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Intelligent  Manufacturing——Main Direction  of "Made  in  China 2025" Zhou Ji China Mechanical Engineering    2015, 26 (17): 2273-2284.   Abstract （7632）      PDF （1586KB）（24262）       Knowledge map    Save How to transform from a big nation in manufacturing  to  a  powerful one is a great subject of China's  economic development in the new era.This paper discussed  the guiding ideology,strategic deployment,basic policy and strategic measure of “made in China 2025” based on detailed analyses of current manufacturing situations  of China,and indicated  that “Internet+advanced manufacturing+modern service industry” will become a new engine of China's economic development.It  is pointed  out that digitization,networking and  intellectualization of manufacturing industries  are the core technologies of  a new round industrial revolution, and should be used as commanding point,breakthrough and main direction of  “made in China 2025”.An overall thorough interpretation of above points was put forward. Related Articles | Metrics

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Feature Extraction Based on Split-merge in Range Image of LIDAR MAN Ceng-Guang, XIE Wen-Hua, LOU Pei-Huang, XIAO Hai-Ning China Mechanical Engineering    2011, 22 (19): 2303-2306.   Abstract （5711）      PDF （444KB）（3074）       Knowledge map    Save For the environmental perception of mobile robots with light detection and ranging(LIDAR), a method based on split-merge framework was presented herein. In splitting stage, a data set was segmented recursively with the IEPF(iterative end point fit) algorithm. In merging stage, both the EPF(end point fit) method and the total least square method were used to fit a new data set composed of the two adjacent segments. If their fitted errors were less than their thresholds respectively, the two data sets were merged into one. Merging stage was a recursive process for that it didn’t terminate until every two adjacent data sets didn’t satisfy the merging condition mentioned above. Results of comparative experiment show that the method presented reduces the probability of over-segmentation and under-segmentation resulted of the fixed threshold of the IEPF algorithm greatly and achieves good results of linear feature extraction. Reference | Related Articles | Metrics

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Additive Manufacturing—Current Situation and Future LU Bingheng, China Mechanical Engineering    Accepted: 17 January 2020

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Lightweight Design Study of Automotive Front Rail with TWB Structure Shi Yuliang;Zhu Ping;Shen Libing;Lin Zhongqin J4    2008, 19 (3): 374-377.   Abstract （3969）      PDF （3567KB）（3183）       Knowledge map    Save A method of redesigning the front rail using tailor-welded blanks was studied, in order to reduce the weight of front rail and enhance its crashworthiness on conditions of satisfying strength and stiffness requirements. By CAE analysis of stress distribution in the rail in the case of self-weight, the number of parent sheets and weld line distribution were determined. By establishing the constraint inequalities of strength, bending stiffness and torsion stiffness, the thickness determination was performed. The full-width frontal impact simulation of the whole car after redesign in the front side rails shows that the front rail of tailor-welded blanks has a better crashworthiness in comparison of original design, while it has a lightweight effect of 17.7%. Related Articles | Metrics

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Development of One Kind of FV520(B) Stainless Steel Matching with Alkalinity Welding Electrode Used on Fan Impeller  ZHANG Min-1, LI Yan-1, 2, LI Ji-Gong-1, LV Jin-Bei-1 China Mechanical Engineering    2011, 22 (22): 2749-2753.   Abstract （3808）      PDF （623KB）（2106）       Knowledge map    Save According to the mechanical property requirements of fan impeller welded joints to high-performance welding electrode and combination with principles of welding material designed to microstructure matching, a kind of welding electrode with good mechanical and processing properties was developed by using metallurgical analysis, mechanical property testing and fracture observation.The results show that the deposited metal of developed welding electrode with the alloy system Cr-Ni-Nb-Cu-Ti and mechanical properties of welding electrode developed is superior to the special welding electrode of FV520(B) stainless steel. Mechanical properties of deposited metal were improved by carbides rich of chromium and alloying.The carbides are Mo2C3,NbCrN and Ti(C,N) which are composed by alloy element of Mo,Nb,Ti,Cr and so all.The welding zone and HAZ microstructure of FV520(B) stainless steel is composed of tempered sorbite, lath martensite, residual austenite and quadratic precipitated phase. However, the fracture mechanism of No.1,No.2 and No.4 welding electrode is quasi-cleavage crack and the No.3 is complex fracture consisting of dimple and cleavage fracture.  Reference | Related Articles | Metrics

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Stability Analysis of Hydrodynamic Journal Bearing System Based on Sommerfeld Number XU Wu-Ban, WANG Tian-Jiang, CHEN Ji-Bing, LI Bing, ZHANG Hong-Xian J4    2009, 20 (23): 2875-2879.   Abstract （3745）      PDF （4437KB）（4480）       Knowledge map    Save The stability analysis method of hydrodynamic journal bearing system based on non-linear oil film force was presented, in which the approach to determine the stability of the system and the mathematical calculating method were introduced. A dimensionless Sommerfeld number was utilized to express the system synthetical parameters. By the Sommerfeld number, the stability and the dynamic characteristics of hydrodynamic journal bearing system can be easily calculated, and a dimensionless stability map of a rigid and symmetrical journal bearing system was presented as an example. Related Articles | Metrics

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Measurement with CMM and Transmission Quality Evaluation of Globoidal Cam Profile Surface Ge Rongyu;Feng Xianying;Song Xianchun;Yang Guanglei J4    2008, 19 (3): 285-288.   Abstract （3712）      PDF （3357KB）（2761）       Knowledge map    Save Based on the analysis of the mathematic model of globoidal cam profile surface, the coordinate measuring machine was used to inspect the point coordinates of cam profile with the equal radius. A point by point comparision method was described with which all the measured data were used to calculate the position relation between the measuring coordinate system and the cam coordinate system. A least squares B spline fitting method was also introduced to approximate all coordinate data in the cam coordinate system. Based on the conjugate relations at the contact point between the fitted curve and the follower, the real follower movement can be solved to evaluate the transmission quality of globoidal cam profile surface. At last, a practical example was given to show the effectiveness and usefulness of the proposed algorithm. Related Articles | Metrics

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Optimal Design of Parallel Manipulator Based on Configuration Bifurcation Chen Weishan;Chen Hua;Xie Tao;Liu Junkao J4    2008, 19 (3): 295-299.   Abstract （3708）      PDF （4445KB）（2550）       Knowledge map    Save For a given set of motion input parameters, the parallel manipulator is possibly at the states of configuration bifurcation. In order that the parallel manipulator can move at will when the lengths of links changed in determinate regions, we optimized the mechanism by considering configuration bifurcation. Based on the idea of analyzing the movement state of parallel manipulator in link space, sixteen kinds of extreme poses for 6-DOF parallel manipulator were described with the vector expressions of link lengths. In order to avoid configuration bifurcations, the bifurcation characteristics of extreme poses were analyzed by homotopy method and static bifurcation condition. The kinematic controllable condition of the designed manipulator was analyzed, which makes the manipulator controllable in the length area of links. Related Articles | Metrics

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Structural Synthesis of Singularity-free Fully-isotropic Parallel Mechanisms with 2T1R-type Zhang Yanbin,;Wu Xin;Liu Hongzhao;Zhang Minghong J4    2008, 19 (3): 277-281.   Abstract （3616）      PDF （3947KB）（2768）       Knowledge map    Save A systemic method of structural synthesis was presented, which was used to achieve singularity-free fully-isotropic three-degrees-of-freedom spatial parallel mechanisms with 2T1R-type. 24 novel uncoupled and 24 fully-isotropic solutions are obtained. The Jacobian matrix linear mapping velocity vector space of the actuators and the moving platform of the fully-isotropic parallel manipulators proposed herein is the identity 3×3 matrix throughout the entire workspace, so all the mechanisms are singularity-free. The difficulty of control problem of parallel manipulators was resolved because there existed a one-to-one corresponding relation between the velocity space of actuated joints and the velocity space of moving platform. Moreover, design principles of limbs for the fully- isotropic parallel mechanism were explored. Related Articles | Metrics

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Research on Active Heave Compensation Control of Remotely Operated Vehicle YANG Wen-Lin, ZHANG Ai-Qun, ZHANG Du-Yang, WEI Su-Fen J4    2009, 20 (23): 2777-2781.   Abstract （3613）      PDF （3849KB）（3412）       Knowledge map    Save The heave motion of supporting ship affects the launching and recovering of remotely operated vehicle(ROV).Active compensation control of hydraulic winch was used to improve the launching and recovering safety of ROV by reducing the heave speed of tether management system (TMS). The model of hydraulic winch was built and active heave compensation feedforward control was set up. Active heave compensation tests of ROV indicate that non-linearity of hydraulic winch decreases the efficiency of active heave compensation. Hydraulic winch active heave compensation predictive control was designed. Simulation test shows that hydraulic winch active compensation predictive control with parameters identification of hydraulic system improves the efficiency of heave compensation. Related Articles | Metrics

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Quantitative Analysis of Roughness Effect on Fatigue Life of Specimen with Open Holes Liu Jun;Liu Yongjun;Liu Yongshou;Yue Zhufeng J4    2008, 19 (3): 327-329.   Abstract （3593）      PDF （5097KB）（2769）       Knowledge map    Save The fatigue testing of the specimen with a central open hole was carried out to investigate the influence of the surface roughness on the fatigue lifetime. Fracture morphology investigations were used by scanning electron microscope. The reliability analysis of specimen was carried out by detail fatigue rating. Related Articles | Metrics

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Product  DSS Model Based on Cloud Service FENG Jing, TU Duo-Fu, YANG Yan-Pu, SONG Gong, LIU Chang-De China Mechanical Engineering    2013, 24 (15): 2053-2059.   Abstract （3572）      PDF （831KB）（2837）       Knowledge map    Save To solve the decision service problems in the process of complex product design,cloud services,requirements-driven and service-oriented architecture were used to DSS.In the DSS,  through cloud service's virtualization and service-orientation to various types of hardware and software,also with its rich semantic web services,the decision support process modeling and dynamic mapping among the actual implementation of decision-making process service could be achieved.In addition, to improve the system's decision-making capacity,based on the system-level model the paper proposed the idea of decision-making task submission and a decomposition model;meanwhile,it discussed the module operation between each model and then developed cloud services platform prototype for DSS to verify the feasibility of this method. Reference | Related Articles | Metrics

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Optimal Measurement Configurations for Robot Calibration Based on Genetic Algorithm Wang Dongshu;Zhang Wenbing J4    2008, 19 (3): 262-266.   Abstract （3538）      PDF （4481KB）（2716）       Knowledge map    Save The selection of measurement configurations in robot calibration was investigated.Observability index of the robot pose measurement configuration was achieved through singular value decomposition, using the observability index as the optimization objective function,a set of robot measurement configurations were selected with genetic algorithm,so that the effect of measurement and modeling errors in parameter estimation can be minimized.Experimental results demonstrate that its calibration effect is superior to that of the random selection measurement configurations. Related Articles | Metrics

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Dynamics Model and Braking Performance Analysis of Multi-axle Vehicle Wan Zhen;Gao Feng;Ding Jing;Wu Xuelei J4    2008, 19 (3): 365-369.   Abstract （3535）      PDF （3658KB）（2813）       Knowledge map    Save Through discussing the problems of calculation for the braking of multi-axle vehicle, which was based on the classical model and described the general dynamics models for the line braking of multi-axle vehicle. The models reserved the constrain of the suspension and introduced the suspension distortion harmonizing equations. Based on the models, it deduced the general formulas for calculating the vertical counterforce from road. Then it put forward a method for getting the lock sequence of multi-axle vehicle, which is easy to be implemented with computer language, and deduced the general calculation formulas for the brake power，braking acceleration and braking distance of the line braking. Related Articles | Metrics

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Auto-body NVH Structure Sensitivity Analysis Based on Modal Analysis Method Yang Bo;Zhu Ping;Yu Haidong;Han Xu J4    2008, 19 (3): 361-364.   Abstract （3432）      PDF （4190KB）（4210）       Knowledge map    Save A SUV auto-body noise,vibration,and harshness(NVH) structure sensitivity was analysed,considering the structure-acoustic coupling based on the modal analysis method.The structure and acoustic vibration mode were gained from coupling analysis while inner noise level from frequency analysis.The given methods reduce noise by identifying the main source to the noise through structure sensitivity analysis. Related Articles | Metrics

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Study on Metal Crack Mode under Laser-shock Processing Ren Xudong;Zhang Yongkang;Zhou Jianzhong;Gu Yongyu;Zhou Lichun J4    2008, 19 (3): 358-360.   Abstract （3404）      PDF （2225KB）（2632）       Knowledge map    Save The relationship of the tip of the crack dynamic stress intensity factor and the velocity of the crack propagation in the metal sheet and laser shock parameters were investigated. A new mode of the tip of the crack was put forth by the theory of fracture dynamics, and then the dynamic stress intensity factor of the crack under the laser shock wave was also obtained. And superposition method was adopted to add dynamic stress intensity factor arisen by the external load and dynamic stress intensity factor arisen by the remains residual stresses. Transformation on the characteristics of aerial alloy Ti6Al4V by laser shock processing and influence on the fatigue life with these transformations were studied.The influence of surface residual stress by laser shock processing and the outer load on crack propagation velocity was discussed. Utilizing these solutions the crack initiation life were developed to evaluate exactitude. Related Articles | Metrics

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Investigation and Test Validation of Vehicle Reference Speed Algorithm for ABS Based on the Information of Wheel Speeds and Pressure Control States Wang Weida;Ding Nenggen;Xu Xiangyang;Yang Lei J4    2008, 19 (3): 370-373.   Abstract （3397）      PDF （3262KB）（3341）       Knowledge map    Save Based on the existing algorithms of vehicle reference speeds for ABS, an improved self-adaptive algorithm was investigated. This algorithm distinguished every control cycle exactly according to the information of wheel speeds and pressure control states. The vehicle deceleration was estimated at the end of each control cycle, and the reference speeds during the next cycle were determined according to the estimated value of deceleration. The codes of this self-adaptive algorithm was written and tested as part of the self-developed ECU of ABS through road tests. Test results show that this algorithm of reference speed is valid and can meet the demands of ABS control. Related Articles | Metrics

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Optimization of NC Machining Parameters Based on Machining Simulation Zhang Chen;Zhou Laishui;An Luling;Zhou Rurong J4    2007, 18 (24): 2955-2960.   Abstract （3347）      PDF （5747KB）（2961）       Knowledge map    Save The presented optimization method partitions cutting depth and cutting width was obtained from NC simulation into sections for the NC machining parameter optimization.All cutting steps within one section formed a machining feature combination step.The multi-objective optimization models were set up within each machining feature combination step to optimize the machining parameters,based on genetic algorithm. The machining parameters in NC programs were auto-modified to reflect the optimization effect. The experimental result of NC machining shows that the proposed optimization models and algorithm are satisfactory. Related Articles | Metrics

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Offset Loading Coefficient Method on the Intensity Analysis of Lift-arms Jiang Feng;Li Jianfeng;Li Fangyi;Wang Yuling J4    2008, 19 (3): 272-276.   Abstract （3338）      PDF （4416KB）（2779）       Knowledge map    Save Through the operating cycle analysis of a loaders, the offset loading coefficient was proposed to accurately compute the force of loaders.In this new method, upright loading was considered as a special instance of offset loading.The force analysis of offset loading and upright loading was unified into the same continuous function. And then the stress changing trend of the lifting arms could be analyzed quantificationally by the aid of finite element software.It is shown that the position damaged greatly may be the joints between lift arms and bucket during the offset loading.But the offset loading with a certain extent can not influence the working equipment greatly.CAE model is improved based on the experimental results and the experimental results show the validity of the improved CAE model. Related Articles | Metrics

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Study and Development of Mobile Robot’s Control Framework Li Wenfeng, Zhang Fan, Yan Xinqing, Yang Xiaozhu, Du Juan, Han Rui China Mechanical Engineering    2008, 19 (1): 114-119.   Abstract （3333）      PDF （4460KB）（3329）       Knowledge map    Save Based on the discussion of features and applications of mobile robots, a survey of their researches was made from the viewpoint of the technologies of their control framework and autonomy. Then control modes and popular systems of mobile robots were discussed and the relative advantages and disadvantages were summarized. The characteristics of the control frameworks of mobile robots were concluded and a few of existing control frameworks were analyzed. According to the development of sensor networks, the combination and cooperation of mobile robots and sensor networks was predicted and the challenges that control frameworks of mobile robots must face to work with sensor networks were pointed out, and a new and reasonable one was put forward at the end. Related Articles | Metrics

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Hardware-In-Loop Simulation of HEV System Based on CAN Hu Jianjun;Zhao Yusheng;Qin Datong J4    2008, 19 (3): 300-304.   Abstract （3328）      PDF （4106KB）（2865）       Knowledge map    Save Using the ISG type mild hybrid electric vehicle(HEV) as research object, a Hardware-In-Loop simulation system of hybrid electric powertrain had been built by using dSPACE. A Hardware-In-Loop simulation experiment of hybrid electric powertrain control unit was carried out based on CAN, and the dynamic characteristics of hybrid electric powertrain was tested and analyzed under different working modes such as engine start-up, accelerating assist and battery charging at equable speed. The research lays a foundation for control strategy optimization of hybrid electric powertrain control unit. Related Articles | Metrics

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Fault Diagnosis of Suction Fan Based on the Synthetically Relational Analysis Fu Mingfu, Xie Mingxiang, Rao Hong, Yang Guotai China Mechanical Engineering    2007, 18 (20): 2403-2405.   Abstract （3310）      PDF （2242KB）（2616）       Knowledge map    Save Based on the theory and method of gray relational analysis, the similar coefficient was introduced to reduce the influent of relational degree affected by the maximum value or the minimum value in data and relational coefficient. The suction fan faults were diagnosed according to the synthetical relational degree composed by the relational degree and the similar coefficient.It is indicated that the method is available for the fault diagnosis of suction fan and has the characteristics of simplicity, low computation and high reliability. Related Articles | Metrics

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Dynamics Analysis of the Main-plate of Stepping-scanning Lithography and Optimization Chen Xuedong, Guo Hezhong, Yan Tianhong, Yu Xianzhong China Mechanical Engineering    2007, 18 (21): 2524-2527.   Abstract （3302）      PDF （5346KB）（2477）       Knowledge map    Save The main-plate of the high-resolution stepping-scanning lithography was studied. Using the finite element analysis theory and modal analysis theory, dynamic characteristics of the main-plate were analyzed, and it proves the structural design is reasonable. Using modal test, the finite element model was validated. Using the finite element model, we carried out sensitive analysis, and implemented the optimization design. Related Articles | Metrics

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SPH Method Simulation of Chip Formation in Ultra-precision Cutting Prorcesses WANG Yong-Gang J4    2009, 20 (23): 2861-2864,2870.   Abstract （3278）      PDF （9570KB）（3064）       Knowledge map    Save In order to investigate the mechanism of chip formation and the influences of some cutting parameters, a SPH method was used to study the ultra-precision cutting AISI-4340 steel with diamond tool. The simulation results show that the chip formation mechanism in ultra-precision cutting process is the adiabatic shear band formation as the same to general cutting under the condition of the bigger cutting thicknesses （0.9μm and 0.6μm）, the chip morphology is like a saw-tooth, and the cutting force is characterized by oscillatory profiles. With the decreases of the cutting thickness up to 0.30μm and 0.15μm, respectively, the shear localized chip formation mechanism is transformed to the extruded-like chip formation behavior, the chip morphology is like a strap, and cutting force maintains approximately a constant value. Related Articles | Metrics

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Simulation and Test of V-shaped Metal Bellow Properties Ma Wei;Li Jishun;Zhong Yuping;Duan Mei;Zong Yingchao J4    2008, 19 (7): 0-881.   Abstract （3277）      PDF （3440KB）（2484）       Knowledge map    Save This paper carried out the calculation of the stiffness and stability of V-shaped metal bellow through finite element method and testified with experiments. Results show that the stiffness and stability of V-shaped metal bellow are of very strong nonlinearity. The calculation through non-linear finite element method consists with experimental results. Non-linear finite element model is suitable to simulate the critical pressure and buckling modal of V-shaped metal bellow. Related Articles | Metrics

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Rough Set-genetic Algorithm-neural Network Compositive Classifier and Its Application in Rotor Faults Diagnosis Chen Guo China Mechanical Engineering    2008, 19 (1): 85-90.   Abstract （3271）      PDF （4825KB）（2713）       Knowledge map    Save The fault diagnosis problem of rotor system was aimed at, on the basis of synthesizing the advantages of Rough Set (RS) theory, Genetic Algorithm (GA) and Neural Network (NN), a new RS-GA-NN compositive classifier was put forward. In the model, the RS was used to carry out selection of sample features; the NN was used to realize the mapping between features and fault type of sample; the GA was used to optimize the structure of NN model in order to make it to reach the best generalization.The rotor fault experimental rig was used to simulate unbalance, misalignment, rubbing and oil whirling faults, and 127 faults samples are obtained. Finally, the RS-GA-NN compositive classifier of multi-faults recognition was established, and the intelligent fault diagnosis experiment was finished, and a very satisfied result is obtained. Related Articles | Metrics

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Real-time Identification and Prediction for Intelligent Control of Rectangular Box Drawing Su Chunjian;Zhao Jun;Guan Yingping;Ma Rui J4    2008, 19 (3): 351-354.   Abstract （3194）      PDF （3341KB）（2237）       Knowledge map    Save In the four basic factors on the intellectualization of sheet metal forming, the real-time identification of the material performance parameter and the prediction of the optimum technological parameter are the most complicated ones. The accuracy of identification and prediction will have direct effect on the success of the intelligence control. Taking the intelligence control of rectangular box as an object of study, feed forward neural network model based on LM algorithm had been established to realize material properties and friction coefficient for deep drawing of rectangular box. By means of real-time monitoring and measuring to identify the material performance parameters and to predict the optimum technological parameters, and a satisfied accuracy of convergence is achieved. Related Articles | Metrics

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Topology Optimization Design of Large-displacement Compliant Mechanisms Using Meshless Methods Du Yixian Chen Liping Luo Zhen China Mechanical Engineering    2008, 19 (2): 130-136.   Abstract （3177）      PDF （5896KB）（2739）       Knowledge map    Save Based on the continuum structural topology optimization, the element-free Galerkin method was applied to design large-displacement compliant mechanisms with geometrical nonlinearities.The multi-criteria mathematical formulation was developed using the SIMP（solidisotropic material with penalization）interpolation scheme and compromise programming,in which the mechanical flexibility and structural stiffness were both considered as the prescribed performances to be optimized. The optimization formulation was solved by optimality criteria method. The element-free Galerkin method was employed to discretize the design domain with the aim of avoiding the undesired mesh distortion caused by adopting finite element methods to deal with geometrical nonlinear problems.Numerical examples have been presented to demonstrate the effectiveness of the proposed approaches by analyzing the results derived from linear and nonlinear cases,respectively. Related Articles | Metrics

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Reliability Sensitivity to the Correlation Coefficients among Variables in Generalized Random Space Wang Shipeng;Zhang Yimin;Xie Yancai J4    2007, 18 (23): 0-2778.   Abstract （3130）      PDF （3347KB）（2512）       Knowledge map    Save The importance and the reliability sensitivity of the correlation coefficients among the basic variables in generalized random space in the reliability analysis were investigated. By the reliability analysis optimal method including operation of the correlation coefficients among the basic random variables in generalized random space, the importance of the correlation coefficients among the basic variables in generalized random space in the reliability analysis was analyzed through calculation of the reliability analysis, and the influence of the correlation coefficients among the basic variables in generalized random space on the structural reliability through calculation of the reliability sensitivity. The method can be used to obtain information such as the importance of the correlation coefficients among basic variables in generalized random space, influence and different influence levels on the structural reliability. Some useful reference to statistical work and reliability design is provided. Related Articles | Metrics

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Research on Inverse Kinematics Algorithm with High Accuracy for a General [STHZ]6R Robot Liu Songguo, Zhu Shiqiang, Cheng Yonglun China Mechanical Engineering    2007, 18 (20): 2414-2418.   Abstract （3024）      PDF （3545KB）（3205）       Knowledge map    Save In order to solve the problem of inverse kinematics for general 6R robots,an algorithm with high accuracy based on symbolic preprocessing and matrix decomposition was proposed.Symbolic preprocessing was performed to obtain the coefficient matrixes of the inverse kinematics equations and avoid the accumulative errors of floating point computations.Singular value decomposition was adopted to ensure the rank stability of coefficient matrixes, eigendecompostion of matrixes and the method of selecting elements with the highest magnitude were applied to minimize the influence of accumulative errors on solving stability and accuracy.All these ensure that the algorithm can get 16 real solutions at most with any required accuracy.Experiments on general 6R robots and PUMA560 robots with small configuration perturbations verify the validity of the proposed algorithm. Related Articles | Metrics

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Scheme Design and Optimal Selection for Hybrid Electric Vehicle Planetary Gear Mechanism SHU Fu-Tang, CHEN,LI,YAN Cheng-Liang, TANG Lin China Mechanical Engineering    2010, 21 (1): 104-109.   Abstract （3017）      PDF （4437KB）（2160）       Knowledge map    Save More and more planetary gear mechanisms are being used in HEV as multi-power coupling mechanism because of their compact structure, high transmission efficiency and strong load bearing capacity. In order to get all the planetary gear schemes that satisfy the requirements of topological characteristics, and the optimal scheme for hybrid electric vehicle planetary gear coupling mechanism (HEV-PGCM) was selected as the references for the following analysis and structural design. Firstly, a variety of HEV-PGCM schemes with required topological characteristics were produced by using the creative design method. Secondly, according to the design requirements of planetary gear transmission and HEV power coupling mechanism, combined with matrix theory, the scheme evaluation indicators and method for HEV-PGCM were presented and used for scheme analysis and optimal selection. The results indicate that this method is general for common use and it can provide reference schemes for the following structural parametrical design and analysis of HEV-PGCM. Reference | Related Articles | Metrics

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Differential Motion Equations of 5R Flexible Parallel Robot Du Zhaocai, Yu Yueqing China Mechanical Engineering    2008, 19 (1): 75-79.   Abstract （3007）      PDF （3704KB）（1223）       Knowledge map    Save To obtain the kinematic and dynamic characteristics of a planar 5R parallel robot with physical flexible links and distributed mass, operating at higher prescribed input speeds, a finite element-based differential motion equation was proposed. Considering the kinematic coupling between the flexible links and rigid moving platform, a modeling method suitable for the mechanism systems which contained flexible bodies and rigid bodies was modified. The transformation matrices of element variables were derived from the system kinematics property. The governing equations for the deflections of the robot members were obtained using the Lagrange equation. The set of equations was discretized using the finite element method. The equations derived herein give a more accurate model by including additional terms as Coriolis damping, centrifugal stiffness and geometric stiffness. The element equations were transformed and assembled to generate the governing differential equations for the robot. In this manner the defects brought by kinematic and dynamic constraints equations were avoided. The procedure was illustrated by a detailed analysis of a planar flexible 5R parallel robot. The model can be used for Kineto-Elastodynamics analysis and optimal design. The flexibility of links is demonstrated to have significant impact on the performance and stability of the flexible robots. Related Articles | Metrics

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Experiments and Dynamic Simulation of External Grind-hardening HAN Zheng-Tong, YANG Gang, DU Chang-Long, SHU Hua, MA Tie-Long J4    2009, 20 (23): 2800-2803.   Abstract （3007）      PDF （4335KB）（1225）       Knowledge map    Save The grind-hardening experiments of 40Cr steel were taken on the external grinder, and the metallurgical structure and microhardness of the samples were measured and analyzed, which was expected to show the feasibility and effectiveness of this new technology. Though finite element analysis using software ANSYS with a new compound heat source model, the temperature field and its changes were simulated and analyzed, and the hardness depth was predicted and verified. The simulation results indicate that it is possible to take the place of experiments when the conditions are not qualified. Related Articles | Metrics

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Design of Partial Porous Air Thrust Bearing Wang Jianmin, Dai Yifan, Li Shengyi China Mechanical Engineering    2008, 19 (1): 38-43.   Abstract （2996）      PDF （4856KB）（1685）       Knowledge map    Save A nonlinear model based on the finite element method was provided to compute the static characteristics of partial porous air thrust bearing considering the tangential velocity slip at the bearing-film interface. Good agreement is achieved between theoretical and experimental results of static load capacity, mass flow and static stiffness. The modified Reynolds equation is verified to be proper to investigate the characteristics of externally pressurized partial porous air thrust bearing. The effects of slip on the steady state characteristics, such as mass rate of flow, load capacity and static stiffness were studied, when the feeding parameters of permeability coefficient, height or diameter of partial porous restrictors were changed. Then the results are presented in form of charts. Based on the analysis, the criterion of designing partial porous air thrust bearing was provided. Furthermore, the performance comparison between the thrust bearings with partial porous restrictors and porous restrictors shows that this kind of bearings have prosperous application for their good performance. Related Articles | Metrics

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Application of Neural Network Trained by Chaos Particle Swarm Optimization to Fault Diagnosis for Rotating Machinery Qiu Guoqing;Tang Xianlun;Zhuang Ling;Yang Zhilong J4    2008, 19 (21): 0-2524.   Abstract （2996）      PDF （2964KB）（2368）       Knowledge map    Save A new particle swarm optimization algorithm with dynamically changing inertia weight based on chaos particle swarm optimization was proposed, in which the inertia weight of the particle was adjusted adaptively based on the premature convergence degree of the swarm and the fitness of the particle, the diversity of inertia weight made a compromise between the global convergence and convergence speed, so it can effectively alleviate the problem of premature convergence. The algorithm was applied to train neural network and a model of fault diagnosis for rotating machinery was established, compared with particle swarm optimization algorithm and genetic algorithm, the proposed algorithm can effectively improve the training efficiency of neural network and obtain good diagnosis results.  Related Articles | Metrics

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Research on the Kinematic Characteristics of Bionic Kangaroo-Hopping Robot during Flight Phase Ge Wenjie, Huang Jie, Yang Fang China Mechanical Engineering    2007, 18 (21): 2521-2524.   Abstract （2994）      PDF （3474KB）（1523）       Knowledge map    Save Based on the body configuration and kinematics characteristics of kangaroo in its flight phase, a new method to analyse the torque characteristics was presented.A model to simulate the kangaroo robot in the flight phase was also founded using D-H method. The equations of the model were derived using Lagrange method and the model was simulated by Matlab at last. The results show that, the hip and knee joints play the most important role in tuning the configuration of kangaroo hopping robot in flight phase,which is the basis for the experimental research and choosing driving actuators. Related Articles | Metrics

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Analysis and Synthesis of Electro-hydraulic Velocity Servo  Control System about Electro-hydraulic Integrated Hydraulic Winder Peng Youduo;Yu Bing;Gao Guanghui;Liu Fanmao J4    2007, 18 (22): 0-2673.   Abstract （2957）      PDF （4255KB）（3092）       Knowledge map    Save The mathematical model of electro-hydraulic velocity servo control system on electro-hydraulic integrated hydraulic winder was established.This model was simplified according to the analysis and contrast of system parameters. By simulink,the simulation models of original and simplified mathematical models were established. By MATLAB,the dynamic characteristics of this system was studied.And then, this system was corrected with lag compensation to satisfy the design demands of system. Related Articles | Metrics

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Study on Multidisciplinary Hierarchic Optimization Method and Its Application CA Tie-Jun, LI Kai J4    2009, 20 (23): 2836-2839.   Abstract （2941）      PDF （3068KB）（1118）       Knowledge map    Save This paper studied multidisciplinary hierarchic compatibility design optimization (MHCDO) method for design of hierarchic system. Based on sensitivity analysis which can reflect the effect of the change of share design variables and state variables on objective function in every optimization, the method can obtain the most adaptive solution of system. Using the MHCDO method in optimal design of fence structure micromachining vibratory rate gyroscope, the optimal results improve the performance of the gyroscope and verify the practicality of MHCDO method.      Related Articles | Metrics

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Adaptive TVAR Time-frequency Analysis Based on Wavelet and Its Application in Fault Diagnosis Wang Shengchun;Han Jie;Li Jianfeng;Li Zhinong J4    2008, 19 (7): 0-761.   Abstract （2938）      PDF （3498KB）（2105）       Knowledge map    Save Time-varying autoregressive (TVAR) modeling method of non-stationary signal was studied. In the proposed method, time-varying parametric identification of non-stationary signal can be translated into a linear time-invariant problem by introducing a set of wavelet basis functions. Then, the parameters were estimated using recursive least square algorithm with a forgetting factor and the adaptive time-frequency analysis was achieved. The simulation results show that the proposed approach is superior to the short time Fourier transform and Wigner distribution. At last, the proposed method is applied to the fault diagnosis of bearing,and experimental result shows the proposed method is effective in feature extraction. Related Articles | Metrics

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Coupled Vibration Analysis of Wind Turbine Jin Xin, He Yulin, Du Jing, Liu Hua China Mechanical Engineering    2008, 19 (1): 9-13.   Abstract （2935）      PDF （4077KB）（2054）       Knowledge map    Save The aerodynamics characteristics of wind turbine were calculated by applying GDW theory and were programmed in MATLAB/Simulink. The drive chain was calculated by applying state space method and also programmed in MATLAB/Simulink. The model of the wind turbine was built in Adams. The simulation of vibration characteristics was carried out so that the aerodynamic loads and the torque were applied to the structure of the rotor. Simultaneously the deformation of the structure also affected the loads. The results show that the method has excellent ability to simulate the vibration characteristics almost the same as test measured. Related Articles | Metrics