Abstract:For the purpose of optimizing control strategy of anti-lock braking system (ABS) under the steering and braking combined working condition, the vehicle steering state should be identified. The steering parameters adapted to ABS application were selected which were composed of vehicle velocity, turning direction and steering angle. The applied direct and indirect measure technologies were compared. According to the principle of kinematics of four-wheel vehicle and stable steering characteristic of two-degree-of-freedom vehicle model, the steering parameters estimation algorithms using ABS wheel speed and control information were researched. System test was carried out by the experiment of the steady static circular running and braked steering. The test results showed good accuracy of the parameters estimation.

Abstract:A DCT structure, which adopted on a certain tracked vehicle, was proposed and system dynamic equations were derived according to the detailed analysis of upshifts and downshifts. The analytical model for the simulation, analysis and control of shift dynamics for DCT vehicles was built by means of Matlab/Simulink. An upshift and a downshift were simulated as case study and simulation results displayed the parameters have important influence on shift quality. A PID controller was proposed to control the oil pressure in on-coming clutch in upshift process and a PI controller was also put forward to control oil throttle in downshift process. Such control strategies can avoid clutch tie-up and engine flare, result in better shift quality.

Abstract:Based on the simulation model of pressure-regulating valve of tractor-brake, a hydraulic torque converter was developed. With Niche genetic algorithms, the optimal result of pressure-regulating valve was obtained. In the process of optimization, the simulation model used Matlab and ITAE was calculated as optimal target value. Finally, dynamic performance was tested in a performance experiment. The results indicated that based on simulation model, the performance of pressure-regulating valve was improved with Niche genetic algorithms and the design process was simplified. 

Abstract:With comprehensive consideration of the structure, kinematics, thermodynamics problems of the automotive disc brake, a time model of brake disk in Matlab, a structure model and a temperature field model of brake disk in ANSYS were built, and the multidisciplinary optimization analysis and design could be made by numerical analysis and calculation. Integrating iSIGHT with Matlab and ANSYS, the platform and simulation processes of multidisciplinary design optimization (MDO) of the disk brake were constructed. In order to achieve the parameters extraction, export and update as well as the data exchanges between the software, the customized development of the software has been made. The result from the platform test demonstrated that the braking effect was improved, the braking time was shortened and the weight of the brake was reduced.

Abstract:90％。Road temperature depends on road condition (dry, wet, snowy, icy) and solar radiation (mapped to season, geographical location, time, air temperature and air humidity), and there is the nonlinear causality among them, thus, road condition can be detected indirectly by road temperature and solar radiation with BP neural network. During the experiment to detect road condition (dry, wet), BP neural network was trained with 1344 group data and validated by 96 group data, the road condition detection accuracy reached 90%.

Abstract:Based on identified driving lane, identification will be extended from single-lane to multi-lane by way of ROI (region of interest) control. The concept of confidence was introduced in order to judge the degree of accuracy on each lane, and the calculation of confidence was given under the complex condition. If the accuracy of some lanes was below the threshold, those ROI of the search parameters would be adjusted accordingly so as to avoid the search target being out of the established ROI. At the same time, by analyzing the image sequences, with the combination of the structural characteristics of each lane, the identification result was judged, that could effectively eliminate the effect of vehicles driving on adjacent lanes and remain no lane next to the driving lane upon identification. In this way, the recognition reliability increased. It is proved that this method could improve the accuracy of multi-lane identification.

Abstract:The result of design was affected by the variation of parameters, and the model of robust optimal design was established with the robust optimal design theory. Considering the variation in the mean value and variance of objective function and constraint function, the optimization model was built, which took decoupling of energy distribution as an objective, and stiffness parameters of mountings as a design variation. Particle swarm optimization (PSO) was adopted to optimize an engine mounting system to the stiffness of mountings, and the Monte Carlo method was used to analyze the optimization values. An example showed the method presented could decrease the sensitivity of decoupling with respect to the stiffness of mountings, and could make the vibration coupling distribution more reasonable. Comparing with the genetic algorithms, the optimization design computational efficiency of engine mounting system could be obtained quickly by PSO.

Abstract:0.90 m/s。3-D topography of white light interference instrument was used to observe the surface topography of biofilm under different velocity rates in PE pipe, and the impact of velocity rate and surface topography of biofilm was analyzed. The results showed that more solid particulate was on biofilm surface with roughness in the middle-velocity zone. In the high-velocity zone, biofilm surface was smoother and biofilm’s thickness was thinner. The relationship between the average thicknesses of biofilm with velocity rate agreed to the exponential law whose maxima velocity rate is 0.22m/s. Under the condition of velocity rate is greater than 0.90m/s, the growth rate of biofilm was decreased faster with the increase of velocity rate, and more biofilm fell off, and hydraulic shear stress force increased rapidly, so cleaning velocity rate of the drip irrigation system should be larger than 0.90m/s.

Abstract:In the traditional water movement model of the furrow irrigation based on water balance method, it is necessary to determine the value of the figure coefficient of infiltration water (σz) before simulating water flow of the furrow irrigation, which affected the precision of the model. The relationship between the figure coefficient of infiltration water and water flow under furrow irrigation was analyzed, an analytic model of furrow irrigation on the basis of water balance method was set up, and the iterative algorithm to the analytic model was determined. The influence of different σs values in 0.70～0.80 on the model compute results was studied, the model results were verified with some research results and field experimental values. The results showed that the problem of getting σz directly with difficulty was solved and the accuracy of the model was improved. It is also found that different σs values in 0.70～0.80has little influence on the model compute results and when the σs value is 0.75, it has better accuracy for the model than that when the σs value is 0.70 or 0.80. The study indicated that the analytic model has some advantages, such as simple calculation method and solution, high accuracy. 

Abstract:80%，成熟期55%。The field experiment was conducted to investigate the effect of irrigation models (drip irrigation under plastic mulching (MDI), drip irrigation (DI) and subsurface drip irrigation (SDI)) and irrigation start point on water consumption and yield of sweet melon. The results showed that under the same irrigation start point: MDI increased the yield by 16.0% compared with DI; MDI increased the yield by 7.5% compared with SDI; SDI increased the yield by 7.9% compared with DI. The average water consumption for MDI, SDI and DI were 193.0mm, 217.3mm, 239.3mm respectively. Under the same drip irrigation model, the treatment of irrigation start point of 60% field capacity in extension vine and flowering fruit stage, yield increased by 21.0% compared with the treatment of 40% field capacity; the treatment of irrigation start point of 80% field capacity in fruitage stage, yield increased by 9.3% compared with the treatment of 70% field capacity. The appropriate irrigation start points (the percentage of field capacity) for the sweet melon were: seedling stage (65%), extension vine and flowering fruit stage (60%), fruitage stage (80%), mature stage (55%).

Abstract:A research was carried out to determine the compensation effects of water stress and re-watering on the function of root shoot by pot experiments. The results show that the post-drought re-watering has obvious compensation effects to rice on the function of root shoot, which is particularly significant after short-duration heavy drought at the late tillering stage and light drought at the early jointing stage. Post-drought re-watering mainly embodies compensation effects in improving the physiological activity of neonatal crop organ. 

Abstract:An L18（37） orthogonal experiment was designed with seven factors and three values including blades numbers, outlet angle, outlet width, etc. 18 impellers were designed totally. The two stages of whole flow field on deep well pump in the operating point for design was simulated by using CFD. The 18 groups of the design scheme for efficiency and head were obtained. Using Latin square test, the effect of geometrical parameters on efficiency and head were researched. The primary and secondary sequence of the design parameters were acquired by the method of variance analysis. According to the test result and optimization design with experimental research, an optimum program to further design was put forward. The result could be instructive to the design of the deep well pump, which was designed by the impeller head maximum approach.

Abstract:0.35%和0.944%。A new optimization method based on genetic algorithm for the optimization of a centrifugal blade profile was presented. Different from the traditional optimization method, the hydraulic performance of centrifugal blade profile was predicted with CFD technology in the new developed method. The hydraulic efficiency and theoretical head were defined as the objective functions for the blade profile optimization using multiobjective genetic algorithm. Three key technologies were employed as the follows: 3-D blade profile parameterization, grid generation & CFD analysis, multiobjective optimization. By this optimization method, a single-stage single-suction centrifugal blade was redesigned and optimized at the design condition. The results showed that the objective function values of the maximum hydraulic efficiency and the theoretical head were increased by 0.35% and 0.944% respectively. 

Abstract:The determining of cavitation monitoring threshold is the key segment of distinguishing pump running state. A series of tests have been put into effect in a laboratory to simulate the cavitation, the signal of inlet sound pressure and enclosure vibration were acquired at 1440 r/min, flow rate at 90, 100, 110, 120 m3/h. The method to determine the cavitation monitoring threshold which based on statistic theory was posed by making use of reference frequency band energy. The results of cavitation experimental study showed that the inlet pressure sound and enclosure vibration signal of pump were followed uniformity by sound pressure rule at the reference frequency band, the energy value first rose then dropped along with cavity number diminishing；using 3σprinciple, the energy curve peak lower limit value was firstly acquired by the experiment, then the value of decreasing 3～5 dB was taken as the reference of cavitation threshold；the reference frequency band energy peak value of sound pressure first rose then dropped along with the increase of flow rate, and its cavitation sensitivity is stronger than the vibration signal.

Abstract:The tooth profile lines of the inside circulation piston pump were studied, and their meshing characteristics were analyzed. According to the motion law of the inside circulation piston pump rotor, and based on the tooth profile lines of the inside rotor as the circular arc, the moving coordinate system was established. Assumed that the outside rotor was fixed and the inside rotor made the relative movement, the calculation formula of the outside rotor profile was deduced for the first time. At last, using an actual design example and motion simulation analysis, the validity of the tooth profile line equation and calculation formula was verified. 

Abstract:Biomass tar catalytic decomposition upon pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was studied by taking naphthalene and phenol as model compound. The effect of reaction temperature, charring conditions, such as the pyrolysis temperature, the heating rate and the precursors on model compound conversion was determined. The results showed that tar conversion increased with the increasing reaction temperature; higher charring temperature and higher heating rate could enlarge the surface area and pore volume of biomass chars and also enhance tar conversion. Conversion of naphthalene and phenol were 55.6% and 76% respectively on biomass char prepared at 850℃ with quick heating rate. Scanning electron microscope (SEM) and test results of char mineral oxides contents showed that catalytic activity of biomass chars was related to their surface morphology and the mineral oxides contents

Abstract:Experimental researches on fast pyrolysis of peanut shell were performed in a self-manufactured bench-scale fluidized bed reactor at 500℃. Mass balance of pyrolysis reaction was carried out. Influence of collecting ways on bio-oil yield was investigated. Results showed that bio-oil yield raised from 40% to 64% after the electrostatic precipitators （ESP）settled at the end part of the fractional condensers which prevented bio-oil from losing together with produced gas and cleaned the produced gas. Energy consumption of peanut shell pyrolysis was monitored at about 2304kJ/kg with a watt-hour meter. The physical properties and application of bio-oil were discussed by means of analysis instruments.

Abstract:Corn stover was taken as the object in the research. The material and compression character, the effects of heating temperature, moisture content and pressure on the physical quality and mechanical properties of corn stover were studied respectively. During the study, axial displacement, diametrical peak displacement and peak stress were all used to scale mechanics properties of corn stover. The results showed that when compression pressure of 60～90MPa applied, moisture content of the grind was 8%～12% and heating temperature was at 75～100℃, the produced briquettes was with high-quality which was easy to store and transport.

Abstract:The qualities of every flow flours were analyzed by physicochemical properties analysis, noodle making and sensory evaluation. The noodle qualities made of different flows were also evaluated by using principal component analysis method, Z values of noodle made by 23 flows were between -15.462 and 34.546. The test graded and recombined those flows according to the principle component analysis, change of noodles taste was remarkable and noodles break and tension force were in the second place among noodle quality differences. The recombination result indicated that the sensory evaluation value of noodle made of No.1 flour exceeded that of noodle made of high quality wheat flour, but the noodle lacked break and tension force.

Abstract:26.86%。In order to solve the problems of low head rice yield (HRY), high energy consumption and unable to reach the anticipate target after once moisture conditioning treatment (MCT) when milling the stored desiccated low-moisture brown rice, a study on the laws of effects that different amounts of moisture, the temperatures during the rice moisturizing and the time between the two MCT have on HRY during the twice MCT for brown rice was conducted with the materials of brown rice (the moisture content was 12%). Based on the single-factor tests, composite tests of quadratic orthogonal rotation were designed and the experimental data was analyzed with SAS. From the testable experiments, it was proved that HRY increased by 15.42% and the energy consumption decreased by 26.86%. When the moisture increased by 1.56% each time, the temperature was 29.6℃and the time between the two experiments was 64.6min.

Abstract:The method of planetary ball mill was applied to produce granular-cold-water-soluble maize starch. Based on the single-factor test, the technical conditions of the ball mill were optimized through Box-Benhnken center composite design and response surface methodology. The properties of granular-cold-water-soluble maize starch were analyzed using polarization microscopy, scanning electronic microscopy and X-ray diffraction. The results showed that the optimum technical conditions are that the milling time is 3.24h, the rotating speed is 555r/min and the ratio of ball to material is 6.52∶1. At the optimum conditions, the average cold water solubility of granular-cold-water-soluble maize starch is 57.95%. The granular morphology of granular-cold-water-soluble maize starches became coarse instead of smooth and Maltese crosses were disappeared, the crystalline structure of granular-cold-water-soluble maize starches were changed from polycrystalline granules to non-crystalline granules gradually, the turbidity of granular-cold-water-soluble maize starch decreased. 

Abstract:The influence of the temperature of the radiation heater, pressure in the chamber and sample mass on the drying characteristics of vacuum far-infrared radiation drying on honeysuckle was studied by using a self-transformed dryer. By means of linearization of moisture ratio curves, the kinetics model equation was determined as MR=exp(-Ktn). Quadratic orthogonal regression was employed to fit the relationship between modeling coefficients (n and K) and drying parameters. The results showed that the calculated values of mathematical model were quite suitable for the experimental data, and the model could illustrate moisture ratio changing regulation of vacuum far-infrared radiation drying on honeysuckle very well.

Abstract:The factors influenced infrared radiation drying rates for Agaricus bisporus, such as radiation intensity, radiation distance, material temperature, material thickness and drying time were analyzed. The network model structure between moisture content and all the controlling factors was built based on feed-forward neural network, the selected structure of the applied neural network, with its five inputs, single output and 11 hidden neurons were used. All data series obtained from different drying runs were used for training and test, mathematical model responding to inner relationship of the experimental data was obtained by finite iteration calculation, and it was trained and simulated systemically by using Matlab neuralnetwork toolbox. It was concluded that the model could be built by the BP neural network, cost-effectively, accurately and rapidly during far infrared drying of Agaricus bisporus within the trial stretch. It was found that the predictions of the artificial neural network model fit the experimental data preferably, and the applications of the artificial neural networks could be used for the online state estimation moisture content with more suitable and accuracy.

Abstract:Combining near infrared spectroscopy technology with virtual instrument technology, a multi-band near infrared detector for grain component was developed. Adopted diffuse reflection principle, the instrument is composed of optical system, circuit system and software system. The working process is as the follows: being frequently modulated, the full spectrum light issued by halogen light was transformed into the scan spectra via the scanning spectral filter through the sample diffuse reflectance, then it was converted to electrical signals after being received by the detector. After that, a conditioning conversion was adopted, and finally it was sent to computer by the acquisition card for further processing. A system-testing was performed based on the 26 prepared samples. Test results showed that the equipment has low noise level, inferior reproducibility, and the forecast-accuracy is not very good. But the accuracy can be improved by way of measuring average after loading repeatedly. The instrument can be used for measuring many ingredients in the grain samples, such as protein, starch and fat.

Abstract:4.7倍。To explore an optimal preparation method of angiotensin converting enzyme (ACE) inhibitor peptides from Porphyra yezoensis with protease, several conditions about batch membrane reaction with raw material feeding were attempted in enzymatic membrane reactor. Radial basis function neural network (RBF-ANN) models were employed to optimize the condition. Some parameters were optimized based on cross-validation to calibrate a robust model. The optimal operating conditions for the maximum protein conversion rate obtained by the model were as followings: substrate concentration 1.0g/mL, enzyme concentration 4%, reaction temperature 50℃, pH value 9.0, pump rotation speed 300 r/min and reaction time 60 min. Under these conditions, protein conversion rate was 55.67%, the yield of peptides was 22.27%, quantity of peptides per gram of enzyme was 13.91 and IC50 was 0.492mg/mL. Base on the optimum conditions enzyme membrane reaction with continuous feeding Porphyra yezoensis was also studied: compared to the traditional methods, protein conversion rate improved by 21.98%, yield of peptides increased by 8.79%, and quantity of peptides per gram of enzyme was improved by 4.7 times.

Abstract:L/(m2?h)、透射比为90.5%。Moderate temperature α-amylase was used during the extrusion and liquefaction of degermed corn. The method of the quadratic orthogonal rotating combination design of five factors (barrel temperature, moderate temperature α-amylase amount used in the extrusion, moderate temperature α-amylase amount used in liquefaction, liquefaction time, amyloglucosidase amount used in saccharifaction) and five levels was applied. The influence of extrusion and producing glucose syrup system parameters on DE value, filtration speed and transparence were studied. The optimized system parameters of extrusion and producing glucose syrup were used to produce glucose syrup, and DE value was 96.8%, filtration speed was 483.6 L/(m2?h), transparence was 94.0%, the results of control test were: DE value was 72.5%, filtration speed 20.2 L/(m2?h), transparence 90.5%.

Abstract:P<0.05）。The effects of the amount of enzyme added, ultrasonic power, enzymolysis temperature, pH value and time on the extraction yield of polysaccharides from longan pulp were optimized by response surface methodology. The optimal technological conditions of extraction by ultrasonic and cellulase were determined, then regression mathematical model was established. The optimal technological parameters are as follows: longan pulp with water ratio is 8.47%, cellulase additive ratios is 2000U/g, ultrasonic power is 250W, enzymolysis temperature is 55 ℃, enzymolysis pH value is 5.0, enzymolysis time is 60min, under such conditions, the polysaccharides extraction rate is 38.71%. This result approximated to the value of mathematical model calculated.

Abstract:The vision navigation control hardware system was set up in the combine harvester and a histogram fusion algorithm for multi-frame navigation lines was put forward. On the basis of kinematics of simplified two-wheel vehicle, model one fuzzy PD controller was constructed. The tests in wheat field show that the rotation and projection algorithm with histogram fusion algorithm is valid to recognize the cut/uncut line, and can improve the precision of the system and robustness, the change of harvesting width is in 0.18m during the working speed, and it could come back to the right path in 2~5s when given manual disturbance using steering wheel.

Abstract:Position accuracy is one of the most important parameters of GPS. Differential GPS（DGPS）can get higher position accuracy significantly, but there are many limitations for its applying ranges, so improving the accuracy by independent positioning method has important significance. Experiments in the non-differential mode by using Trimble AgGPS132 were conducted. First, the frequency distribution of the experimental data was analyzed. A method to eliminate outliers was raised, and GPS precision operating was compared before and after eliminating outliers. Finally, how to eliminate the influence of error was pointed out according to the different conditions. The results showed that adopting the Levin special criteria to eliminate outliers could improve the positioning accuracy effectively, and adding control point could correct the drift data of GPS dynamic positioning.

Abstract:Field information collecting device has the problems of high energy consumption, high cost, unable to conduct fixed and mobile collecting field information simultaneously. In order to solve these problems, a new type of agricultural information service system was designed. It is composed of three parts: ZigBee wireless sensor modules with the functions of acquiring information from farmland; mobile terminals base on DSP and ARM9 with the function of passing the field information to the agricultural producers; WebGIS agricultural information management system with the function of guiding the policy-makers for decision-making. Finally, the experiment was carried out and some explanations and indications were given to the problems of the system that need to be improved.

Abstract:12 mm。Aimed at the demand of recognition and location in computer vision for harvest robots, the embedded vision sensor plat was designed which contained 1.3 million pixel CMOS image chip, MCU with open structure, and brightness adapting module controlled by the expert database to solve the problem of outdoor light changing which affected the visual inspection. Two sensors were used to construct binocular vision sensor system which was coordinated by master-slave frame. The algorithm of image segmentation and distance measurement was applied to get the location data of harvesting object. The binocular vision sensor system ran smoothly and reliably. The performance test results showed that the success ratio of identifying is 96% and the measure error is within ±12mm when the system took ripe tomato as an measuring object and the measure distance limits was in machine pick-arm range.

Abstract:To deal with the localization problem of robot equipped with laser sensor, a mobile robot Monte Carlo self-localization method based on adaptive curvature estimation for environmental features extracted was proposed. During the mobile robot localization, poses of the robot were predicted by motion-model, and then distribution of particles set was updated according to the similarity measurements of geometry by observation model, and robot self-localization was realized. Simulation experiments showed the proposed method could satisfy the requirements of the mobile robot self-localization in greenhouse.

Abstract:It is difficult to detect white foreign fibers in cotton by traditional machine vision systems and image segmentation methods, because the color of the targets and background is very close. To solve the problem, an image segmentation algorithm for a machine vision system with an irregular imaging function was presented. Using Gabor operator to extract the orientation feature vectors of an image, combined them into a feature map, thus the contrast between the background and targets was improved by the algorithm. Then a threshold was calculated according to the statistical characteristics of the feature maps. Finally, the white foreign fibers were separated from cotton in the binary image, and the image noises were eliminated by a morphological operation. The experimental results indicated that the algorithm is anti-noise and capable of detecting the targets.

Abstract:内准确率达88%。The conventional manual methods for egg volume(V) and surface area(S) detection are usually slow, inefficient and not able to meet the actual production requirements, so machine vision technology was researched to replace them. Assumed the ideal egg image was symmetric about longitudinal diameter, the definition of volume pixel(Vp), surface areas pixel(Sp) and the calculation were proposed. Then, the module between volume (surface area) and Vp (Sp) was established. Experimental results showed that the determination coefficient of volume module and surface area was 0.965 and 0.971, respectively; the test accuracy of egg volume module and surface area reached 92% with ±1 cm3 error and 88% with ±1cm2 error respectively.

Abstract:The leaflevel winter wheat hyperspectral response to its chlorophyll content was examined. Firstly, after the 316 scan line images were acquired, the cube image data was constructed and the region of interest (ROI)was selected, then after the average pixel intensity acquired, using correlation analysis combined with stepwise discrimination method for the origin reflective spectrum and the first derivative spectrum, the optimal wavelengths were selected respectively; the chlorophyll content model using multivariate linear regression (MLR) was constructed based on the above seven optimal wavelengths. After statistical significance testing, three wavelengths were abandoned, and the residual four wavelengths, i.e., 710.85,767.42,650 and 520nm were used to construct chlorophyll content prediction model. The prediction results showed that the determination coefficient were R2=0.8434 and R2=0.7093 for the training dataset and the validation dataset respectively. All of these indicated that with the hyperspectral technology, chlorophyll content of winter wheat could be predicted precisely. 

Abstract:Machine vision was introduced into the vaccine preparation to detect the fertility of middle-stage hatching egg by using the image processing. According to the special requirements that all the infertile eggs should be detected and the original embryos fertility in eggs should not be affected by the detection, the design of imaging system and the method of how to detect the fertility by using the images were proposed. Firstly, images were enhanced and the special quality of shade was detected by multi-scale morphological transformation; secondly, the main blood-vessels in the hatching egg images was extracted by using local adaptive segmentation based on histogram-based WFCM; finally, the fertility by counting the number of the blood-vessels was detected. The method was simulated with 150 images under the Matlab7.0 environment. The detection accuracy rate, undetected error rate and false detected rate were respectively 99.33%, 0% and 0.67%. The detection of a single egg is 0.21s on average. The results showed that the method was efficient, but not sensitive to noise, color of egg shell, nor to the other pollution on the eggshell. It is capable to improve the detection accuracy and efficiency by replacing manual detection in vaccine preparation.

Abstract:The components and work principle of the separate meter in and separate meter out (SMISMO) load sensing electro hydraulic system were introduced. The simulation model of studied system was built, a flow rate and pressure controller was designed to control both velocity of piston in the cylinder and pressure in the cylinder chamber. The flow rate controller was designed based on the calculation flow rate feedback, and the pressure flow compound control was realized based on the pressure close loop pressure controller. Simulation and experiment showed that the novel control system possessed high velocity control precise and good energy saving characteristics, the effects of SMISMO valve element frequency and damping on system control performance were studied by simulation. It provided theory support for design and application of the novel system.

Abstract:The average sliding friction coefficient was derived in the mixed elastohydrodynamic lubrication state, with complete elastohydrodynamic and boundary lubrication. Based on the geometry and load contact characteristics of spiral bevel gears, the sliding friction power loss of each point on the long axis of the instantaneous contact ellipse was calculated. Meanwhile, the function of sliding friction power loss in a meshing period was established. The meshing efficiency of spiral bevel gears was calculated by integrating the function under the condition of mixed elastohydrodynamic lubrication. This algorithm was demonstrated to be correct and precise compared with Gleason corporation’s method of calculating the meshing efficiency of bevel gears.

Abstract:To improve the efficiency of the micro-thermophotovoltaic system, the radiation energy output of micro-combustor has to be uniform and possibly in the short-wave photon energy range, which requires high and uniform temperature along the micro-combustor’s external wall. In order to further optimize the micro-combustor, different porous media combustors with the inner and external diameters of 2.4mm and 3.0mm were designed. After stable combustion of hydrogen and oxygen in the porous media combustors, experimental investigation was carried out against micro-combustor with different hydrogen-oxygen volume ratios, mixing gas flux and porosity, the combustion performance and external wall temperature distribution under different conditions were analyzed. The results indicated that the porosity, mixing gas flux and hydrogen-oxygen volume mixing ratio had significant effect on the mixture combustion in micro-combustor. When the porosity, mixing gas flux and hydrogen-oxygen volume mixing ratio were separately 0.50, 750cm3/min and 2∶1, the micro-combustor showed a better combustion performance, including high and uniform temperature distribution along the external wall of micro-combustor, which was suitable for application to micro-thermophotovoltaic system.

Abstract:Electrostatically actuated circular diaphragm exhibits an instability known as pull-in phenomena, short circuit caused by pull-in with contact is destructive to electrostatic micropump operation. In order to avoid pull-in instability caused by high driving voltage, pull-in voltage should be calculated accurately. Therefore a reduced order model (ROM) based on numerical calculation and mode superposition method was constructed, which could take account of residual stress and geometric nonlinearity. The pull-in voltage and pull-in position computed by ROM have been compared with the existed results and the results calculated by 3-D finite element analysis. It showed that the ROM sped up computational process without sacrificing the accuracy. The effects of different parameters such as residual stress, initial gap, diaphragm radius, diaphragm thickness on pull-in voltage and pull-in position were also investigated by the ROM. In addition, the design criteria of pump diaphragm were obtained, which provided an effective theoretical basis for the optimization design of electrostatic micropump.

Abstract:123 mL/min。A new type of piezoelectric pump with active valve was designed. By means of derivation piezoelectric pump flux formula, main factors which influenced flux of the active valve were analyzed, i.e. inside diameter and the width of the valve seat. The test result showed that working frequency, the power supply voltage, the output backpressure, phase difference between the driving signal of active valve and the pump were the most influential factors on the performance of piezoelectric pump with the active valve. The designed initiative piezoelectric pump has the capacity of delivering liquid in two directions. The experimental results showed that the flux of designed piezoelectric pump could reach 123mL/min, under the condition of sinusoidal driving signal at 30 Hz and 120 V.

Abstract:Based on the theory of orthogonal frame, a general equation in form of vector function was established for scroll profile. Engagement condition of meshed profiles was derived. According to the parameter equation of Cartesian coordinate, the function of curvature radius could be expressed by integration of tangential angle. Curvature radius function based on differential equation of profile was deduced. Furthermore, demonstrated by four typical profiles, the corresponding relation among radius of curvature, general generating radius and general basic radius was determined. The differential equation for the involute of a regular triangle was demonstrated in form of function of radius of curvature. The integration profile could not only cover the existed profiles, but also be used to optimize properties of these profiles by controlling coefficients of series of tangential angles. The conclusions could be applied in flexible design of scroll fluid machine. 

Abstract:Due to the complex geometry of free-form surfaces, the generating optimization trajectories of spray gun satisfy the requirement of uniformity paint became a challenge. A quadratic function of the paint deposition rate on a plane was proposed according to the experimental data, and a model of paint deposition rate on a free-form surface was established. The point cloud model was obtained directly by scanning the surface of workpiece, and the position and pose of spray gun was obtained by point cloud slicing technique. The change of the surface curvature caused non-uniform paint deposition on freeform surface. An algorithm of variable spray speed optimization was established to compensate for the curvature change and improve the uniformity of paint deposition along passes. An algorithm for selecting the spacing between the passes was established to improve the deposition uniformity vertical to passes, and to reduce cycle time and paint waste. Finally, the simulation and experimental results illustrated the feasibility and availability of these optimization algorithms. 

Abstract:1.6 s。Utilizing a new type shape memory alloy(SMA)biometal-fiberR(BMF) as the convertor from electrical energy to mechanical energy, a pneumatic micro-servo valve was developed. Input-output characteristics of BMF100, including displacement output and load output were investigated by the experiments. The voltage hysteresis of BMF100 was 0.2V at 0.1N load and 10V maximum driving voltage, and the value was 0.4V at 1.0N load and 11V maximum driving voltage. 3-D model of servo valve was simulated by the software of CATIA. As an important part, the allowable stress and strain of coniform core of valve was studied by the numerical simulation of finite element method with software of ANSYS. Response time of pressure output of the valve was 0.3s. The result shows that it is feasible to use BMF as the convertor from electrical energy to mechanical energy of pneumatic servo micro-valve.

Abstract:In order to assure the accuracy of trimming springback of multi-step forming by finite element method, a trimming algorithm based on self-adaptive template of trimmed elements was proposed. In this algorithm, the intersection calculation between 3D trimming lines and mesh of part was executed at first. Then the accepting and rejecting judgement of elements was achieved. Finally, the method of trimming element by element along the path of the section lines was used in trimming operation. Therefore, the problems of boundary serration, axial symmetry and boundary gap have been totally avoided, and multi-trimming on refined mesh was achieved to improve the efficiency of trimming operation. The present algorithm has been integrated into the independently developed KMAS forming analysis system. By using the numerical simulation on automotive underbody cross member which was provided by benchmark test of NUMISHEET 2005, the applicability and reliability of introduced algorithm were verified.