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Table of Content

    11 June 2010, Volume 21 Issue 11
    Analytical Method for Forward Kinematics Analysis of General 6-SPS Parallel Mechanisms
    CHENG Shi-Li, TUN Hong-Chao, WANG Chao-Qun, TAO Yu, SHU Jian-Yang
    2010, 21(11):  1261-1264. 
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    The coupling relationship among the positional and orientational variables of the moving platform of general 6-SPS parallel mechanisms was studied. Six in nine variables were expressed by the three remainder variables, so the position variables were expressed by orientational variables. Applying Grbner basis algorithm, fifteen four order compatible algebraic equations were obtained, which contained the three remainder variables. The orthogonal complement method was used several times to eliminate the redundant variables, by this way the problem of the forward kinematics analysis of the general 6-SPS parallel mechanisms can be simplified as several twenty order algebraic equations in the end. It is verified that these equations have the same solutions. 
    Design and Analysis of an Out-pipe Anticorrosive Robot
    WANG Cheng-Jun, MA Lv-Zhong
    2010, 21(11):  1265-1270. 
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    A prototype of out-pipe anticorrosive robot was developed by the authors. The anticorrosive robot can complete the anticorrosion task of a steel-made pipe for transport oil and natural gas underground to substitute human beings. The structure composition and working principles of the anticorrosive robot was introduced and a design scheme of a double chain-wheel walking driving mechanism and the robot circumferential motion system was proposed based on incomplete-roller chain drive mechanism. And the motion performance of the circumferential motion system and walking mechanism was analyzed. The robot has good performance of obstacle crossing, swerving and circumferential motion. The results show that the theoretical analysis is similar to the experimental ones. And it meets the demands of anticorrosion construction. 
    Vibration Characteristics Analysis of Bladed Disks with Two Interphase Cracked Blades
    WANG Ai-Lun, HUANG Fei
    2010, 21(11):  1270-1274. 
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    The effect of two interphase cracked blades on vibration characteristics of bladed disks was investigated herein.An analytical model for a bladed disk was formulated using lumped-mass beam. The equation of motion of the mistuning structure, with two interphase crack blades, was derived. Comparing the vibration characteristics of bladed disk with two interphase crack blades to with the single crack blade, the results demonstrate that cracked blades cause repeated natural frequency of the structure to separate, and increase the level of vibratory localization,make the vibration characteristics of the bladed disk became more complex. Besides, it is discovered that two peculiar blades are extremely insensitive to changing of the crack depth, hence providing the guidance required for blade crack detection procedures.
    Deduction of Jacobian Matrix for Free-Floating Branching Space Robot Based on Recursion of Screw
    LIU Yun-Beng, TUN Hong-Chao
    2010, 21(11):  1275-1277,1347. 
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    For more degree of freedom, complex topology and high coupling between base and manipulator, the kinematics and dynamics of large free-floating branching robot system are difficult to analyse. A free-floating branching robot system was researched by dividing into two parts, ground robot of fixed base and locking joint robot of floating base. Then it can avoid the analysis of the coupling between base and manipulator,so the Jacobian matrix can be achieved simple and efficiency. And the computional efficiency is improved by the methods of combining screw and recursive operator, which is the foundation of the dynamics.
    Study on Grinding Forces for Glass Grinding with Single Diamond Grit
    HUANG Hui, LIN Sai-Huang, XU Xi-Feng
    2010, 21(11):  1278-1282. 
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    The grinding forces were measured in brittle grinding of glass with three typical shape diamond grits. The influences of grinding parameters and cutting angle of grits on the grinding forces were discussed. The experiment results show that the force signal curves are not symmetric distribution with scratching profile. There are obvious oscillations on the curves of normal force signals. The value and curve shape of grinding forces of the down-grinding are as same as those of the up-grinding. Grinding forces increase with grinding depth, but decrease with the grinding velocity. The grinding forces obviously increase with the cutting angle of grits. With the same cutting velocity, the grinding forces have good linear relationship with plowed surface area. There is a very good linear relationship between the normal forces and tangential forces for different grits.
    Efficient Method for Harmonic Response of Structure with Damping Based on Reduced-basis Method
    HUANG Fen, HAN Xu, HUANG Yong-Hui
    2010, 21(11):  1283-1288. 
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    The harmonic response of linear elastic structures with damping was analyzed using a reduced-basis method (RBM). Firstly the frequency domain was discretized into limited points. And a logarithmic sampling method was used to select samples. The greedy algorithm was suggested to train the samples adaptively and a series vectors were obtained. A Gram-Schmidt algorithm was used to orthogonalize the vectors, then a optimum reduced-basis space was constructed. After the Galerkin projection of matrices into the reduced basis space, a reduced system was obtained and can be solved efficiently. The reduced solution was obtained. By projecting the reduced solution back into the original space, the approximate solution of the original system subjected to a harmonic load was obtained efficiently and accurately. The numerical examples herein demonstrate that reduced-basis method can perform harmonic response analysis of linear structures with damping well. 
    Vision-based Localization of OutLand1000 ROV
    XU Xiao-Long, XU Guo-Hua
    2010, 21(11):  1288-1292. 
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    Calibration experiments were carried out on OutLand1000 ROV and the intrinsic parameters were presented herein. For the underwater camera model, the distortion coefficients of radial and tangential were considered and the improved underwater localization algorithm was presented. A series of experiments were performed, and the localization accuracy is improved from the results showed in the paper.
    Research on Friction Power Loss of Metal Belt Continuously Variable Transmission
    ZHANG Wu, LIU Kai, ZHOU Chun-Guo, ZHANG Hai-Yuan, ZHANG Bao-Feng
    2010, 21(11):  1293-1297. 
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    In order to improve the transmission efficiency of metal belt. The power loss of metal belt CVT was determined as four parts, by synthetically considering the effect of the slip on the power loss, the calculation formulate of power loss was found. Take the transmission ratio i=0.85,i=1.00 and i=2.35 for examples, every power loss was calculated, the results indicate that friction between segment and pulley is the main factor, with the increase of transmission ratio, power loss is increased after reducing and efficiency is reduced after increasing for a while. The efficiency is the highest when transmission ratio equals to 1.00.
    An Interval Analysis Method of Non-Probabilistic Reliability Model for Vehicle Semiaxle
    GU Qiu-Gong, LIAO Lin-Qing, JUE Xiang, XIAO Yan
    2010, 21(11):  1298-1300. 
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    The uncertain parameters of vehicle semiaxle were described by interval numbers,combining interval analysis with reliability design method,a non-probabilistic reliability model of vehicle semiaxle was presented.It discussed a measurement method of reliability with non-linear function for multiple interval variables.Based on interval analysis,a non-probabilistic reliability design idea for vehicle semiaxle was proposed.Finally,on condition that distribution function of parameters was unknown and interval numbers were known,an example of reliability design of vehicle parts was given,a maximum response stress was obtained.The research shows that the approach is reasonable,and the initialization is brief required.The most important is that it can be applied to other parts of the reliability design.
    Kinematics and Singularity Analysis of a Novel 2R Fully-decoupled Parallel Manipulator
    FAN Cai-Xia, LIU Hong-Zhao, ZHANG Pan-Bin, YUAN Ge-Xia
    2010, 21(11):  1301-1305. 
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    This paper presented a novel two degree-of-freedom (DOF) fully-decoupled parallel mechanism(PM) with two dimensional rotation. First,based on the DOF feature matrix kinematic type was analyzed, and using single open-chain theory the calculation of the DOF of the mechanism and selection of the actuated pairs were performed. Next, the displacement and velocity of the mechanism were analyzed,and according to the direct and the inverse Jacobian matrices of the manipulator singularity conditions were discussed systematically. At last the motion of the mechanism was fully decoupled for the Jacobian matrix being a triangular matrix,which can simplify control and trajectory planning of the mechanism.
    A Method for Calculating Tooth Bending Stress of a Herringbone Planetary Train System in Engagement Process
    CHANG Le-Gao, LIU Geng, TUN Li-Yan, XU Yi-Pei
    2010, 21(11):  1305-1309. 
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    Using linear programming method, the load distributions for each gear were computed at different meshing positions. Then the changing course of root bending stress along with the variation of meshing position was gained for each gear of the planetary trains. The whole calculating course realized the automatic definition of loads and boundary conditions and found out the value and position when the tooth root has maximum stress. The results show that the maximum stress usually appears near the position when the tooth bears most of the load. The results can provide reference for checking tooth bending strength of herringbone gears in a planetary system.
    Three-dimensional Rotor Optimization in Multi-blade Row of a Dual Stage Counter-rotating Compressor
    WANG Yan-Gang, NIU Nan, LIN Sai-Yuan, LIU Bei
    2010, 21(11):  1310-1314. 
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    Based on the detailed study of a counter-rotating compressor in the laboratory, three-dimensional optimization had been carried out in multi-blade row surrounding by approximate function methods combining with genetic algorithm. The second rotor had been optimized by this method to improve the performance of counter-rotating compressor. Compared with the initial compressor the results show that: at design point, the efficiency of the optimized counter-rotating compressor is increased by 0.69%, the mass flow rate and pressure ratio remaines basically unchanged, however the surge margin is improved. The efficiency of the rotor downstream increases by 1.36%, its pressure ratio is almost invariant, at the same time the performance of the rotor upstream retain a higher level at design point. By further contrast the flow structure of the optimized and initial counter-rotating compressor, the optimization reduces the wake mixing losses at the middle and tip of the rotor downstream, but increases the wake mixing losses at the root, the optimization improves the flow structure of outlet guide vane as well.
    A Method to Frequency Response Analysis of Hydraulic Pulsation Dampers Based on CFD
    DU Run, LIU Xiao-Gong, XU Lan-Yang, KE Jian
    2010, 21(11):  1315-1319. 
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    Simulation of transient state of hydraulic pulsation dampers with a CFD code was done to get their frequency response. Under laminar conditions, transient state of pulsation dampers was computed with M-sequence pressure signals acting as a kind of boundary to simulate pressure wave and compressibility of fluid being considered. Frequency response was done via FFT of transient pressure sequences. Comparison between CFD model and traditional precise analysis model was presented and this new method was applied to frequency analysis of a complicated structure damper. The results show: the agreement between CFD numerical analysis and traditional precise analysis is satisfactory, and CFD analysis is practical to analyze frequency response of the complicated structure hydraulic pulsation dampers.
    Non-fragile Guaranteed Cost H∞ Control of Underactuated Robots Based on T-S Model
    TUN Zhong-Jiang, LIU Li-Ling
    2010, 21(11):  1319-1324. 
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    The non-fragile guaranteed cost H∞ control of underactuated robots were discussed. The underactuated joints were derived to desired positions by the coupling of joints, and braked. The robot with underactuated joints braked become full-drive system. Combining with the theory of non-fragile guaranteed cost control and the theory of H∞ control, a non-fragile guaranteed cost H∞ control of underactuated robots based on T-S model was provided to make this system capable of handling position tracking. The simulation of a two-link robot shows the validity and the practicality.
    Evaluation and Data Processing Model for RFID Application Reliability in Manufacturing System
    ZHENG Lin-Jiang, LIU Wei-Ning, SUN Dai-Hua
    2010, 21(11):  1325-1330. 
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    To improve RFID application reliability in complex manufacturing environment, a set of evaluation indexes for evaluating RFID application reliability were suggested, and a layered data processing model was presented to improve RFID application reliability. The model consisted of two layers, the primitive event processing layer and the complex event processing layer. The former received primitive reading events from the reader-network, cleaned duplicated events by duplication elimination constraint. Thus tidy and exclusive logic reading events were obtained. Then based on establishing application integrity constraints and analyzing logic reading events, the complex event processing layer detected and corrected false positive readings and false negative readings. Taking physical object’s route constraint as an example, the identifying method of false positive readings and false negative readings were described. The results of application show the availability of the model.
    A Micro-motion Measurement Algorithm Considering Accuracy and Efficiency
    LEI Qing-Hua, ZHANG Xian-Min, FAN Pan-Bin
    2010, 21(11):  1330-1333. 
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    A micro-motion measurement method having good performance was proposed herein considering accuracy as well as efficiency. According to the bias-time performance evaluation approach, a micro-motion measurement method can be found by choosing the suitable parameters of this algorithm. Such an approach can offer good performance in accuracy and efficiency. Experimental simulations show that the proposed micro-motion measurement method performs well in efficiency, and the maximal measurement bias reaches 0.025 pixels for the motions near 2 pixels for MEMS images.
    Technology and Implement Process of Feature Recognition Based on STEP
    FU Feng, YU Wei-Zheng
    2010, 21(11):  1334-1337. 
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    Aiming at recognizing features from different 3D CAD models, this paper described the implementation process of feature recognition based on STEP. First, an object oriented method was introduced. The predefined feature was presented using object of class instead of attribute table so the code reusability of the feature recognition system can be improved. Second, the mapping relationship of STEP data type and C++ structure was established. So the topological-geometrical tree can be extracted from STEP-based neutral file. According to the topological and geometrical representation of STEP, it recognized the type and geometric parameter of topological layer including face and loop. At last, it recognized the predefined feature by attribute adjacent graph decomposition using sub-graph matching and base-face decomposition method. 
    Research on Multiple-objective Design Optimization and Multivariable Nonlinear Regressing of Hot Extrusion Process
    ZHANG Jin-Biao, WANG Jing-Wen
    2010, 21(11):  1338-1341. 
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    A method of extrusion process multiple-objective optimization was proposed based on numerical simulation and genetic algorithm. The extrusion force and the damages of the final forging were considered into the multiple-objective function. The hot extrusion forming was simulated by Deform software. The data of extrusion force and damages were acquired by designing the friction factor, extrusion speed and extrusion ratio. The mathematics models of deformation force and damages were established via multivariable nonlinear regressing. The evaluation model of multiple-objective design optimization was constructed by using the weighting function method. The optimal solution of the extrusion process parameters was calculated by an improved genetic algorithm. A case study was conducted for a thermal brass rod hot extrusion process, and the optimal parameters were obtained.
    Effective Fault Tolerant Control on Electro Hydraulic Servo Synchro System
    NI Jing, BANG Li-Hui, XIANG Tie-Qin
    2010, 21(11):  1342-1347. 
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    An effective fault tolerant control approach with system state diagnosis, crossing coupled PID theory and quantitative feedback theory was put forward to address synchronization motion control in electro-hydraulic servo system. The proposed controller firstly monitored synchronous errors in dual-cylinder motion, then switched the suitable controller among crossing coupled PID controller for "normal" system and quantitative feedback robust controller for "anormal" system. In this way, the presented controller can achieve the requirements of system tracking and robustness. Application in travelling crane with dual-cylinder shows that the provided approach with well capability of coordination and tracking response, can preferably address synchro motion control in electro-hydraulic servo system.
    Study on Synchronous Vibration Control of an Electrohydraulic Vibration Exciter
    GU Wen-Ang, RUAN Jian, LIN Yan
    2010, 21(11):  1348-1352. 
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    A mathematical model of electrohydraulic vibration exciter was established; the relation among piston displacement of cylinder, the rotary speed and axial sliding of spool was studied by using the numerical simulation program in Runge-Kutta method, the phase-frequency waveform of the exciter was given and discussed. Finally the test equipment was established to verify the simulation results. It is classified that phase difference is changed little while the ratio value between the excitation frequency and natural frequency is in 0.048~0.870. So the phase synchronization can be achieved in multi-axis fatigue test system consisting of electrohydraulic vibration exciter controlled by 2D valve among that frequency band.
    Experimental Research on Micro Electrochemical Milling of Nickel Based Alloys
    TU Hong-Bing, CENG Yong-Ban, LIU Yong, SHU Di
    2010, 21(11):  1353-1356,1361. 
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    A new process of micro electrochemical milling by layer was proposed for the micro cavity of high aspect ratio and the complex structure. The cylindrical micro electrodes for micro electrochemical milling can be fabricated on-line by electrochemical etching. A series of experiments were carried out to investigate the influence of the predominant parameters such as machining voltage, pulse on-time, electrode diameter on machining accuracy of nickel based alloys, and micro structures with high precision were fabricated successfully.
    Fault Localization Method of Hydraulic System Based on Minimum Cut Sets’ Comprehensive Rank
    TAO Cheng-Yu, CHEN Dong-Ning
    2010, 21(11):  1357-1361. 
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    On the basis of fault tree analysis, fault localization of hydraulic system was investigated by comprehensive consideration of search cost, fault probability, impact degree and other factors of the minimum cut sets. The number and attribute of minimum cut sets were determined according to the system characteristics, and weighted normalized decision matrix of fault localization was established by use of weighted least-square method, then search sequence was calculated based on minimum cut sets’ comprehensive rank by means of relative closeness method. For the master cylinder’s failure to work speed caused by charging valve faults in the engineering practice of the assembling press, rapid and accurate fault localization was realized combined with the search sequence given by the algorithm, and the effectiveness of the algorithm was verified.
    Design and Optimization of Rectangular Container Used in Polyurethane Rubber Pad Forming
    HUA Lin, LIU Yan-Xiong, LAN Jian, WEI Xi, WANG Shou-Yang
    2010, 21(11):  1362-1365. 
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    A mathematical relationship between the interior size and the ex-radius of a container which was used in rubber pad forming process was obtained by building mechanical model of the container at the working state, performing the finite element analysis and optimizing the fillet radius of the container at the corner. To validate the mathematical relationship, the rubber pad forming experiment was carried out. Finally, design and strength checking of the container were performed by taking the results of calculation and the FE simulation.
    Effects of ZrC Particles on Thermodynamic Conditions of Low Carbon Steel during Deformation Induced Ferrite Transformation
    KUANG Jian-Xin, TANG Meng-Hua, LIU Zhi-Xi, HU Shuang-Kai, LI Chun-Yuan
    2010, 21(11):  1366-1370. 
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    The effects of ZrC particles on thermodynamic conditions of low carbon steel during DIFT were studied by unidirectional compression thermal simulating experiment.The results show that ZrC particles with definite radius and suitable volume fraction as the nucleus of deformation and recrystallization,it can improve the start temperature and reduce critical deformation of DIFT, and greatly improve α-Fe nucleating rate which leads to the ferrite grains further refinement.However,the role of ZrC particles in promoting nucleation exists a critical value, an excessive amount of particles will produce inhibition of ferrite core, it is not conducive to the organization refinement. Based on thermodynamic theory of phase transitions, a laboratory rolling process is developed, and obtains the ferrite grain size of low carbon steel plate up to 3.9μm, material yield strength reached 802MPa, it significantly improves overall performance.
    Finite Element Method and Experiments on High-pressure Torsion of Cone-shaped Part Prepared by Pure Al Powder Sintered Material
    LI Qi, LI Ping, XUE Ke-Min, WANG Xiao-Xi, GU Jian-Lei
    2010, 21(11):  1370-1373,1385. 
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    Cone-shaped part prepared by pure Al powder sintered material processed by HPT was studied by compressible rigid plastic FEM, the distribution and the variational trend of strain and density in HPT process were analyzed; The specimen was deformed by HPT equipment and die, microstructure, microhardness and density of different points in undeformed and deformed specimens had been examined. The results show that HPT process is a useful tool for reducing the porosity in specimen, the relative density of specimen is above 0.996 in FEM, while it reaches to 0.98 in the experiment; the strain-effective of different points in specimen are different, it reaches to the highest in the edge of specimen, about 4.5, microhardness reaches to 61.12HV0.1/10 in the edge of specimen, it is also the highest.
    Modeling and Simulation of Adaptive Cruise Control System for Intelligent Vehicles
    LI Si-Nong, JI Jie, ZHENG Ling, DIAO Shu-En
    2010, 21(11):  1374-1381. 
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    In order to realize the adaptive cruise function of intelligent vehicles, an adaptive cruise control system with a two-level structure was designed based on fuzzy logic and slide mode control theory. The system can control throttle angle and brake pressure coordinately so as to make the vehicle follow the desired acceleration command accurately, a logic switch rule between throttle and brake control was also designed to ensure the coordinations of this control system. The simulation results show that the proposed control system provides satisfactory tracking performances and suitability in situations such as traction, vehicle following and braking.
    Low Frequency Interior Noise Control of a Certain SRV
    CHEN Jian, WEN Zhi-Meng, LI Ji-Feng
    2010, 21(11):  1381-1385. 
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    To a certain SRV(sport recreational vehicle),firstly BIP(body in prime) FE model and acoustic FE model were built by experiments and CAE modal analysis. FEM and BEM were used to analyse the dynamic response of the BIP and acoustic cavity. Then panel contribution analysis and dynamic sensitivity analysis were made at the frequencies where the peak values were found. Lastly, according to the results of dynamic sensitivity analysis, interior noise is improved effectively by optimizing the thickness of some panels.