Abstract:This paper presented a real-time rollover prediction algorithm based on roll state estimator. An extended 3-DOF vehicle model considering tire nonlinear characteristics was firstly proposed, the parameters of the tire model were obtained by using nonlinear least square method. Vehicle roll state was estimated using sliding mode(SM) observer based on the super twisting algorithm. A rollover critical index(RCI), which indicated the risk of rollover, was developed by a fuzzy inference system(FIS) based on current vehicle state and its trend. The veDYNA dynamic simulation software was used to verify the performances of roll state estimator and roll motion prediction.

Abstract:The dynamics model of electric vehicle with motorized-wheel-drive based on AMESim was built, and the differential drive assist steering (DDAS) control system model was built using Matlab/Simulink. On this basis, the control strategy of torque distribution between right and left front steerable wheels was presented, aiming for the reduction of the steering efforts and assisting the steering wheel return to center, as well as the yaw compensation produced by differential drive of the rear two wheels. The co-simulation results validated that the proposed DDAS control system could improve steering handiness, steering feel and returnability of the steering wheel, including stability compensation and practicability enhancement for DDAS system. Furthermore, the double-lane change road experiments for rapid control prototyping of DDAS control strategy were conducted. Experimental results verified the feasibility of providing steering assistance and the ability to keep road feeling of DDAS system.

Abstract:Steering control was the principal problem and technological challenge for hydrostatic drive tracked vehicle. Considering steering safety and maximum system pressure limitation, the relative steering ratio dependence of the speed was discussed based on the analysis of steering kinematics and dynamics. A steering dynamic system model was developed by Simulink of Matlab, and steering control strategy for tracked vehicle with hydrostatic drive was also designed. This steering control strategy can preferentially achieve the driver’s expected steering radius exactly by reducing average vehicle speed in the case of not exceeding the system pressure threshold and no sideslip.

Abstract:With heavy load and high center of gravity, the Stewart platform based on kinematics control strategy vibrated in one degree of freedom will cause the vibration in other degrees of freedom. To solve this problem, a vibration control strategy used in the position closed loop was presented based on the Stewart platform dynamics. According to this control strategy, the actuator force, calculated by the dynamics model, was used to control the platform vibration, and the control precision was improved. At last this vibration control strategy was validated with the Stewart platform in 15°pitch posture. Comparing the vibration response of the Stewart platform controlled by kinematics and dynamics respectively, the results showed that the proposed control strategy could reduce the coupling vibration caused by the platform load effectively, and could achieve the precise vibration control in any platform pose.

Abstract:92.1 m。In order to obtain optimum structure parameters of frictional brake and contactless wheel retarder integrated system, the optimization design was used. The influence law between the main structure parameters of the integrated system and brake torque was analyzed in order to improve brake torque. Meanwhile, with the proposed method, different structure parameters was compared, simulation analysis on the automobile equipped with the integrated system and the automobile equipped with the frictional brake was performed. The results showed that the proposed optimization design could reduce automobile braking time and distance by 5.9 s and 92.1 m, respectively.

Abstract:The parametric design and optimum design method of variable speed hydrodynamic coupling based on UG and CFD was proposed. The parametric model and optimum design flow of variable speed hydrodynamic coupling were established. The original characteristic curve based on flow-field numerical solution matched with the experiment result well, so CFD could be used for the complex gas-liquid two-phase flow of hydrodynamic coupling. Numerical simulation and performance prediction were conducted respectively to three different parametric schemes under brake condition, traction condition and rated condition, and compared with the base-type coupling. The second scheme had a more reasonable flow distribution, its pressure and velocity difference was smaller, pump torque coefficient was larger, and was the reasonable optimization scheme of base-type coupling.

Abstract:In the common design of diesel engine, it’s necessary to optimize the engine in order to improve the dynamical characteristic and the fuel economic characteristic of the truck. The truck’s power balance equation was confirmed and verified by experiment，the dynamical characteristic and the fuel economic characteristic were analyzed based on the power balance equation and universal characteristic of engine. The results showed that the power utilization and the fuel economic characteristic were poor in the common cases. The optimized turbocharger and fuel injection pump for the diesel engine showed that the fuel consumption of 100km was reduced at the speed of 40～70km/h, and accelerating ability was improved. 

Abstract:This paper aimed at the technological development of agricultural tractor in the world. The current technology and performance of the vehicles and parts were explained. The technology characteristics and configuration of the agricultural tractors in each power range were summarized and analyzed. Finally, the technical development and disadvantages of Chinese agricultural tractors were analyzed and the key technologies were proposed.

Abstract:In order to quantitative evaluate the wind erosion effect of wind speed in wind tunnel center, vegetation coverage and their interaction，orthogonal experimental design and wind tunnel testing in situ field was adopted. The soil erosion experiment of grassland was completed. Test results were analyzed by using grey correlation, range analysis and partial least-square regression theory. The results showed that the sequence of factors influencing on sediment transport rate from larger to little was the center wind speed of wind tunnel, vegetation coverage, their interaction.

Abstract:In order to obtain better anti-blocking device on no-till planter, a finite element analysis on gap disc with ANSYS was conducted. Through element type selecting and material properties setting, ANSYS could transfer gap disc image into mesh size and generate a finite element model, in which loadings consisted of straw-cutting resistance and soil-penetrating resistance. Then the gap disc model was calculated, a series figure of different components of stress was obtained. Theoretical basis of further modification and optimization for gap disc was given.

Abstract:Working principle of vegetable seed metering device in pneumatic plate-type was put forward. Correlative structure was designed. Qingjiang cabbage seeds were selected for sowing performance test. Single factor test results showed that with the increase of diameter of suction hole, single-seed rate began to increase and then decreased, multi-seed rate increased, empty-seed rate began to decrease and then increased. Influence of diameter of suction hole on single-seed rate, multi-seed rate and empty-seed rate was highly significant. With the increase of relative pressure, single-seed rate first increased and then decreased, multi-seed rate first increased, then decreased and last increased, empty-seed rate first decreased and then increased. Influence of relative pressure on single-seed rate and empty-seed rate was highly significant, while on multi-seed rate was not significant. With the increase of sowing efficiency, single-seed rate first increased and then decreased, multi-seed rate first decreased and then increased, empty-seed rate increased. Influence of sowing efficiency on single-seed rate and empty-seed rate was highly significant, while on multi-seed rate was not so significant. 

Abstract:Series design of transplanting parts of vegetable transplanter was achieved by the digital design based on UG and VB.NET. First of all, mathematical model of rotary ordered transplanter was established. 3-D model of parts and virtual assembly of transplanting device were completed with UG software. By means of VB.NET and secondary development tools UGOPEN in UG, special custom menu items were added in UG software; the user could input or change relevant parameters based on agronomic requirements of different vegetables, then 3-D model of the corresponding mechanism was automatically generated to achieve digital variant design of transplanting device. The results showed that this digital design method shortened design cycle and improved design efficiency. 

Abstract:method. Results showed that the tensile strength of erect crownvetch strain stems were maximum (14.88～26.80MPa). The average largest load of creeping type, half crawl type and erect crownvetch strain were 88.88N, 152.70N and 187.10N, respectively; the cellulose contents of above stems were 13.59%, 13.87% and 15.52%, respectively; the lignin contents of above stems were 4.47%, 4.18% and 3.95%, respectively; the protein contents of above stems were 3.83%, 4.55% and 2.74%, respectively. The cellulose contents, lignin contents and protein contents increased with the reduction of moisture content. The strength and stiffness of creeping tangled forage stems mainly depended on the content, connection mode and alignment of cellulose and lignin. Erect crownvetch strain were easier to mechanized harvest than others because of its low ratio of lignin to cellulose.

Abstract:86%。Based on CAN bus and ISO11783 protocol, a direct injection variable-rate sprayer based on the prescription map was developed with the goal of realizing precision pesticide application and improving pesticide application efficiency. The spraying uniformity and accuracy of the direct injection variable-rate sprayer was analyzed through the comparison experiments between constant-rate spraying and variable-rate spraying. The field experiments showed that the spraying variable coefficient was below 10%. On a given field, the area, on which the spray volume difference between the actual spray volume and the volume supposed was less than 15%, was up to 86% of the total.

Abstract:To improve the original design flaws of air duct of air-assisted boom sprayer, a multi-objective optimization approach integrated relevance vector machines (RVM), multi-objective genetic algorithms (MOGA) and fuzzy system were presented. First of all, the multi-objectives of the air duct were constructed to improve the capability of reduced spray drift and increased penetration. The computational fluid dynamics (CFD) analysis of air-flow generating duct were utilized for sampling scheme given by uniform design to collect the train dataset. Sequentially, RVM based on meta-model as fitness function was combined with MOGA to obtain the Pareto optimal set. Finally, a fuzzy inference system was established as decision-making support to obtain the optimum preference solution. Therefore, the optimized air duct structure with the round solution analyzed by CFD showed the promising improvement on flow speed variation. The modified physical prototype proofed feasibility and efficiency of this approach.

Abstract:A spring-tooth weeding working in paddy field was designed. Weed cutter with arc-shaped bend could reduce the injury rate of seedlings in some extent. The steel soft shaft was selected as transmission parts of the device. The quadratic rotation-orthogonal test was applied in 7 and 14 days respectively. The effects of interaction of cutter rotation speed, forward velocity of machine, buried depth on weeding ratio and seeding injury ratio were attained. The optimal combination in 7 days’ test was: the cutter rotation speed was 230r/min, the forward velocity was 1.02m/s, the buried depth was 18 mm, weeding rate was 73%, and miller injury rate was 0.13%. The optimal combination in 14 days’ test was: the cutter rotation speed was 230r/min, the forward velocity was 0.48m/s, the buried depth was 27mm. The verification test was carried on according to the optimal operational parameters combination. The results showed that this operational parameter combination could fulfils the request of weeding ratio; meanwhile, the seeding injury ratio was the lowest.

Abstract:2015年将达到40537MW。In view of the limitations in single prediction models and linear combined prediction model，nonlinear combined prediction model for total power of agricultural machinery was put forward on the basis of establishing single prediction models for total power of agricultural machinery in Heilongjiang province. The results of error analysis showed that mean absolute percent error of proposed nonlinear combined prediction model was 3.03%, which was lower than 6.26%,4.65%,4.88% and 3.72% of one-variable liner regression model, exponential model, GM（1，1）model and cubic exponent smooth model, and a little higher than 2.86% of the linear combined prediction model based on the minimum sum of error square. Predicting total power of agricultural machinery from 2006 to 2008 proved that this prediction model could efficiently improve prediction accuracy for total power of agricultural machinery. The total powers of agricultural machinery were predicted from 2009 to 2015 in Heilongjiang province. The prediction results showed that total power of agricultural machinery would maintain swift growth tendency in the future several years, it would be 40537MW in 2015.

Abstract:Step-wise pyrolysis of fir was conducted in the presence of catalysts by using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The effects of catalysts and temperature on composition and content of the pyrolysis products were studied. The results showed that few types of the products were found in the first-step 300℃ pyrolysis and the main products were extractives, while a great variety of products were detected in the second-step 500℃ pyrolysis. ZSM-5 and MCM-41 could reduce the contents of carbonyls and macromolecular lignin derivatives. ZSM-5 catalyst was helpful to reduce the content of acetic acid, and produced lots of aromatic hydrocarbons in the pyrolysis products. The content of acetic acid and furfural in the prolysis products were obviously increased by the presence of MCM-41 catalyst. 

Abstract:According to toxic response factor of different forms of heavy metals, rational application rate of sewage sludge compost was determined. Pollution index and geoaccumulation index were used to evaluate contamination degree of sewage sludge compost. Rational application rate of sewage sludge compost in Yangling was 3.69t/(hm2?a). This method stressed the importance of the forms of heavy metals and made up for the shortage of only controlling the total amount of heavy metals in the past. Results showed Cd was the most important element to restrict application of sewage sludge compost in this area.

Abstract:A storage test was carried out to evaluate the effects of temperature and relative humidity (RH) on the storage quality of Agricus bisporus, and mathematical models were established. Models of the storage quality of Agricus bisporus in terms of temperature were M=(1.3949+0.3519T)t and F=(2.4153-0.0204T+0.0225T2)t, which developed from the slopes of weight loss and firmness versus time for five temperatures (0、3、6、9、12℃) and 95%RH. Models of the storage quality of Agricus bisporus in terms of RH wereMr=(61.0605-124.8105RH+63.985R2H)tandFr=(9.6579-11.7530RH+4.2651R2H)t, which developed from the slopes of weight loss and firmness versus time for five relative humidity and 2℃. Study results suggested that, the quality deterioration of Agricus bisporus during storage was well described by the obtained models, and agreed well with the experiment data. Results of the study can be applied to the storage of Agaricus bisporus

Abstract:Three typical farm products storage systems were adopted to detect the temperature drifts respectively. The cell circuit was improved according to the designing principal of the instrument electrocircuit. As the results, the error of the storage temperature was dramatically reduced from 3.5℃ to 0. 3℃ and the cold storage temperature fluctuations decreased from 5.3℃ to 1.4℃. Besides, three simple temperature compensation methods were also selected. These methods were applicable to those places which were unsuitable for the instrument circuit improvement.

Abstract:77.38%。Many factors have effects on the separating ratio, moisture contents of the stems and leaves in fresh chopped alfalfa drying and separating processing. Four major factors: inlet temperature, inlet velocity, rotational speed of rotary drum, and feeding speed were analyzed in leaf-stem separation equipment. A quadratic orthogonal rotation design with 4 factors was introduced to do the regression analysis. Then models were developed and optimized. The results showed that the developed models fit the experiment data well. The inlet temperature affected the drying and separating processing most significantly and then the let velocity, rotational speed of rotary drum, feeding speed, respectively. It was analyzed that the most optimized parameters were 400℃ of inlet temperature, 14m/s of inlet velocity, 12r/min of rotational speed of rotary drum, and 8kg/min of feeding speed, respectively. Under these conditions, the leaf moisture content was 13.42%, the steam moisture content was 14.24%, and leaf-steam separation ratio was 77.38%.

Abstract:1.19%。The influence of drying temperature and pressure in the chamber on the drying characteristics of vacuum drying on Cornus officinalis was studied. The regression mathematical models of drying time and content of loganin versus drying temperature and pressure were established. The optimal combination of the parameters for vacuum drying of Cornus officinalis was obtained through nonlinear optimization method with multiple targets. The results showed that the regression mathematical models agreed well with the experimental data, and under the conditions of drying temperature 68.1℃ and pressure 1kPa, the optimal integrative values were obtained as drying time 248min and content of loganin 1.19%, respectively.

Abstract:The influence of different dosages of irradiation, temperatures of hot air, thicknesses of the slice carrot on the characters of dehydration and surface temperature for the irradiated carrot were studied. The results showed that three factors affected the characters of dehydration: irradiation dosage, temperature of hot air, and thickness of the slice carrot. With the increase of the dosage, both the rate of dehydration and the surface temperature for carrot increased. Then, the microstructure and water activity were also studied. The results showed that the membrane of the cell wall and vacuole of the irradiated samples were broken. The great dosage brought on the high water activity. These changes were the main cause for the characters of dehydration and surface temperature irradiated carrot. 

Abstract:The traditional drying models fitted to experimental data and the drying coefficients were determined by means of nonlinear least square based on the Matlab software using the Gauss-Newton algorithm. The experimental data from infrared radiation drying of apple slices were used as measured samples. The tests were performed with the materials temperature of 60℃, the radiation power of 750W, the radiation distances of 100mm and materials thickness of 5mm. 15 different mathematical drying models were compared by some evaluation targets such as coefficient of determination (R2), square sum of error (SSE) and root mean square error (RMSE). It showed that the Modified Page equationⅡ model could sufficiently predict and control the infrared radiation drying process of apple slices.

Abstract:Effects of different pulping conducts on mechanical properties of celery paper were analyzed in order to raise the tensile strength. Four kinds of combined pulping conduct were organized and four types of sample celery paper were prepared under the condition of middle scale production. Several reports of fiber analyses were given by Swedish L&W fiber tester. The structure characteristics of celery paper were presented through the photograph of Olympus microscope. Mechanical property reports were issued by authorized department. After analysis of fiber and structure as well as property, the maximum tensile strength was 1.765 times as much as the minimum among four types of sample celery paper. Therefore different mechanical pulping conducts really could raise tensile strength of celery paper.

Abstract:The optimal conditions of supercritical fluid extraction were obtained as follows, CO2 flow rate of 8L/h, static extraction time of 120min, dynamic extraction time of 60min, entrainer ethanol dosage of 3mL/g defatted soybean residues, extraction temperature of 55℃ and extraction pressure of 30MPa, by single factor test and four factors and three levels orthogonal design method. The kinetic model of supercritical fluid extraction accurately described the distribution of isoflavone genistin in the extraction bed was developed based on adsorption and desorption theory. The model parameter kLa was determined by BP neural network and trial and error method. 

Abstract:The ultrahigh pressure technology was used to make yolk rapidly denaturalize and molded. It could effectively solve those problems such as material’s utilization lowing, the processing period’s long, and so on. Taking the fresh egg-yolk as raw material, it was molded by ultrahigh pressure in salt solution. The influence on salty egg-yolk’s quality by the immersion times, the pressures and presses times was researched separately. Orthogonal test was used to discuss the optimal technological conditions. The results of optimal processing technology were as follows: the yolk could be rapidly molded when it was immersed at room temperature for 4hour and kept under 400MPa pressure for 15minutes. The molding salty egg-yolks achieved the standard of salty egg-yolk which could be used in moon cake. The texture analysis results indicated: the texture index of ultrahigh salty egg-yolk was better than quickly salty egg-yolk. The mastication index had the best improvement. The coherency and adhesiveness had better improvement. Therefore, the salty egg-yolk could be molding by ultrahigh pressure technology. 

Abstract:Based on ARM and DSP, an real-time agricultural information sampling terminal was designed. S3C2440 and TMS320C6713 was used as the main processor and the assistant processor, repectively. The principle of HPI interface was expounded. The HPI device driver and the collection of electric circuits for the farmland information were designed. By using Multisim, the emulation verification which could be amplified were made to the electric circuits. The collected latitude and the longitude of the farmland, image information, soil temperature, moisture, strength of illumination and other information were encoded. The experiment on the farm showed that various sensor information could be collected and uploaded reliably by this system. The time-lapse experiment showed that images were usually demonstrated incompletely when GPRS net delayed too much.

Abstract:In order to help the farmers to obtain the agricultural knowledge to prevent and control the pests and diseases as well as to carry on the remote diagnosis by telephone, a call center system was presented for agricultural knowledge based on the remote diagnosis of pests and diseases. Based on the union of the call center technology and the traditional expert system, this system adopted the implementation plan of call center IVR flow transferring the expert system knowledge base automatically, and coordinated the call center CTI server the traditional database server and Web server to provide the function of carried on the remote diagnosis of agricultural pests and diseases with the aid of the telephone network; the system also provided the functions of knowledge browsing, case gaining and expert consultation, and could satisfy the farmers needs to gain the agricultural knowledge as well as to carry on the remote diagnosis.

Abstract:The automatic picking system of fruit harvesting robot was designed based on stereo vision. Firstly, the fruit objects were recognized in image space by using the Hough transform. Some pixels of each object obeying the uniform distribution in the image space were sampled randomly. Then the sphere model of fruit was constructed in 3-D space with these pixels, and the coordinates of the center of each fruit object were obtained directly. Secondly, hand-eye calibration was carried out through the least square method. Finally, the path planning of the harvesting robot was analyzed simply. Experimental results showed that the effects of the partial occlusion and invalidation of stereo matching in the presence of complex scene on the automatic picking system was weakened, and the positioning accuracy of the fruit object was less than 8mm. Therefore the reliability and precision of fruit gripping were improved significantly. 

Abstract:Weak perspective model of camera was adopted. First of all, image of calibration target was captured to obtain pixel coordinates of 48 target centroids. Then hidden parameters matrix of camera was calculated by using least square based on DLT. Location tests of ordered and disordered weeds in indoor soil trough showed that positioning errors of ordered and disordered weeds were 19.2mm and 22.8mm respectively by using established hidden parameters matrix of camera. The positioning accuracy could meet the requirement of precise spraying of herbicide. 

Abstract:5%左右。The online monitoring of grain loss was important for improving the effect of harvest. Based on the requirement of measurement, the polyvinyliden fluoride(PVDF) piezoelectric-film was applied to develop a novel grain loss sensor array. The design of conditioning circuit was also discussed. The spatial distribution of grain loss could be easily obtained by proposed sensor array. Three kinds of full rice seeds with different moisture were prepared for the experiment, and the results indicated the measuring error of the sensor were within 5%.

Abstract:The problems about extracting cleaning signals in the heavy noise and its hardware implementation were discussed. The Butterworth filter was proposed to distinguish the vibration noise and the grain signals. The lowest order of filter to meet performance was determined according to its transition region width and stop-band attenuation. An 8-order Butterworth filter used VCVS topology structure as basic units was constructed by class-bind method. Analogue simulation of the high order filter was proceeding on EWB and refining test was proceeding on the combine. Experimental results was well coincided with simulation results and showed good filtering property in extracting grain signals in the heavy noise of combine.

Abstract:A skeletonization algorithm of foreign fibers in lint cotton was proposed. Distance transformation was implemented to the original image and the distance map was obtained. The local maxima points of the distance map were treated as the seed points and the skeleton was extended forward in all directions along the ridge points. Then the local maxima points were connected through the ridge lines. The skeleton points set scan and skeletonthinning process were carried on to eliminate the duplicated points, which had no use to the skeleton connectivity. Then the pruning process was implemented to remove the pseudo-skeletons and the accurate skeletons were obtained. The proposed algorithm guaranteed the connectivity of the skeleton and single-pixel in width. Furthermore, it could extract accurate skeletons of foreign fibers with slender shape and discontinuous parts. Test showed that the proposed algorithm had low computing complexity and could achieve the fast extraction of foreign fiber skeletons. 

Abstract:ZigBee网络。In the remote detection of orchard environmental parameters, gateway nodes suffer from two deficiencies that remain to be solved: short transmission distance of ZigBee module due to electromagnetic interference; failure to meet the dynamic configuration of ZigBee network. The hardware design adopted the structure of kernel board plus motherboard and modularized interface to improve antielectromagnetic interference performance. The software design adopted two strategies, i.e. serial programming and single thread communication, to realize dynamic configuration of ZigBee network. To reduce energy consumption of the system, gateway nodes decided whether to upload data according to the difference between consecutivelyreceived data and the variation tendency. The test results indicated that gateway nodes could realize stable data acquisition and remote data transmission. Due to the improvement of antielectromagnetic interference performance, communication distance was doubled compared with the design of integrated circuits board. Moreover, the ZigBee network could be configured flexibly and dynamically.

Abstract:A CAD/CAE integration analytical method of machine tool mechanism was proposed based on the 3-D design software SolidWorks and the finite element analysis software ABAQUS, the CAD/CAE integration and automatic computation were realized by integrating the parametric modeling function of CAD and the finite element analysis function of CAE. Stepwise regression modeling based on Latin hypercube sampling and CAD/CAE integration was also proposed to improve the modeling efficiency of machine tool structural performance, it could reduce the samples and ensure the modeling accuracy by monitoring the stepwise regression model. The CAD/CAE integration analysis and stepwise regression model were carried out on spiral bevel gear milling machine, and proved to be feasible. 

Abstract:A mathematical model which described the hydrogen diffusivity near blunt crack tip was proposed. Coupled calculation model for structure and hydrogen diffusion analysis were put forward. Using finite element, the relations between hydrostatic pressure, plastic deformation and hydrogen diffusion were revealed. The synergy influence rules of plastic deformation and hydrogen near the crack tip were analyzed. Finite element method was used to evaluate the large deformation elasto-plastic behavior of the material with the hydrogen diffusion analysis results. Finite element analysis was employed to solve the coupled boundary-value problem of large strain elasto-plasticity and equilibrium hydrogen distributions near blunt crack tip by taking into consideration the effect of hydrogen on local flow stress. 

Abstract:In order to avoid small field-of-view and limited depth-of-field of micro-vision, image definition based on gradient field and wavelet transformation was used. Microscope was set on the macro-micro dual-drive table in order to ensure the positioning precision. A selective focusing technique was developed to auto focus on the objects in different depth. Closed-loop feedback control was carried out. Experimental results showed that dynamic performance and stability of the system was satisfied, the response velocity of system increased from 0.3s-1 to 3s-1, meanwhile, collision-avoidance was executed according to vertical position relations computed by image definition.

Abstract:The kinetic model of flexible pneumatic torsion (FPA) joint was established based on equilibrium of moments, and the dynamic models for inflating and deflating process were built based on adiabatic gas conservation of energy. The influences of FPA initial shell-thickness, average radius, initial angle, and connector outlet area on the dynamic characteristics of torsion joint were analyzed. Simulation results showed that the initial shell-thickness, average radius and initial angle of FPA influenced both the turning-angle and dynamic process of torsion joint, while the connector outlet area had no effect on the turning-angle and dynamic process. Experimental results were close to that of simulation, which implied that the established model of flexible pneumatic torsion joint could fairly describe its dynamic process and characteristics. 

Abstract:In order to design the high-speed planar 3-DOF parallel mechanism, the direct kinematics was studied comprehensively. Velocity and acceleration characteristics of mechanism were gained. With the driving parts movement, all the forward position configurations were obtained. According to the continuity conditions of movement, the optimal trajectory of moving platform was planned. The velocity and acceleration characteristics of mechanism were implied. The mechanism was divided into stroke unit and plane triangle unit. The finite element model of the mechanism was established. By combining kinematics, the moving platform was moving along the planning track, the modal frequency and main vibration mode of the mechanism with the change of mechanism position and posture were analyzed. Variation law of elastic displacement error and the dynamic stress of mechanism was obtained by researching the dynamic response of mechanism in drive force and inertial force excitation. Therefore, the kinematics and the dynamic performance of mechanism were assessed comprehensively. 

Abstract:Cushion structure of high-speed cylinder of the 550kV high voltage circuit breakers was analyzed. The flow characteristics of the cushion structure were estimated by Reynolds number and a simulation model was built with the results of CFD analysis. Pressure, velocity and displacement characteristics of the cylinder were simulated. The simulation results and the test results were compared. It indicated that the simulation method was effective and the simulation model was accurate. Dynamic characteristics of the cushion process of high speed hydraulic cylinder were revealed, and reasons for high peak pressure and high end-velocity were pointed out. The proposed method could help the optimization of cushion structure. 

Abstract:The weld shapes of St12 and St16 deep-drawing steels were influenced by transient temperature distributions. Based on the influence of temperature dependence, latent heat of fusion, convection and radiation, the weld shapes prediction model was built. Additionally, the first and last nodes control method was used in heat loading in order to make sure all nodes could be selected. Experimental results showed that there were no significant differences between the predictive and actual weld shapes. Furthermore, multiple regression prediction models of grain size in weld and heat affected zone (HAZ) were put forward based on PLS. The prediction accuracy of grain size in weld and HAZ was above 95%. Therefore, the proposed models are reasonable and applicable to examine deep-drawing steel for demonstrative purposes. 