Abstract:Stochastic preview control with time-delay consideration was investigated for an active vehicle suspension system with look-ahead sensor. The road roughness height was modeled as a filtered white noise stochastic process and the rate of change in the road profile at some distances in front of the vehicle was measured by the look-ahead sensor. The suspension system was optimized by minimizing the performance index containing the mean-square values of body acceleration, suspension rattle space, tire deflection and control force. Only partial state variables were assumed able to be measured and the measurement noises were taken into consideration. Design of the preview compensator that may be called stochastic optimal, output feedback, preview regulator problem with time-delay consideration was reduced to the classical linear quadratic Gaussian (LQG) control problem, by converting the state equations and the performance index into discrete forms and augmenting the state and output vectors. Simulation results demonstrated that time delay should be considered in the stochastic preview control of an active suspension system, especially when large time delay exited. If the suspension system with time delay was controlled by the optimal controller designed with no consideration of time delay, instability in responses might occur and the control effects possibly got worse with preview time increase.

Abstract:Taking the driving wheel force as input and driving wheel angular acceleration as output, the kinemics model of track vehicle was built and the whole vehicle was equaled to wheel inertia based on actual pavement condition and test platform structure. Transmission function of test bed was recognized. The strategy of speed track, combined with single side speed closed-loop and both sides loaded control, was proposed. Test results showed that there was no abrupt change in speed during shift and slope process. The change of output torque was accord with actual road situation. The proposed method was proved to be valid and precisions in vehicle test.

Abstract:A nonlinear mathematical model of the gas oil mixed hydro-pneumatic suspension used on mining dump trucks was presented. The gas dissolution effect, as well as the oil compressibility was taken into account in the model. The effects of gas dissolution and oil compressibility on the pressure changes within the hydro-pneumatic suspension were analyzed by solving the nonlinear mathematical equations. And the simulation results were compared with the experimental results. The results showed that the proposed model could describe the output force and pressure change of hydro-pneumatic suspension more accurately, and the effects of gas dissolution and oil compressibility couldn’t be ignored in hydro-pneumatic suspension research and design. Meanwhile, the effects were greater in compression stroke than expansion stroke. 

Abstract:Based on the analysis of kinematic model and dynamic model of vehicle with four Mecanum wheel, the fuzzy PID dual closed-loop control system was designed based on parameter distributor. The Mecanum wheels based electric chassis with the proposed system was analyzed and tested. The control system was proved to have a good response time and steady-state error precision, which satisfied the requirement of precise movement of electric chassis in tight space. 

Abstract:The braking test of the experimental vehicle was conducted, which could indirectly get the braking torque by measuring the bending moment of the braking arm. The braking torque coefficient was obtained by means of the system identification method. Firstly, the relationship between the strain voltage and the braking torque was calibrated. Secondly, the transfer function between the braking pressure and the braking torque was acquired by identifying the collected test data of the experimental vehicle. The experimental results showed that the relationship between the braking pressure and the braking torque of the front and rear wheels could be applied under the different conditions. The gain coefficients obtained from the hydraulic disk brake theoretical model and test model respectively were compared and found in good agreement. However, the test model had the first-order inertia so that it could more exactly express the relationship between the hydraulic pressure and the braking moment of the real vehicle.

Abstract:With the aim of improving the gearbox shift quality of tractor hydro-mechanical continuously variable transmission (CVT), the effects of factors on shift quality were investigated by bench test. Then, the orders of the above factors were obtained. The working test of tractor with full load was carried out. The research had theoretical significance and practical value in transmission shift quality and control methods of hydro-machinery CVT.

Abstract:The experiment results in 2009-2012 showed that the average yield in conservation tillage high yield and benefit system (CTHYBS) was 29% higher than that in traditional tillage without input increasing, which was more than the expected goal of 20%. It was preliminarily proved that conservation tillage (CT) could realize high yield and benefit under normal weather condition. In order to improve the yield and benefit of wheat, optimum planting mode (12 cm+28 cm narrow/wide row), sowing rate increasing(10%～20%) and furrow irrigation were adopted based on elementary technique system of CT, therefore, an high yield and benefit technique system was formed. The soil and moisture advantages in CT could be transferred to advantages of yield and benefit with CTHYBS. 

Abstract:In order to solve the serious problems of clay soil and large amount of rice stubble with strong toughness, a no-till wheat seeder with two-axel drive anti-blocking mechanism was designed to meet the requirements of no-till seeder. Based on the work principle of rotating parts, including milling, impacting, crushing and throwing, the seeder could accomplish stubble chopping, furrow opening, anti-blocking, active covering soil and compacting at one time with strip rotary tillage and crushing technology. The results of field seeding experiments showed that stubble cutting and furrowing could be well finished by strip rotary tillage. The collected soil was effectively chopped twice, so the soil could be well-covered. The variation coefficient of sowing depth and fertilizer depth were 4.33% and 2.73%, respectively. The passing ability of seeder satisfied the agronomic requirements. 

Abstract:In order to improve the working quality and reduce the consumption of the machine for straw returning, the structure and the working mechanism of the twin-roller cultivator for straw returning were discussed. Based on the soil bin test-bed, a laboratory test device was designed for the rotary tillage components. The result of the soil bin test verified that the twin-roller working model with well coverage performance and relatively lower consumption was feasible. The cultivator was developed and the filed test of maize straw returning was conducted. The result showed that the machine had a high working quality. The qualification rate of straw chopping, stubble breaking and vegetation coverage rate all reached up to 90%.

Abstract:A sowing leakage monitoring and marking system for sugarcane planter was designed. Light curtain sensor was used to monitor sowing leakage. When sowing leakage was detected, marking device marked the position of leakage in the field with lime stone powder. Experiments were conducted respectively on test bench in laboratory and on planter in field. The results showed that the regression coefficient R2 was 0.991 between monitoring system and manual measurement. In field experiments, the mean of the error (Qp) between marked point and the position real happed in the starting point of sowing leakage was -83 mm. The mean of that error (Zp) in the terminal point of sowing leakage was -63 mm. The standard deviation of Qp and Zp were 216.1mm and 155.6 mm, respectively. The sowing leakage position marked by system could be used for artificial reseeding.

Abstract:A kind of precision seeder for rice seedling-growing tray made of paddy-straw was developed. The key factors which had effect on seeder sowing accuracy were tested and optimized. The proposed seeder could sow 3～5 seeds in each holl and accomplish subsoil covering, seeds sowing, topsoil covering and other processes in one working time. The results showed that sowing uniformity was 98.2%, the ratio of cavity was 0.01%, single grain was 0, and seed production rate was 420 trays per hour, which met the requirements of rice seedling-growing tray made of paddy-straw seeding. 

Abstract:Aiming at the problem of nonlinearity, fuzziness, strong coupling and multi-objective of the pick-up mechanism of planetary gear train with ellipse gears and incomplete non-circular gear in optimization process, firstly, the kinematical model and optimization objective function were established. Using parameter-guided optimization method, the kinematical optimization software was developed with Visual Basic visualization platform. A set of parameters were obtained and optimized which could meet the work trajectory requirements of pick-up mechanism. Finally, the fetching test was carried on experimental prototype to verify the rationality and effectiveness of the parameters of pick-up mechanism.

Abstract:A type of direct nozzle injection sprayer was developed. By comparing with traditional spraying machines, the detailed structure and advantage of direct nozzle injection sprayer, especially to the injection unit, were analyzed. In order to dose pesticide precisely, a type of fast reaction valve based on electromagnetic principle was designed. The structure and control strategy were discussed in detail. The test of sprayer performance was carried out. The results showed that there existed a polynomial relationship between the water injection and the water pressure, and an exponential relationship between the pesticide injection and the opening time of PWM signal. The determination coefficients of both models were above 0.9. Besides, the uniformity of the six injection units within one boom section was tested and showed good performance.

Abstract:Taking the rotation speed of mobile fan as the initial value of simulation, grids within the computational regions inside the air duct were divided into sections based on the dynamic reference model. The structure of air-blast sprayer was optimized by using numerical experiments and orthogonal experiment. The flow speed at the outlet of air duct was simulated. In order to verify the correctness of model, flow speed at the outlet of air duct was measured at each corresponding fan rotation speed. The coverage rate statistics and χ2-test were carried out between measured and simulated value. The results indicated that the order of factors which affected the duct pressure loss and outlet flow speed was: the diameter of outlet, the cylindrical duct length and the tapered duct length. Meanwhile, at the sampling spot of air duct outlet, the measured flow speed in simulation was 95%. The simulated flow speed at the air duct outlet was submissive with the measured distribution when χ2-test result was under 0.05. It was reliable to simulate outlet flow speed of air duct by using dynamic reference model with fan rotation speed as initial value. 

Abstract:To explore relationships between uniformity coefficient and distribution coefficient, the fluidic sprinkler with circular outlet cover plate (OCP) was chosen as the object. Five different OCP diameters were designed. The sprinkler cannot rotate when the diameter was less than 5.0 mm or more than 7.0 mm. Experiments were carried out under the operating pressure of 200 kPa, 250 kPa and 300 kPa and the radial water distribution of 5.5 mm, 6.0 mm and 6.5 mm, respectively. Square layout and combination spacing with 7～15 m were chosen. CU and DU were calculated by using the method of interpolation. The results showed that for the circular OCP, more water was distributed near the sprinkler with the increasing operating pressure. The optimal OCP diameter was 6.0mm. Combination of CU and DU was slightly influenced by the operating pressure. As well as the increasing of the combination spacing, CU variation was stable firstly but sharply decreased later, and DU variation experienced three processes of becoming lower, becoming higher to attach the maximum value and becoming lower again for the reason of leakage spraying. The formula between CU and DU was put forward which was hoped to be a theoretical foundation for the project.

Abstract:In order to improve flexibility and operation efficiency of combine harvester, a pivot steering transmission was designed and tested. A clutch system with wet friction plate was used to transmit the positive and negative power Results showed that the exchange between forward rotation power and reverse rotation power was soft and reliable. Theoretical turning radius of combine harvester was zero. When steering at the same angle, the turning stroke and power consumption were reduced by 50% and 41.43% respectively, compared with traditional turning mechanism in one side brake. It could also reduce the damage to soil. The pivot steering transmission could reduce the idle stroke of field working and improve intelligence of combine harvester.

Abstract:An ellipsoid particle model was established according to the physical properties of rice grain. The discrete element method was used to simulate the impact process of a grain with a detection sensor. The results indicated that the peak normal contact force Fn max was increased with the increasing of curvature radius during the central impact process. Rotation of grain was driven during the eccentric impact process which reduced the value of Fn max. The differences of Fn max was enlarged with the increasing of grain radius ratio γ, and the minimal value of peak force ratio ηwas lower than 45% with γof 3. The asymmetric variation behavior of ηwas shown during the oblique impact process and the variation range of η was increased. The minimal value of peak force ratio ηwas about 30% with γof 3. The rise time of impact force tr was in the range of 14～26 μs. Then, a detection sensor using piezo-electric polyvinylidene fluoride (PVDF) film as sensitive material was presented and the rice grains impact tests were carried out. The results showed that the peak output voltage was fluctuated in 2～4 V, and the rise time of impact force tr was 15～35 μs. 

Abstract:Simulation study on random motion and mixing characteristic of soybean in a horizontal rotary drum was carried out based on discrete element method with EDEM. The effect of the rotation speed and load of the drum on particle random motion and mixing index was analyzed. It was found that the increasing of the rotation speed improved the random motion of particle, enhanced the mixing effect of particles, and speeded up the mixing process. Soybean load had the opposite effect. With the increasing of load, although the particle random motion was increased in the radial direction of the drum, the phenomenon of accumulation was more obvious and the random motion was significantly lower along the rotary drum axis direction. The mixing rate of particles was slow and the mixing effect became poor. 

Abstract:The issue on the theme of efficient utilization of water and fertilizer in dry-land agriculture was discussed. The mechanism of action of three typical chemical agents (soil conditioner—PAM, water retaining agent—SAP, antitranspirant—FA) in regulation of water and fertilizer and its application methods were introduced. Research of chemical regulating technology on four important parts were emphatically reviewed (enhancement of the accumulation of water and fertilizer, improvement of the soil and water conservation, improvement of the utilization of crop to water and fertilizer, increasing of the crop yield and quality) in dry-land agriculture production. Finally, the future important research directions were proposed.

Abstract:Five typical case areas at different ecologic and environmental conditions and social development degrees in Henan province were chosen respectively to conduct the correlative analysis between spatial distribution of water and soil resources. Diversity theory and methodology were used in analyzing the spatial distribution discreteness of surface water. The spatial distribution diversity index in 1 km×1 km grid scale of surface water and the soil constituent diversity index were calculated. The intrinsic relationships between them were finally explored. Results showed that the diversity theory and methodology had maneuverability and broad application prospects in the discreteness evaluation of water and soil distribution. There was a positive relationship between regional total area and spatial distribution discreteness of surface water, the correlation coefficient was about 0.70 at the broader case area scale and 0.45 at subarea smaller scale. There was a negative correlation trend between surface water spatial distribution diversity and soil family numbers, and this trend was enhanced with the increase of regional area or decrease of human disturbance. Water distribution has an important impact on the spatial constituent of the related soil families. 

Abstract:Using indoor experimental tanks, a simulated rainfall experiment was conducted to explore the effect of soil macropore on slope Br- loss. Results revealed that the total amount and average rate of Br- loss over slope land with soil macropore were less than those without soil macropore. A model of solute loss on slope was built based on fuzzy neural network. The characteristic scale of macropore, rainfall intensity, rainfall duration and adsorption coefficient of ions were used as input variables and the cumulative solute loss quantity on slope was output. Comparing with 160 sets of measured data, simulation results reflected real cumulative solute loss quantity on slope, which showed the established model was effective. 

Abstract:To explore the role of sand column in improving the saline soil, a series of experiments combining soil column simulation and field monitoring were carried out. The results indicated that the average water infiltration rate of the soil column reached to 0.132mm/min in three washing repeats with the help of sand columns, which was 1.73times higher than that of the soil column without sand columns. And the salinity decreased from 3.78% to 0.51% with sand columns, which was 1.45times higher than that of the soil column without sand columns. Moreover, the former’s pH value decreased by 0.12 compared with the latter’s after washing. Similar results could be found in the field contrast experiments. The increase in density of the sand column could enhance the desalination rate and the evenness of salt washing, and also inhibit the growing of pH value. The desalination rate reached to 83.9% and the vertical evenness difference was 3.9% with sand columns at an interval of 0.67m in field contrast experiments. But without sand columns, the desalinating rate was just 53.2% and the vertical evenness difference stood at 33.1%. The pH value decreased by 0.59 with the sand columns. To a certain degree, there was a correlation among the salt content, pH value and the water infiltration rate. The salinity went down with the increase of pH value and water infiltration rate. With all factors taken into consideration, the 0.67 m interval of sand column was the best. 

Abstract:Multi-nesting spatial variability and source analysis of statistical technology were applied to the typical plots which consist of brunisolic soil. By means of the sample testing results on five elements of heavy metals: Pb, Cd, Hg, Cu, Cr, with As element, which could reflect the levels of the soil pollution, aforementioned geo-statistical analysis process was done. Optimal model was selected by kriging interpolation method. And then, the reasonable sampling spacing was well determined. Combined with semivariance and fractal dimension analysis, the reasonable sampling scale was obtained. The method combined PCA with semivariance analysis together to trace to the source was adopted forward to guide agricultural management measures. The results indicated that the origin of farmland soil heavy metal composition was composed of three main source formations, which were soil parent material, precipitation and irrigation, and pesticide application. Medium scale jibed with semivariance model fitting. The value of range varied from 319m to 752m. The spherical model was thought more suitable to describe space distribution of soil heavy metal. 

Abstract:The experiments were conducted to investigate the effect of sandy soils amendment with fly ash and polyacrylamide (PAM) on corn growth. The experimental design factors included three fly ash application rates (weight percent of sandy soil was 0%, 5%, 10%, and 15%, respectively) and three PAM application rates (0, 60, and 120 mg/kg). Treatment added neither fly ash nor PAM was used as control treatment. The results indicated that fly ash and PAM could promote the growth of corn leaves and restrain the height of corn. The corn yield of the sandy soil amended with 5% fly ash was increased by 9% than that of the control. However, higher fly ash application rates (10% and 15%) led to a decrease in corn yield, maximum 21% compared with the control. The combination of fly ash and PAM could reduce the negative effect of fly ash at a high application rate on corn yield. There was no significant effect on germination when fly ash was applied at 5% rate in sandy soil. The utilization of fly ash at 10% or 15% rate could postpone and decrease germination rate, which could be improved by the addition of PAM. The application of PAM would add nitrogen content in the fly ash-amended soil. 

Abstract:The situ test in a grass field was conducted in three kinds of vegetation cover grass at three wind speeds, then the velocity profile and sediment discharge were obtained for different vegetation coverage of grassland by using mobile wind erosion wind tunnel device. The results showed that grass wind profile was exponent in generally and increased rapidly with the increase of height of surface elevation. There was a good fitting results for sediment discharge and height by using exponential function in the height of 0~70 cm for different vegetation coverage grasses, and the sediment discharge was mainly concentrated under the height of 30 cm of surface elevation. The barrier effect of near-surface wind speed was similar between 55% and 80% vegetation coverage of grassland under the height of 10 cm. The sediment discharge curve was very close between 55% and 80% grassland vegetation coverage, but the former was far from the sediment discharge curve of degraded grassland in 30% grassland vegetation coverage. Therefore, the minimum vegetation coverage was about 50% for preventing wind erosion effectively in the northern of Yinshan mountain. 

Abstract:Through experimental study on resistance loss of water delivery in pipeline system, the variation laws of resistance loss for clean and muddy water were researched respectively. In clean water experiment, the quantitative formula between resistance loss coefficient of clean water and Reynolds number was achieved. It could be used to calculate resistance loss of clean water. In muddy water experiment, the variation law of resistance loss with the difference of velocity and sediment content was focused on, which the resistance loss increased with the increasing of velocity. On the condition of small sediment content the resistance loss increased with the increasing of sediment content, while it decreased with the increasing of sediment content on the condition of large sediment content. The reason for producing this variation law of resistance loss was analyzed from turbulence prevention and drag reduction by sediment. Based on this analysis, the variation law of resistance loss coefficient for muddy water was researched, and the calculation formula between the resistance loss coefficient and the dimensionless comprehensive factor was developed. Comparison between the experimental results and standard Durand and Chen Guangwen calculation model showed that there was large difference between them, and the existing models couldnt applied to calculate the resistance loss of muddy water. According to the results of experiment, the quantitative formula, between resistance loss and the product of the flow Froude number and sediment concentration, and the Froude number of sediment deposition was developed. Result showed that the correlation coefficient R was 0.90. 

Abstract:The current research progress of biological hydrogen production technology with photosynthetic bacteria was presented. The main factors that influenced the development of hydrogen production technology with photosynthetic bacterial were discussed. The improving hydrogen production efficiency with biological and engineering technology were analyzed. The obstacles and problems of the biological hydrogen production technology with photosynthetic bacteria were indicated. The development trends of hydrogen production with photosynthetic bacteria were also previewed. 

Abstract:The scheme of biomass microwave pyrolysis reactor system, gas chromatography and mass spectrometry analysis instrument, temperature adsorption analyzer, and other analysis equipment were used to study the influence of cotton stalks with NaCl, K2CO3 and MgCl2 on microwave pyrolysis characteristics. The results showed that three kinds of metal salt additives made the yield of liquid product decrease and the yield of solid product increase. The introduction of additives can simplify the bio-oil components and improve the quality effect of bio-oil obviously. Phenolic compounds were significantly lower in the product and the peak area percentage of acetic acid increased to 37.57% from 11.87%, while the surface pore structure of solid coke was also significantly improved.

Abstract:In order to improve the reliability of the whole circulation process about pork product, GO methodology was applied in the reliability research. First, the structure model of the whole circulation process about pork product was built up, and the influencing factors of each step, including pig-breeding, slaughter-process, storage-transportation and sales, were diagnosed. Secondly, with the GO methodology the whole circulation process about pork product was transformed into the GO chart, and then the failure probability of influencing factors were determined by the method of frequency statistics and fuzzy analytic hierarchy process and the process reliability was calculated in detail. Finally, reliability of the whole circulation process about pork product was analyzed qualitatively and the importance degree of minimal cut sets was calculated so that the main factors influenced the reliability of whole circulation process about pork product were determined. The quantative and qualitative methods were compared and the result showed that the GO method had effectiveness and superior performance in research on reliability of the whole circulation process about pork product. 

Abstract:In order to improve and enhance the cooling performance of the refrigerated trucks, a mathematical model of cooling process was established in a refrigerated compartment based on dynamic thermal equilibrium theory, by considering heat transfer of the external sol-air temperature through the compartment structure, air and water vapor leakage, and respiratory heat of goods within the refrigerated compartment. The correctness of mathematical model was proved by test. The test results showed that the air temperature decreased exponentially with time during the cooling process of air in refrigerated compartment. The cooling time increased when the thickness of compartment insulation material or cooling capacity of refrigeration system was reduced, or the thermal conductivity of compartment insulation material, solar radiation absorption coefficient of the compartment external surface, vehicle speed, leakage ratio of the compartment, respiratory heat of goods were increased. On the contrary, cooling time would decrease. The thermal conductivity of compartment insulation material, cooling capacity of refrigeration system, and respiratory heat of goods were thought to be the most influential factors. Besides, when the thermal conductivity increased 0.001 W/(m·K), the thickness of compartment insulation material would be required to increase 5 mm on the insulation capacity. The cooling time kept basically unchanged when vehicle speed in the range of 0~40km/h. However, the cooling time would be significantly extended along with the vehicle speed increase in the range of 40~80 km/h. The cooling time was not influenced by the air velocity within refrigerated compartment. 

Abstract:Research was conducted to design an electronic tongue based on MCU and ion-selective electrodes, software based on machine learning technology. Ion-selective electrodes were used to compose a sensors-array. MCU and A/D chip were used to compose data acquisition system. In Matlab environment, principal component analysis (PCA), back propagation neural network (BPNN), probability neural network (PNN) and support vector machine (SVM) were used to achieve pattern recognition of four kinds of drinking water and five kinds of ciders. The results showed that this electronic tongue system displayed great application potential in drinking waters and ciders analysis and also had good expansibility.

Abstract:A beef image on-line acquisition system based on TMS320DM642 was developed according to the technological requirements of beef automatic grading. The rib-eye beef images were collected online by using the developed system. Then a mask was constructed for background segmentation of each acquired image. As DM642 adopted three chrominance components of YCbCr model to display and save images respectively, in order to reduce calculating time, only Cr chrominance component of beef image was considered in the following image processing. After the Cr chrominance component of beef images were binarized, region labeling algorithms and small regions removing method were employed to extract the effective rib-eye region. Experiments showed that the proposed DM642 system could be used for beef image acquisition online and rib-eye region segmentation. The average extraction accuracy of effective rib-eye region was 92.9%.

Abstract:Taking the complex influences of two-phase flow, heat transfer, mass transfer, and cracking reactions into account, a 3-D gas-solid two-phase flow-reaction CFD model for vortex reactor was established based on gas-solid two-phase turbulent flow model and kinetics of reactions. Related numerical solution was formed and numerical simulation was carried out to show the details of flow, heat transfer, mass transfer and reactions in the vortex reactors.

Abstract:Plasma seed processing technology was carried on green onion seeds for less than 20 s. The effect of the proposed technology on seed germination and seedling growth was analyzed. Different low-temperature plasma technologies were used on green onion seeds. The results showed that both germination potential and germination rate had obvious change after different low-temperature plasma process. The germination experiment was carried out after 20 d since low-temperature plasma process completing. When the treatment intensity was 240 W, the germination potential and germination rate increased by 10.6% and 5.2%, respectively, compared with the contrast. The germination experiment was also carried out after 4 d since low-temperature plasma process completing. The germination potential and germination rate also changed obviously.

Abstract:In order to improve the performance of rice seed germination, cold plasma processer with the medium of air and helium (He) in vacuum environment was used respectively to process three kinds of rice seed, Zheyou023, Xiushui134, and Zheyou6326. The powers used in processing were 60W, 70W, 80W, 90W and 100W. The germination test was conducted after cold plasma treatment. It turned out that the cold plasma treatment had obvious promoting effects to rice seed germination when the power was 60W to 100W. Compared with the untreated group, germination vigor of the above three experimental groups increased by 1.75% to 13.5% with the air and helium (He) processing medium, while the percentage germination increased by 1.0% to 8.75%. The best treatment power of Zheyou023, Xiushui134, Zheyou6326 were 90W, 100W, 80W in air processing medium, respectively. And when it came to helium (He) medium, Xiushui134, Zheyou6326 were better to be processed at 60W. Zheyou023, however, was not suitable to treat in helium (He) condition. 

Abstract:Parts of 20090716 and 20090730 HJ-1 CCD multi-spectral images were cut as the experimental areas. The thick cloud, thin cloud and cloud shadow were detected based on object-oriented method. And then, the substitution method was used to remove the cloud and cloud shadow. The comparison of pixel gray mean, maximum, standard deviation and entropy of original image and restored image indicated that the restored image accorded with the ground truth. The object-oriented and substitution could be an important method in the cloud detection and removal of HJ-1 CCD multi-spectral image.

Abstract:Since the obstacle detection methods based on color and height information could only detect some of all obstacles in farmland, a detection method based on frequency was proposed. The wavelet multi-resolution decomposition was developed to find the frequency layer of crops and it was observed that the total frequency of crops was more dominant than others and the distribution of crops row were considered. Then the positions and horizontal dimension of possible obstacles crossed the crop rows in the image were detected based on frequency distribution of the selection layer. The others could be detected in the highest frequency layer due to the lower frequency of this kind of obstacles. Then the stereo rectification and the prior frequency knowledge of obstacles were adopted to confirm if the detection was obstacle. The experiment showed that the proposed method could detect the mound, the edge of farmland and other obstacles effectively. The average time of processing each frame was 79ms.

Abstract:For the problems of poor real-time of rice planthopper recognition and a certain error of BP neural network classifier, a rice planthopper recognition system was designed based on DSP hardware system and genetic algorithm optimized BP neural network. AT89S52 microcontroller was used to control the mobile device. DM6437 was used as processing platform. Mathematical morphology algorithm, improved Hu moment, and genetic algorithm optimized BP neural network algorithm were used for segmentation. The video camera was used to shoot crop video. Then, the video signal images were transformed to the DSP recognition system. The rice planthopper could be identified from these images. The experiment was carried out on 80 samples, including rice planthopper, ephydrid and miner. Results showed that the accuracy of genetic algorithm optimized BP neural network reached to 90%.

Abstract:It is difficult to detect plant leaf edge in green house environment because of noise and incompletion. For this problem, an edge detection based on fuzzy logic was proposed. Firstly, according to the statistics characteristic of neighbor pixels and color difference between plant and soil, membership function of noise and edge was defined by using linear function. Secondly, fuzzy rules were deduced by using Sugeno fuzzy model, so as to decrease the rule amounts. Then, with the results of fuzzy reasoning, fuzzy filter and fuzzy edge detection were performed. The experiment results indicated that the proposed method could overcome the problem of large amounts of false edges which caused by color difference between leaves and backgrounds in conventional algorithms. The proposed algorithm could detect edges in noisy environment effectively and could be used for the plant leaf edge detection in greenhouse monitoring. 

Abstract:A machine vision based plug tray localization and detection system for automatic transplanting robot was proposed. This system could not only get the plug tray’s position on the conveyor belt, but also obtain the depth and the 3-D shape of the substrate inside each cave. Based on the registration of the color image and depth image, the contour of the plug tray was detected from the color image. Combined with the plug tray’s dimension, each cave was segmented from the depth image and the 3-D point cloud was generated. With K-nearest-neighbor (KNN) algorithm and principle component analysis (PCA) algorithm, the normal vector for each point was calculated. Based on the normal vector, the cave’s side wall was segmented from the substrate and the depth of the substrate was computed. The experiment result showed that this system could effectively localize and detect the plug tray with a localization error of 3.5 mm and a depth detection error of 4.9 mm which met the control requirement of the automatic transplanting robot for grafting seedlings. 

Abstract:Two low power consumption mechanism, named active transmission of node dynamical package and weighted control transmission of environmental variables, were proposed. A large number of duplicate and redundant data in transmission was reduced. The facilities flower environmental monitoring and its low-power transmission system based on Zigbee was achieved. The multivariable fuzzy control method in facilities flower environment was proposed, which solved the coupling problem in environmental variables and helped greenhouse to reach the comfortable environment of flowers rapidly and keep balance. CC2430 chip was used as the core of the node. SHT10 temperature and humidity sensor, BH1750FVI light sensor, and COZIR carbon dioxide sensor were also used in accordance with the environmental parameters which would affect the growth of flowers, so the nodes could collect and transmit a variety of environmental parameters at the same time, which reduced the cost of hardware. Networking test was carried out in Nanjing Agricultural University. Test results showed that the proposed system reduced energy consumption by 85.97% compared with traditional cycle node (cycle was 1 min), and measurement accuracy was more than 98.5%. The average loss rate of network packet was 0.84%. 

Abstract:A wing temperature dynamic monitoring equipment for hens was designed for monitoring hens body temperature and avoiding direct contact with animals. The system was composed of DS18B20 temperature sensor, ATmega 16 MCU and nRF2401 wireless transmission module. The system programmed with C# language could achieve real-time acquisition, storage, display and inquiry of hen’s temperature data. Results showed that errors of the proposed device was 0.1%, the maximum transfer distance was 100 m, the transfer distance of sensor node on the hens was 50 m, and the loss rate of network passage was 0.89%. The power consumption was decreased with different collecting frequencies and sleep mode. The proposed device could meet the measuring requirement. 

Abstract:The tolerance distribution model of quality control points oriented to assembly accuracy was established to characterize the nonlinear coupling relationship among the different kinds of quality control points and reveal accumulation law of assembly error. The chaos theory and two-stage variation strategy were adopted to improve multiple objective particle swarm optimization (MOPSO). Before the assembly process, the initial distribution results of quality control points were calculated. The redistribution mechanism was implemented when upstream quality control points were instantiated. Then the tolerance of downstream quality control points would be redistributed to provide decision support for the instantiation of subsequent quality control points. The online optimization and former feed-forward control of assembly quality were achieved. The online optimization of gasket-selection and tighten lock nut in the active gear axle assembly process was given to verify the feasibility and effectiveness of the proposed method.

Abstract:A calibration method was presented by off-line parameters identification in order to enhance the position measuring accuracy of the Delta mechanism. Based on structure and kinematic model of mechanism, the error sources influenced accuracy of operation end were analyzed. A forward kinematic model contained errors sources was built. By analyzing the effect of error sources on position error of operation end, twelve assembling errors that made more effect on position of operation end were presented and solved, and the forward kinematic model was calibrated. The experiment results showed that the calibrated Delta mechanism improved the measurement accuracy of position.

Abstract:Taking 6-DOF motion as research objective, a motion recording method based on the multi-sensor information fusion was proposed. According to the accelerations getting from the acceleration module, the angular information of the motion was calculated by using a decoupling method. It can obtain the displacement information of 6-DOF motion by correcting the image matrix with angle information and recalculating image translation. Experimental results demonstrated that this motion recording method was feasible.

Abstract:Two kinds of bivariate basis functions with two shape parameters over the triangular domain were presented. The corresponding triangular surfaces inherited the most properties of classical triangular Bézier surface, and adjusted the shape by changing the value of shape parameters with the fixed control points. When the shape parameters were equal to some specified values, the new triangular surfaces degenerated to the triangular Bézier surface. The obvious geometric significance of shape parameters made it easier for the designer to adjust the shape of new surfaces, even if when the boundaries of triangular surfaces were fixed. The numerical examples indicated that the new surfaces were valid and easy for operation. 

Abstract:A flexible acceleration and deceleration control algorithm of the servo motor was proposed, in which the two trigonometric functions of different cycles were used to construct the acceleration and deceleration function. This algorithm could better match with the servo motor’s characteristics, and reduce the requirement of servo motor power. The calculation formulas of displacement, velocity, acceleration and jerk of the servo motor were derived. The performance of this algorithm was compared with the trigonometric function acceleration and deceleration control algorithm. The experimental results showed that this algorithm could be applied to plan the drawing profiles for the servo press. 

Abstract:To solve the camshaft’s deformation compressed by the continuous and variable force when grinding, the influence of grinding force on the cams curve accuracy was analyzed. The axial deformation and radial deformation were decoupled. The deformation value solution equation in variable position and angle was deduced. The interpolation principle of the CNC (computer numerical control) camshaft grinder was analyzed. The X-C linkage kinematics equation which included deformation errors, workpiece rotation axis, and grinding wheel axis was built. The soft error compensation manner by adding the errors to the interpolation value was proposed. The deformation error of one intake-exhaust camshaft was modeled and simulated. The CNC camshaft grinder was compensated and the manufacturing test was executed. The simulation and manufacturing result showed that camshafts contours accuracy was improved 5μm by the deformation compensation.

Abstract:To reduce the pressure mutation in transition zone of high-pressure gear pump, a parametric design method for floating lateral plate damping structure was proposed by studying the relation between the transition zone pressure variation and the damping structure of floating lateral plate. Taking the model of high-pressure external gear pump CBAk as an example, the transition zone flow field of it was analyzed. With the method of response surface methodology (RSM), an approximated pressure variation model of the transition zone of CBAk was established. With the guarantee of volume efficiency of gear pump, an optimal design to the damping structure of high-pressure tank on the floating lateral plates was put forward with an optimization goal focusing on the minimum pressure variation. Results showed that the pressure mutation of transition zone was reduced from 10.162 MPa to 3.670 MPa.

Abstract:Based on the modified MB fractal model and mechanism of contact normal damping dissipating energy, a fractal model of normal damping of joint interfaces was proposed. Furthermore, numerical simulation revealed that the micro concave nonlinear relation of normal damping versus dimensionless total normal load was very evident, which decreased with increasing fractal dimension and normal total load, and increased with increasing fractal scale parameter in the smaller fractal dimension. Besides, the micro convex nonlinear relation of normal damping versus dimensionless total normal load was also very evident, which increased with increasing fractal dimension and normal total load, and decreased with increasing fractal scale parameter in the larger fractal dimension. But the micro concave nonlinear relation of normal dissipation factor versus dimensionless total normal load was very evident, which decreased with increasing normal total load, and increased with increasing fractal scale parameter and fractal dimension. 

Abstract:研究了由微粗糙表面与光滑平面形成的混合接触承载性能。混合接触由固体-边界膜-固体三体接触和固体-流体-固体三体接触组成。两表面相对滑动时表面间形成许多个微阶梯轴承。这些微阶梯轴承的承载量之和构成两接触表面承载量。微阶梯轴承的入口区为传统流体区域，出口区为边界膜区域。给出了微阶梯轴承承载能力分析方法，研究了边界膜对混合接触承载能力和接触性能的影响。