Abstract:Through the research of pump in hydraulic control unit (HCU) of electronic stability program (ESP), a design method that actively build up brake pressure without pre-pressure was established. After that, a simulation model in AMESim to analyze the structure parameters of the HCU of ESP was proposed, especially the influence to increasing pressure rate with different pump flows and motor speed parameters. Based on the above, the pump flow and motor type can be defined when the hardware was matched by ESP. Finally, a bench test was carried out to prove the function of the pump that could build up pressure without a prepressing unit. 

Abstract:The mathematical model of semi-active air suspension was built. Adjustable damper, semi-active air suspension controller and bench test system were designed. On the basis of simulation, adjustable damper and 1/4 model of semi-active air suspension bench were tested, the influence of semi-active air suspension and its control system to vehicle dynamic performance were analyzed. Calculation and test results were basically identical. The ride comfort of vehicles was improved.

Abstract:By adding a hydraulic propulsion system made up of pumps and motors primarily in a traditional heavy vehicle, it is changed to a four-wheel driven vehicle from a two-wheel driven vehicle. The principle of the system configuration and working modes were analyzed. The system dynamics equations were established. The whole vehicle system was modeled by a co-simulation method with Matlab/Simulink and AMESim software. The vehicle’s traction force and climbing capacity was simulated and compared. The results showed that after using the hydraulic propulsion system, the vehicle traction force was increased by 13.4% and the climbing capacity was improved by 14.4%, which means the vehicle passability was also improved significantly.

Abstract:To improve the efficiency of auto-body design, an algorithm of morphing design for auto-body based on free form deformation and isoparametric transformation was proposed. In this algorithm, the control finite element model (FEM) model was consisted of a collection of polyhedral elements, such as hexahedron, pentahedron and tetrahedron. Then the correspondence of isoparametric transformation between FEM model and control parametric volume was established, and the deformation of control parametric volume was propagated to the embedding FEM model. The algorithm avoided the problem of computational cost of the parameterization of local coordinates through the given isoparametric transformation and its inverse transformation. From the numerical simulation on FEM model of an auto-body, the validity and efficiency of proposed algorithm were verified.

Abstract:Aiming at the problem that there are unmodeled dynamics by theoretic modeling and it is also difficult to identify, a Pseudo-Hammerstein-Wiener model with cascade connection of a two-segment polynomial nonlinearity block, a time-invariant linear system, and a backlash nonlinear term was adopted to model the electro-hydraulic servo system of excavator arm. The key term separation principle was used to decompose the model into a linear-in-parameter format, and a refined recursive least square method supplemented with the estimation of internal variables was proposed to identify the decomposed parameters. Experiments demonstrated that the identified Pseudo-Hammerstein-Wiener model approximated the actual system well. Comparing with Hammerstein and ARX model, the error of the Pseudo-Hammerstein-Wiener was reduced by 29% and 68%, respectively. 

Abstract:According to modern orchard planting pattern, a kind of self-propelled air-blowing orchard sprayer was developed. Adopting theoretical calculation and virtual prototype technology, the whole structure design and the key components technical parameters were determined. A ring fan was designed for modern orchard. The impeller was 0.7 m and outlet width was 0.13 m. The step-less transmission of fan was accomplished from 0 to 2000 r/min. The field experiment showed that the front deposition reached to 61.22% and other side reached to 20.90% inside the trees. In the surface of the trees, the front deposition reached to 77.22% and other side reached to 37.17%. The operation efficiency reached to 1.02 hm2/h. 

Abstract:Aiming at the shortcomings of specialized plant protection machinery for trellised vine and the low-level efficiency of pesticide application, a Π-type recycling tunnel sprayer for the liquid that was not retained by the leaves was developed. Spray recycling and deposit in canopy were measured. Results showed that it could increase chemical recovery rate up to 44.0% and 18.4% respectively and increase the deposition on the underside of leaves and leaved inside canopy by assembling booms interlaced and turning nozzles upward. Grid end shield could deflect air direction effectively to increase chemical recovery rate more than 10%.

Abstract:In order to meet the pest control requirement of hedge crop, tunnel sprayer was researched to entrap the droplets which were not deposited on the target and recycled. Tunnel sprayer was compared with conventional air-assist orchard sprayer on anti-drift performance. The result showed that, the drift in air of tunnel sprayer was reduced by 97.9% compared with conventional orchard sprayer in down wind direction; the ground drift of tunnel sprayer was reduced by 99.3% in drift distance.

Abstract:Nozzle flow model is indispensable in variable-rate spraying control based on pulse width modulation (PWM) technology, especially when nozzles are controlled independently. A variable-rate test platform which could control spraying pressure precisely and was easy to set PWM parameters was designed. The central composite orthogonal regression tests were completed by using the test platform, and the flow models of TEEJET AITXA nozzles of type 8002, 8003 and 8004 were obtained. The results of equation hypothesis test and test for lack of fit of flow models showed that the three flow models were agreeable. The maximum relative error of the TEEJET AITXA nozzle model of type 8002 was 7.05%, while the minimum relative error was 0.14%. For the type 8003, the maximum and minimum relative errors were 7.27% and 0.31%. And for the type 8004, the maximum and minimum relative errors were 7.94% and 0.71%. Nozzle flow model validation trials showed that the relative errors between model flow and actual flow were small. 

Abstract:A swing, automatic variables and greenhouse mist sprayer equipped with the sprinkler swing function and automatic dosing and discharge liquid system was presented. In order to verify and optimize pesticide application efficiency of mist sprayer, parameters such as spraying flow rate，spraying distance, sprinkler swing speed and sprayer forward velocity were selected as independent variables, which would influence distribution of droplets deposition. Subsequently, the Box-Behnken experimental design with four factors and three levels was performed, and the mathematical model was established by using Design-Expert software, then the effects of various parameters and their interactions were analyzed as well. The results showed that effects order of four parameters on distribution of droplets deposition were as follows: sprinkler swing speed, sprayer forward velocity, spraying distance, and spraying flow rate. The optimal spraying parameters were spraying flow rate of 185mL/min, spraying distance of 2m, sprayer forward velocity of 8cm/s and sprinkler swing speed of 5(°)/s, then the coefficient of variation of droplets distribution of 1.632% was obtained.

Abstract:A prototype of inside-filling air-blow seed-metering device was developed to overcome the deficiency of mechanical precision metering device with high rate of cell blocked and seeds absent. Simulation analysis of flow in the prototype was carried out with software ANSYS/CFX. The simulation results showed that the pressure fluctuation in the prototype with stomata was fewer 93Pa than it without stomata. The laboratory test results indicated that seeding performances of the seed-metering devices with stomata was much better than it without stomata: quality of feed index and miss index of the devices without airblowing drop, with no-stomata air-blowing drop and with stomata air-blowing drop was 66.8%, 78.4 %, 82.0% and 14.4%, 4.4%, 2.4%, respectively.

Abstract:Based on the rotating rate of planetary frame of 110 r/min, the pressure of liquid pump of 0.3 MPa, the diameter of valve core hole of distributor of 3 mm, the diameter of spraying-fertilizer needle nozzle of 2 mm, the working processes of pricking hole and spraying fertilizer of pricking hole mechanism were shot by high-speed camera. The movement laws of pricking hole and spraying fertilizer were analyzed by high-speed camera techniques and image processing technology, which showed that the fertilization time was 0.1 s from spraying-fertilizer needle went into the soil and began spraying fertilizer to it went out of the soil and stopped spraying fertilizer, the fertilization loss rate was 0.48%, the change of real trajectory width was 256 mm, and the change of height was 502 mm. The results showed that the processes of pricking hole and spraying fertilizer of pricking hole mechanism had good synchronicities, and fertilization loss rate was far less than the operation requirement 3.5%.

Abstract:In order to solve the problem of high impurity rate and stalk broken rate existing in the leaf-stripping process of the whole stalk sugarcane combine harvester, the elastic dentation roller type leaf-stripping test device was designed. The main structure of feeding roller, output roller and leaf-stripping roller and the principle of leaf-stripping were introduced. The structure parameters of main parts were determined. The orthogonal experiments were conducted to study the influence between the following four factors, the installation angle of leaf-stripping component, the center distance between the top and bottom leaf-stripping rollers, rotate speed of leaf-stripping rollers and rotate speed of feeding and output rollers, and the following three indexes on leaf-stripping quality, impurity rate, stalk broken rate and top broken rate. The result showed that the optimal parameters were as following: the installation angle of leaf-stripping component was 90°, the center distance between the top and bottom leaf-stripping rollers was 310 mm, rotate speed of leaf-stripping rollers equaled 700 r/min and rotate speed of feeding and output rollers equaled 150 r/min. In the meantime, when the total weight of 319.19kg sugarcane was fed continuously into the device in the way of single stalk, the impurity rate, stalk broken rate and top broken rate reached to 1.56%, 20.45% and 65.97%. Otherwise, when the total weight of 274.52 kg sugarcane was fed continuously into the device in the way of three to five stalks simultaneously, the final result was 2.38%, 25.93% and 75.59% respectively. 

Abstract:To further study mechanism on the processing tomato separation, separation device vibrator movement was analyzed. Its theoretical model by using dAlembert principle was established. Virtual prototype movement based on SolidWorks was simulated. Separation roller motion process was filmed by highspeed camera on homemade FS-35 type separation test rig and the test video was analyzed by blasting software Blaster’s Mas. The simulation results and test analysis showed separation unit movement followed the rule of theoretical model, which verified the correctness of the theoretical derivation.

Abstract:Multi-dimensional vibration screening test bench based on the theory of parallel mechanism was designed to solve the problem that multi-dimensional vibration could not be attained by traditional vibration screening device. This multi-dimensional vibration screening test bench took fully decoupled multi-dimensional main exciting mechanism as center, and adopted highpower linear motor as linear reciprocating vibration power source. It had the characteristics of shorter driving chain and convenient adjustment of mechanical structure and motion parameters to obtain material pellets vibration performance under several conditions and motion law of material on the screen. The test bench used computer and PMAC control card as the core of hardware control system. Measurement and control software system could collect real-timely, display, process and analyze the amplitude, velocity, frequency, torque and power to provide the design basis of multi-dimensional vibration equipment.

Abstract:The shortcomings such as high water content, low energy density and difficulty to storage, have limited the large-scale applications of agricultural straw. The torrefaction characteristic of four typical straws in China such as rice straw, cotton stalks, corn stalks, wheat straw, was investigated, which was carried out in the fixed-bed reactor and focused on the evolution of physical and chemical properties of straw during torrefaction. After torrefaction, the apparent volume of agricultural straw was significantly reduced and a more uniform distribution of particle size was observed which suggested the grinding performance could be significantly improved. Meanwhile, the number of solid oxygen-containing functional groups in the solid product reduced. The significantly increasing of the fixed carbon content and the significantly decreasing of the oxygen content improved the heat value of solid products. Although the mass and energy production yield ratio decreased after torrefaction, the energy production yield ratio was better than the mass. The torrefaction was benefit to the improvement of energy property and material characteristics of straw and had a positive effect on the quality of biomass material.

Abstract:The compression process LS-SVM model of biomass compound coal mixed with sawdust, coal and rice hull was established according to the published experimental data. The test result showed that the maximum relative error of predicted and experimental values of two models was 3.46% and 5.83%, which proved the efficiency of model. On this base, the multi-objective optimization objective function of compression process was designed and fitted, by which the Pareto optimal solutions were gained in a single run. According to the standard target of solid biomass fuels and CV value which represented the comprehensive performance of biomass compound coal, the efficient solutions that are suitable for compression process were selected from the Pareto optimal solutions under different indicators for compound coal mixed with sawdust, coal and rice hull.

Abstract:The tolerance of Saccharomyces cerevisiae and Pachysolen tannophilus to inhibitors including furfural, 5-hydroxymethyl furfural and levulinic acid in diluted acid hydrolysis from rape straw was investigated. S. cerevisiae was capable of tolerating 2 g/L furfural, 2 g/L 5-hydroxymethyl furfural and 8 g/L levulinic acid in glucose broth. However, ethanol production by P. tannophilus was strongly inhibited in xylose broth added with 2 g/L furfural, 2 g/L 5-hydroxymethyl furfural and 8 g/L levulinic acid, respectively. In glucose broth containing 2 g/L furfural, the ethanol yields of S. cerevisiae and P. tannophilus were respectively 85.05% and 46.70% compared with those of the control, while in xylose broth added with 2 g/L furfural, the ethanol yield of P. tannophilus was 12.40% compared with that of the control. Enzymatic hydrolysis of rape straw could effectively relieve the inhibition of 2g/L furfural on both the S. cerevisiae and P. tannophilus, whose ethanol yields were respectively 98.40% and 91.00% compared with those of the control. The results showed that the tolerance capacity of S. cerevisiae on fermentation inhibitors including furfural, 5-hydroxymethyl furfural and levulinic acid was stronger than that of P. tannophilus. 

Abstract:In the process of concentrating anaerobic fermentation slurry to commercialized liquid organic fertilizer with membrane filtration devices, UF membrane fouling was always a serious problem. The influence of in-line coagulation pretreatment on UF membrane filtration flux was investigated. The experiment applied six inorganic coagulants (ferric trichloride, ferrous sulfate, aluminum sulfate, potassium sulfate, sodium silicate, PAC), and separately studied the best coagulant and its optimal dosage in two groups. Results showed that ferric trichloride was most efficient and relatively less cost. At FeCl3 dosage of 8 g/L, the stable flux was 14.38 times more than the raw water, and only one third of the PAC dosage with the same effect. With the increasing of ferric trichloride dosage, the stable flux increased first and reached to the maximum under the dosage of 10 g/L, then decreased, which is closely related to re-steady phenomenon. Based on an overall consideration of flux improvement, pollutants removal and dosage, FeCl3 dosage at 8 g/L was considered to be the optimal dosage.

Abstract:Swine manure was mixed with corn stalk powder as a bulking agent, and the mixtures were amended with flyash at 0, 2.5%, 5.0%, 7.5% and 10% and composted for 90 days. Addition of flyash raised the pH value of the swine manure compost throughout the composting period, but significant inhibited the rise of electricity conductivity during the later period with the ratio of flyash increasing. C/N ratio decreased according to composting time, whereas total N showed an opposite trend for all treatments except 10% flyash was amended. There was no significant loss ofNH+4-N during the thermophilic phase by ash amendment. While, addition of flyash also inhibited the nitrification process as indicated by the lower soluble NO3-N content in ash-amended swine manure composts but had no effect on TP and TK increasing. The GI and germination rate of potherb mustard (Ardisiasquamulosa presl) seed increased with composting time, while the root growth was significant inhibited when flyash was amended and the germination rate indicated that flyash amendment did not affect compost maturity in 90 days composting.

Abstract:In order to solve such problems as low-level security of traceability code for agricultural products and difficulty to guarantee the traceability code was unique for one product, taking aquatic products as research object, an encryption algorithm of traceability code for aquatic products was put forward. At the base of analysis to coding solution of traceability code and AES encryption algorithm, the aquatic product was coded. Then, this supervision code was compressed and encrypted by an algorithm namely decimal and equal-length to generate the traceability code for aquatic products. The experimental results showed that the proposed algorithm was feasible and reliable. It ensured the deployment security of traceability system owing to the feature of uniqueness and dynamic cipher of traceability code. An example of the application solution of the encryption algorithm in aquatic products traceability system was introduced. 

Abstract:Since fruit and vegetable are highly perishable, and have strong timeliness in selling and consuming, the delivery routes of transport vehicles must be planned reasonably. On the path of fruit and vegetable delivery, a transport vehicle may encounter some unusual circumstances and may not arrive at the next distribution site in time. In this case, the vehicle routes of other transport vehicles should be replanned. A mathematical model for vehicle route replanning with time windows for fruit and vegetable delivery was established, and an improved ant colony algorithm was used to resolve the model. Simulation experiment results showed that the new dispatching routing of fruit and vegetable could be optimized efficiently by using the proposed model and adopted algorithm. This research could provide theoretical support for enterprises which hoped to decrease rot loss of fruit and vegetable, increase sales income and control operating cost effectively.

Abstract:The extruded okara-maize blend was studied on rheological properties to improve the usage of okara and expand the application range. The effects of process temperature, feed moisture, and okara concentration on the rheological properties of okara-maize blend were investigated.The sample was tested in both frequency sweep and creep-recovery test modes. The frequency sweep test data was regressed with power law model. The creep test data could be regressed with Burgers model. Both tests obeyed the corresponding model well.

Abstract:Drum drying characteristics of pumpkin pulp were investigated by using a single drum dryer with applicator rolls. The drum drying process was divided into two phases: pulp phase and flake phase. Under these two conditions, moisture content of the samples under different steam pressures was measured in order to analyze the relationship of the drying rate with the inner pressure and drying time. It indicated from the results that, most of the moisture evaporated during the pulp phase. The higher the steam pressure was, the higher the drying rate became. It was also shown that during the flake phase, only falling rate period was taken place. As the steam pressure increased, on one hand, the initial moisture content of flake phase became less and the drying rate became decreased, on the other hand, the decreasing of the drying rate was slow down and the drying time was much shorter. The experimental moisture loss data were fitted with 10 thin-layer drying models. Consequently, of all the drying models, a semi-theoretical Midilli-Kucuk model was fitted best.

Abstract:In order to achieve ohmic heating for liquid food, by using rectifier and inverter technology, continuous ohmic heating device was designed. The equipment was consisted of controllable pulsed power supply, ohmic heating chamber, pump and flow controller. Controllable pulsed power supply can output bipolar-rectangle waveform pulse voltage with high frequency. The frequency, amplitude and duty ratio were adjustable. The output capacity could reach to 50kW. The result showed that the device could be controlled speedily and easily. It could meet the requirement of liquid food process and without pollution. 

Abstract:To explore the distribution and the estimation model of the basic geometry parameters related to the automatic direction of the tip side and blunt side of eggs, geometry, quality center location, volume and quality of poultry eggs were measured. Relationships between egg geometry and the volume, quality were studied. The results showed that the geometry and quality of eggs were normal distribution. It was found that the quality center of poultry eggs was at the midpoint of the length. The distance from the quality center to the intersection of the length and the breadth was within 3～5mm. The supporting method was better than weighing method. The correlation coefficient of estimated volume using standard ellipsoid volume methods and actual volume of native egg, feed egg and duck egg were all more than 0.94. The correlation between the weight and the approximate volume of eggs was better than that with the length, breadth, their ratio in a cubic regression, also that with the oval area over the length in a linear regression. The correlation coefficient of the weight model of native egg, feed egg and duck egg were all more than 0.95.

Abstract:Color-difference was presented to assess the lycopene content conveniently and non-destructively. Due to excessive affecting factors and strong correlation among the parameters in the process, the support vector machine (SVM) was used to set up the predict model. The selection and simplification of the feature parameters was discussed. A compound optimal objective function based on Akaike information criterion (AIC) was constructed. The particle swarm optimization (PSO) algorithm was used to search the optimal value of the objective function and enhance the efficiency. The predictable method had good performance in assessing the lycopene content of different maturity stages.

Abstract:The optimum extraction technology and antioxidant activity of glycoprotein from Camellia oleifera seed were performed for future development and utilization of the Camellia oleifera. On the base of singlefactor experiment, the optimum parameters of extraction for glycoprotein from Camellia oleifera seed were determined by response surface methodology. The antioxidant activity of glycoprotein was examined by using various antioxidant assays with vitamin C co-assayed as positive control. As a result, the optimized condition of glycoprotein extraction was as follows: extraction time of 8.81h, salinity of 0.12mol/L, pH value of 8.77, ratio of liquid to solid of 11.62mL/g. At the optimum conditions, the yield of protein reached to 8.76%, and the yield of saccharide reached to 10.14%. The results of above antioxidant tests demonstrated that the glycoprotein from Camellia oleifera seed has certain antioxidant activities.

Abstract:In order to achieve precise control effect of greenhouse environmental factors, an innovative optimization control system arithmetic based on CFD was presented. By using orthogonal experiment in DOE, controller design in the optimal system was obtained, meanwhile, iteration times of CFD could be reduced as soon as possible. Taking control temperature field as an example, through setting up temperature distribution index and making its minimum by the strategy of using iterative algorithm with CFD calculated, the difference of temperature distribution could be decreased. The greenhouse comprehensive production efficiency was improved. Lastly, an experiment was illustrated by proposed method. The results showed that the algorithm was proved to achieve the control law easily. 

Abstract:For finding a way to guard against theft and operate irrigation and spray equipment automatically of remote orchard pump house, an intelligent monitoring system was developed and tested. The system can accomplish two functions, including telephone dialing alarm and remote control with micro controller unit as the core, with dual-tone multi-frequency remote data transmission technology. The system was tested in the given orchard and it proved that the successful rate of accomplishing the functions was 96.5%, the alarm average response time was 4.58 s, the remote controlling average response time was 23.27 s, and every time the cost of communication was the normal telephone fee. Experiments show that the system can accomplish its functions and satisfy the requirements of guarding against theft and remote controlling irrigation and spray equipment of orchard pump house. 

Abstract:In order to study the temperature distribution along the porous pipes, the vertical temperature gradient in space below greenhouse canopy and the relation between temperature gradient and its main influencing factors on the basis of heat dissipation of pores, the heating system of greenhouse canopy with hot blast based on porous pipes was established with inlet temperature, inlet pressure and diameter of outlet as the experimental factors. Through thermal insulating porous pipes, the temperature of the front outlets, middle outlets and end outlets of porous pipes and its distribution in vertical space were measured. The results showed that the outlet temperature decreased along the porous pipes, while the temperature in vertical space decreased after an increasing trend. Under different inlet temperatures and inlet pressures, the temperature in 800～1200 mm height space of thermal insulated room rose 2.5～6.2℃.

Abstract:The agricultural intelligent mobile platform is the premise and basis of farmland intelligent operation, so a prototype of agricultural intelligent operation was developed. It was consisted of mechanical system and control system. The mobile platform can navigate autonomously. It showed a certain openness which could meet various requirement of farmland intelligent operations. The autonomous navigation program and human-machine interface were programmed with VC++6.0. The field navigation tests of the prototype were carried out in the orchard of Feng county in Jiangsu province. Results revealed that this platform performed well in the integrated navigation mode and the error was 0.05m during straight path movement, whereas in curved path the error increased to 0.11m.

Abstract:The over goal of this study was to develop a laser scanner based automatic navigation system capable of guiding an autonomous mobile robot traveling in the orchard. An automatic navigation system, which consisted of a laser scanner, an inertial sensor, a DC PWM servo motor and a computer was developed and mounted on the mobile robot. A program based on quadratic curve was developed as the algorithm to planning navigation path. A controller based on fuzzy control was designed. The performance of the control system was tested in sinusoid condition at the travel speed of 0.54m/s, the maximum error was 0.40m and the mean error was 0.12m in the test. The test result demonstrated that the system could navigate the mobile robot to traverse a curve alleyway of a simulative orchard condition with a relatively good accuracy.

Abstract:It is significant for constructing real corn leaf model by extracting midvein from 3-D point cloud model. Three algorithms, including curvature computation of meshes, parameterization of meshes and skeleton extraction of point cloud, were used to extract midvein from 3-D point cloud model. The whole algorithm was consisted of three steps, including incomplete 3-D point cloud extraction of midvein, complete point cloud extraction of midvein and 3-D midvein reconstruction. Through experiments on different kinds of corn leaves, it indicated that the proposed algorithm could extract the midvein of corn leaf faithfully with less runtime.

Abstract:In order to identify maize purity rapidly and efficiently, the image processing technology and clustering algorithm were studied according to the maize seed and characteristics of the seed images. An improved DBSCAN on the basis of farthest first traversal algorithm (FFT) adapting to maize seeds purity identification was proposed. The color features parameters of the RGB, HIS and Lab color models of maize crown core area were extracted. H, S and B were selected to be the effective characteristic vector. The abnormal points of different density characteristic vector points were separated by FFT. Then clustering results were combined after local density cluster by DBSCAN. Experiment results showed that the method played a great role in improving the accuracy of maize purity identification. 

Abstract:The detection system for stored-grain live insects was developed based on visible-near infrared computer vision. The system included an automatic sieving subsystem of insects, an automatic transporting subsystem of insects, an illumination box and an image acquisition subsystem. The insects could be rapidly and efficiently separated from the grain sample, and removed dust automatically in the automatic sieving subsystem of insects. The automatic transporting subsystem of insects could accurately receive the sieve material, and transport the collection box to the image vision acquisition part for image acquisition. The even illumination chamber could provide even visible and near-infrared diffuse light for the sieve material in the collection box. The image acquisition subsystem could simultaneously acquire the visual image and the near infrared image of the sieve material. The sieving accuracy of the detection system was 96.06% for the nine species of the most destructive live insects. The experiment showed that the system was practical and feasible.

Abstract:A variable frequency electro-hydraulic control system based on energy regulation was developed to improve slow respondence of the conventional variable frequency electro-hydraulic systems. An energy regulation device which could store redundant energy while hydraulic system was in decelerating period as well as release energy while the system was in accelerating period was employed in the variable frequency electro-hydraulic control system. This will enhance the dynamic characteristics of the variable frequency electrohydraulic control system. The experiments results which were compared with two other control systems showed that the variable frequency electro-hydraulic control system had excellent dynamic characteristics which like valve control systems. Furthermore, the throttle and relief energy loss of this system was little and even lower than conventional variable frequency hydraulic control systems.

Abstract:A thermo-mechanical coupling model for a flat plane and a rough surface based on 3-D fractal theory was established. The model considered the interaction between asperities, and integrated the heat flux coupling between the sliding surfaces. By using the nonlinear multiphysics field of the ANSYS software, the frictional sliding process of the elastic rough surface and the rigid flat plane (E/R model), and that of the elasto-plastic rough surface and the rigid flat plane (P/R model) were simulated. The frictional temperature, the contact pressure and the contact area under two different deformation characteristic of the rough solid during the sliding process were analyzed. The numerical results from the analysis and simulation showed that the maximum contact temperature of the rough surface rose slowly during the constant sliding. The maximum contact pressure and the contact area fluctuated within a certain range. The contact pressure and the frictional temperature of the elastic contact (E/R model) were larger than those of the elasto-plastic contact (P/R model), but the contact area was much smaller. The results demonstrated that the elasto-plastic deformation of the rough body had significant influence on the result during the thermo-mechanical analysis of the rough solid in the friction. 

Abstract:An undamped mode of pre-stressed straight beam was used as spectral function of Galerkin mapping to solve the dynamic problem for electrostatic-nonlinear beam coupling. The dynamic process of Pull-in and Pull-off for device was simulated. The proposed model was validated by comparing with the finite element results and the literature results. It was indicated that the proposed model not only had fast simulation ability with different action loads, but also suit for fast predicting the device characters variation with the different geometry size and different material parameters. The calculating results had sufficient accuracy and the computational costs were significantly reduced.

Abstract:According to practical requirements, a 3-SPS-S parallel manipulator mechanism was proposed to be rotation fine-tuning manipulator in shield tunneling machines. Also the kinematics of the mechanism was investigated. Furthermore, the local stiffness, local dexterity and driving force which were important factors for evaluating the performance of the mechanisms on the basis of kinematic model, inverse kinematics and Jacobian matrix were investigated. The kinematic performance of the mechanism was evaluated according to the specific requirements. The results showed that the proposed mechanism had good kinematic performances and could be used in fields like shield tunneling machines.

Abstract:A parallel mechanism was used in spray painting equipment for large and flat cube workpiece. A 5-axes decoupling hybrid spraying robot was designed. The mechanism design, working principle, kinematical analysis, drive mode, hardware composition and control method of control system for the spraying robot were expounded. The robot had compact structure, high spraying efficiency, uniform coating thickness, simple operation, and good prospect.

Abstract:A six pyramid parallel robot was taken as the object, and the dynamic model of the robot was established by using the Lagrange method. The relationship between the drive current and tasks trajectory was analyzed combined with the design principle of linear motor. With the goal of minimum instantaneous kinetic energy, motor drive was optimized based on genetic algorithm. Energy consumption optimized was reduced by 47.6% compared with non redundant tasks. The experiment of redundant track tasks was carried out. The experimental results showed that the current change was in good agreement with the simulation results, and the feasibility and rationality of this optimization method was verified. 

Abstract:Six-link transmission mechanism optimization design was proposed with the multi-objective demand of path, velocity and acceleration. A brief uniform mathematical description of the slide motion path was established using Fourier series theory. Then the formulas of the slide velocity and acceleration were obtained. According to the constraint conditions of mechanism engineering design, taking the minimum deviation error of slide kinematics data and the minimum mechanism height as the optimization object, the optimization model of transmission mechanism design was established. It was performed by the composite optimization algorithms based on penalty function and complex algorithm. The validity and effectiveness of the proposed method were verified by a practical instance.

Abstract:The micro-displacement turret of ultra-precision CNC lathe was designed, which could meet the needs for precision machining. The power source of the turret was piezoelectric displacement actuators. The guide of the turret was double parallel four-pole flexible hinge institution. The main parameters of the turret were the maximum output displacement. The structure of micro-displacement turret was designed and calculated. The stiffness of flexible hinge institution was calculated by theoretical modeling and finite element analysis, and the output displacement of 2-D micro-displacement turret was tested. The results showed that the results theoretical calculations, finite element simulation coincided with experimental data, which could verify the reliable of the design method.