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    25 December 2012, Volume 23 Issue 24
    Research on Structure Design of Elastic Composite Cylindrical Roller Bearing
    TAO Ji-Shui-1, 2, YANG Wen-2, TU Jiang-Hong-2, ZHANG Ran-2
    2012, 23(24):  2899-2902. 
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    According to the principle of combinational innovation,a study of structure innovation of cylindrical roller bearing was made,and a new method of structure design of elastic composite cylindrical roller bearing which embedded PTFE in the hollow cylindrical roller was put forward.In order to determine the size of elastic composite cylindrical roller and define the rolling element filling K=d/D,ANSYS software was used in finite element modeling of the bearing.Analysis was made to identify the influence of the contact stress,von Mises stress,bending stress and load of elastic composite cylindrical roller bearing on overloaded.It is found that the best rolling element filling is 55% in the overloaded case.The accuracy of the analysis was verified through the experiments.The study results provide the basic data for the design of elastic composite cylindrical roller bearing.

    Research and Typical Application of Monitorability-based Design of a Mechanical System
    YAN Xin-Beng-1, 2, ZHANG Ru-Lei-1, 3
    2012, 23(24):  2903-2907,2912. 
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    The monitorability-based design theory was presented based on the condition monitoring and modern design technology herein.Theoretical system of  the monitorability-based design was discussed from the system theory point of view.The connotation of the monitorability-based design theory was described by discussing the design contents,key factors and related technology fields.It concludes that the research contents of theoretical system of monitorability-based design can be divided into four aspects parallelly.These aspects include (1)study on the connotation of the monitorability-based design theory,(2)research on design methods of the monitorability-based design theory,(3)investigation on allocation methods of the monitorability-based design theory,and (4) assessment on the monitorability-based design.At last,marine power mechanical system was regarded as practical application study object of monitorability-based design theory.Monitorability of marine power mechanical system was considered in detail before its design.

    Application of DEPSO Algorithm to Permanent Magnet Linear  Motor Structure Optimization Design
    LIN Jian, HUANG Jia-Cai, HONG Mu-Lan, CHENG Dang-Gong
    2012, 23(24):  2908-2912. 
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    Since most of traditional algorithms were applied to optimization design of linear motor structure to reduce the force ripple,the optimization efficiency was low for the premature convergence and slowed convergence speed of traditional algorithms,and the force ripple can not be calculated accurately by analytical method because of linear motor peculiar magnetic field effect.A hybrid optimization algorithm
    (DEPSO) was proposed based on the combination of DE and PSO to overcome traditional algorithms limitations.Differential mutation,crossover and selection operators were employed to produce a personal best position in the process of particle evolution,the direction of particle evolution was optimized.Motor structure parameters were optimized based on combination of the FEM and DEPSO algorithm.The experimental results show that the detent peak force reduces significantly via the optimization,the proposed technique is proven to be effective for solving such problems.

    Design of Multi-channel Data Acquisition Device for Sheet Metal Multiple Point Incremental Forming Force
    CA Gai-Pin, GENG Cong-Wen, LUO Xiao-Yan, JIANG Zhi-Hong
    2012, 23(24):  2913-2917. 
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    According to the characteristics of longer acquisition time and larger quantity of data of  forming force in incremental forming process,a multi-channel and time sharing data acquisition device based on AT89S51 was designed.The paper introduced the work principles of detecting device for the forming force,
    and gave parts of the hardware circuit and software programs.The force curve with deforming time was got by experiments,and shows the detection device fits the data
      requirements for long periods of time,uninterrupted,and continuous acquisition in incremental forming process.

    Dynamics Research of Linear Array Deployable Structures Based on Structure of Scissor-like Element
    SUN Yuan-Chao, WANG San-Min, LIU Xia
    2012, 23(24):  2917-2919,2925. 
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    Based on the Cartesian frame,the paper established a dynamics model of the linear array deployable structures based on scissor-like element.The motion constraint equations can be established by
    constraints' conditions such as kinematic pairs.Using Runge-Kutta method for
    numerical calculation,the laws of the structure,such as velocity and acceleration,
    can be obtained in motion,and kinematic curve is also able to be drawn,
    and then it provides the foundation of this structure of the application.
    The results show that the linear array SLE in an process does not have consistent
    level speed.

    A Disturbance Rejection Control of First-oder Speed for Permanent Magnetic Linear Synchronous Motors
    CHEN Bing-1, YAN Guang-E-2, AI Wu-1
    2012, 23(24):  2920-2925. 
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    For PMLSM direct driven mode,multiple disturbed forces,including load force,friction and magnetic resistance,are acted directly on the rotor of PMLSM without any cushioning,so that they affect the speed stability of PMLSM.This paper presented a PMLSM speed control strategy with disturbance
    rejection,that was based on the expansion state observer used to
    observe multiple disturbed forces in dynamic process of PMLSM speed,a tracking differentiator(TD) and nonlinear state error feedback(NLSEF).The disturbance can be compensated,thus the first-order speed control with disturbance rejection of PMLSM can be achieved. 

    Study on Dynamic Load in Load-lifting System of Wire Rope
    PU Han-Jun-1, XIE Xiao-Feng-1, NIU Gao-Chan-1, LIANG An-Chi-2
    2012, 23(24):  2926-2929. 
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    A dynamic model for load-lifting system of wire rope was established herein,with which a high precision direct precise integration method was proposed for calculating the dynamic load of the system,and the relationship between dynamic lifting coefficient and rigidity of rigging was discussed.Calculation results show the dynamic characteristics of lifting process truly,and experiments demonstrate that this method,with the advantages of high accuracy,taking less computing time,is simple and effective to analyze the dynamic load of the system in various lifting velocity cases.

    Optimization Design of Birotary Arm Type of Separating-transplanting Mechanism with Differential Eccentric Gear Train
    YIN Jian-Jun-1, WU Chuan-Yu-2, LIU Yan-1
    2012, 23(24):  2930-2935. 
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    In view of the requirements of transplanting sparsely of the super rice, a kind of birotary arm type of separating-transplanting mechanism with differential eccentric gear train was presented herein. Angle relationship between multilevel gears round both sides of the center gear in gear box was firstly computed based on inequality model. The center distance of eccentric gear transmission was optimized when the optimization objectives were determined as nonnegative minimal normal backlash of tooth flank and positive bottom clearance. Visual design method of human-computer interaction was used to optimize the parameters of the two-link transplanting-seedling manipulator by taking minimal taking-seedling angle and pushing-seedling angle of the manipulator's claw as optimization objectives, and the results may make the claw of manipulator basically get in and out seedling door along the direction of seedling slope and erectly insert into the soil. The inversion method was used to build up kinematic model of the pushing-seedling mechanism driven by non-uniform planetary gear, and its structural parameters were optimized. Accurate cam contour and its motion relationship of pushing seedling were obtained, and the optimization made cam mechanism have proper pressure angle which theoretically overcome heavier motion impact of shifting fork. Motion simulation shows that optimized parameters are right and can make the separating-transplanting mechanism work well. The separating-transplanting mechanism suits to transplant the seedlings whose heights are less than 352mm when planting distance varies from 200mm to 280mm, and it is especially suitable for transplanting the super rice seedling.

    Middle Surface Generation with Variable Thickness CAD Model Based on Point Matching
    CHEN Zhi-Yang-1, YU Gu-Ming-1, ZHANG Yin-2
    2012, 23(24):  2936-2941,2967. 
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    An algorithm of mid-surface abstraction was proposed based on variable thickness model. This method included applying the algorithm of fillet recognition and suppression based on feature chain to the initial CAD model(B-Rep model) pretreatment, pair selection and invariable(variable) thickness model mid-surface abstraction algorithm. In view of the present research of the variable thickness model focused on the variable thickness model that just has plane variable thickness, this paper studied contained spline variable thickness etc., proposed the algorithm of middle surface generation with variable thickness CAD model based on surface point matching and face point matching, various kinds of situation. The model testing results show that the algorithm has universal.

    #br# Study on Classification Algorithm of Electrode Grouping Based on 3D Model Retrieval and Its Applications
    WANG Hua-Chang, LI Jian-Jun, LI Zhi-Gang
    2012, 23(24):  2942-2946. 
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    Regarding the problem of reusing the knowledge and experience about electrode NC programming, a resolution method of classification and retrieval of electrode was presented based on 3D model retrieval according to principles of group technology.The main idea was to construct an algorithm for recognizing the form features of
    3D model of electrodes by calculating 3D polar radius surface matrix and to acquire a vector of form features, then to define similarity operator of Minkowski distance and to divide
     electrodes into different classifications automatically, finally to gain the standard templates of electrode NC processes. The adopted method has several advantages such as avoiding human errors and having a fast speed and gaining high quality of classification and accurate retrieval result.

    #br# A Trajectory Planning Method Based on Newton Interpolation and Polynomial for Manipulator
    HU Xiao-Beng, BANG Chao, ZUO Fu-Yong
    2012, 23(24):  2946-2949. 
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    For multi-station manipulator tasks in multi-node,a trajectory planning method was proposed,which combined polynomial interpolation and Newton interpolation in joint space.In the initial and final section,
    five polynomial interpolations were used,and the Newton interpolation was used
    in the middle section.
    The method was applied to a class of  four DOF manipulator trajectory planning,the results show that in six given path point trajectory plannings,using trajectory planning
    method proposed herein continuous paths are obtained,thus meeting multi-station manipulator task requirements.

    #br# Experimental Research on Machining Hardening of 0Cr18Ni9 Austenite Stainless Steel
    WANG Zhi-Guang, YANG Wen-Yu, YAN Lin
    2012, 23(24):  2950-2955. 
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    Rational experiments based on Taguchi methods were designed according to the characteristics of difficult-to-machine material 0Cr18Ni9 stainless steel.Work hardening was discussed from the micro-hardness and microstructure.Micro-hardness distribution of the machined sub-surfaces was
    got with the Vickers hardness measurement.And an empirical formula was established
    for predicting the yield strength with hardness.
    Microstructure of the hardened layer was observed with scanning electron microscopy.
    The results show serious hardening that the degree of work hardening is more than
    150%,and the depth of machining affected zone is more than 100μm.The yield strength
     follows a similar trend as that of the measured value of micro-hardness.Metallographic
    observation shows that sub-hardened layer consists of the thermal-force influenced layer
    and the force influenced layer,while the thermal-force influenced layer contains defects,
    and it is easy to peel off. These results indicate that great changes have happened in the surface and subsurface after turning, and it is important to use reasonable cutting parameters to reduce cutting forces and cutting temperature and then reduce work hardening.

    Three DOF Internal Resonances of Electromechanical Integrating Toroidal Drive System
    HAO Xiu-Gong, HU Li-Zhong
    2012, 23(24):  2955-2961. 
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    Electromechanical integrating toroidal drive is a new-style generalized composite transmission,where the power and control are integrated.Considering multiple relations of more natural frequencies in derive system,nonlinear differential equations with multiple internal resonances were presented.
    Then,time responses figures of free vibration system were obtained by multiscale method,
    and vibration performance were studied when excited frequency was near to a natural
    frequency.The results show that energy transfers among modes because of internal resonances,Transient responses of all parts slow decay compared with non-internal resonances.When excited frequency is near to a natural frequency of derive system,amplitudes of
    all parts will increase larger,and vibration offsets occur.Nonlinear characteristics
    become very complicated and there are more resonance regions,so internal resonances should be avoided during parametric design.

    Robust Tolerancing for Aircraft Assembly Based on Tolerant Lexicographic Method
    TAN Chang-Bai, YUAN Jun, ZHOU Lai-Shui
    2012, 23(24):  2962-2967. 
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    Attributing to variations of process capability index and tolerance in aircraft manufacturing,such cases will occur that the assembly quality specifications were violated or the manufacturing cost fluctuated  a lot.So,a novel tolerancing methodology based on feasible and sensitive robust design was
    developed.On one hand,taking into account the effects  of design parameters such as
    tolerances on the assembly feasiblity,the feasible robust tolerancing could ensure the
     achievement of the designed  assembly function in occurrence of design variations.
    On the other hand,the sensitive robust tolerancing took the effects of design parameters
    on manufacturing cost and assembly quality into consideration,which could minimize the
     influence of design variations on manufacturing cost and assembly accuracy.
    Furthermore,a toleant lexicotraphic method was proposed to solve the multiobjective
    optimization problem in feasible and sensitive robust tolerancing.Such factors as manufacturing costs, fluctuations of assembly quality and fluctuations of manufacturing cost were sorted according to their effects in tolerancing.Above all,the general tolerance with
    minimized manufacturing cost could be achieved.Then,
    under the tolerant constraint of minimized cost,the tolerance was deduced by minimizing
    the fluctuation of assembly quality.Finally,under the tolerant constraints of cost and
    fluctuation of assembly quality,the optimal tolerance with minimized cost fluctuation was
    obtained.The proposed methodology was proved to be feasible and effective by
    an example.

    Research on Point Cloud Registration about Sensor from Different View Points Based on Surface Fit
    CHEN Tian-Fan-1, 2, GAO Cheng-Hui-1, HE Bing-Wei-1
    2012, 23(24):  2968-2971. 
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    Focusing on discreteness of point cloud data acquisition from  an object surface,a method of point cloud accurate registration was proposed based on surface fit.Firstly,initial point cloud registration about sensor from different view points was completed.Then,selecting three local surface from the surface overlap
    areas of point cloud by contain sphere,the local surface fitting with three-dimensional quadratic
    surface equation,the rotation transformation using quaternion method,the translation and
    rotation parameters about accurate registration were obtained by means of nonlinear least square optimizing method.The algorithm has faster convergence and higher registration precision.The experimental results indicate the effectiveness of the proposed method.

    Study on Thermal EHL for a Spherical Roller
    SUN Gao-Xiang-1, ZHANG Yan-Beng-1, HUA Tong-Shu-2
    2012, 23(24):  2972-2975. 
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    Using finite line EHL numerical model, the lubrication properties of spherical rollers were studied. It is concluded that the lubrication of spherical rollers performs as point EHL characteristics when the actual contact length is smaller than the nominal contact length; while with the increase of the elliptical ratio or load, it transforms to line EHL, i.e., edge pressure rising and edge film droping down, and the appearance of edge effect is always corresponding to the disappearance of endclosure. Therefore, enough nominal contact length should be given in the design of such friction pairs.

    Research on Adaptive Chirplet Atomic Decomposition Method
    TUN Xue-Meng, XU De-Ge, CHEN Xiang-Min
    2012, 23(24):  2976-2983. 
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    A new atomic decomposition method based on adaptive chirplet for multi-component non-stationary signals was proposed herein.This method can decompose in adaptive mode a complex signal into several PF(production function) components,each of which was the product of an envelope signal and a pure frequency-modulated signal.Favorable aggregation of time-frequency,strong noise immunity and no quadric time-frequency interference term made the method more preponderant to decompose non-stationary vibration signals compared with   empirical mode decomposition(EMD),local mean decomposition(LMD) and Wigner-Ville distribution(WVD).The analysis results of a gearbox vibration signals prove the effectiveness of the method.

    #br# A Structural Layout Optimization Method Considering Displacement Constraints
    YI Ji-Jun-1, 2, LI Yan-Mei-3, RONG Jian-Hua-2, CENG Tao-1
    2012, 23(24):  2984-2990. 
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    A continuum structural optimum method considering simultaneously both the topology and the size design variables was investigated herein. In the proposed method,the combinatorial optimization of two kind of variables was transformed into continuous variables between 0 and 1 by normalization method and the RAMP(rational approximation of material properties) material model. Based on dual optimization method, a new solving algorithm of optimum model and an adjustment scheme of topology design space and size variables were presented. Two examples were given, the results show that the proposed method is of good convergence, and makes the optimum structure obtained be of good 0-1 distribution material property.

    Backlash  Elimination Characteristics of Dual Motor Driving Systems
    FANG Li-Jin, SUN Long-Fei
    2012, 23(24):  2991-2996. 
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    According to meshing states in backlash elimination process and typical working modes of dual motor
    systems,torque relationships that met the requirements of sharing load and elimination backlash were established.The analysis results show that at  the opposite meshing state the motors need to provide a driving torque to drag load and a compensation torque to eliminate backlash at the same time;the output torque value of each motor reaches more than one time of that in the single-motor system to maintain the opposite meshing state.The compensation torque value will vary according to different states;and the output torques of two motors need to be controlled in a dynamic way if it is simultaneously required to share load and eliminate backlash.

    Research on Laser Character Marking Technology for Rotary Solid Carbide Cutting Tool
    LONG Cun-Chen, XU Feng, ZUO Dui-Wen, TUN Xiao-Jun, HU Hai-Feng
    2012, 23(24):  2997-3001. 
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    A new method of tool marking and identification was
    introduced,which can mark number code on rotary solid carbide cutting tool's
    surface directly with laser.First the law of laser etching carbide was studied,
    and the best marking parameters were acquired by single factor experiments.
    Then in order to solve the problem of distortion when capturing images of
    rotating tool with bigger curvature,a character was improved by using the method of
    increasing the bottom line width of the nixie tube character far from the brightly lighted
    section.At last,mutation position and line width information were introduced in the traditional eigenvector algorithm.A comprehensive eigenvector recognition method was
    introduced,and its accuracy rate has reached 95%,which can satisfy the demands of
    tool marking and identification in area of tool life cycle management.

    #br# Study on Effects of Flow Field Depth on Performance of PEMFC by AC Impedance Spectroscopy
    JIAN Zheng, YANG Dai-Jun, LIU Jin-Ling, SHI Wei-Cheng, MA Jian-Xin
    2012, 23(24):  3002-3006. 
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    AC impedance spectroscopy was adopted to characterize the H2/Air PEMFC with thin polar plates.The results show that the influences of the cathode flow field depth are minor and can be ignored;meanwhile the performances of PEMFCs decreases with the thinning of  the  anode flow fields.AC impedance spectroscopy testing of five single cells with different thin anode polar plates were then
    conducted,as well as polarization curve tested.Apparent performance dropping can be
    found at higher current density when the anode flow field depth decreases from 1mm to
     0.4mm.At the current density of 1200mA/cm2,the concentration polarization is further exacerbated,which results in the decrease of maximum output power.
    The volumetric specific power of the fuel cell is still promoted greatly due to the
    thinning of the polar plate.

    Front Suspension Uncertainty Optimization of a Car Based on Kriging Approximation Model
    LI Wei-Beng, ZHANG Bao-Zhen, WANG Lei, XIE Feng
    2012, 23(24):  3006-3012. 
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    For the optimization of a front suspension was almost based on certainty optimization without considering all kinds of uncertainty in the process of practical work,a uncertainty optimization method of the front suspension was proposed. Macpherson suspension model of a car was built based on ADAMS/Car.The design parameter's sensitivity was analyzed by ADAMS/insight.And then,a Kriging approximate model was established for the greater sensitivity of design parameters and uncertain parameters in the wheel beating which simplified the optimization process.The model's stability was analyzed,the NSGA-Ⅱ and the IP-GA were used to solve the multi-objective uncertainty optimization problem.The optimization results indicate that these methods have high accuracy and validity.
    Finally,the results were compared with those of certainty optimization,which proves that
    uncertainty optimization has better robustness.

    Optimal Robust Fault Tolerant Control for Vehicle Active Suspension System Based on  H2/H∞ Approach
    YANG Liu-Jing-1, 2, CHEN Mo-Wei-1, HONG Hong-Bei-1
    2012, 23(24):  3013-3019. 
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    To improve control reliability and performance of a vehicle active suspension system,an optimal robust fault tolerant control method was put forward based on H2/H∞ control for active suspension system with suspension parameter disturbance and actuator fault.The fault suspension models were built considering
    the ordinary actuator faults and parameter disturbance for suspension's stiffness disturbance and damping coefficient disturbance.Based on the multi-objective H2/H∞ state-feedback control approach and by bounded real cited theorem,the
    design condition of the optimal robust fault tolerant control for the suspension models was derived.
    By linear matrix inequality toolbox, an optimal robust fault tolerant controller under out-line state was designed for fault closed-loop system.
    Finally under the MATLAB/Simulink environment, the considerable simulations were carried out.The results show that proposed controller can improve
    the ride comfort performance of vehicle active suspension and of
    fault suspension too.Furthermore, control performance of the optimal
    robust fault tolerant controller is superior to the controller designed under the state of perfect suspension without faults.

    Research on Development Platform for Vehicle Dynamic Stability Control System
    PI Da-Wei-1, LIU Hui-Min-2, ZHANG Bing-Jun-3, ZHONG Guo-Hua-1, 3
    2012, 23(24):  3020-3023. 
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    A development platform for VDSCsystem was designed based on AUTOBOX.An electronic control unit(ECU) for VDSC system was designed according to the functional module divided
    by system requirements based on TMS320F2812.Hardware configuration was devised according to the specified target of different development stages of VDSC system.The development platform of hardware-in-loop simulation and road test were proposed. Experimental results show that the target of specified development stage of VDSC system can be achieved based on the proposed platform,and it provides a feasible solution for VDSC system research.