Abstract:Based on self designed burner-type system diesel particulate filter (DPF), the temperature of both gas in burner mixed with combusted combustion gas by several fuel-air matching forms and diesel exhaust gas was experimentally studied. The pyrogenation regeneration model for a channel of DPF was used to obtain the regeneration computational result, which is verified to match with experimental results well. Further, according to simulation results, the problem of fuel-air matching forms on idle condition was analyzed in regeneration performance requirements, such as wall maximum temperature, temperature gradient, regeneration time and so on, to achieve the reasonable matching for burner-type DPF.

Abstract:Aimed at the starting condition of light hybrid diesel engine with ISG technology in normal temperature, the working models of diesel engine and ISG electromotor were established. Then, the diesel engine moment of resistance on the starting condition was calculated to obtain the torque and the power from the ISG electrical machinery. And, the simulation to the starting process was carried out. Finally, the test of the ISG electromotor dragging diesel engine under the different voltage was performed to confirm the simulation result. The results showed that with the ISG technology, the diesel engine can be dragged to meet the requirement speed on the battery voltage of 36～60V. The average starting torque of ISG motor is 87.4N?m, the line current of each start winding is 30～150A. and the output power of ISG fall after the first increase with the peak power of 4.98kW. The simulated starting time from 0 to fire is 0.4s, compared with the test result of 0.5s; while time from 0 to stable idling in the simulation is only 2.8s, the test result is 3.1s. So, the test result is tallied with the simulation.

Abstract:This paper presented the feasibility of improving engine performance and pollutant emissions of a ZS195 diesel engine by EGR and intake hydrogen enrichment. At rated speed, the effects of EGR rate and hydrogen addition on the engine performance, pollutant emissions and economic characteristics were experimentally investigated. The results showed that when EGR rate is constant, peak pressure and maximum rate of pressure rise increase with hydrogen addition. The EGR and intake hydrogen enrichment can reduce HC, CO and smoke level, but the NOx emission increases. The combustion speed and thermal efficiency increase with the hydrogen addition when EGR technique is adopted.

Abstract:For a direct-injection spark-ignition (DISI) methanol engine retrofitted from a four-cylinder diesel engine, fuel is injected into the cylinder during the intake stroke to realize the homogeneous charge combustion for the high power output. The cylinder pressure of typical operating conditions was measured and analyzed. The effects of different parameters on methanol engine combustion characteristics were investigated. The results showed that the maximum power output and torque of the methanol engine are 5.88% and 20.90% higher than original diesel engine, respectively. The maximum brake thermal efficiency reaches 35.3% at a speed of 1500r/min, and a brake mean effective pressure of 0.85MPa, which is higher than the conventional gasoline engine. The ignition delay period and rapid combustion phase increase with decreasing load. The start of combustion is postponed with increasing speed at full load. The ignition delay period and rapid combustion phase increase with increasing speed under full load. The change of the cyclic variations has the approximate trend with that of the ignition delay period at different operating conditions.

Abstract:A nine-zone model accounting for both mass exchange and heat loss was developed by modifying the SENKIN program. Combining with the SKLE simplified chemical kinetics model of n-heptane, the model was used to simulate the combustion and emissions of homogeneous charge compression ignition (HCCI) engine with charge-temperature stratification. The results showed that the simulation is able to reproduce the major combustion and emission characteristics of the experiments very well. In HCCI engine with charge-temperature stratification, the outer core zone, the boundary zone and the crevice zone are the source of CO and HC emissions. The CO and HC emissions in the outer core zone result from the partial-oxidation and unburned fuels which flow into the outer core zone from both the boundary zone and the crevice zone at the expand stroke. Most of NOx emissions are produced in the inner core zones with higher temperature compared to the other zones. High efficiency combustion and extra low emissions are achieved simultaneously by increasing the wall temperature properly in HCCI engine with charge-temperature stratification.

Abstract:Fluid-solid coupling numerical simulation on the flow and heat transfer of cooling water-jacket in cylinder head for 226B diesel engine was performed using the commercial CFD software STARCD and the FEA software ABAQUS. In order to consider the influence of boiling heat transfer, a boiling heat transfer model was developed based on FORTRAN and built into STAR-CD. Comparison between simulation and experiment showed that the two results are in good agreement with each other. Comparing with the results of simulation without the boiling heat transfer model, maximum deviation drops from 18% to 7%. So the simulation provides a more dependable theoretical evidence for diesel water-jacket optimization.

Abstract:This paper studied the influencing mechanism on combustion noise in DT-diesel engines for turbocharged conditions. By measuring parameters of influencing combustion noise between natural aspirated and turbocharged diesel engine in constant torque and increasing speed transient and steady conditions, the change law of combustion noise in diesel engines was clarified. The testing result was thoroughly analyzed from the point of the combustion chamber’s wall temperature, aerodynamic load and high-frequency oscillation of combustion pressure. The result showed that the combustion noise of DI-diesel with turbocharger is reduced, and the reduction under turbocharged condition in steady condition is more obvious than that in constant torque and increasing speed transient condition, the effect of turbocharged condition on combustion noise is better in intermediate speed and middle load.

Abstract:As sandy fixation materials to protect building residue soil (BRS) from wind erosion，liquefied corn stover (LCS) and polyurethane based on LCS were investigated by a wind tunnel. The results indicated that various particles on the soil surface are connected by LCS or polyurethane to form a protective crust which increases the soil resistance to wind erosion. At a low spraying amount of LCS, with an increase of wind speed, the protective action of LCS to the BRS disappears gradually due to low mechanical strength of LCS crust, and wind erosion ratio widely increases. Compared with LCS, the polyurethane is a more effective sandy fixation material. The threshold wind velocity of BRS is morn than 20m/s at a polyurethane spraying amount of 120.37g/m2; at a same protective action, the amounts of polyurethane used is a half of LCS’s. Moreover, at a high wind speed, the protective action of polyurethane is still good due to a more mechanical strength of polyurethane crust.

Abstract:An oriented system for no-tillage planters, which consists of guiding frame, hydraulic system and control unit was designed according to the problem of no-tillage planting quality resulted from the unefficient maize row-following capacity of no-tillage planter in annual double cropping areas. The main parameters of guiding frame determine on the matched tractor. Furthermore, the force analyses in different positions of the outside frame of guiding frame indicates that the guiding system can meet the requirements of the maximum load for adjusting planter direction in the planting. By employing JDT654L tractor as a test platform, the system performance analysis was conducted, and the results showed that the adjusting range of actuator is -10.8°～10.7°. Moreover, the outcomes also indicated that the system is capable of commutating steadily and rapidly, and performs a fair response capability and satisfactory control accuracy to input signals, with maximum error angle of no more than 1.5°, which assures that the implements direction could be timely corrected.

Abstract:16.5%。Traditional straw return implements slowly after the operation, and delays farming time, as well as, the straw burning causes environmental pollution. In light of the above problems, a fast decomposition straw returning machine which adopts the returning principle of combining decomposition agent spraying with mechanical straw shattering was designed. Field experiments show that straw decomposition rate of farmland when using this machine reaches 97.2% after 7 months, which is 17.1% higher than a single mechanical grinding treatment, and average wheat production is 16.5% higher than mechanical crushing method in the same area.

Abstract:In order to realize the high-speed work of liquid fertilizer applicator, the elliptic gear planetary galaxy as the pricking hole mechanism was designed, which presented the simple structure and steady movement. Then, the mathematical model for this mechanism was established. By Visual Basic 6.0 program, taken the distance between hole 200mm and buried depth 120～150mm as the optimization goal, the most optimum parameters range of the mechanism was obtained as follows: the initial angle between planet frame and the line formed from spraying-fertilizer needle-tip and planet wheel axle was -45°～-40°, the initial angular displacement of planet frame was 40°～50°, the distance between spraying-fertilizer needle-tip and the planetary gear axle center was 280～300mm, simultaneously, the semi-major axis of elliptic gear was 29.364mm, the teeth quantity was 23, the ratio of semi-minor axes and semi-major axis was 0.958, the radius of circular gear was 25mm. Among the optimization operational parameters, a group of parameters were selected to design the pricking hole mechanism by using Pro/E simulation. The simulation result shows that the designed pricking hole mechanism can satisfy the design requirements of the distance between holes and the buried depth.

Abstract:An intra-row mechanical weeding device was designed. The device is one part of intelligent weeding machine. It has eight hoes that could turn in or turn out of intra-row area in the intelligent control system to eliminate the intra-row weeds. A 3-D parametric model of intra-row mechanical weeding device was built up with Pro/E, and was input ADAMS. The device was simulated on kinematics by ADAMS to get the track of each hoe. By analyzing the tracks, the area for each hoe with the superposition of adjacent hoe were figure out. Based on analysis result, the optimal proportion of rotation speed and forward speed was obtained (λ=0.754). Simulation proved that the device could satisfy the need of intra-row weeding.

Abstract:With the aim to study the point of run-off and the maximum retention of spray liquid on cucumber leaves in greenhouse, the spraying experiment was performed with various charged voltage and spray volume. Taking the barbette model pressure atomization axial-flow air-carried high-voltage electrostatic spraying system as the experiment platform, the retention volume on cucumber leaves surface was measured by micro-weighing method. The factors on the retention volume were analyzed based on basic theory of Young’s equation, including spray distance, droplet contact angle and spray volume. The results show that with the increasing distance, point of run-off and maximum retention rises firstly and then declines; the contact angle θ, adhesion force β, adhesion work Wa, critical surface tension γ0 is 85.07°, 6.17mN/m, 77.97mJ/m2, 61.23mN/m, respectively; the retention volume reaches the peak in spray volume range from 1.26kL/hm2to 3.36kL/hm2, and then reduces and gradually stabilizes with the increasing spray volume.

Abstract:A new method for spatial analysis of droplet deposition was presented, by which the parameters of spraying deposition in greenhouse were analyzed, including droplets equivalent diameter, spraying coverage and droplets density. The experimental results showed that the droplets equivalent diameter and spraying coverage is larger in both sides than central axis of the greenhouse, while droplets density is opposite. The peak value of droplets equivalent diameter and spraying coverage respectively appears in both sides of the greenhouse 25m away from entrance, and three peak values of droplets density occur in central axis of the greenhouse with the distance of 13, 35 and 52m from entrance, respectively. The results also indicated that the method of spatial analysis can more objectively reflect the droplets deposition distribution in greenhouse by contrast to simple curve analysis.

Abstract:To enlarge the scope of working pressure for complete fluidic sprinkler, turning angle was applied in the effuser, which can increase intrinsic driving moment. The important geometrical parameters for the turning angle effuser included angle and arm of force. The equations of total driving moment and stepping angle were deduced. Experiments were carried out on seven types of effusers with different turning angles or arms of force. The results showed that testing value agrees well with the theoretical analyzing. Working pressure, with a small infection on stepping angle, positively influences wetted diameter, uniformity coefficient and stepping frequency. Turning angle positively influences stepping angle and uniformity coefficient, and negatively influenced stepping frequency. Turning arm of force positively influenced stepping angle, negatively influenced wetted diameter.

Abstract:A kind of sugarcane segmentation combine on the basis of assimilation and absorption of imported advanced sugarcane harvester technology was designed. The machine could finish the processes of separating sugarcanes in different rows, cutting cane at bottom, conveying sugarcane, cutting sugarcane into segments, eliminating trash by air classification, and gathering sugarcane segments in a bag in one pass. The designs on main devices of these processes were introduced. Field tests were done to measure the main performance indexes of a prototype. The results were that total loss factor was 2.25%, broken biennial root rate was 11.3%, dirt percentage was 7.75%, segments percent of pass 94.55%, and cutting-height percent of pass 94.3%. The results showed that this prototype could smoothly work in the field where serious lodging sugarcane existed, and all main parameters reached their design requirements. The development of this sugarcane harvester provides a kind of practical sugarcane combine.

Abstract:2.79％。In order to improve the operation performance of 4HLB-2 peanut combine harvester, the impact factors including soil moisture content, harvest time, stalk clamping height, clapping frequency and amplitude of clod removing unit, rotate speed of peanut picking roller and clamping chain speed were investigated by single or double factorial experiments. The results show that soil moisture content ranging from 8% to 15% is suitable for peanut harvesting in sandy loam soil. Dropped peanut loss during clod removing increases gradually along with the delaying of harvest time. The dropped peanut loss rate is higher than 2% under the snap force of peanut root below 5N. The optimum stalk clamping height is in the range from 150mm to 200mm, keeping total loss rate and clod content less than 6% and 4%, respectively. Lower frequency and smaller amplitude of clod clapping operation contributes to smaller dropped peanut loss rate, but higher clod content, whereas, higher frequency and larger amplitude contributed to lower clod content and higher dropped peanut loss rate. The peanut loss of peanut picking operation is kept at lower level with higher picking roller speed and lower clamping chain speed. In this experiment, loss rate of peanut picking is 2.79% at 390r/min of picking roller speed and 0.5m/s of clamping chain speed.

Abstract:Four kinds of leguminous and gramineous forage stems in harvesting period were chosen to perform tensile experiments by the electronic testing machine CMT2502. The cellulose, lignin and protein content of forage stems in different conditions were tested. The microstructure was observed. The SEM images of transverse section were got by scanning electron microscopy. The results indicated that, the stress-strain curve of bottom stems obeyed Hooke’s law; the tensile strength of Bromus inermis was higher than Coronilla varia, but the elastic was smaller; the tensile strength and cellulose contents of Coronilla varia were smallest (13.87%) in the four species. A forage stem is a natural anisotropic polymeric composite. The strength and stiffness of forage stems depends on the content, linking and sequence of cellulose and lignin, together with the thickness of thick-walled cells, the numbers of vascular bundles and the connection and strength of cells in stems.

Abstract:The methods for interface technology of agricultural equipment model on virtual reality were researched. Several typical methods of the modeling technology were compared and discussed. The model transformation was achieved from UG to Creator through the secondary development based on UG and Creator. Meanwhile, in the process of transformation, the model was simplified or refined through the various control parameters. Finally the agricultural equipment model on virtual reality was built.

Abstract:Fuzzy mathematics, reliability theory and multi-objective optimization technology were applied to design tractor’s final transmission with external single-stage spur gear based on comprehensive consideration on its loading capacity, structure, tooth face wear and transmission efficiency. The mathematical model for the multi-objective reliability optimization design was set up under the objective of the minimal volume and gears’ maximal sliding coefficients, and the maximal efficiency of the mechanism, with the design variable of module, teeth number of the pinion, teeth width and meshing angle. Then, the fuzzy solution of multi-objective optimization and genetic algorithm were used to solve this model. On the premise of ensuring the maximal sliding coefficient below the allowable value, the final transmission’s volume reduces by 1.55% and 6.74% of the common reliability optimization and original design scheme respectively, and the efficiency improves.

Abstract:20mg/m3以下。A novel and efficient low-tar gasification technology was put forward based on the mechanics of tar generation and pyrolysis. This technology contains such two separate sub-process as pyrolysis occurring between 350℃ and 500℃, and gasification reacting in the high temperature condition about 1000℃. The high-temperature gasification ensures the tar pyrolyze into small molecule non-condensable gases with the equivalence ratio of gasification agent about 0.3. As a result, the quality of biogas is highly improved and the mass concentration of original tar in the biogas is significantly reduced below 20 mg/m3.

Abstract:COD去除率为91.6%，最高的TS去除率为32.7%。 Under high temperature condition, the effects of inoculation rates and moisture contents on anaerobic digestion of air-dried food waste were studied. The results showed that air-dried food waste could effectively alleviate the acidosis at the initial acidification phase. The interaction of inoculation rates and moisture contents makes an impact on the methane production. High inoculation rate and low moisture content is advantage to anaerobic digestion of air-dried food waste which gives the system a higher buffer capacity. When the inoculation rate is 55% and the moisture content is 92%, the process of anaerobic digestion operates normally with the methane production rate of 0.246L/g. The highest methane production rate reaches to 0.471L/g at 75% inoculation rate and 88% moisture content. The removal rates of COD and TS increase with inoculation rate, and the highest is 91.6% and 32.7%, respectively.

Abstract:The effects of oxygen concentration on storage quality of Agaricus bisporus were studied at 3℃ and 95% relative humidity under controlled atmosphere storage. The results show that 5% oxygen concentration inhibits the respiration and postpones the arrival of respiratory climacteric of mushroom. Weight losing rate, browning degree and firmness of Agaricus bisporus all decreases with the reduction of oxygen concentration. The soluble solid of mushroom is maintained and the ripening is delayed with the low oxygen concentration.

Abstract:In order to investigate the effect of irradiation on the sprout inhibition and the relationship between endogenous hormones and germination of embryo for fresh walnut, the germination rate and changes of endogenous hormones of embryo for ‘Liaohe4’ fresh walnut were studied, which were exposed to 60Coγ-radiation at different dose and stored at the room temperature (20±3)℃ and at the constant temperature (27±1)℃ after being stored at (0±1)℃ for 30d. The results showed, at the two storage conditions, the control sprouts at the 20d and 12d respectively, accompanied by ABA content decreased, by the increase of the content of GA3, IAA, ZR and the ratio of w(GA3)/w(ABA), w(IAA)/w(ABA) and w(ZR)/w(ABA), with the largest decreasing and increasing rate against control group. It is proved that endogenous hormone ABA is an inhibitory substance, and GA3, IAA, ZR are simulative material during the process of germination, the germination of embryo of fresh walnut is completely inhibited with the radiation dose of 0.05kGy.

Abstract:8%。 The temperature and humidity monitoring and controlling system in a tunnel-type dryer was developed, based on supervisory control and data acquisition (SCADA) systems, industrial personal computer (IPC) and programmable logic controller (PLC). The customized IPC software of monitoring and controlling system monitors real-time temperature and humidity through the communication between IPC and PLC. The software functions realized drying processing parameters inputting, real-time data acquisition and displaying, dynamic and historical data curves, database inquiry and report forms printout. The accuracy of temperature and humidity controlling meets with the requirement of the drying room, with the maximum track error as 2℃ for temperature and 8% for relative humidity.

Abstract:It is of great significance for optimal controlling the freeze-drying process to determine the end of sublimation drying and desorption. The drying dynamical characteristics test for Fuji apple were carried out using the JDG-0.2 type vacuum freeze-drying machine. Based on the homemade real-time online measurement system, the moisture content of apple blocks was measured, and the changing curve was drawn during the freeze-drying process. According to the measured data, the freeze-drying dynamical characteristics were analyzed, the judgment method for the end of sublimation drying and desorption was proposed. It provides the means for optimal controlling parameters during the freeze-drying process.

Abstract:By using the 500N microcomputer control material testing machine, based on the load-depth curve, the hardness of the grains was experimentally studied adopting needlepoint pressing-in method. The peas, horsebeans, rice, mung beans, wheat, lentils as well as corn at different moisture and component parts were tested and analyzed, with the measured hardness range of 2～75MPa. The research showed that at the loading speed in 0.25～2.00mm/s and depth of indentation in 0.25～1.50mm, no obvious effect appears in the test results. The taper of needlepoint and the value of grain hardness have a quantitative relation in the measurement.

Abstract:EC50值分别为145.62μg/mL和139.38μg/mL。 Optimization of the extraction technology for total phenol from betel nut seed was carried out. On the basis of one factor tests, the method of response surface analysis with 3 factors including extracting temperature, time and solvent-material ratio on the content of total phenol was adopted. The optimal extracting conditions are as follows: extraction temperature 58℃; extraction time 4h; solvent-material ratio 47mL/g. The predicted value and measured value of total phenol is 148.09mg/g and 146.63mg/g, respectively. The results indicate that the obtained mode developed by response surface methodology is feasible for practical prediction. The experiments of antioxidant activity show that the betel nut seed extract presents the strong antioxidant activities to the DPPH and ABTS radical, and the EC50 is 145.62μg/mL and 139.38μg/mL, respectively.

Abstract:107 cfu/mL以上。 To improve the protective efficacy of Bifidobacterium longum BBMN68, various cryoprotectants were evaluated and optimized. Based on its viability and activity after frozen, the effects of eighteen cryoprotectants belonging to four different types were evaluated. Six of them including skim milk, trehalose, fructose, glycerol, Vitamin C and L-Glu were proved to be effective. Then the complex formulas made of the six kinds of the selected compounds was optimized by using a quadratic regression orthogonal experiment. And the optimized composition is as follows: skim milk 8%, trehalose 5%, fructose 5%, glycerol 3%, Vitamin C 0.05% and L-Glu 0.05%. With the protection of the optimized cryoptotectans, the stability of starters is good with a stable logarithm value about 10.5 lg(cfu/mL) during storage, and when applied in yoghurt fermentation it presents an excellent performance, with a total counts of culturable cells above 107cfu/mL during 21 days of storage.

Abstract:Aimed at the discoloration problems in processing of eucommia male flower tea, color protection treatments such as salt ions, citric acid, ascorbic acid, and deactivation of enzymes were used to inhibit the browning. The influencing factors on the liquor color of the male flower tea were evaluated based on the single factor experiment by using SAS software. The concentrations of Zn2+ and citric acid for flower preparation and the duration for flower steaming were selected as the main effect factors. The mathematical model of green-protecting techniques in processing of male flower tea was established with the central-composite model of response surface methodology in Design-Expert software. The optimal technique of green-protecting during the male flower tea processing were: to spray 0.04% Zn2+ and 0.4% citric acid aqueous solution on the male flowers with the solid-liquid ratio of 10g/mL, and then steam the male flower for about 40 second. With the above treatment, the browning and quality decreasing of the male flower tea can be avoided.

Abstract:0.5mm。 An object locating method for strawberry-harvesting robot was proposed and evaluated in view of aimed at the “hill culture” planting pattern and characteristic of liable to damage for strawberry. The method includes two steps: “2-D information acquisition”, during which “mirror-image match method” is used to locate the strawberry’s fruit axis; “distance judgment between object and end-effector”, in which laser is used to assist distance judgment. The experiment results showed that the system is suitable for locating long-conical strawberries. The average time required for locating the picking position is 381 ms, the maximum measurement error of the distance is 1.6mm and the average error is 0.5mm.

Abstract:2%。 A method for extracting and reconstructing 3-D maize skeleton was presented based on stereo vision. Firstly, extracts the 2-D skeleton from two images taken from special angles, then uses epipolar constraint algorithm and appropriate matching criterions to match the feature points on the skeleton. The point cloud of the 3-D skeleton is then obtained. After de-noising operation, the final 3-D skeleton model of maize can be achieved by using B-spline curve fitting. Based on the skeleton model, some important agricultural geometric parameters, such as leaf length and the angle between stem and leaf, can be calculated easily. The experimental results show that the method can quickly reconstruct the 3-D skeleton of maize, with a deviation no more than 2%.

Abstract:Based on public areas and contours of touching kernels, an approach to search segmentation points was developed, realizing automatic segmentation of touching corn kernels. For two touching kernels, the public area could be obtained in the process of continuous erosion-dilation. Non-closed curve segment was extracted by getting intersection of the public area and one kernel contour. The endpoints of the curve segment were segmentation points. Then the two touching kernels were separated by linking two segmentation points with Bresenham algorithm. For massive touching kernels, every single kernel could be stripped using the similar method. The experimental results on 100 touching kernels images showed that the correction rate of segmentation is 96%. The kernels after segmentation have small deformation and smooth boundaries.

Abstract:95.3%。 A method for maize cultivars identification was proposed, by using the combination algorithm of K-L transform and least square support vector machines (LS-SVM)．Firstly, labeling algorithm and multi-scale wavelet analysis were used to acquire single corn kernel images; secondly, K-L transform was employed to extract the features of corn kernel images; at last, the method of LS-SVM with a binary tree architecture was developed to identify maize cultivars by using feature data．According to the result of test, the reasonable state space dimension (L=3) is acquired, and this method gives a correct recognition rate of 95.3%．

Abstract:An optimal feature subset selection method based on improved genetic algorithm (IGA) was presented. A novel scheme named segmented chromosome management was adopted in IGA. This scheme encodes the chromosome in binary as a whole while separates it logically into three segments for local management. These three segments are segment C for color feature, segment S for shape feature and segment T for texture feature separately. A segmented crossover operator and a segmented mutation operator are designed to operate on these segments to generate new chromosomes. These two operators avoid invalid chromosomes, thus improve the search efficiency extremely. The probabilities of crossover and mutation are adjusted automatically according to the generation number and the fitness value. By this way, the IGA could obtain strong search ability at the beginning of the evolution and achieve accelerated convergence along evolution. The experiment results indicate that IGA has stronger search ability and faster convergence speed than the simple genetic algorithm (SGA). The optimal feature subset that the IGA obtained has much smaller size than that of the SGA did, so it is more suitable for the online classification of foreign fibers.

Abstract:Prior research indicated that leaves at different positions responds differentially to the spectral characteristics under different nitrogen rates. A method based on the computer vision technology was proposed, by comparing the spatial differences of color parameters which was captured from the scanned images of upper fully expanded leaves. The result illustrated that the diagnosis of rice based on the scanned image under different N rates is able to partly reflect the hyperspectral properties. And the B、b、b/(r+g)、b/r、b/g were selected as the optimum color parameters. The coefficient of variation (CV) of the color parameters is higher at low N condition than normal. Furthermore, CV decreases with the increased leaf position. Meanwhile, the difference of CV at different part of the leaf is not obviously. The preliminary research concluded that the third fully expanded leaf can be applied as the ideal indicator to quantify the different status of nitrogen.

Abstract:11cm。 According to the specifications of ISO 11783 standard, an automatic navigation control system was built. In the system, there were five ECUs, and the hardware and software design of steering control ECU were described in detail. At last the network service performance of the navigation control system was analyzed, and line path experiments were finished with the designed navigation control system. Experiments indicated that tractor navigation control system can satisfy the need of real time and could realize line path tracking. The lateral error is less than 11cm tractor tracking line path at a speed of 1m/s.

Abstract:0.1951m下降为-0.0022m。 The GPS positioning error and its correlation were analyzed, and then corresponding static and dynamic error were described as AR model by using time series methods. Finally, the process for dealing with the positioning error in navigation was presented, and the experiment was carried out with self-made agricultural robot. The experimental results showed that the proposed approach improves the positioning precision of GPS, and the correlation within the positioning error is decreased, similar to white noise. The average value of positioning error is reduced to -0.0022m from 0.1951m. So it can be applied to achieve high precision navigation of agricultural machinery.

Abstract:Mole rat, as a typical soil-burrowing animal, has a high working efficiency in digging hole in earth，its fore claws are main digging organ. The geometric characteristics of the claws of mole rats(Scaptochirus moschatus) was analyzed by stereoscopy, the quantitative analysis of geometrically characteristic features of the surfaces was performed by reverse engineering, and the second derivative and curvature of the surface profile curves were calculated. The curvature variation of longitudinal profile of claw changes gently and the longitudinal surface was smooth, which assures the tidiness of inner wall when mole rat dug holes. The curvature variation of transverse fitted curves shows a rapid change, and the bending of the transverse fitted curves increase from tip to rear, this kind of structure is easier for cutting in and hole-enlarging. The results provide some information for the design of the soil-cutting tools and excavation tools in energy-saving property and cutting efficiency.

Abstract:Singularity is an inherent nature of mechanism, which make a significant impact on mechanism’s work performance. The singularity loci of a spatial rotation 3-SPS-1-S parallel mechanism was studied. The parallel robot kinematics model was constructed. The equations for inverse displacement and velocity kinematics were derived, and the Jacobian matrix of this mechanism was analyzed. The singularity criterion was proposed，and two types of singularity were determined to be singular configuration. Manipulability degree was introduced to evaluate kinematical performance of the parallel manipulator for the singularity loci analysis. The results showed that the parallel mechanism has a good manageability and kinematics performance in the specified task space, but the special motion position should be turned away to avoid the occurrence of singularity.

Abstract:The precision of trajectory tracking of hybrid machine was debased because of velocity fluctuation in constant velocity motor and uncertainties in the system. The strategy for control servo motor grounded on tracking the motion was proposed, to compensate the velocity fluctuation of constant velocity motor. Considering the uncertainties of the system, an adaptive sliding mode controller based on RBF neural network was designed for trajectory tracking of hybrid machine. The sum of uncertainties of the system was compensated by control gain with RBF neural network, and the output weight of in network was adjusted by adaptive algorithm. The simulation result indicated the robustness and effectiveness of the controller.

Abstract:Kinematic characteristic of wafer driving initiatively in plane lapping process was analysised based on the model of lapping geometry. A new rule was deduced for evaluate the uniformity of lapping trajectory by trajectory numbers of each unit wafer area. The effects of rotating ratio and eccentricity on the uniformity of the lapping trajectory were theoretically analysed. Lower eccentricity is helpful to improve the trajectory uniform distribution, for the errors of the relative rotating speed are augmented with large eccentricity. Forever, improvement of rotating ratio is also to enlarge the standard deviation of trajectory points in the same area, and make a bad uniformity. The same angular velocity for lapping plate as wafer is recommended to improve the trajectory uniformity.

Abstract:Continuous multipoint forming method(CMFM) was introduced simply. The key rollers of continuous multipoint forming device(CMFD) were studied in different disposals and different drives. The drive of three rollers at two sides was felicitous realized, and the CMFD was developed. The process of roll bending was discussed. The results showed that one-step forming is adopt on mini deformation, but when the press displacement of top roller exceeds stated value, the procedure can’t be continued, the multi-step forming is advantaged of inducing sheet metal deformed, eliminates the sides winkle, and reduces the spring back with each mini deformation.

Abstract:Fault feature is always hidden by strong noise background in gear fault signal. Based on morphological wavelet de-noising, a novel method was proposed to extract gear fault feature. Morphological wavelet de-noising has a good performance in extracting morphological feature in signal. Firstly, the signal was decomposed by morphological wavelet. Secondly, detail coefficient in each level was processed using soft threshold de-noising. Finally, fault feature was extracted by reconstructing original signal. Simulation and experiment results showed that this method is effective in gear feature extraction. Morphological wavelet de-noising algorithm includes addition, subtraction, maximum and minimum operations, and does not involve multiplication and division. It is suitable for on-line monitor and gear fault diagnosis.

Abstract:The non-linear behaviour for wearing fault of reciprocating membrane pump was investigated with chaos theory and fractal technology. The vibration acceleration signals of the wearing in different joint were collected to analyse. Poincare sections were drew to study the status of the system. Correlation dimension and the largest Lyapunov exponent were calculated to recognize the different wearing. The results showed that non-abrasion pump system is in quasi-period state, while the fault status is in chaos. The research also indicated that different wearing fault has different largest Lyapunov exponent and different correlation dimension, which can be used as the characteristics for the pump’s monitoring and fault diagnosis.