Abstract:Through active intervention in the vehicle vertical, horizontal and vertical dynamics, electronic control systems can improve stability and steerability of vehicle, thereby ensuring the safe driving. According to the mechanical properties of the tire, this article will coordinate active steering, active yaw moment control and active suspension with the use of model predictive control and tire force allocation strategy to achieve the coordination among the vertical, horizontal and vertical dynamics. Computer simulation results showed that the control strategy could effectively improve vehicle active safety.

Abstract:In order to coordinate the conflicts of the EPS system and EPS system in steering and braking condition, the integrated control logic of the systems was put forward. First, EPS controller and ABS controller were designed separately, and then an integrated controller was set up and controller area network was carried out to integrated control system，the results of simulation and hard-in-loop (HIL) experiment under LabView proved that the proposed integrated control logic was correct and feasible. It could apparently improve the overall performance of vehicle.

Abstract:Controller area network (CAN) can not deal with eventtriggered traffic and timetriggered traffic simultaneously and efficiently in real time system. Considering the flexibility of design and schedule, flexible time triggered CAN (FTTCAN) was introduced to manage the power transmission system in vehicle and build up in vehicle networks with CAN by linking with gateway. The method of allot messages in scheduling table (SchT) in synchronous phase was introduced. The analysis results of system such as real time performance and dependability verified the proposed scheme was feasible and showed perfect performance.

Abstract:For steer-by-wire (SBW) system removes mechanical linkages between steering system and front wheels, driver is unable to sense road information, a dynamic model of SBW system was established to analyze the road feel theory of vehicle steer system. The road feel control method of SBW system was designed to produce the steering road feel almost the same as that obtained in a conventional electric power steering (EPS) system. Road feel was computed by rack force of steer system and assist characteristics of EPS system. For rack force was difficult to measure, an algorithm was proposed to estimate rack force by Kalman filter. The test results showed that drivers could effective get road feel information and SBW system could improve the vehicle maneuverability by the proposed road feel control method.

Abstract:Particle filter (PF) algorithm was used in vehicle states estimation. A vehicle dynamics system containing constant noise and nonlinear tire model was established. First, the particles were predicted through nonlinear state transition function; then the weights of the predicted particles were evaluated based on current measurements. Finally, the key states were estimated though resample step. The PF estimator was compared with other estimators based on extended Kalman filter (EKF) and unscented Kalman filter (UKF). The results of virtual experiment based on ADAMS/Car and real vehicle experiment demonstrated that PF was available in vehicle states estimation.

Abstract:In order to study the influence of the random dynamic load of vehicles on the performance of half rigid asphalt road, the driving dynamic model of heavy truck was established by SIMPACK and each dynamic normal tyre force was extracted. A 3-D finite element analysis (FEA) model of half rigid asphalt road was established, and the dynamic responses of half rigid asphalt road under random dynamic load was analyzed. The results showed that the stress change of half rigid road was relative to the number of axles. When the wheels of a triaxial vehicle ran over the road in turn, the stress of each layer changed abruptly three times, and the maximal stress appeared when the middle axle and rear axle ran over. Within the vehicle driving region, the maximal press and tensile stress of each point on the pavement varied with the changes of driving distance and dynamic normal tyre force. The varied frequencies of the vertical stress, horizontal stress, transverse stress and horizontal shear stress of the points on the central line of the wheel track were similar to the varied frequency of the dynamic normal tyre force of middle and rear axles; and the varied frequency of transverse shearing stress were similar to the dynamic normal tyre force of front axle. However, the varied frequency of transverse shear stress of the points on the edge of wheel track was similar to the dynamic normal tyre force of middle and rear axles.

Abstract:Based on the characteristics of four-tracked vehicles, the mathematical model of steady steering on firm ground was established, considering the crawler width and skidsteering. The influences of the factors on the steering performance were analyzed. The virtual prototype of a fourtracked vehicle was built based on the multibody dynamics software RecurDyn and the steering tests were completed. The virtual prototype simulation results accorded well with the numerical results, which verified the correction of the theoretical model.

Abstract:A 4 axle driven hill terrain vehicle was made in China. To improve the vehicle fatigue strength and reliability, the dynamics models of 4 axle-load were founded when it crossing obstacle. According to the dynamics models, the axleload distributions of the vehicle crossing obstacle were calculated when offroad adhesion coefficient φ is 0.1~1.0. The results showed its axleload distributions had more different among 4-axle when the vehicle crossing obstacle, the distribution law was analyzed. The design of 4-axle different strength and improving the 4-axle strength was put forward. The paper provided a mathematic model for reliability design and optimizing distribution of torque when the hill-ground crossing obstacle.

Abstract:The hydraulic system of electronic-continuously variable transmission (e-CVT) of full hybrid electric vehicle was designed. Hydraulic scheme was confirmed based on the structure and driving modes of the hybrid system. Oil pump was driven by output shaft or electric motor in order to match the flow requirement of different driving situation. The structure dimension of hydraulic valves was designed by theoretical calculation. The dynamic model of hydraulic system was established by ITI-SimulationX to investigate the characteristics of oil flow and pressure. Simulation results indicated the hydraulic system could satisfy the design flow and pressure requirement.

Abstract:The existing mathematical model of magneto-rheological damper (MRD) could not describe its characteristics correctly, so dynamic characteristic test on large scaled MRD was carried out. According to the test data, the dynamic nonlinear feature on elastic, damping and current saturation characteristics of MRD was analyzed with variable excitation displacement, excitation velocity and controlling current. Bouc-Wen model was not accurate enough to reflect hysteretic loop in low speed and lack hysteretic characteristics in high speed. It was also unable to express the offset phenomenon of damping force caused by pressure accumulator in single rod damper. Thus, a modified Bouc-Wen model was established. The parameters of the new model were identified with the test data, and the slope and width of hysteretic loop in velocityforce curves under high and low speed emphatically analyzed. The modified Bouc-Wen model was verified by experiment data finally.

Abstract:The 2BMG-24Q pneumatic no-till wheat planter was designed. Seeds were transported into seeder pipes with high-speed air current to perform precision metering. The wavy disc coulters were used to cut stubble for sowing, and the double disc coulters were used to open furrow for fertilizing. The test results showed that the quanlification percent of seed depth and fertilizer depth were 88.3% and 85.2%, respectively.

Abstract:A 3-D, incompressible, viscous, RNG turbulence model and the SIMPLE method were used with computational fluid dynamics(CFD), and flow fields of suction cylinder-seeder with different sockets were simulated by Fluent. When under pressure was -4kPa, productivity was 350 trays per hour, row spacing of sockets was 23mm and pitch of holes was 31.4mm, the pressure was uniform, the velocity was stable. Energy loss mainly occured nearby slots and export, and there was almost no interaction among socketsslots, which indicated that sockets of cylinderseeder were distributed reasonably in axial and circumference. The hemispherical socket was more appropriate by contrasting different sockets on average turbulent kinetic energy, average vacuum and maximum velocity difference in side of slots. The experimental results showed that hemispherical socket had the best seeding performance(85.34%) which was consistent with simulant results.

Abstract:A slot wheeled precision metering device for rapeseeds was designed. The structure and working principle were studied. The metering mechanism mainly consisted of a seed-cleaning wheel axle, a seed-retaining belt and a weed pushing ringed wire-steel. By experiments, the key structure and performance parameters were analyzed and determined, the lowest seed damage index was obtained when the speed of seedcleaning wheel axle was 104r/min, the diameter of shaped hole was 2.8mm and the inclined angle of wire steel was 33°

Abstract:Magnetic seed-metering element is the core components of the magnetic precision seeder. In order to improve performance, a new seed-metering element with magnetic shield was put forward. By using FEA software, the magnetic field characteristics were analyzed for two kinds of seedmetering elements with and without magnetic shields, respectively. The distribution of magnetic induction intensity was obtained at head face, as well as air-gap space of the two kinds of seedmetering elements. The research results showed that the magnetic energy utilization and magnetic induction of the seed-metering element with magnetic shield was higher than the other one which had no magnetic shield, and the intensity of magnetic induction at the end of seed-metering element which had magnetic shield was higher, 30.41% than that non-magnetic shield element on the same number of amperes turns, so it was lustrated that the performance of the element with magnetic shield should be better than non-magnetic shield element. By analyzing and comparing axial and transverse magnetic induction for the three kinds of seed-metering elements with magnetic shields, obtained cone element was the optimal model. The experiments including the intensity of magnetic induction, the lowest electric current and seed-metering performance verified the theoretical analysis and optimized element were correct.

Abstract:A real-time precision monitoring system for precision seeder was developed, and a single-chip microcomputer was used to process the signal of seeds dropping obtained by a photoelectric sensor. The information of seeds quantity, missing rate and multiples rate was all recorded in this system. A linear laser and patched photosensitive diodes which were arranged tightly in line were used as the emitter and receiver to achieve a no blind spot monitoring, it is better to monitoring seeds with an effective diameter of about 2mm or larger. A self-cleaning device was designed thereby guaranteed reliable operation of the monitoring system in severe environment. A pneumatic corn seeder and corn seeds “Nongda 86” were used in the experiment, meanwhile, a highspeed line camera was used to verify the accuracy of the system. Results indicated that the monitoring system had an accuracy of 98% in seeding quantity, an accuracy of 96% in missing detecting and a high reliability.

Abstract:Based on force analysis of key weeding components, 3ZS-150 paddy weeding-cultivating machine which could remove the weeds between seeding lines and inter-rows was designed. The machine motive power from the transplanter and equipped with the spring-tooth cutterhead、inter-row weeding hoe. The field performance testing showed that when the average cultivating depth was 31mm, the cutterhead rotation speed was 186～190r/min, and the forward velocity was 0.35m/s, the average cleaning rate was 80.46%，the injury seedling rate was 4.76%.

Abstract:In order to reduce throwing soil as fertilizing the field, mathematical model of pricking hole mechanism was built, computer aided analysis software was developed in VB language. Simulation results showed that the effort factors of fertilize related to spraying needle, rocker, angle of spraying needle and rocker, planet carrier and so on. One of the optimum parameters were that, the length of rocker was 197mm, spraying needle was 180mm, angle of spraying needle and rocker was 76°, the initial planet carrier of angle was 31° and the initial angle between the line of connection with planet wheel axle and spraying fertilizer needle’s D and the line of the center connection of planet carrier was -70°. The optimal model was verified to get well effect on pricking hole mechanism.

Abstract:The 3-D parameterized model of apple seeding lifter was created using autodesk inventor professional (AIP) system. The finite element analysis (FEA) of the lifter were performed through ANSYS technology embedded in AIP analysis types based on the structure, material, loads and forces of the lifter, the 3-D FEA mesh was created, and stress, displacement, and safety factor were obtained after finite element calculation. Then some modifications of lifter configuration were made according to the FEA results. The new lifter with L shape could save materials, reduce resistance. The safety factor could also achieve design purpose. The experiment of lifting seeding results showed that the lifter could provide better working performance with less resistance and obtain the expected effect.

Abstract:To meet the agronomic requirements of maintaining the garlic clove upright with its root downward during the process of garlic planting,operating principles of rice transplanting mechanism was used as the optimal design basis of planting system of garlic planting machinery. Equations of cave width, space, depth were obtained through kinematic analysis. Mathematical optimization model was established with required cave width as objective function and restrained conditions not reported previously. Parameters affecting cave width were discussed, and optimized using Matlab. Optimization results indicated that the difference between desired and actual cave width was 0.02mm. Planting system of garlic planting machinery was simulated and analyzed using ADAMS. The results showed that the system met the garlic planting requirements.

Abstract:In order to lift severely lodging sugarcane in harvesting, the combined-lifter composed of spiral roller and chainlifter was designed, which was experimented on the vehicle of soil. The orthogonal experiments were conducted to study the following factors: the state, rotational speed of spiral roller, distance between sugarcane and spiral roller center and advancing velocity. According to the best combination of orthogonal test, the single experiments were conducted to study the following factors: the angle between the cylinder axis and ground, the blade pitch of helical spiral roller and rotational speed of spiral roller. The double experiments were conducted with the rotational speed and advancing velocity. High-speed photography experiments were conducted to analyze the process of lifting. In the optimal parameters, the results showed that eligible rate of lifting was up to 90% by the combined-lifter.

Abstract:On the basis of analysis of biomechanics of corn kernel and structure of rooster beak, experiment of rooster beak pecking corn kernel on single corn ear was conducted. The experimental results showed that under suitable moisture content, in order to make kernel low damage thresh, the supportive role between kernels must be broken firstly according to certain law. Under the same moisture content, capacity loaded was different for three surfaces of corn kernel. Force loaded at ventro-surface of corn kernel was the largest. The force at the top surface of corn kernel was the least. While choose position loaded, it’s better to avoid top surface loaded of kernel. Rooster beak not only had good ability of inserting kernel cleft, but also stronger ability of pecking corn kernel. The partition that rooster beak inserted corn ear was gap between longitudinal lines. The process that rooster beak inserted corn kernel was the functional process that a triangular wedge inserted corn kernel cleft, that rooster beak inserted same partition could make kernel low damage thresh or loose. When rooster beak pecks lax kernel, it could produce the pull, and corn kernel could thresh, as the pull was bigger than the connection force of fruit handle of corn kernel. This research could provide a bionics basis on improving the geometrical shape of threshing parts and designing low damage seed corn thresher.

Abstract:In order to improve the thresh efficiency of maize pair seeds and reduce the percentage of damaged seeds, experiments were carried out about the maize pair seeds thresher. The variety of maize was Meiyu No.3. The quadratic orthogonal tests were used. The effect of average water content, maize ear average diameter, thresher drilling tool diameter and drill angle on thresh percentage of pair seeds and damaged seeds of maize was analyzed. The mathematical model was developed. Taken the highest thresh percentage of pair seeds and the lowest percentage of damaged seeds as an evaluation index, the optimal parameters of thresher were obtained through multigoal nonlinear optimizing method. When the average diameter of maize ear was 39mm, the ear water content was 44%, the drilling tool diameter was 23mm and its angle was 74°. When the maize ear average diameter was 42mm, the ear water content was 44%, the drilling tool diameter was 24mm and its angle was 72°. When the maize ear average diameter was 47mm, the ear water content was 44%, the drilling tool diameter was 25mm and its angle was 70°.

Abstract:A linear model for individual pitch of wind turbine system was established，and the loads of blade roots were transferred into a mean value and variations on two orthogonal axis using Park’s transformation. The model-free adaptive controllers (MFA) were designed to control the loads components of the two orthogonal axes. The wind turbine nonlinear model FAST built by NREL was used to verify the controller. Test results showed that individual pitch based on MFA could eliminate the imbalance loads effectively. Compared to collective pitch control, the for-aft torque was decreased by 62.5%, yaw torque was decreased by 60.1%, and the value of output power changed a little.

Abstract:In order to analyze the influence of different dimensions on aerodynamic performance prediction of wind turbine airfoil, the flow fields surrounding 2-D airfoil of DU93-W-210 and 3-D straight blade were simulated by solving the N-S equations. Experimental results were compared to predict aerodynamic performances. The results revealed that if the flow did not separate, the aerodynamic performance and streamline between the 2-D airfoil and 3-D straight blade were similar, and the 3-D straight blade could be simplified into 2-D airfoil. If it separated, the flow field of 3-D straight blade had significant 3-D flow effects, the predicted aerodynamic performance was closer to experimental value than 2-D airfoil, but the 3-D straight blade could not be simplified into 2-D airfoil. The best span wise length of 3-D straight blade was 2~4 times of the chord.

Abstract:Considering the unsteady aerodynamic characteristics of the vertical axis wind turbine (VAWT) blade at low speed ratios, the B-L dynamic stall model was modified. The finite aspect ratio effects and blade tip loss were taken into account to modify the aerodynamic characteristics for constant chord blade. Based on the double-multiple stream tube method (DMST) in aerodynamic analysis, an improved aerodynamic performance prediction model for VAWT was developed combining with the dynamic stall model and predicting method for the effects of finite aspect ratio. The aerodynamic performance of 17m VAWT by Sandia National Laboratory was calculated. The effects of the dynamic stall and finite aspect ratios were analyzed, and the rotor power and power coefficients were compared and analyzed between the test and evaluation results. Feasibility of the prediction model to evaluate the aerodynamic performance for VAWT was proved.

Abstract:Freeze-drying microscopy was used to investigate the effect of freezing rate, pressure and mass fraction on the collapse temperature (Tc) during freeze-drying of aqueous solutions, and differential scanning calorimetry was used to investigate the glass transition temperature (T′g) of the maximally freeze concentrated solution. The experimental results showed that for 10% sucrose/water binary solution, the freezing rate had little effect on Tc although it could affect the size of ice crystals. For 10% tertiary butyl alcohol/10% sucrose/water ternary solution, both T′g and Tc decreased with the increase of freezing rate. Few variations in collapse temperatures could be expected when varying the pressure. For sucrose aqueous solutions at different mass fractions (5%～25%), the variation of collapse temperature was less than 1℃

Abstract:In order to seek an effective deastringency and crispness-keeping technique for astringent persimmons, the effects of different 1-MCP concentration, polyvinylhloride(PVC) and vacuum packaging methods on physiology and storage of Mopan persimmons under ambient temperature were investigated. Results showed that 1-MCP combined with individual vacuum packaging effectively inhibited the decline of fruit firmness, the increase of ethylene production and respiration intensity, malondialdehyde (MDA) content and peel tissue relative conductance, prevented the evaporation of fruit moisture during storage, promoted the change of the soluble tannin content to insoluble tannin content and prolonged ambient shelf life time to 14d. Therefore, 0.5 to 1.0μL/L 1-MCP of combined with individual vacuum packaging was a suitable treatment method for Mopan persimmons.

Abstract:The quaternary amino groups containing cationic starch with the degree of substitution 0.3903 was prepared via the reaction of potato starch with 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride using predrying dry process. Then the cationic starch (CS) and poly ferric sulfate (PFS) would be used to treat potato starch waste water. And the cleaning efficiency of the chemical oxygen demand (COD) in the wastewater was studied by changing the experiment conditions. Though the orthogonal test, the optimal conditions were as follows: CS addition 0.15%, PFS addition 0.15%, initial reaction pH 7.0. The removal rate of COD was 64.31%.

Abstract:Effects of reaction conditions of cross-linked beet pectin and stability of protein stabilized emulsions between horse radish peroxidase (HRP) and Laccase in the aqueous phase was analyzed. Both of the results from UV-VIS spectrophotometry and Fourier transform infrared spectrum indicated that the HRP and Laccase could catalyze the beets pectin to form covalent cross-linking. The HRP reaction system was as follows: 5 mL reaction system in total contained 6 mg beet pectin, 20U HRP, 0.5% H2O2(mass fraction) and could react 2h under 35℃. The Laccase reaction system was as follows: 5 mL reaction system in total contained 6 mg beet pectin, 15U Laccase and could react 24h under 40℃. When controlled this reaction on the interface of emulsion, the results of laser diffraction granulometer showed that the character of emulsion was inconsistent under different reaction systems. Laccase system will cause layer between bovine serum albumin and whey protein isolated emulsions. The longer of reacting time, the more obvious of layers. While in HRP reaction system, it brought improvement to the stability of bovine serum albumin emulsion.

Abstract:For reasonably determining the parameters of saccharification technology for extrusion cooked rice used as beer adjunct, influence regularity of the parameters of saccharification technology was studied through experiments. These parameters included saccharification time of 65℃, saccharification time of 71℃, the add content of thermostable α-amylase. The indexes included the recoverable ratio of wort extract, the iodine value of mash and the ratio of starch residues in adjunct. The research results indicated the recoverable ratio of wort extract for extruded rice was 76.25%, the iodine value of mash was 0.15, the ratio of starch residues in adjunct was 0.52%, when the saccharification time of 65℃ was 60min,the saccharification time of 71℃ was 15min, the add content of thermostable α-amylase was 2.1mL. In addition, it was proved that the extruded rice could be used as beer adjunct with the chemical analysis of mash.

Abstract:A humanoid manipulator applying to the end effector of an apple picking robot was introduced. Substituting a tendon-actuated manipulator for the simple gripper can improve the adaptability for the end effector to catch apples in intricate surroundings. To realize the open-loop control of the tendon-actuated manipulator, the relationship model of the actuating force and grasping force is necessary. By simulation, the model was established in this paper. Under the same actuating force, the grasping force of the tendonactuated humanoid manipulator was related to the parameters of mechanism. The virtual grasping force was determined by the length and thickness of fingers. The distribution of grasping force was determined by the lengthy proportions of the phalanges. The original angle between the fingers determined the radius range of the apples. As the radius of apples increased, the virtual grasping force decreased. Frictions could homogenize the distribution of grasping force as well as enlarge the virtual force.

Abstract:In order to improve locating accuracy of cutting point and avoid injury of fruit and stem for cucumber harvesting robot, an end-effector with special position feedback was developed based on machine vision. As the differences of H and S distribution on HIS space between cucumber and background, the thresholds was used for image segmentation. Subsequently, the region for robotic harvesting was extracted with edge detection on G channel of RGB space and shape features analysis. Upon the data from the firstlylocating system, the spatial coordinate of the cutting point was acquired with respect to the model of linear projection. The position correction was fed back to the robot controller. The results showed that the maximum error for the cutting point location was less than 2mm, which met the demands of the robotic harvesting operation.

Abstract:The algorithm of automatic grid recognition for irregular fields was introduced based on the algorithm of automatic grid recognition for regular fields. The controller received pulse signals from the sensor and calculated the working distance of the variable rate applicator, thus the working grid could be identified by the algorithm of automatic grid recognition. The field experimental results showed that using this positioning algorithm, the applicator could be automatically recognized in different grid.

Abstract:The responses of canopy spectral reflectance, optimum spectral indices and monitoring models for leaf nitrogen accumulation (LNA) in wheat to the changes in bandwidths were analyzed on the basis of the sensitive bands of 720nm, 860nm and 990nm. The results showed that with increasing bandwidth, the reflectance increased sharply at 720nm and slowly at 990nm, but decreased at 860nm. The values of NDSI(R860, R720) and RSI(R990, R720) decreased gradually, along with reduced accuracy of calibration and validation for monitoring models. The monitoring models based on NDSI(R860, R720) displayed stable performance with the bandwidths of the key bands less than 96nm and 28nm, respectively, while those of RSI(R990, R720) less than 3nm and 13nm, respectively. These results helped to provide theoretical basis and technical approach for manufacturing economical portable nitrogen monitoring instrument.

Abstract:A variable concentrate feeding system for individual dairy cow was developed. The system identified the dairy cow with the RFID technology. According to the differences of the basic diet intake and the individual milk yield, the system could automatically and quantificationally discharge and mingle four kinds of the different concentrates feeds. The experimental results indicated that the response time was 1.47s, the time for discharging compensated feeds was 15.15s, the time to open the railing of the entrance guard was 3.92s, the reading distance of the RFID reading system was 52.3cm, the alarm level height was 21.5cm, the identification accuracy of cow was 100%, and the four kinds of concentrates were mixed well, the measurement error was less than 5%, which could satisfy the demands of feeding. Moreover, the system can query and print feeding information online.

Abstract:The relations between tomato crops and soil transpiration and the microclimatic factors inside and outside bispan greenhouse were analyzed. The computational fluid dynamics (CFD) model was used to solve the temperature and relative humidity (RH) distributions based on water vapor transmission and solar radiation with the porous models, and the boundary conditions were discussed. The 3D temperature numerical simulations were tested by means of Fluent software. The results showed the average relative errors of the simulated and the measured values were 5.7% and2.1%, respectively. The CFD model and the boundary conditions were proved to be validated. Compared to cloudy days, the average temperature was 1.6℃ higher and relative humidity was 3% lower in sunny days. The solar radiation had an effect on the temperature and RH distributions. The average temperature was 0.8℃ higher and RH was 19% higher for the double density plants than that of single density plants. The temperature and RH distributions were lower near the leeward than the windward inside greenhouse, but a homogeneous pattern was observed in cropping region.

Abstract:Considering the nonlinear dynamic response of the greenhouse measurement and control system based on switch devices combination control, a discrete predictive model was proposed. The model had simple structure and uncomplex computation. Within the time domain not less than the maximum distribution delay of the system, the devices combination was keeped invariably and optimized rollingly to carry out predictive control, so the predictive control complexity of the system was greatly simplified, the problem of long distribution delays of the system was relieved. The simulation analysis and root mean square of the temperature showed that the optimization combination predictive control method was effective for the greenhouse measurement and control system with long distribution delays.

Abstract:To solve flexible job-shop multiobjective scheduling problem, the optimization model was set up. Considering of the makespan, manufacturing cost and earliness/tardiness penalties, a crowding distance sorting based on multiobjective particle swarm optimization algorithm was proposed. With the elitism strategy, dominant individuals were preserved in evolution process. The shrink of the external population and update of the global best were achieved by the individuals’ crowding distance sorting in descending order. A small ratio mutation was introduced to enhance the diversity of solutions and the global searching capacity of the algorithm. Finally, the feasibility and validity of the method was proved by the simulation results of a flexible job-shop multiobjective scheduling in a workshop.

Abstract:According to the situation that there is no general model to express both main profile and modified top profile, a general integration equation expressed in tangential angle series was established for scroll profile. The start part of profile was reconstructed with zeroth-order curve and firstorder curve, respectively. The influence of parameters of top profile on thickness of scroll tooth was analyzed quantitatively. Furthermore, the geometrical models of area of compression chamber were set up based on curvature radius function of base line. The effect of curvature radius parameters on area property was explored. This study showed that first-order curve construction of top scroll could achieve higher performance by improving volume ratio while maintain reasonable tooth strength. With continuity equation of scroll baseline in form of radius of curvature, a fullymeshed profile and complete tooth profile could be obtained in the stage of machine design, so that there was no need to modify top scroll in later stages. The results could be applied in the scroll profile design.

Abstract:On the basis of fractal model of tangential contact stiffness of joint surfaces, and combining with the fractal model of two cylinders’ contact stress, calculating fractal model of tangential contact stiffness of gear joint surfaces was set up. This model synthetically considered the microcosmic characters and macroscopical factors of gear joint surfaces, and the results by the model showed no relationship with the resolving ability of the instruments and dimension independency. Simulation results indicated that the tangential contact stiffness was proportional to fractal dimension, material properties parameters and the number of gear teeth, and inversely proportional to roughness amplitude.

Abstract:The mean friction coefficient on tooth surface was calculated under mixed elastohydrodynamic lubrication based on Bloks flash temperature formula. Furthermore, the mean friction coefficient of the formula was modified, and the formula was improved. Meanwhile, through calculating the tangential velocity, half width of Hertz contact zone and load distribution factor along the meshing point of spiral bevel gears, the formulas to calculate the flash temperatures along the contact path and whole tooth surface of spiral bevel gears under mixed elastohydrodynamic lubrication were proposed respectively, which provided a comprehensive and accurate method for its calculation of scuffing load capacity. The results of analyzing the calculation example indicated that the maximum flash temperature along the contact path located in the middle recess path, and the one of the whole tooth surface was between the pitch cone and dedendum of gear, where the scuffing failure showed the most possibly.

Abstract:By taking the data acquisition scheme as an example, an analytical method for dynamic data frame format of the data acquisition system was proposed based on the XidML file. It achieved the real-time test data monitoring and the playback of the acquisition data including load spectrum/environmental spectrum tests and the reliability enhancement testing for the combines, tractors and other agricultural equipment. This method significantly improved the efficiency of field testing.

Abstract:In the analysis of the typical failure mode, randomness and fuzziness were taken into consideration, time between failures was defined as a random fuzzy variable, then the occurrence chance model was built. Random fuzzy method was used to calculate the occurrence chances of typical failure modes and the ranking. By virtue of the analysis of the occurrence chances and occurrence frequencies, some important conclusions could be made out. The failure mode which influenced the machining center most could be found out, the conclusions provided useful basis on how to eliminate these failure models and how to improve the reliability of machining center of this type.

Abstract:Based on the Pareto genetic algorithm, an algorithm was proposed for the cutting parameters selection and optimization to solve the decisionmaking problems of the cutting parameters in a computer aided process planning (CAPP) system. First, a multi-objective model was built by analysis of restraint with cutting speed and feed as optimization variables and cutting efficiency and the tool life as optimization objectives. Second, the selection operator was improved. In order to ensure the search direction, a non-inferior set was set up to save Pareto optimal solutions which were generated by competition during evolutionary processes. The crowing mechanism based on niche technology was established to keep population diversity. And then, genes were recombined by means of mixed crossover operator and step-size mutation operator and an optimal set which distributed uniformly along the Pareto front was obtained after a few times iteration. Experiments results showed that this algorithm was feasible and effective.

Abstract:An analytical model of vertex’s shear strain and shear strain rate was developed based on the process of serrated chip formation with geometry shape of serrated chip as a trapezoid. The chip deformations under different cutting speeds for GH4169 were discussed with the proposed model. The results showed that with the cutting speed increasing, the degree of chip deformation increased. The maximums of strain and strain rate were respectively 4.91 and 4.59×106s-1 with applied cutting speed range in 200~1000m/min.

Abstract:Direct replication of biological surface morphology using micro-electroforming method to form biomimetic surfaces with relatively vivid morphology is a new process extension from polymer forming to metal deposition forming of the bio-replicated forming technology. Taking shark skins as the replication templates, the conducting layer was deposited on the shark scales with the inclined magnetron sputtering process according to the structural characteristics of shark skins. Then the micro-electroforming process adopting the pulse-reverse currents was conducted. Finally the shark skin micro-electroforming template and the biomimetic shark skin were obtained. The preliminary analysis on replication precision indicated that the micro-electroforming method could be used to replicate the outward morphology of the shark skins with good precision, which validated the application of the bio-replicated forming technology in the direct replication of the complex and microscale biological surface morphology.