Abstract:The vehicle easily loses yaw stability in the emergency obstacle avoidance manoeuvre, and the vehicle yaw stability control can be accomplished by applying the vehicle additional yaw moment by means of four wheels differential braking. As the vehicle dynamic model is nonlinear and its parameters and environment is uncertainty, the vehicle additional yaw moment decided by the optimal control is always unable to maintain optimal in reality. The generalized predictive control (GPC) method was proposed for deciding the vehicle additional yaw moment. The nonlinear 7-DOF vehicle model was built as the predictive model, and its accuracy was verified by vehicle tests. The control performances of GPC method were verified by virtual tests in the Simulink/Carsim, test results showed that the GPC method was more effective than the LQR method in improving the vehicle active safety. 

Abstract:A numerical methodology for designing observer feedback gains based on local linearization was proposed to make employing tire models with a higher accuracy and more complicated expressions become possible. The proposed methodology was implemented by discretization of the nonlinear system in the state space and calculation of the feedback gains at a certain given number of operating points using numerical approaches. The gains at discretized operating points were fitted to the expressions with respect to state variables to facilitate realtime observation and implementations. The effectiveness and parameter variation robustness of the proposed methodology were evaluated in a highfidelity vehicle dynamics simulation environment, and the simulation results show that the proposed methodology has a high estimation accuracy and good robustness.

Abstract:With the aim to obtain the time-varying braking performance of emergency oil-filling process of hydraulic retarder, a numerical simulation model of flow channel was established based on transient CFD method. The inlet velocity, outlet velocity and a steady flow field result were calculated and applied as the boundary condition and initial condition. Then the transient simulation of emergency oil-filling process was calculated when the initial rotor rotating speed was 2640r/min. The pressure, the velocity and the turbulence kinetic energy distribution of internal flow field under different braking time were studied, and the time-varying braking torque was calculated by CFD post-processing analysis. Comparison of the experimental data and simulation results showed that the calculation tolerance of the braking torque was 12.7%. It is indicated that the simulation method and model are accurate and reliable, and the transient simulation method is more appropriate to predict the time-varying braking performance of hydraulic retarder.

Abstract:Hybrid architecture of autonomous vehicle system was built based both on function and behavior so that requirements in autonomy, real-time and adaptability could be met. Functional decomposition architecture was used to automatically control the vehicle while behavioral decomposition architecture was used to handle the complexity and variability of environment which highly challenged responsiveness and adaptability of vehicle’s planning system. Experimental results showed that a hybrid architecture based system enabled the vehicle to drive autonomously while having sufficient adaptability and realtime as the environment changes.

Abstract:A vision-based self-localization method was proposed for underground mining vehicle by using landmarks. Firstly, several artificial landmarks were located in a simulating tunnel, and then a vision sensor in vehicle was used to find and recognize them. After the distances between the vehicle and the recognized landmarks were calculated by a visual distance measurement method, the location of the vehicle was computed according to triangulation finally. In this self-localization method, landmarks were encoded by interleaved 2 of 5, a type of 1-D barcode with high density. Each landmark has obvious visual feature and there is a unique corresponding location data to it in the landmark database. Distance between a landmark and the vehicle was calculated on the basis of the ratio of the coding area’s actual height to its height in the image according to the pinhole imaging principle. Experimental results showed that the self-localization method suggested almost meets the requirement for autonomous driving vehicle because of its high efficiency and precision.

Abstract:According to the working principle of the two-actuator fuel injection system, the available control modes were discussed firstly, the delay time from control signal to fuel injection was analyzed, variation characteristics of NOP at different speeds were figured out and injection characteristics were explored then, the experimental results showed that the difference between SV and NCV control angle could change the value of NOP, NCP and MFIP effectively. Finally, the control algorithms were explored emphatically, calculating method for NCV desired SOI and durations were introduced and the control strategy of two-actuator fuel injection system was proposed, and the NOP control MAP that reflected it tendency with different speeds and the control angle difference was analyzed, which provided the basic theory for vehicle purpose.

Abstract:A set of steady temperature measurement device was developed. A high accuracy of ±1℃ could be obtained by the system as long as the error was calibrated. The piston temperature was measured at the engine speeds of 1000r/min, 1500r/min and 2100r/min on the external characteristics of the engine of EQD180N—20, respectively. The piston temperature variation test was performed from 1000r/min to 2100r/min simultaneously. The results show that the proposed system is stable and reliable. On the external characteristics, the temperature of each feature point increased firstly and then declined slightly as the engine speed increased, and a maximum value was observed at 1500r/min; on the stable working condition, the highest temperature appeared in the piston top surface with a value of 264℃, The first piston ring slot temperature is about 215℃.

Abstract:The low specific-speed centrifugal pump with the specific speed of 26 was selected to be the numerical model. Under the condition of other geometric parameters of the volute and impeller maintained constant, the radial reflux balance hole, the traditional axial balance hole and none balance hole were designed to couple with the low-specific centrifugal impeller respectively. Based on the continuity equation, momentum equation, standard k—ε turbulence model, homogeneous multiphase model and Rayleigh—Plesset equation, the cavitation performances of the pump with different reflux balance holes were simulated. The trend of simulated H—LNPSHa curves were consistent with the experimental data, in addition, the accuracy of numerical simulation was also verified. The results showed that with equipped radial reflux balance hole, the anti-cavitation performance of the pump can be improved obviously due to the coincidence between the balance-hole backflow with impeller inflow. 

Abstract:The dynamic stress analysis for a large double-suction centrifugal pump impeller was presented by using the finite element method. This analysis was based on the sequential fluid-structure interaction theory. The pressure pulsation obtained from flow simulation by using CFD code was set as the force boundary condition. The dynamic stress characteristics of the impeller under five flow conditions (0.6Qd, 0.8Qd, Qd, 1.1Qd, 1.2Qd) were given. The results showed that the maximum stress of the impeller appeared at trailing edge or leading edge region of the blade near shroud. The stress distributions on impeller blade surfaces under different flow rate conditions are similar to each other. The level of dynamic stress under 0.6Qd is the highest. The dynamic stress varies periodically with the impeller rotating. It is also found that the fundamental frequencies of the dynamic stress are the rotating frequency and its harmonic frequency.

Abstract:The optimization design of vortex pump impeller parameter was done by using the orthogonal design method. Orthogonal scheme of five factors and two levels was designed, and the influence of geometrical parameters on the characteristics was studied. Reynolds averaged Navier—Stokes method was adopted to simulate every set of parameters obtained by the orthogonal design method. Optimal scheme of the characteristics was found by analyzing the contrast of performance curves. The influence orders of geometrical parameters to the characteristics were obtained with range analysis. The optimization parameter combination was obtained with comprehensive balance analysis and comparison to the data result. Meanwhile, the optimized design scheme was determined, and corresponding test was carried out. It demonstrated that the experimental purpose was reached, the design method was reasonable, and it had the property of both high efficiency and non-overload.

Abstract:The steady and unsteady interflow fields in centrifugal pump with double curvature blade were investigated by CFD, which was compared with general centrifugal pump in the same design parameters. The characteristic of interflow fields and pressure fluctuations at different monitoring points were obtained. The results showed that it can prevent the impeller from emerging and developing wake flow in double curvature blade centrifugal pump. The main factor which created the pressure fluctuation in the pump was the interaction between the impeller and the tongue, and with the flow rate increased, the pressure fluctuations at the tongue were getting bigger. At the same flow rate, the pressure fluctuation’s amplitude value on double curvature blade type centrifugal pump was smaller than the ordinary centrifugal pump, which reduced the pump’s hydraulic loss to some extent. The results are served as the theory basis in optimization of pump structure and reduction of pump’s noise and vibration.

Abstract:A method of compacted soil rotary tilling with variant frequency vibrationis proposed. The tea garden soil physical parameters was measured with soil triaxial test referring to the MAT147 soil model from LS—DYNA material library, then a soil constitutive model of the southern hills’ harden soils and the finite element numerical simulation model for soil vibratory rotary cutting process were built. Through 3-D numerical simulation and analysis, the influence rules on soil cutting resistance caused by many factors of external vibration excitation such as amplitude, frequency and vibration model were studied, and the optimal vibration operation parameters conducive to soil cutting resistance reducing was deduced and confirmed. The results show that the finite element method SPH is effective for large strain and high strain rate numerical simulation of compacted soil rotary cutting, and choosing appropriate vibration frequency, amplitude and vibration types of vibration excitation can reduce tillage mechanism power and improve working efficiency.

Abstract:The relationships between the soil water repellency and soil moisture were studied by measuring WDPT using 10 different water repellent soils collected from Israel. A single peak curve correlation of the relationships between the WDPT and soil moisture was obtained after analysis. Three mathematic models, namely Gaussian, Lorentzian and Lognormal distributions were used for fitting the models by regression analysis, and the Lorentzian distribution was found to be the best model for the practical use. The peak soil moisture, the peak WDPT and the critical soil moisture can be computed by the model of part measured WDPT and soil moisture. It can provide the theory for amelioration of soil and compare of the different repellent soils.

Abstract:The basic concept of soil water repellency was introduced, the effects of soil water repellency on field water cycle, soil and water conservation, and groundwater environment was summed up. The reasons of soil water repellency were analyzed. The domestic and international methods used for detecting the degree of soil water repellency and their characteristics were introduced. The research advancement of spatial variability for soil water repellency, soil water movement of water repellent soil during infiltration and evaporation process, and measures for improving infiltration ability of hydrophobic soil were also reviewed and assessed thoroughly. Since there were closed associations between soil water repellency and filed water cycle, microbe activity, runoff and sediment production, and pollution of ground water environment, it was urgent to do related research.

Abstract:Four typical superabsorbent polymers were tested to study their impact on the physical properties of sandy soil and the growth of corn. Results showed that superabsorbent polymers evidently ameliorated soil water characteristics. Concentration of SAP from 0.50% to 1.00% had a typical significance to Ordos sandy soil. Superabsorbent polymers effectively improved the water holding capacity of soil, and the ameliorating effect in low soil water suctions(＜0.8MPa) obviously superior to the high soil water suctions(＞0.8MPa). In terms of soil available water of Ordos sandy soil, polymers of polyacrylate had better performance than polymers of polyacrylamide in lower SAP concentrations (＜0.5%),while in the higher SAP concentrations (＞0.5%) is the opposite. Soil bulk densities were decreased with the increase of concentration of superabsorbent polymers. Soil total porosities were increased with the increase of concentration of superabsorbent polymers. The survival time of maize was longer when the amounts of superabsorbent polymer were higher.

Abstract:Based on the field experiments carried out in Yangling, the values of irrigation performance were simulated by the WinSRFR software, and the influence of border length, field slope, unit discharge and cutoff time on irrigation application efficiency, distribution uniformity and storage efficiency were analyzed. On this basis, combined with uniform design and multiple regression analysis，a single-objective optimization model was established including irrigation application efficiency, distribution uniformity and storage efficiency, and taking unit discharge and cutoff time as variables. The model was solved by genetic algorithms, the optimized combination of irrigation technique element under different theories of water requirement were proposed in Wangshang Village, the results show that it can realize a high irrigation performance and water saving for border irrigation through a proper selection of unit discharge and cutoff time.

Abstract:In order to search for more timeliness and accuracy of forecasting methods, Yutian County, Hebei Province was chosen as the pilot site. A three-year field experiments were conducted on winter wheat. During different growing periods, three yield-contribution factors were measured in situ and the analysis was done. The results revealed that single-factor model of application allowed the prediction of time ahead of winter wheat yield to the heading stage; the prediction accuracy can reach to 88%. Prediction of two-factor model can be advanced to the heading stage to the early filling stage, and the AI is more than 90%. This study provided an effective method namely the multi-stage prediction model to effectively predict crop yield. It can overcome the regular operation problems and provide important references for agriculture warning system by remoter sensing at all levels of agricultural crop production forecast.

Abstract:The process of biomass gasify has the characteristics of nonlinear, large delay and strong load disturbance. For these features, a double-loop intelligent control based on gray ant combination prediction algorithm was presented. Firstly, the gray prediction algorithm was used to establish temperature model of gasifies. Secondly, considering possible disturbance, the ant algorithm was introduced to optimize the gray temperature model. The temperature sub-control system was based on the optimized gray temperature model. Finally, the variable universe fuzzy control algorithm was used in the oxygen content sub-control system. The gasify-air was controlled by the fuzzy rules in order to stabilize the temperature of gasifies, and reduce the oxygen content of the combustible gases. The validity and superiority was showed in the results of simulation and work site.

Abstract:With the aim to evaluate the appropriate upward flow velocity in UASB reactor, the separation efficiency of solid, liquid, gas in three-phase separator (TS) of USAB reactor was simulated via CFD technology based on Eulerian multi-phase model. Five upward flow velocities (UFV) as 0.50, 0.75, 1.00, 1.25, 1.50m/h were adopted in simulation for a typical UASB reactor. The result showed that the UFV had an obvious effect on the flow pattern inside the TS, the average velocity of liquid in the whole UASB reactor was around 3 times of the designed UFV, the average velocity of gas was 10% higher than that of the liquid, the average velocity of solid was lower and about half of the designed UFV, and the maximal solid UFV was in the same level with the UFV. The separation efficiency of solid and gas was higher in low UFV than that in the higher situation, while the difference was less than 2%. Site experiment showed a good agreement between the simulated data and measured one with a relative error within 8%.

Abstract:Wheat straw, corn stover, and saw dust were added into the main composting material, swine manure, respectively to study the effects on the aerobic composting. Dry weight of each material was 10%, 15% and 20% of the total dry weight respectively. The piles were turned over once every 5 days by labor. By the comprehensive research, the composting with materials of wheat straw and corn straw were better than others. The result showed adding more corn straw could get better effect, increasing the proportion of corn straw (when the proportion of corn straw reached 20%) can gain better composting effect than adding wheat straw, while the best proportion of wheat straw was 15%, under that condition, the best effect of composting could be obtained. The composting with litter ration of saw dust was relatively poor.

Abstract:With the cattle manure and lignite slag for fermentation materials, based on the single-factor test in the laboratory, C/N, moisture content, room temperature, ventilation time, pH value, organic matter were analyzed by orthogonal optimization to determine the optimum laboratory fermentation parameters as the basis for large-scale production. SPSS 12.0 was used to analyze the optimum parameters of large-scale production to determine the relationship of the factors which affected the fermentation process. The follows were obtained: the factors which affected the fermentation process are C/N, moisture content, room temperature, ventilation time, pH value, organic matter; the optimum parameters of large-scale production are moisture content of raw materials 65%，C/N 30, agent inoculums concentration 2.5L/m3, the number of turning: once every three days; the time of forced ventilation: 30min, these are consistent with laboratory parameters; the temperature from the fermented material surface (0~30cm) of the large-scale production was highest that was incompatible with the result obtained from equipment measurement. It has a remarkable linear correlation with side temperature,y=1.1487x+4.2773. All the detection indicators of the organic fertilizer in this process reached China’s industry standard NY 525-2002.

Abstract:The utilization of wood vinegar, a by-product of biomass pyrolysis, treated as wastes of agriculture and forest, has been attracting increasing interests all over the world. The anaerobic initial adsorption and degradation of wood vinegar to produce methane was investigated by using the activated sludge. The results indicated that the pseudoequilibrium of the anaerobic initial adsorption could be established in 10min and the rate of degradation was 15.6% while the physical adsorption played a significant role. Physical and biological adsorption was interacted after 10min. Accompanied by the acidification, the content of acetic acid and propionic acid were increased resulted in the pH value decreased. The style of organic matter adsorbed and degraded was mainly on phenolic compounds detected by GC—MS technique. The adsorption can be well described by the Freundlich equilibrium model. Methane analyzed by GC technique was increased with the increasing initial volume fraction of wood vinegar. The way of anaerobic adsorption and degradation on the activated sludge is the new path to treat the wood vinegar.

Abstract:‘Qinmei’ kiwifruit was used to investigate the change of electric properties and physiological parameters with the extension of storage time under the condition of storage at 20℃. Complex impedance (Z), parallel equivalent capacitance (Cp) and impedance angle (θ) three electrical parameters and 12 physiological parameters of fruits such as firmness were measured synchronously. The results showed that the Z of Kiwi dropped significantly on the late period of storage, Cp increased significantly on the late period of storage. Firmness and total acid (TA) of fruits were increased and total soluble sugar (TSS) was decreased with the extension of storage time. The reducing of content of starch and cellulose was positively correlated with the declining of fruit firmness.Z can quantify eight physiological parameters such as firmness of fruits, impedance angle (θ) can quantify five physiological parameters in the characteristic frequency of 0.1kHz.Cp can quantify six physiological parameters in the characteristic frequency of 1MHz and 1.58MHz.

Abstract:To obtain an overall view on transcript modification during the tomato fruit in response to postharvest UV-C irradiation (4kJ/m2), a microarrary analysis was performed by using Affymetrix tomato genechip arrays. The results showed that 331 and 150 genes were up- or down-regulated, respectively, more than two folds in postharvest UV-C irradiated tomato fruit as compared with that in control fruit. The up-regulated genes mainly involved cell wall related, signal transduction, stress related and defense response. Conversely, genes related to ethylene and primary metabolism were generally down-regulated. These results opened ways to probe into the molecular mechanisms of the effects of postharvest UV-C irradiation on increasing disease resistance, delaying ripening and prolonging postharvest life in tomato fruit.

Abstract:The effects of carrageenan, carboxymethyl cellulose solution and their complex film on the physiology and quality of mushrooms stored at (2±1) ℃ were studied. The minimum loss of weight was obtained in fruits coated with CMC coating, the minimum value of respiration rate, PPO activity, membrane permeability and the maximum hardness and L* value were obtained in mushrooms coated with carrageenan coating. Overall, the preservation effect of carrageenan film is the best, and it can extend the shelf-life of Agaricus bisporus to more than 12d.

Abstract:With in-depth development of the technologies of internet of things (IOT), they have been increasingly applied in food and agri-food areas. The RFID (radio frequency identification) and WSN (wireless sensor networks) in principles, techniques and other related information were introduced, a more comprehensive summarization and analysis of these technologies and applications in agricultural and food industry during recent years were given, such as food processing, food-safety control, the food supply chain traceability and tracking, etc. The problems and solutions were also discussed. Furthermore, suggestions for future research and application areas were put forward.

Abstract:The effect of die diameter, expanding temperature, feed rate, mass moisture content on the pre-pressed cake oil residue of rapeseed and the optimal conditions for lower cake oil residue were studied by response surface methodology. The results showed that pre-pressed cake oil residue was more significantly affected by the feed rate and mass moisture content, the pre-pressing cake oil residue was significantly affected by the die diameter; the pre-pressing cake oil residue was non-significant affected by expanding temperature. By frequency analysis, optimization of process parameters range is as follows: die hole diameter is 9.3~10mm, expanding temperature is 95.3~98℃, feed rate is 33.6~35.1t/h, material moisture content is 8.8%~9.5%. Under the condition of the parameters of the above mentioned, the residue oil content of pre-pressed cake is less than 13.5% as a possibility with 95% probability.

Abstract:With the aim to take full advantage of coumarin in cassava peel, the extraction technology of total coumarin was first researched from cassava peels by ultrasonic-assist. The optimal extraction technology condition of total coumarin was determined by the single factor experiment and Box-Behnken design test. The results indicated that the optimal extraction conditions were as follows: ethanol concentration 95%, ultrasonic power 550W, ultrasonic extraction time 90min, and ultrasonic extraction temperature 60℃, liquid-solid ratio 12mL/g. Under the optimal extraction conditions, the average content of total coumarin in avtive extraction was 2.48mg/g.The effect sequence of four main factors for the content of total coumarin are as follows: ultrasonic power, extraction temperature, extraction time, liquid-solid ratio. Compared with the traditional solvent extraction, ultrasonic extraction has obvious advantages including the higher content of total coumarin, faster extraction speed, good activity extracts, less solvent and etc.

Abstract:In order to better understand the wind affects the tree architecture deformation intuitively, an efficient modeling strategy of virtual tree swaying in wind was proposed based on the analysis of the existing thought and methods to simulate the tree movement in wind. The method used procedure function with stochastic factor to simulate the wind field; and the cantilever beam was used to simulate a segment of a stem as the mechanical analysis unit, the deformation of the beam in wind force based on the theory of wind projection and beam element was computed. Then the force transmission and movement compounding method was used to solve the whole tree movement in wind. Furthermore, some software function modules, which integrated with the parametric tree modeling prototype system, were developed. Taking Phyllostachys pubescens as an example, the tree swaying was simulated in different wind velocities and with different modulus of elasticity. The result is in accordance with the practical visual effects.

Abstract:With the aim to deal with the localization disadvantage of robot equipped with only single class sensor, a novel mobile robot particle filter self-localization method based on combination of the heterogeneous sensors was proposed. Perception model of LRF (laser range finder sensor) and monocular camera were established, and self-localization was achieved after the particle sets had been updated with fusion perception information. The experimental results showed that characteristics of fast and accurate updates of LRF and global of monocular camera was fully utilized, convergence time of particle sets was reduced by 14.3% than using a single class of sensor, and mobile robot located accuracy was improved by 16.7%.

Abstract:In order to improve the transplanter automatic operation level and realize remote automatic control of steering operation, with the Kubota NSD8 rice transplanter as the study platform, and under the condition of guarantee the usability of existing steering mechanism, a kind of remote automatic steering system was designed. The system mainly comprised steering actuator and microcomputer control unit, remote transmitter installation and receiver installation, angle sensor, and stepping motor. The system can realize remote automatic control of rice transplanter steering. Experiment on automatic steering performance of remote transplanter was accomplished by the system, transfer function of the steering actuator system was gained via experimental data and exploiting the way of system identification, and the system performance was analysed. The analysis showed that automatic steering system can provide reliable guarantee for realizing remote rice transplanter. It was tested about 180° and 90° of flat ground steering, test showed that automatic steering system can realize steering operation process of field work track predetermined.

Abstract:A digital intelligent monitoring system based on CAN bus was constructed. Based on CAN 2.0B frame structure, the principle and method of the CAN bus application-layer protocol constitution were addressed by analyzing the message identifier of extended superframe. The CAN bus application-layer protocol of monitoring system suited for cotton-picking machine was proposed. This protocol was applied on the prototype of cotton-picking machine. The experiment results showed that the proposed protocol not only met the need of intelligent monitoring system, but also be characterized by good portability and scalability. The research results can also be applied in other agricultural and engineer machinery.

Abstract:The heating test was conducted in a glass-covering multi-span greenhouse (756m2) with groundwater-style GSHP technology. The heat quantity estimating models based on air enthalpy difference method (AEDM) were developed according to the heating characteristics of GSHP. The economical performance and carbon footprint (greenhouse gas emission level) of the GSHP was analyzed and compared with currently widely used coal fired heating system (CFHs）and natural gas fired heating system (GFHs) based on investigated various energy sources price during heating tests. According to the compared results, the GSHPs heating cost is higher than CFHs, but lower than GFHs. Meanwhile, GSHPs CO2 emission during heating is higher than GFHs, but lower than CFHs.

Abstract:In view of the strong coupling between temperature and relative humidity in the greenhouse simulation system, an adaptive decoupling method based on dynamic matrix control was proposed. Taking the measure of feedforward compensation to eliminate interaction between channels of temperature and humidity, an adaptive decoupling algorithm by weighting was designed. The proposed method can adjust the decoupling parameters online under different operating modes, effectively overcome the effect of model severe mismatch to control accuracy. Compared with the traditional PID control, simulation and experimental results both indicated the proposed strategy greatly improved the control performance.

Abstract:The design quality information and matching method based on semantic distance was presented in product designing process. Product design process was divided into five phases, and then the model of product design quality information was built. According to the model, the design task, designer and design quality information were analyzed. The task meta, object meta and information meta were described and the data structure was built. Using hierarchical network of concepts (HNC) and combining with semantic distance calculation, the quantification and comparing of text similarity can be realized based on framework of context text similarity. Finally, the conceptual design of injection molding machine was taken as an example, the result showed the effectiveness of the proposed method.

Abstract:The strategy was proposed based on model and reference to adaptive control according to the properties of parameter variations and unpredictable, un-modeled error in parallel mechanism. Parameter variations and un-modeled error of mechanism system were treated as a disturbance to the practical system, an ideal reference model was established, and adaptive feedback rule was constructed depend on system status and the error. The adaptive control rule was derived by stability theory, and the practical mechanism had the same dynamic characteristics as parameter model. Example showed that adaptive controller could effectively restrain motion error which caused by parameter variations and un-modeled error, the mechanism has high tracking precision to planed target movement.

Abstract:An optimal synthesis method of adjustable spherical four-bar mechanisms for multi-function generation was put forward. Different functions can be generated by the same mechanism through adjusting the length of the connecting frame poles. Based on the function relation between the input angle and the output angle of the spherical four-bar mechanism, the optimization model was established. The objective function was given with the aim of minimizing the maximum of the absolute structural error, and the constraints were given to ensure the crack existed and that the mechanisms have good transmission quality. After this, the immune genetic algorithm was chosen for multi-function generation of adjustable spherical four-bar mechanisms. The result of the synthesis example verified the effectiveness of the proposed method.

Abstract:A modified fractal model of static friction coefficient of joint interfaces based on normal load model and modified size distribution is proposed. Furthermore, numerical simulation was carried out to obtain the complicated nonlinear relations. The results showed that the static friction coefficient versus the micro convex nonlinear relation with the normal load and increased with the normal load and material property increase, decreased with fractal characteristic length scale parameter G*, but complicatedly with D. This is explained that the modified model could be used to analyze and predict static friction coefficient.

Abstract:Big radius arc of stator curve in intra-vane type pump was replaced by an equal velocity curve whose radius was changed according to rotation angle. And advance rising pressure of oil in working room, contract force of vane and flow characteristic of pump were studied for intra-vane type pump. It is found that the amplitude of advance rising pressure of oil in working room was decreased after the rotor rotated 2°from the beginning of transition curve of vane pump when the big radius arc of vane pump stator curve was replaced by equal velocity curve. When the value of variable radius between the beginning and end of equal velocity curve was 0.1mm, the contract force of vane could be decreased by 160N and the rate of flow decreased by only 10－4m3/s. So the improved stator curve has little influence on flow characteristic, and the condition of dynamics characteristic of vane can be improved, with which the abrasion of vane and noise of pump can be reduced.

Abstract:The dragonfly wings were taken as the study objects, CAD and finite element analysis software ANSYS were applied to establish the finite element model of dragonfly wings. Through static analysis, the main vein structure was determined as load-bearing structure in dragonfly wings, the main vein and secondary veins coordinating so as to make the overall structure more reasonable. According to the characteristics of dragonfly wings wrinkled structure, the mesh model of rectangular and staggered quadrilateral fold structure was established, different mechanical properties under load were analyzed. The results showed that under the same uniform load, the greater the height of wrinkling was, the smaller structural deformation, and the greater structural stiffness would be. The analysis of quadrilateral mesh (no membrane) model in a different uniform deformation under load of the trend can be seen in the same wrinkle height, as the load increased, the deformation also increased, but as the wrinkle height increased, and with the smaller amount of deformation of the load increased, the quadrilateral mesh stiffness of the structure became slightly larger than staggered quadrilateral mesh structure. Under the same load, the deformation of a membrane mesh structure was always less than no membrane mesh structure.

Abstract:The bionic chewing equipment and parodontium were designed by bionic technology and two stages, a signal amplifying circuit was made, the testing software was developed by Visual C++, and then the bionic food texture analyzer was set up. Apples and carrots were measured by using this texture analyzer and the corresponding experiments were done and results were contrasted with those from panelists and the universal food texture analyzer. Pearson correlation coefficients showed that test values of the bionic food texture analyzer and sensory evaluation had a good relationship, the correlation coefficients with apple’s hardness, crunchiness were 0.970, 0.904, and with carrot’s hardness, crunchiness were 0.961, 0.971. The data are better than the coefficients from the universal food texture analyzer and sensory evaluation.