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Table of Content

    25 January 2013, Volume 24 Issue 02
    Reliability Analysis of a Hydraulic System of Tray Automatic Exchange Device of Machining Center
    ZHANG Gen-Bao, LI Yue, LIU Jian, CHU Lin
    2013, 24(02):  143-149. 
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    According to the fact that the existing reliability prediction technology cannot reflect well the effects of processes under different working conditions on reliability due to neglecting changes of reliability and failure rate with running time,a practical reliability prediction analysis model was proposed by combining the
    GO method and the grey system theory considering various operating conditions of the components of a machining center.This method was used in reliability analysis of the hydraulic system of tray automatic exchange device(TAED) of a machining center.Firstly,through a systematical analysis of hydraulic system of tray automatic exchange device of  the machining center,its basic structural model was summarized,and the model of GO chart for the hydraulic system was established.Then,the gray dynamic prediction for the hydraulic system was derived based on GM(1,1) model combining the GO method.Finally,
    the availability and accuracy of this method in the analysis and reliability evaluation of the machining center were verified by comparing the calculated results of this method with that of the traditional static GO method and the FTA.This approach provides a theoretical basis for the prevention of failures of the hydraulic system of tray automatic exchange device, the improvement of the system reliability and security, and the development of security controls.

    #br# Applications of Cone Structure on Piezoelectric Synthetic Jet Actuator
    ZHANG Li-1, WANG Bang-Feng-1, ZHOU Yong-2
    2013, 24(02):  149-152. 
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    Cone structure was introduced into the design of piezoelectric synthetic jet actuator.The specimen was made.And the velocities of outflows were detected by hotwire anemometer.The frequency response of time-average velocities and the frequency response of maximum velocity during one period were obtained.The results were compared to normal actuators' performances.It shows that:the jet velocity increases with the frequency of the actuator;the performance of the actuator with the cone structure is evidently enhanced;the region that the actuator effected on is obviously enlarged.Over all,the application of the cone structure is successful to the actuator.

    Research on Target Positioning Strategy of an Under-location Underwater Vehicle
    SHEN Xiong-1, XU Guo-Hua-1, TU Kun-2, YA Meng-Chong-3
    2013, 24(02):  153-158. 
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    Based on analyses of the development of underwater vehicles and the characteristics of underwater tasks,the paper illustrated a task strategy for small target positioning by an under-actuated remotely operated vehicle(ROV) in complex terrain.With the consideration of the work environment for the special and small target search,a control strategy based on isobath and multi-sensors for path planning was also presented.Furthermore,beam interpolating method and coordinate transform method were used,the edge refinement for the object was available for accuracy of feature extraction.The experimental conclusion shows they are certified to feasibility and effectiveness for underwater small target position task.

    Effects of  Packing Time on Relative Refractive Index of Microinjection Molded Plano-lenses
    YANG Can, YIN Xiao-Gong
    2013, 24(02):  158-162. 
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    Based on the facts that transparent devices required excellent optical properties,an approach  was proposed for controlling devices' optical properties by investigating and controlling the relative refractive index.Taking the microinjection molded thin optical lens as an example,the wavefront of a parallel laser light source coming through the optical devices was measured and reconstructed.Then the theoretical relationship between the reconstructed wavefront and the relative refractive index was analyzed
    and deduced,and the relative refractive index distributions of the optical
    lenses were calculated.At last,the packing time's effects in microinjection molding on the relative refractive index distribution were  investigated.
    The experimental results show that as the packing time increases from 1s to 3s,the relative refractive index distribution inside the lenses is more uniform,and the range of the refractive index decreases from
    6.1×10-3 to 2.9×10-3.The proposed characterization method with respect to relative refractive index is effective for controlling the optical devices' properties. 

    #br# Study on Concurrent Negotiation Model for Supply Chains Based on Game Theory
    HU Xiao-Jian, CHEN Qi-Ping
    2013, 24(02):  163-168. 
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    For the flexibility and the timeliness where the automotive supply chain responds to customer needs,the multi-agent technology and the game theory were introduced to the automotive supply chain environment,and a game model of multi-agent concurrent negotiation with time-limited and incomplete information was proposed.In multi-agent environment,the model studied multi-issue negotiation and its continuous concurrency deeply by the bargaining among resource requirements and resource providing.It made a win-win solution for negotiation participants from the game matrix and utility comparison.An example of automobile manufacturing process was presented to illustrate the feasibility and the effectiveness of concurrent negotiation,and verified the superiority of the model compared with the multi-stage negotiation model.

    Forced Response Characteristics of Mistuned Bladed Disk with Breathing Crack
    WANG Ai-Lun, LI Shuai
    2013, 24(02):  169-174. 
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    The assumption of bladed disk with open cracks  is
    unrealistical and inaccurate for analyzing the vibration response of bladed disk,
    so a model of bladed disk with breathing cracks was established based on the Euler-Bernoulli beam theory and the local flexibility theory of linear elastic fracture mechanics.The
    natural characteristics and vibration response of bladed disk with breathing cracks
     or open cracks were compared,and the effects of breathing cracks on vibration response localization of bladed disk
    were researched.The results show that breathing crack model can cause forced vibration response of bladed disk to appear the complicated nonlinear characteristics.
    Furthermore,comparing with bladed disk based on open crack model,the bladed disk based on breathing crack model is more sensitive to mistuning.

    Method of Industrial Robot Accuracy Compensation Based on Particle Swarm Optimization Neural Network
    ZHOU Wei-1, LIAO Wen-He-1, TIAN Wei-1, MO Shi-Meng-2, LIU Yong-2
    2013, 24(02):  174-179. 
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    For the absolute positioning accuracy of industrial robots used in aircraft flexible automated assembly cannot meet assembly precision,a neural network-based integrated accuracy compensation approach taking into account ambient temperature change factor was proposed based on robot spatial grid accuracy compensation method.Neural network's initial weights and thresholds were optimized by using particle swarm optimization method in order to prevent from falling into local minima in training.The experimental  results show that the maximum value of the robot positioning error is as  0.32mm, and the mean value is as0.19mm with the temperature in the range of 20℃ to 30℃,which are much more better than the previous values 1~3mm,the absolute positioning accuracy can satisfy the requirements of aircraft automatic assembly.

    2D Sectional Method  Correction in High Strength Steel Rail Panel's Springback and Compensation
    NIE Cuan-1, SHEN Dan-Feng-2
    2013, 24(02):  180-185,194. 
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    The longitudinal springback and undercut problem of HSS(high strength steel) rail panels was prevalent in their forming.It is difficult to solve the problem like estimation and compensation of springback with the existing 2D sectional method.Thus,the existing method was corrected and revised based on longitudinal
    springback and undercut of rail panels.The revised method took into account longitudinal springback of key sections.It also corrected compensation algorithm of sections.In order to improve the efficiency and precision of iteration,a revised method introduced material coefficient and energy coefficient to ensure rationality and feasibility of algorithm.According to different wall sprigback modes,the revised method took into account angle springback and curl springback of different deformation modes.Taking a typical welded rail panel for example,the existing 2D sectional method and the revised method were compared on estimation and compensation of springback.Practice proves the feasibility of the revised method. 

    Design and Kinematical Simulation of Conical Cam Stepless Speed Variator
    ZHANG Jin-Xi, YANG Xin-Jun, GUO Hua-Qin
    2013, 24(02):  186-189. 
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    This paper introduced a conical cam structure stepless speed variator,which had a good performance motion.Three symmetrically located cams with constant velocity motion and their oscillating bars,
    through roller clutches' changing,constant speed rotation output was reached.SolidWorks 2010 Motion was used to simulate its kinematic and dynamic features,a very good result was obtained. 

    Fault Feature Extraction for Gear Crack Based on Bispectral Entropy
    ZHOU Yan-Bing-1, LIU Yi-Bing-1, LI Hong-2, TENG Wei-1, LI Zhuang-1
    2013, 24(02):  190-194. 
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    Due to gear crack leads to the change of non-Gaussian characteristics of vibration signals,bispectral entropy was proposed to deal with the signals and quantitatively describe the distribution morphology of non-Gaussian components in
    bifrequency domain.The fault information was extracted by this method,and the feature
    trend of gear crack in its generation and extension period was obtained.The results show
    that,bispectral entropy is not based on the information of signal energy,and it is less influenced by the non-fault factors.Meanwhile it can inhibit the Gaussian noise efficiently and
    be sensitive to the weak fault.So bispectral entropy supplies a new efficient path for
    the follow-up fault diagnosis and trend prediction.

    #br# Research on Local Characteristic-scale Decomposition and Its Stopping Criteria
    YANG Yu, CENG Ming, CHENG Jun-Ku
    2013, 24(02):  195-201,208. 
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    A novel adaptive time-frequency analysis method,LCD was proposed based on the study of ITD.By using the presented method,a complicated multi-component signal could be adaptively decomposed into a number of intrinsic scale components with physically meaningful instantaneous frequencies.Basic principle of LCD was described in detail after a brief introduction to ITD.To investigate stopping criteria for iterative process,standard deviation criterion was applied to LCD,which was introduced in empirical mode decomposition(EMD).Varying with the selected adaptive time-frequency analysis method,the threshold of standard deviation criterion had no adaptability.Given the drawback of standard deviation criterion,a new adaptive stopping criterion named extreme monotonicity criterion was proposed,which needed not to set any thresholds.Analysis results of signals demonstrate validity of the two stopping criteria.Moreover,extreme monotonicity criterion gains more applicability than standard deviation criterion and can be also directly applied to EMD.Additionally,computational efficiency of LCD and EMD was investigated,and the comparative analysis results show that LCD is superior to EMD in computational efficiency.

    Process Route Optimization of Complex Housing-type Parts Based on Feature Machining Element
    XU Li-Yun, SHI Nan, DUAN Jian-Guo, LI Ai-Beng
    2013, 24(02):  202-208. 
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    According to the current problems of process route optimization during the process design,the complex part features were divided into several feature machining elements,then the optimization of
    process route was changed to the priority of feature machining elements considering the problems in the process of optimization and related process constraints.An objective function was built by minimizing the transform of machine tools,fixtures and cutting tools,using an improved genetic algorithm to avoid the premature defects of the genetic algorithm. Finally, a case of cylinder block was illustrated to verify the efficiency of the hybrid algorithm, and the results show that the improved algorithm has a good convergence.

    Complex Product Virtual Maintenance Training Method Based on Knowledge Map
    YANG Yan-Pu, TU Duo-Fu, CHEN De-Kai, FENG Jing
    2013, 24(02):  209-214. 
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    To improve the efficiency and reduce training costs of complex product maintenance,a method using knowledge map was proposed to manage the knowledge of complex product maintenance.By analyzing the types and composition,maintenance knowledge information cell was used to represent the knowledge of complex product and compose knowledge map system.On the basis of knowledge map,complex product virtual maintenance training system was constructed,which contained methods of self-learning by browsing knowledge map,interactive learning of multimedia courses and training practice of virtual assembly,
    and virtual maintenance training of an aircraft was used as an example to implement
     and verify the method.

    #br# Application of Stochastic Resonance and LMD to Bearing Fault Diagnosis
    ZHANG Chao-1, 2, CHEN Jian-Jun-2
    2013, 24(02):  214-219. 
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    In view of the difficulties of fault feature extraction from strong
    background noise in actual fault diagnosis,a method of bearing fault diagnosis based
    on LMD was presented.First,SR was employed as the pretreatment to remove noise in bearing vibration signals by virtue of its good effect in enhancing the signal-to-noise ratio; then the de-noised signals were decomposed by LMD.Through calculating the amplitude spectrums of the PF,fault frequency of bearing was found.The experimental results show that this method can improve signal-to-noise ratio,and realize the weak signal detection,and apply to the bearing fault diagnosis more effectively.

    #br# Research on Production Lot-size and Lead Time Based on Logistics Shifting Bottleneck in Manufacturing Shop
    LIU Meng-Zhou-1, LING Lin-1, TANG Juan-2
    2013, 24(02):  220-225. 
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    In manufacturing shops,there are a lot of uncertain factors,such as the changes of machine/worker status and emergency order,which will cause logistics bottleneck frequent shifts,so the planned
    production lot-size and lead time are hard to satisfy the real-time production conditions.
    Aiming at this problem,based on the research of the logistics shifting bottleneck,a method of seting the lot-size and lead time was proposed.Using bottleneck index and bottleneck shifting index to measure the capability of the production unit becoming the bottleneck and introducing queuing theory,the optimum lot-size and lead time can be determined to minimize the non-value-added process time and the difference of the production speeds of the adjacent units.Finally,an example of calculating the production lot-size and lead time in one shop was given to prove the validation and practicability of the method.

    Statistical Selective Assembly Technique and Its Applications
    ZHANG Yu, YIN Yan-Hu, YANG Mu-Sheng, DUO Wen-Chao, YUAN Guang-Meng
    2013, 24(02):  226-233. 
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    A statistical selective assembly technique based on the quality-oriented statistical tolerancing was presented via the research for selective assembly technique to assure and realize the designed matchable degree and fit quality indices.The factors that affected the matchable degree and fit quality indices were analyzed,the mathematic model and design method with high maneuverability for statistical tolerance were developed for assuring fit quality and matchable degree.Three typical applications for this new approach were given,including predicting fit quality according to the statistical parameters of the mating batches,statistical tolerancing based on the way of concurrent design for selective assembly,and coordinated statistical tolerancing and controlling to the processes of the mating batch based on the required fit quality indices and statistical parameters of the manufactured mating batch. 

    Non-cooperative Game for Manufacturing Resources Configuration Driven by Job Load Competition
    CHEN Bing, LIU Kai, YANG Ting
    2013, 24(02):  233-239. 
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    Manufacturing resources configuration is to load the manufacturing processes onto relevant equipment,and the equipment to accomplish the manufacturing job within certain working time,human and cost.There are free competition relationships between equipment and manufacturing duties in the
    configuration processes.The game theory was introduced to describe their restrictive relation.Then an optimization method on manufacturing resources configuration based on
     non-cooperative game was proposed.The equipment was regarded as player,
    while player's strategy and payoff were built.And by fuzzy cluster analysis the
    players were clustered to solve Nash equilibrium.Finally,an example was given by compared with GA,PSO and Tabu search.The results show that task load strategy obtained by the
    proposed algorithm can guarantee the overall equipment utilization is higher.
    Therefore,the effectiveness and correctness of algorithms herein were proved. 

    Research on New Style Squeeze Film Air Bearing and Its Controller
    SHU Da-Yun, MA Xi-Zhi
    2013, 24(02):  240-244. 
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    To effectively overcome the shortcomings of conventional air bearings,a new style squeeze film air bearing was developed according to the ultrasonic wave suspension and air squeeze film.In order to get the size and the control parameter,the modal analysis and the harmonic response analysis of the piezoelectric ceramic actuator used in the bearing were carried out by the finite element method.The capacity of the bearing was given by using numerical solution methods theoretically.The working frequency of the piezoelectric ceramic actuator was determined by the modal experiments.Also,the ultrasonic sound pressure which produced by bearing was analyzed by means of finite element method.On this basis of above,a digital controller adopting STC single chip micyoco(SCM) and incomplete differential PID control strategy was developed and actual operation of the system was also carried out.The results show that the capacity of the bearing is determined  theorelically.And what the bearing with ultrasonic vibration may have levitation force is proved through experimental method.

    #br# Simulation of Sliding Efficiency for Belt Driving in Beam Pumping Units
    GENG Meng-Meng, DONG Shi-Min
    2013, 24(02):  245-251. 
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    Considering great fluctuation of load torque of the belt driving
    device in a beam pumping unit,belt longitudinal vibration of beam pumping unit,
    the relative sliding speed between belt and pulley and instantaneous sliding efficiency
    were researched.The belt was simplified to elastic body of longitudinal vibration,
    the mechanical model of longitudinal vibration of the belt which was excited by alternating friction was established,and the mathematical model of the wave equation form was
    built.The numerical simulation model of wave equation was established with the superposition method of vibration mode.Simulation model of belt instantaneous sliding speed
    relative to pulley and simulation model of belt instantaneous sliding efficiency were established.The factors of affecting sliding efficiency were pointed out,such as oscillation amplitude of alternating torque and initial tension of belt in beam pumping unit.The following conclusions are obtained by the simulation results:load torque fluctuations of beam pumping unit will lead to lower sliding efficiency;sliding efficiency of belt driving decreases
    obviously
    when crank torque of beam pumping units is negative;under condition that the beam pumping unit
    operates regularly,the belt efficiency increases with the increasing of initial tension.

    #br# Research on Function Module Dynamic Partition for Product Innovation Design
    CHEN Ji-Wen-1, 2, ZHANG Jin-Sheng-1, WANG Zhi-1, HUANG Bei-1, WANG Fa-Kai-1
    2013, 24(02):  251-257. 
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    Recently,technical evolution factors are not considered in function module partition for product innovation.From the point of customer
    demands,flow and technology,function module dynamic partition was researched.Function correlation matrix was established based on function structure.
    The dynamic cluster analysis of fuzzy equivalence matrix was used to dynamic parting
    function module.The function module partitions were evaluated by average polymerization
    degree in a module and average coupling degree among modules.Example of multi wire diamond saw shows the presented dynamic module partition method has strong
    distinguish ability and can be used to module dynamic partition for product innovation design.

    A Novel Method for Flatness Pattern Recognition via MLSSVR
    ZHANG Xiu-Ling-1, 2, ZHANG Shao-Yu-1, DIAO Wen-Bao-1, XU Teng-1
    2013, 24(02):  258-263. 
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    In order to overcome the disadvantages that LS-SVR algorithm is not suitable to
    multiple input multiple output system modeling directly,a novel algorithm defined as
    MLSSVR was proposed by adding sample absolute errors in objective function.And a novel flatness pattern recognition method
    based on MLSSVR was put forward by applying MLSSVR algorithm on pattern
    recognition.Then,comparison between the MLSSVR recognition method and the combination method of LS-SVR was conducted,and the recognition ability of MLSSVR recognition model was tested and analyzed. Experimental results demonstrate the validity of the MLSSVR algorithm. The flatness pattern recognition model based on MLSSVR can
    avoid complex computation of LS-SVR combination method,enhance the recognition speed effectively,and  has higher recognition accuracy and good generalization ability.
     

    #br# Research on Energy Absorption Characteristics of Rail  Vehicle Energy-absorbing Component in Cutting Way
    LEI Cheng-1, 2, XIAO Shou-Ne-1, LUO Shi-Hui-1
    2013, 24(02):  263-267. 
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    In view of using axial cutting process of metal thin-walled structure as energy-absorbing principle,the predictive models of interface force stable value and energy of cutting energy-absorbing
    process were developed by using multi-linear regression analysis.The variance analyses were applied to check the significances of regression equation and coefficient of regression model.The effects of tool rake angel,chip central angel,cutting depth and cutting speed on properties of cutting energy-absorbing process were studied.The results show that the regression equation of predictive models is of significances,tool rake angle and chip central angle on interface stable value is of significances,cutting depth and cutting speed on interface force stable value is not of significances;tool rake angle, chip central angle and cutting depth on energy-absorbing is of significances,cutting speed on energy-absorbing is not of significances.

    Numerical Simulation of  Mixing Performance in a Multi-channel Spiral Static Mixer
    WANG Zong-Yong, CHEN Chao
    2013, 24(02):  268-273,279. 
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    Using the multiphase flow mixture model under the laminar flowing condition,the mixing performance of two kinds of similar fluids in the multi-channel spiral static mixer was studied.The conclusion indicates that more channels can improve the mixing velocity of the fluids,and reduce the required mixing element length to achieve the same mixing effect,but it can increase the system energy consumption at the same time.Under the condition of the same mixing element length,it should be preferred the spiral static mixer with two channels from the view point of energy consumption.For the reason that the mixer space is small and mixing element length should be short,it should be preferred the spiral static mixer with four channels.

    #br# A Refined Method to Identify Material Parameters of Weld Line Based on DIC Technique and Hardness Test
    FU Lei-1, LIU Di-Hui-1, SUN Guang-Yong-1, 2, LI Guang-Yao-1, XU Feng-Xiang-1, CHEN Shui-Sheng-1
    2013, 24(02):  274-279. 
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    A refined method was proposed to identify the material parameters of a weld line based on the DIC technique and hardness test.According to the metallographic test and hardness test,the regions of the TWB were divided into the weld zones,heat affected zones,base metal zones according to hardness values.The values of the major and minor strain on which localized
    necking occured were obtained by DIC technique,and the hardness values of the weld zone were gained by the hardness test.Then,the relationship of the strain hardening
    exponent n and the major and minor strain were obtained according to plasticity
    theories.In addition,the relationship of strength coefficient  K and hardness
    values were  also derived.Thus,the material parameters of weld zone and two heat affected zones
    were obtained with the derived theoretical formula.Examples based on finite
    element simulation and experiments were used to verify the accuracy of this method,
    and the results show that the refined method is better than the traditional
    method,and the investigation has certain reference values for engineering analyses.

    Investigation of Size Effects of 304 Stainless Steel Foils in Microforming Processes
    MENG Qiang-Dang-1, LI He-Zong-2, DONG Xiang-Fu-1, BANG Fang-1, WANG Qian-1
    2013, 24(02):  280-283. 
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    Uniaxial tension and microbending tests were conducted using 304 stainless steel foils with varied thicknesses from 10μm to 200μm.In the tests,the yield stress and springback angle increased with decreasing foil thickness,showing the size effects of  “the thinner the stronger”.The Hall-Petch equation was modified by introducing the influence of foil relative thickness,and applied to calculate yield stress with better agreement with test results.
    The modified Nix-Gao strain gradient hardening model was used to predict the relationship between springback angle and foil thickness,which agree with the test results.