manufacturing industry, the two-grade fuzzy comprehensive evaluation method was introduced and the international competitiveness of China, USA, Japan and Germany in Chinese market, American market and African market were analyzed respectively. It can be concluded that the industrial international competitiveness from large to small are China, Janpan,USA and Germany in Chinese market, while in American market, that are USA, Germany, Japan, China , and in African market, that are China, USA, Japan, Germany.

Abstract:With the aim to improve the production efficiency of paddy rice in double cropping area in south China, the panel data of cost and profit from 1995 to 2010 was analyzed. Total factor productivity, technical progress rate and technical efficiency was calculated and their time series characteristics were analyzed. The result showed that the total factor productivity was observed with a constant decline from 2004 to 2010, which was mainly caused by technical progress decline. The result also showed that the total factor productivity in double cropping area was much lower than that in Heilongjiang and Jiangsu Province, and there was significant variation between provinces and autonomous regions. Strengthening adaptability and advancement of paddy rice production technologies, promoting the innovation of management and mechanism, and narrowing the gap between provinces are key countermeasures to improve the capability of paddy rice production efficiency.

Abstract:By using survey data from 186 rural farmers in Jilin Province, the influencing factors on farmers’ adoption of maize mechanized harvesting was analyzed by using Logistic model. The results show that gender, technological training, scale of planting, proportion of non-agricultural income, perceived effectiveness, cooperative association membership, the support from the government policies and demonstration projects are positively and significantly correlated with the adoption of maize mechanized harvesting, whereas serious natural disasters plays significant negative effect on it. The policy proposal recommended is enhancement of technological training, acceleration of land integration and circulation, promotion of rural labor transfer, strengthening against disaster ability, as well as governmental supportive policy contributing to acceleration of the spread of corn producing entire mechanization and adoption of maize mechanized harvesting.

Abstract:Based on the early single factor test, quadratic regression orthogonal rotating combination design was applied. The whole gas production was taken as response value. Effects of four factors on anaerobic fermentation were studied. These four factors are the ratio of food garbage and cow dung, temperature, pH value and the ratio of inoculum and quality of fermentation. The mathematical mode about mixed fermentation of food garbage and cow dung was established, regression equation was optimized and analyzed, in addition, the optimal condition and interactive effects were exposed. The optimum technological conditions for the mixed-fermentation was as the followings: the ratio of food garbage and cow dung was 2.5, temperature was 37.5℃, the pH value was 7.0 and the ratio of inoculum volume and quality of fermentation was 4. The order of the influence of four factors on mixed-fermentation of food garbage and cow dung was as follows: the ratio of inoculum and quality of fermentation, temperature, the ratio of food garbage and cow dung, and pH value. The gas production of the optimum technological condition and the random experiment also showed no significant difference with the predictive value. The model fitted well.

Abstract:A pilot plant of dry anaerobic digestion was constructed in the dairy farm of Chinese Academy of Agricultural Mechanization Sciences. The plant included pretreatment system, solid feed-in system, horizontal anaerobic reactor, biogas storage and purification system, insulation warming system, and digestate discharging system. Specially designed low-speed horizontal rod-gear agitators used in the horizontal anaerobic reactor enhanced mass and heat transfer efficiency and overcame high solid feedstock feeding and discharging difficulties. Pilot-scale experiment of continuous dry thermophilic anaerobic digestion of dairy manure was conducted in the pilot plan. The experiment results showed that the pilot plant could efficiently dispose high solid dairy manure, and average volume biogas production was 3.0m3/(m3?d). 

Abstract:Measurements of gas emissions (CH4 and NH3) during pig digested slurry storage were carried out by using a dynamic chamber system. Gas emission patterns were obtained. Methane was continuously sampled with gas sampling system (GSS) and analyzed with gas analyzer TEI55i. Ammonia was collected with atmospheric sampling instrument and analyzed with chemical analysis at intervals. The result showed methane and ammonia concentration were both higher at the early days of the storage period. The methane concentration increased in the first 12d, then began to reduce to only 1.44mg/m3 on the 32th day. The ammonia concentration increased sharply in the first 12d, but was not evident in the last two weeks, and reduced to less than 3mg/m3 after the 40th day. Abatement of methane and ammonia emissions should be effective if mitigation options were implemented in the first 30 days and 40 days of digested slurry storage.

Abstract:New materials and equipment according to the combustible fraction of diesel miscible flammable characteristics of biomass tar was analyzed. Diesel engine fueled with different proportions of combustible biomass tar distillates and diesel miscible oil power performance was proposed. Experimental results showed that biomass tar combustible miscible distillate and diesel oil had good power and economy. When the power of agricultural diesel was low, the consumption of miscible oil sample was less than diesel. When the power of agricultural diesel was high, the consumption of miscible oil was less than diesel with the replacement ratio of 10% in diesel, but higher than diesel with replacement ratio of 20%. The maximum power of agricultural diesel engine with miscible oil was higher than the rated power of the agricultural diesel engines which met the power requirements of agricultural diesel engines.

Abstract:In order to research operation parameters of corn straw adjusting material device based on horizontal roller on the influence law of power consumption, a self-developed straw adjusting material test device and power measurement and control system were used to implement continuous adjusting material orthogonal test of corn straw. The influence of the adjusting material roller’s working clearance, the adjusting material roller’s speed of rotation and the feeding speed of straw on power consumption of the straw adjusting material was analyzed. Research showed that the adjusting material roller’s working clearance significantly influenced on the power consumption. The parameters combination were the adjusting material roller’s working clearance of 2.5mm, the adjusting material roller’s speed of rotation of 88～95r/min, the feeding speed of 3.3～4.0km/h, which met the requirements of adjusting material performance and reducing power consumption.

Abstract:A rapid and nondestructive detection device for pork freshness with associated composite quality parameters based on multispectral imaging technology was designed. The system included hardware system and software system. Hardware system consisted of a single-chip microcomputer control unit, light source unit, image acquisition system, data processing unit and LCM display unit. Software system was designed in the ICCAVR development environment programmed by C language. The software was built to control image acquisition module, filter switching module, LCM display module and communication module with a PC. After debugging and experiment of the software and hardware systems, this device could meet the speed requirement of detecting a sample in less than 10s, having the function of nondestructive and rapid detection.

Abstract:The beef-marbling detecting system combined with spectral and computer vision technology was created. Working principle, hardware structure, choice of hardware parameters and the software of the detecting system ware introduced. Center wavelength of the filter used in this detecting system was 530nm, and the image of sample under this wavelength was taken by an industrial camera. Image processing software used to detect beef-marbling was developed. The results of experiment show that detect accuracy of the system can match the demand of beef-marbling detect.

Abstract:In order to explore a nondestructive approach to predict total soluble solids (TSS) of Bamfild nave orange, multiplicative scatter correction (MSC) was used to preprocess the NIR spectra (1000~2500nm) of navel orange. Partial least square (PLS), interval partial least square (iPLS) and synergy interval partial least square (siPLS) methods were employed to establish the calibration models of TSS. The results showed that siPLS model was obtained with 17 intervals and the optimal combinations of intervals selected were No.4(1267~1355nm), No.5(1356~1443nm), No.9(1708~1795nm) and No.15(2236~2323nm). The coefficient of determination r was 0.9109 and RMSECV was 0.3312 in calibration set, and r was 0.8789 and RMSEP was 0.4487 in prediction set. It was achieved with six factors. This work demonstrated that NIR spectroscopy with siPLS model could not only select the efficient regions for TSS of orange and simplify the model, but also improve precision.

Abstract:The airflow field in cartons of the pressure-difference pre-cooling litchi was simulated by using Fluent software based on standard model and SIMPLE algorithm. The fitting equation of the relationship about length of cartoon and static pressure in cartoon was gotten with the fitting accuracy 0.817, which was verified by experiment. The experiment and simulation shows that the law between the internal pressure and length of the cartoon is positive correlation, and the pressure of air entrance is high, the pressure of air outlet is low.

Abstract:According to the principles and characteristics of drying and cross-flow belt drying machine, the double cross-flow drying test bed was designed. The test bed mainly consists of the upper circulatory system and the lower circulatory system, and every system can be operated independently with cross-flow wind speed of 0~10m/s, temperature range of 30~150℃, humidity range of 0~100%, maximum thickness of 600mm etc. The system can achieve automatic moisture exhaust , the show of energy consumption, all parameters display and record function etc. By the drying experiment of red peppers in the test bed, the effects of pre-drying temperature, post-drying temperature, thickness of red peppers on the impact of energy consumption were investigated. Furthermore the dry parameters of minimum consumption were obtained, at pre-drying temperature 70℃(20min dried)+ 60℃(40min dried), post-drying temperature 55℃, thickness of red peppers 14cm.

Abstract:Aiming at herbage seed drying equipment problems of power consumption, air discharge and solar energy application, a drying mode was proposed. Basis heating was supplied by thermalstored solar energy, and air charge was dehumidified and reused by heat pump. Main working parts, such as thermal collector, thermal storage and heat pump, and whole drying machine were designed. Using movable design idea, thermal collector was controllable and whole machine was placed safely. Performance test results showed that handling capacity reached to 161kg/h, power handling capacity achieved to 8.4kg/(kW?h), the drying capacity reached to 3.367kg?%/h, and dry strength achieved to 6.7kg/(m3?h). The power consumption ration of solar PCM heat-storage drying, solar energy and heat pump teamwork drying, heat-pump drying and electricity power drying was 0.9∶1.0∶1.2∶1.5. 

Abstract:In the improved process of solar energy forage drying equipment, the key component of solar energy forage drying equipment was air heat collector. In order to improve equipment productivity, the structure and working principle of air heater were analyzed. Air heat collecting efficiency was improved. Through the performance experiment, the honeycomb structure of the air collector was very important in the solar energy forage drying equipment. Productivity increased by 20%. The air collector efficiency increased by 50%.

Abstract:The dry and wet harvesting technology of the hay and green grass was analyzed though experiments. Alfalfa drying rate of air drying was analyzed. Law of nutrition variation and dry matter loss was studied. The out-of-sync problem was resolved and nutrition retention rate was improved. The nutrition was up to 90% and dry matter loss was below 2%.

Abstract:In order to study the distribution of airflow and construct the movement model of airflow velocity in traditional solar drying chamber, the numerical simulation of three-dimensional steady-state model was carried out to analyze the effect of wind speeds on the airflow distribution in drying chamber by using CFD software Fluent and the k—ε model. The results showed that compared with the airflow speed of 2m/s and 10m/s, the internal wind speed and airflow distribution were better when airflow velocity was 6m/s.

Abstract:The ripening color and growth cultured germination of chestnuts after microwave processing was observed to analyze microwave radiation damage to materials. Short time and high-power processing will reduce the ripening degree of the chestnut, but whether chestnut life activity or rice life activity in the microwave would be affected. Rice germination rate is only 0~8% after microwave treatment if 10% of the rice water is removed, so special attention to the impact on the life activity is necessary in the processing of microwave materials like seeds.

Abstract:The method of shape feature extraction based on depth image for the classification of tomatoes shape was proposed. Firstly, the shape of tomatoes was separated from the background through the segmentation of image in color space. Secondly, the point cloud of tomatoes was obtained by unitizing a 3-D machine vision measuring device. In order to implement the shape feature extraction of tomatoes in the same scale, the depth values of tomatoes were normalized. The depth map of tomatoes was formed according to the result of segment and the depth information of tomato. Further the depth map was sampled in polar coordinates and the sampling data was re-plotted in Cartesian coordinates. Finally, the depth image was re-plotted in the form of the Fourier transform in the Cartesian coordinates. The generic Fourier descriptor（GFD）was calculated based on depth map. The descriptor was characterized by the invariance of transformation of translation, rotation and scaling. The GFD based on depth image and the general GFD were successively used in the experiment of tomato grading. The result showed that the mean accuracy of the former classification was up to 92% and higher than the latter.

Abstract:The size of sweet cherries is an important indicator of ripeness and quality. However, as a manual process heavily relying on individual judgment, the operation is labor intensive and subjective. A machine vision system was developed. Three methods were used to measure cheery size. Tests showed that standard deviation was 0.48mm by using ellipse fitting method. This method was better than others, such as circle fitting method and rotation searching method.

Abstract:A visual positioning system of litchi picking manipulator was established based on the binocular stereo vision. By analyzing the color features of mature litchi, the YCbCr color model was selected. The Otsu algorithm was combined with fuzzy C-means clustering (FCM) to segment litchi fruit and peduncle. The experimental results showed that the effective recognition accuracy of litchi fruit and peduncle reached to 94.2%. The maximum distance between the fruit centroid and peduncle was calculated to determine litchi picking point. The color image matching method based on hue component of color image and the limiting binding method were used to achieve the stereo match of picking point, which realized the spatial position of picking point. Through the analysis of position error, the linear interpolation method was used to realize the positioning error compensation. The positioning experimental results showed that the depth value error was less than 10mm, which could satisfy the visual accurate position requirements of litchi manipulator.

Abstract:Based on studies of automatic sequencing and supplying of grafting clips, the mechanical model of clips in disc-shaped vibratory feeder was established. The conditions of clip bouncing and sliding in delivering were determined. When disc acceleration a2 was larger than 2.37g, clips began to bounce. When a1l was 0.47g,a2l was 0.41g, perfect state continuous sliding of clips could be achieved. The device included disc-shaped vibratory feeder and automatic clip-delivering mechanism. The disc was controlled by the adoption of anticlockwise clip-delivering and frequency adjustment. The automatic clip-delivering mechanism was driven by cylinder. Experiments showed that when vibration frequency was 48Hz, the angle of slideway was 45°, clip-pushing pressure was 0.4MPa, delivering speed was 60 clips per minute, and success average of clipping was 96%, which could meet the need of the type TJ—800 grafting machine.

Abstract:In order to improve positioning accuracy of GPS/DR integrated navigation, the fuzzy adaptive Kalman filter method was analyzed. Experiment was carried out on the modified agricultural machinery. Experiment results showed that the fuzzy adaptive Kalman filtering could inhibit the influence of unusual values on the localization precision of the system, and the system positioning accuracy of the proposed method was better than single GPS. The average positioning error of the x and y directions were 0.13m and 0.20m by using the fuzzy adaptive Kalman filter. Positioning curves was smoother after filer.

Abstract:Aimed at visual navigation of grain combine harvester, an algorithm was proposed for walking goal line detection on improved Hough transform (HT) on grain combine harvester. Through the improvement for image threshold segmentation of the 1-D maximum entropy, the computing speed was increased. After scanning the rows and columns of binary images, the end position of the walk goal line and the candidate points on the direction of the walk goal line were determined. Then the candidate points were used as points set, least squares methods and the end position of the goal line were combined to determine the point from the test line. The improved HT has finished the test line detection. Compared with the traditional HT, the improved HT transfers binary mapping into 1-D mapping, the computing speed was accelerated, and the space occupied was reduced. Meanwhile, the anti-interference ability was improved effectively. After testing thousands of pictures, the algorithm was well proved with effectively detecting the linear parameters, and the processing time was about 100ms.

Abstract:According to combine visual navigation of real-time and robustness requirement，based on the DaVinci platform, a path recognition algorithm was designed. After analyzing the texture measure in the image of wheat harvest, the path recognition algorithm of visual navigation, on account of an improved smoothness texture feature, was put forward. The original brightness image was converted into horizontal smoothness image, by the image texture feature of the horizontal smoothness. The harvest boundary was extracted from the smoothness image by using adaptive threshold segmentation, and finally visual navigation path could be determined by Hough transform. In order to validate the algorithm in the operation of the DaVinci platform， the navigation experiments of wheat harvest by combine harvester were conducted. The experimental results showed that the algorithm had the high real-time and good robustness. Its average rate of recognizing navigation line was up to 28.6 frame per second. Path recognition effect was good in a variety of environments. Algorithm operation was stable and reliable, and to continue operating time was unlimited.

Abstract:In order to decrease the cost and improve the testing efficiency, a four channel detection system for soil macronutrients rapid determination was developed and evaluated. The system was mainly composed of an ion selective electrodes (ISEs) array, a laptop computer, a microchip and the signal conditioning circuit. As a sensing unit, the ISEs array was integrated with a pH electrode, a nitrate ISE, potassium ISE and a phosphate ISE. According to the testing results, the input impedance of each channel was around 1012Ω, and the input current was about 1pA. The detection range was between -2000~2000mV,which indicated the good compatibility with the majority of ion-selective electrodes. According to the validation results, the testing accuracy and detection range of soil pH value, nitrate-nitrogen and potassium could meet the needs of site-specific fertilization.

Abstract:In order to detect soil total nitrogen (TN) content, a portable soil TN detector was developed. The stability, accuracy and precision of the detector were tested with the sixty soil samples collected from Shangzhuang Experiment Station of China Agricultural University. The models were evaluated by the correlation coefficient of calibration (RC), the correlation coefficient of validation (RV), root mean square error of calibration (RMSEC), root mean square error of prediction (RMSEP) and residual prediction deviation (RPD). The results showed that the repeatability error of 940nm, 1050nm, 1100nm, 1200nm, 1300nm, 1450nm and 1550nm were 1.57%, 1.80%, 1.59%, 0.94%, 0.61%, 0.64% and 3.13%, respectively. The correlation coefficients between the absorbance of soil TN detector and that of MATRIX_I Fourier spectral analyzer were 0.971, 0.948, 0.928, 0.873, 0.920, 0.901 and 0.913, respectively. The RC, RV, RMSEC, RMSEP and RPD of the model established by BP neural network was 0.81, 0.80, 0.029, 0.019 and 3.44, respectively. The experiment indicated that the portable soil TN detector performed well. 

Abstract:The avian influenza virus (AIV) was diagnosed by measuring the impedance of the biological chip’s electrodes, which was a development direction of the AIV rapid detection. The high precision impedance conversion chip (AD5933) and the ATmega16 MCU were used. Through the circuit design and commissioning, an impedance testing instrument with the energizing frequency range of 1~100kHz was developed. The impedance measurement range was 1~1000kΩ. This impedance testing instrument has capacity to measure one frequency point and sweep frequency testing. To ensure the accuracy of the instrument, a calibration network with 35 different combinations of impedance was used for providing real-time calibration. The BK866(accuracy of 0.2%) impedance testing instrument for adjusting the system can make sure that the testing accuracy of captance was above 3%.

Abstract:Micro flow-through PCR could make not only qualitative analysis, but also quantitative analysis of the water sample. The special heater arrangement allows the implementation of up to 40 cycles on the footprint of a sample. The key factor of PCR instrument is precise temperature control, so the temperature control algorithm occupies an important position in whole system. PID and fuzzy-PID algorithms were designed. The simulation model was constructed and experimented with Simulink of Matlab software．The simulation results showed that overshoot of PID algorithm was 8.5 %, adjustment time was 3.4s, the control accuracy was 0.044℃. Overshoot of fuzzy-PID algorithm was 1.45%, adjustment time was only 1.94s, the control accuracy was 0.015℃. Obviously, fuzzy-PID algorithm would overcome the defect of large overshoot of traditional PID, and the adjustment time was shorter.

Abstract:The visible and near infrared spectral reflectance was measured for the leaves by using Shimadzu UV—2450 spectrograph. At the same time, the nitrogen content of apple tree leaves were measured in Kjeldahl nitrogen method. The rapid determination model of apple leaf nitrogen content suitable for portable detector was built. The spectral properties were explored and the analysis of correlation was conducted among the nitrogen content of apple tree leaves and their spectral reflectance. Then two sensitive wavebands (652nm, 772nm) were obtained. At the same time, by adopting the method of segment reduced precise sampling, the detailed NDVI within the range of 350~730nm and 740~880nm were constructed, and then the wavebands (859nm,364nm) of the highest correlation with nitrogen content were selected to construct NDVI for apple tree. Finally the nitrogen partial least square regression model of apple tree leaves was established based on apple tree NDVI (859nm,364nm) and reflectance at 652nm and 772nm. The R2 of the calibration model reached to 0.9048, RMSEC was 0.1597, and the R2 of predicted model reached to 0.917, RMSEP was 0.2833. The model reaches practical level and can be used as the nitrogen content rapid determination model to develop a portable apple tree nutrition detector.

Abstract:A method which can forecast generating capacity of automatic tracking power system on inflatable membrane greenhouse attached photovoltaic was proposed based on the self-adaptive variation particle swarm neural network by adding with weather information. Firstly, through combining historical data of electricity production and meteorological data, the main factors of the impact on generating capacity of power generation system on inflatable membrane greenhouse attached photovoltaic was analyzed. Then, the neural network forecasting model was established by combining the weather forecast. The self-adaptive variation particle swarm algorithm was introduced to improve the training effect by tackling the problems of slowly converging, easily falling into local optimum, and difficultly converging existed in traditional neural network forecasting model based on gradient-descent BP algorithm. The neural network was optimized with adaptable mutation particle swarm optimization(AMPSO) algorithm. The mutation was put into particle swarm optimization(PSO) algorithm to find local optimal value. Experimental results showed that the entire convergence performance was significantly improved by adopting AMPSO and the premature convergence problem can be effectively avoided in PSO.

Abstract:The process of wheel compacted soil was simulated by using DEM. The results showed that after the compaction, soil hardness of different depths increased and changed obviously with depth. With the frequency increased, soil particle’s contact force increased and longitudinal influence domain deepened. When wheel passed in the first three times, the increasing trend of soil’s hardness was obvious. When wheel passed more than three times, the soil’s hardness also increased. But the increasing was not obvious. When the layer deep was 15cm, the hardness of compacted soil would increase by 155.2% when compared with the soil without compaction, the soil compacted six times would only increase by 22.9% when compared with the one compacted three times.

Abstract:A impact-based method, which can be used to measure the real-time velocity and the mass flow rate of the granules flow, was presented. And a way to dynamically estimate the measurement error of the velocity and mass flow rate was also provided. Using the self-designed experimental equipment, experiments with the soy bean as the experimental object to estimate the measurement error had been done. It was shown during the experiments that the maximal estimated error of the mass flow rate was 4.00% and the average value was 1.44%, the maximal estimated error of the velocity was 9.69% and had an average value of 5.03%. A positive correlation between the dynamic measurement accuracy and the measurement accuracy of gross mass was also found.

Abstract:The virtual assembly model of mechanical gearbox was researched and its virtual assembly process was realized. By analyzing the information of the virtual assembly object and the relationship between the assembly objects, the virtual assembly model was divided into the object model describing inherent information and dynamic information in the assembly parts, the assembly tree model describing assembly-level information of assembly members, and the relational model describing the parts assembly constraints between the assembly parts. The assembly model information was obtained by the conversion of model data between CAD system and virtual assembly system. Then the assembly model was developed in the virtual assembly system and the implementation of the motion constraints in the virtual assembly process was proposed. By analyzing the DOF based on the space position and geometric constraints, the motion constraints were determined. Using EON and its secondary development tool, the virtual assembly module was built, and then the virtual assembly process of mechanical gearbox was implemented.

Abstract:In order to solve the problems of excessive dependence on importation, independent design and over-prolonged traditional design cycle and so on, the expression methods and reasoning mechanism of high-speed transplanters were applied. Finally, a designing inference engine and parametric parts models were built. Taking Visual Studio 2008, Oracle, Pro/E as major development platforms, the technologies of secondary development and database programming were adopted in developing the interface of the design system software. By combining the design knowledge, inference engine and parametric model of high-speed transplanter chassis, the knowledge-based rapid design of high-speed transplanter chassis was achieved.

Abstract:A mathematics model of double-action variable displacement plunger pump was built for sugarcane harvester based on power bond graph. Some nonlinear influence factors were linearized or neglected for the model. The response characteristic of flow, pressure and reversing were analyzed in Matlab/Simulink by changing swash plate angle of Eaton series 1 model No.64 displacement plunger pump. The results showed that the proposed double-action variable displacement plunger pump had good dynamic response characteristics. It could meet the requirements of the hydraulic drive system on sugarcane harvester.

Abstract:In order to investigate the gait of Chinese mitten crab, a motion images recorded and analyzed systems was established with high speed camera and 3-D motion analysis software. The results showed that Chinese mitten crab performed alternating tetrapod gait when walking on smooth road. Adjacent ipsilateral and segmental pairs of legs alternated with each other; Subadjacent ipsilateral legs and diagonal pairs of legs moved together. Duty factor of each leg was (55.60±7.53)%, which indicated that Chinese mitten crab made its body more stable during walking through increasing support phase.

Abstract:The surface roughness and tribological properties of Cyclina sinensis shell cuticle were studied by using confocal laser scanning microscopy (CSLM) and UMT—2 micro-friction and wear testing machine respectively. The results showed that the descending order of the roughness of different parts of Cyclina sinensis shell cuticle was as follows: dorsal Cyclina sinensis shell, posterior part of Cyclina sinensis shell, abdominal Cyclina sinensis shell and anterior part of Cyclina sinensis shell. The transverse friction coefficient (TFC) was greater than the longitudinal friction coefficient (LFC) of the cuticle surface in the front and abdomen of Cyclina sinensis shell. However, TFC was less than LFC of that of posterior and back of Cyclina sinensis shell. This suggested that the tribological properties of Cyclina sinensis shell cuticle transverse and longitudinal had heterosexual characteristics. Comparing to the anhydrous test conditions, under the water lubrication conditions, TFC and LFC of the cuticle surface of the front of Cyclina sinensis shell both increased, TFC and LFC of the cuticle surface of the back of Cyclina sinensis shell both decreased, and TFC of the surface of the cuticle of the abdomen of Cyclina sinensis shell decreased, but LFC increased.

Abstract:Bionic structure of jute fiber was designed. The mechanical properties of jute fiber with bionic structure were tested. First, jute fiber was divided into filaments. The surface treatment was used on jute fiber filaments: three shares of jute fiber were woven into a different helix angles bionic helical structure by using the spiral knitting machine and stereotypes. The size of the helix angle could be controlled by adjusting the speed of the spiral knitting machine. Its mechanical properties were tested. Results showed that, the breaking load of jute fiber which had bionic helical structure first increased and then decreased. Spiral fiber elongation was declined with the decrease of helix angle. Jute fiber with bionic helical structure had optimum comprehensive mechanical properties at the helix angle of 66°. When the helix angle was more than 66°, the stress of the fiber was unbalance, and then the fiber was fractured. When the helix angle is less than 66°, the fiber force increased with the decreasing of helix angle’s.

Abstract:Taking hair and wool fibers as the prototype, the structure bionics of jute fibers was conducted in two modified ways: room temperature alkali treatment and heat treatment. The impact of bionic spiral jute fibers on the frictional properties of the friction materials was investigated. The results showed that when the content of spiral jute fiber was 3% and the helix angle was 66°,friction factor met the brake requirements and its abrasion resistance achieved the most excellent. Spiral jute fiber increased the friction factor of friction material at 100℃ and 150℃. The friction factor of the spiral jute fiber reinforced friction materials decreased with the increase of fiber at 200℃ and 250℃. The friction factor of straight jute fiber got the highest. Spiral jute fiber friction materials showed good wear resistance at 300℃ and 350℃. The friction factor of the friction material decreased with the decrease of helix angle of spiral jute fiber.

Abstract:In order to achieve the performance of lunar rover simulation assessment in a variety of state of motion, based on programming in the Pro/E modeling environment, 3-D terrain profile and vehicle models were changed to SQlite database directly. Lunar rover dynamic model was set up with Vortex’s API functions. And then, visualized objects can be rendered by using OSG graphic engine. The typical terrain mechanical models in Vortex were evaluated and fixed based on wheel soil bench tests. Finally, 3-D visualized software was developed with Microsoft MFC framework, which had function of interrupt, call-back and simulation’s datum recurring.