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Table of Content

    25 September 2012, Volume 23 Issue 18
    Product Disassembly Sequence Planning Based on Uncertain Programming
    WANG Chu-Wang, LIU Zhi-Feng, HU Di, GAO Xiang, JIANG Gao
    2012, 23(18):  2143-2148. 
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    By analyzing the uncertainty of a product disassembly sequence planning,the product disassembly sequence planning was transformed into an issue of uncertain programming problem based on product disassembly model of the composite drawing.By using the chance-constrained programming model,
    the product disassembly sequence planning solving process and algorithm based on
     simulated annealing algorithm were given.Finally,a simplified computer mainframe
    box was given as an example to show the effectiveness and superiority of the proposed method.

    Research on Camshaft Grinding Speed Optimization and Automatic NC Programming
    CAO De-Fang-1, DENG Chao-Hui-2, LIU Wei-1, ZHANG Xiao-Gong-1, WANG Juan-1
    2012, 23(18):  2149-2155. 
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    In order to improve the machining precision,surface quality and processing efficiency of a camshaft,a theoretical model of constant linear velocity grinding process of the camshaft was established according to the X-C axis linkage motion principle of grinding machine.Based on this theoretical model,a numerical calculation model of grinding speed optimization and regulation was also built by means of cubic spline fitting interpolation method.Combined with the specific camshaft part and the real parameter of the grinding process plan,the processing motion data of  the all grinding machine kinematic axises were calculated.And then the motion data were changed automatically into NC processing program of specified numerical control system under the conditions of no process faults.Thereby the automatic NC programming of camshaft grinding was realized.At last,one experiment was done on a NC high speed camshaft grinding machine,CNC8312A.In this experiment,the admission cams and the exhaust cams of Qianjiang 32F camshaft were ground separately,and the expected machining effects were also achieved.With the experimental evidence,it is shown that the methods of the grinding speed optimization and regulation and automatic NC programming are feasible whether theoretically or practically.And the methods meet the needs of the practical camshaft production well.

    #br# Bonding Effects on Stability of Structures in MEMS
    JIANG Meng-Xia, WANG Lei, TANG Ji-Ying
    2012, 23(18):  2155-2159. 
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    MEMS devices with movable structures can be influenced by unmatched stress introduced by packaging process, leading to the change of structural reliability. The packaging effects on stability of MEMS structures were studied, and structural unstablity behaviors,such as buckling and adhesion, were observed after packaging. Analytical models of vibration and adhesion of beam structure were set up to predict the unstable behaviors. Experiments on surfaced-micromachined polysilicon structures indicate that compression stress is introduced after bonding, and the resonant frequency and contact resistance change considerably after the stability of devices is changed.

    #br# Absorption System of a Negative Pressure Wall Climbing Robot
    BANG Jin-Min-1, LI Ji-Ze-1, SHAO Ji-2, LI Jun-2
    2012, 23(18):  2160-2164,2168. 
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    A negative pressure absorption system of climbing robots was deeply studied.Based on the utilization rate of the negative pressure climbing robot,the impacts of locomotion system on adsorption force's allocation were studied.According to the differences in the utilization rate of adsorption force,a number of locomotion mechanisms and sealing devices were presented and their compositive performances were analyzed.Through the thermo-dynamic analysis of the component,the process of state changes in suction's flow field was described,and the principles of the adsorption system were revealed.In order to illustrate the essence of the adsorption force provided by suction system,the airflow state changes of the system
     was simulated by CFD.A climbing robot was presented to verify the stability and reliability of the absorption system.

    #br# Type Synthesis of Mechanism with All Prismatic Pairs
    LI Jia-1, KONG Jian-Yi-1, LIAO Han-Yuan-1, HOU Yu-1, HUANG Zhen-2
    2012, 23(18):  2165-2168. 
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    The relationship among the numbers of links in a kinematic chains,the numbers of slider joints,the numbers of linkage which has different numbers of nodes per link,the circle numbers of kinematic chains and the degrees of freedom of mechanism was obtained based on a mathematical method for the mechanism
    which was restricted to only slider joints,and the relationship was represented by a numerical calculation formula.A new method was used to study the types of kinematic chains and their isomers of machenism which was restricted to only slider joints based on the characteristic value of  kinematic chains.For the machenism which was restricted to only slider joints and its numbers of links was less than 6,then 23 types of kinematic chains and their isomers obtained based on the characteristic value of  kinematic chains.The movability for this machenism was demonstrated by using the software of ADAMS.

    Toric Spectacle Lens by Using Slow Tool Servo Turning
    WANG Xin-Cheng, KANG Min
    2012, 23(18):  2169-2173. 
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    To solve the difficulties of processing non-rotationally symmetric aspherical spectacle lens,a method of
    machining toric spectacle lens with slow tool servo was discussed.A mathematical model of toric was established,and its cutting path was generated.The plan of cutting contact point discretization and cutting tool compensation,and the space extension problem of prism surface were analyzed.At last,an example shows that the proposed method based on slow tool servo is feasible and toric spectacle lens with diopter accuracy within 0.05D can be achieved.

    Thickness Measurement and Growth Behaviors of Oxide Layers on Grinding Wheel Surface in Pre-dressing Process of ELID
    WANG Dang-Li, MA Bao-Ji, NING Sheng-Ke
    2012, 23(18):  2173-2175,2207. 
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    In order to measure thickness and study on growth behaviors of oxide layers on grinding wheel surface in ELID, the measurement system accuracy was verificated with laser and eddy current sensor for simulation measurement of oxide layers, Growth behaviour of oxide layers were measured in pre-dressing process, and the results indicate inward growth speed of oxide layer is greater than outward growth speed along the radius of grinding wheel in the early , oxide layers keep linear growth and growth speed is the fastest. In the late,inward growth speed of oxide layer slows, outward growth speed is slightly faster, but overall oxide layer growth slows down. 

    #br# Optimization for Lot Sizing Production Planning with Product Remanufacturing and Demand Substitution
    JING Yi-1, WANG Xu-1, LI Wen-Chuan-2, CHEN Meng-3
    2012, 23(18):  2176-2181. 
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    In order to solve manufacturing and remanufacturing lot sizing planning problems under the situation of hybrid production,a mixed integer programming model was established with capacity constrains of inventory and production,in which the return products were processed into two kinds of remanufactured products with different quality levels.The remanufactured products with high quality level were regarded as identical with new products.And the demands for remanufactured products with low quality level can be also satisfied by the items with high quality level.An improved co-operative co-evolutionary genetic algorithm was designed.The evaluation of the population diversity was adopted to adjust dynamically the number of the representation,in order to balance between the computational complexity and the algorithm performance.Results of the simulation indicate the proposed algorithm has better efficiency and optimization performance.

    Web Service Selection Approach Based on Resource Constraint in Service Workflow
    LI Hai-Bei, LI Feng-Fei, YU Xiao-Guang
    2012, 23(18):  2182-2187. 
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    In service-oriented workflow management system,most service selection approaches are based on quality of service's information which is difficult to acquire accurately and currently.Service selection should be met the requirements based on business firstly,rather than quality of services.Based on analyzing relativity between resource constraints,timeliness of constraint satisfaction,etc.,a method of service selection based on resource constraint satisfaction,and corresponding algorithms were proposed.Constraint conditions were separated from a workflow model using the method,and were decided its satisfiability before selecting a service at runtime,so that web services of meeting business requirements can be selected.Finally,an example analysis shows that the method has generality and practicality.

    Modeling for Dynamic Cellular Assembly Systems Design and Reconfiguration on Mass Customization
    LIAO Shi-Long-1, 2, YI Shu-Beng-1, GAO Qiang-Xuan-1
    2012, 23(18):  2187-2193. 
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    To solve the problem in MC that the products must be satisfied to the individual demands of customers,at the same time the customized products are similar to that of the product in mass production,a thinking was proposed that cellular assembly systems were used for assembly operations in MC.By considering the several key factors including dynamic assembly cell reconfiguration,worker assignment,multi-period production planning,backorder cost,and hiring firing cost etc.,this paper presented an integer mathematical programming model for the design of cellular assembly systems in a dynamic environment in MC.
    Numerical examples were presented to demonstrate the model and its potential benefits.

    #br# Surface Local Deformation of Restoration Based on Minimum Energy Method
    YAN Guo-Dong-1, DAI Ning-1, LIAO Wen-He-1, ZHANG Chang-Dong-1, SUN Yu-Chun-2, WANG Yong-2, LV Pei-Jun-2
    2012, 23(18):  2194-2199. 
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    The surface local deformation of tooth restoration is a key technology in dental CAD/CAM system,which determines whether restoration shape can fit to the patient's tooth articulation environment.Aiming at the problem,a local deformation algorithm for dental surface design based on minimum energy method was proposed.Firstly,the control handle and deformed region were defined on restoration surface with region selected tool.Secondly,the deformation matrix was preprocessed for improving computational efficiency,then the control handle was translated to complete the local deformation of restoration.Experimental results verify the effectiveness and practicability of the algorithm.

    Method of Evaluating Product Concepts Based on Improved Rough Set Grey Analysis
    JIN Chao-1, ZHANG Na-2
    2012, 23(18):  2200-2203. 
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    Based on the improved rough set gray analysis,a new method was proposed to valuate the quality of the products with different indexes and different coefficients,combining the strengths of the fuzzy to deal with fuzzy problem and grey correlation analysis to make decision of multiple attributes.An example shows that this method can be used for evaluation and choice of multiple products with standard operation and can save assessment time.

    #br# Application of PSO -based RBF Neural Network in Fault Diagnosis of CSTR
    CHEN Bei-1, BO Hai-Feng-1, DENG Zhi-Hui-2
    2012, 23(18):  2204-2207. 
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    A new PSO algorithm with dynamically changing inertia weight and study factors based on improved adaptive PSO was proposed,where the inertia weight of the particle was adjusted adaptively based on fitness of the particle.The diversity of inertia weight made a compromise between the global convergence and local convergence speed,so it can alleviate the problem of premature convergence effectively.The algorithm was applied to train RBF neural network and a model of fault diagnosis for CSTR was established,compared with PSO algorithm,the proposed algorithm can improve the training efficiency of neural network effectively and obtain good diagnosis results. 

    Design and Study of Profile of Formed Milling Cutter for Screw of Oil Extraction Progressing Cavity Pump
    FAN Jin-Wei, LI Yun, LI Wei, MENG Shun-Zheng, LUO Tuo, LUO Jian-Beng
    2012, 23(18):  2208-2212. 
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    Through analyzing the shape of screw of oil extraction progressing cavity pump,a spiral surface equation of  the screw was established;and from the relative motion between formed milling cutter and screw,the basic profile equation of formed milling cutter was established with molding milling principles and coordinate transformation theory.According to the actual use of milling cutter,aimed at the causes of processing errors after wear of formed milling cutter,a complete profile equation of formed milling cutter was established which had proper rank and constant clearance angle.Through interference checking for profile equation of formed milling cutter,the correctness of profile equation was ensured.The profile equation provides a theoretical foundation for design and manufacture of the formed milling cutter,and it will have great significance to actual production.

    Type Synthesis of a Rotational Decoupled Leveling Mechanism Based on Screw Theory
    CA Wei-Lin, XIONG Chao, YIN Zhou-Beng
    2012, 23(18):  2213-2217,2242. 
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    A leveling mechanism for adjusting the parallelism between the chip and substrate is a key part of flip chip bonder and it takes significant effect on the yield of product developed by flip chip technology.The basic condition to develop a two-degree-of-freedom rotational decoupled mechanism was proposed based on screw theory,and type synthesis of this kind of parallel mechanism was accomplished.Each of these mechanisms had three legs,the first of which was only made up of two passive revolute joints and the other two of which each owned an active joint to drive platform to rotate about one of the axes of revolute joints in the first leg respectively.Furthermore,mobility analysis,the selection of inputs and kinematics
    simulation using ADAMS were dealt with in sequence for one type of mechanism which was only constructed by revolute and prismatic joints.Results show that this mechanism is applicable to flip chip bonder,
    precision worktable and other circumstance.

    Optimization Design of Scraper Conveyor Chain for Maintenance Based on Reliability Simulation
    FU Guo-Gong-1, HUANG Liang-Pei-2, YUE Wen-Hui-2
    2012, 23(18):  2218-2223. 
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    Based on the time-to-failure density function of ring chains,a scraper chain reliability model for maintenance was reconstructed and the change course of the scraper chain reliability was analyzed by means of reliability model simulation.Then considering maintenance period,maintenance cost,system reliability,
    the scraper chain optimal design models were established,and the reliability-based optimization methods for scraper chain systems were developed.Finally,simulation results show that this design method can help to select the design scheme of scraper chains preferably,to decide a reasonable configuration for ring chains,and to optimize maintenance cycle of scraper chain systems.

    #br# Study on Mass Flow Data Fusion for Restraining Pressure Disturbance
    HONG Hong-Bei, TANG Zhi-Guo, MA Pei-Yong, LIN Qing
    2012, 23(18):  2223-2227. 
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    The mass flow measurement precision was affected by the pressure,and the precision was becoming worse with the pressure grew.Multi mass flow sensors were applied to obtain the measurement data which were fused by an adaptive weighted data fusion method.Besides,the back propagation(BP) neural network was utilized for carrying out the mass flow data fusion for restraining the pressure disturbance,so as to eliminate the sensitiveness of the mass flow measurement to pressure disturbance.The research results demonstrate that the mass flow measurement precision can be improved largely after the BP neural network data fusion than after the adaptive weighted fusion,and the BP neural network is with the highest fusion precision by additional momentum algorithm,worse by adaptive learning speed regulating algorithm and the worst one by gradient descending algorithm.

    Research on Numerical Simulation of Structural Characteristics for Twin-Screw Rotors
    WEI Jing, SUN Xu-Jian, SUN Wei
    2012, 23(18):  2228-2233. 
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    Based on fluid-solid coupling theory,the effect of different working conditions,such as fluid pressure,torque,on the twin-screw rotors' stress and deformation was studied by solving the fluid solid coupling equations between internal fluid of kneader and the twin-screw rotors.Theoretical analysis shows that the deformation and stress of screw rotors mainly caused by the different working conditions of  torque,fluid field pressure,and the effect between coupled fields.From the analysis results,it is concluded that:
    the effects of the clearance between screw rotors on the performance of kneaders are so important, and the maximum deformation of rotors is one of the key factors to design the best clearance between rotors.Under a certain power,the maximum deformation and stress of rotors are positively correlated with torque of rotors,and positively correlated with the fluid field pressure.Under a certain speed of rotors,the maximum deformation and stress of rotors are also positively correlated with the kneader's power.The results provide a theoretical basis for performance prediction and reasonable design for the novel twin-screw kneader. 

    #br# #br# Effects of Grooved Surface Texture on Friction Noise
    CHAN Huan-Le-1, MO Ji-Liang-1, CHEN Guang-Xiong-1, SHAO Tian-Min-2, ZHOU Zhong-Rong-1
    2012, 23(18):  2233-2237. 
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    Grooved surface texture was manufactured on the surface of compacted graphite iron samples(brake disc material) by electromachining,with the grooves of  30μm in depth,150μm in width and 500μm in pitch.Comparative friction noise tests between groove-textured and smooth surfaces were performed in a ball-on-flat configuration by using Si3N4 ball with diameter of 10mm as counterpart and the influence of grooved surface texture on friction noise was investigated.The test results (applicable only to the grooved surface texture adopted herein) show that the normal load has little influence on the friction noise level of the groove-textured surface,but significant influence on that of the smooth surface.Friction noise has a greater tendency to be generated at the groove-textured surface under low normal load.However,friction noise generated at the smooth surface increases its level rapidly approaching to that of the groove-textured surface,as the normal load increases from 5N to 10N.The grooved surface texture makes the friction system easier to generate multi-frequency friction vibration,and thus earlier friction noise with more dominant frequency components.The groove-textured surface has higher coefficient of friction and wear resistance as compared to the smooth surface.The existence of surface texture does change the fiction and wear behaviors as well as friction noise properties of the frictional surfaces, but their corresponding relationship requires further study.

    Work-hardening Characterization of Flow Control Forming Process for Sheet Metal Part with Step Cross-section
    LIU Yong, LEI Jian-Feng, SHU Hui, LI Hu-Feng
    2012, 23(18):  2238-2242. 
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    A new flow control forming(FCF) of sheet metal process for parts with step cross-section was performed using aluminum sheet materials. The equivalent stress and strain distribution were obtained through deforming simulation of parts during pressing and cold forging multiple processes using DEFORM through finite element analysis. The work-hardening characterization of parts was analyzed through measuring the hardness of part surfaces after forming. Experimental results indicate that the work-hardening effect of parts with step cross-section including triplex processes (blanking, extrusion and coining), is higher than that of parts with sole pressing or cold forging. The hardness in the low surface of parts is higher with the range of 5%~10% than that in the upper surface of parts. The hardening effects of parts in both low and upper surfaces will be weakening gradually within 0~1.4t (t represents thickness), with radial direction starting from inner hole or outer edge. One new work-hardening model was suggested. 

    Constitutive Model of  Stainless Steel 0Cr18Ni9 and Its Influence on Cutting Force Prediction
    LING Ling, LI Xing-Xing, WANG Hua-Lin, HU Xu-Jin
    2012, 23(18):  2243-2248. 
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    The static and dynamic mechanical properties of stainless steel 0Cr18Ni9,with solution heat treatment under temperature 1100℃, were analyzed herein,through experiments with material testing system(MTS) and split Hopkinson pressure bar(SHPB) apparatus.On the basis of  the above work,the constitutive
     relations of the material were built using Johnson-Cook constitutive model.In addition,the material parameters of  the model were observed by using the orthogonal experimental design.The two sets of the material parameters obtained from SHPB and cutting test were applied to predict cutting force under various machining conditions,and their applicability was compared.The comparison results provide the reference for the analysis model in stainless steel cutting research as well as the selection of material flow stress model during numerical computation. 

    Investigation on Error  Compensatory Process of  Pyramidal Parts Formed by Single Point Incremental Forming
    SHI Xiao-Fan, XU Yan, GAO Lin, CHEN Chang-Yan, LEI Ren-Wei-
    2012, 23(18):  2248-2253. 
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    Bad performance in accuracy is an important factor which makes single point incremental forming was not used widely.According to the measurement of the pyramidal parts,it was suggested that the accuracy was high near the corner and in the vertical direction.A method to describe the shape of the surface of pyramidal parts in single point incremental forming was proposed.Compared with the data gained by experiments,the accuracy of the model is acceptable.A compensatory process was also proposed to increase the part accuracy significantly.

    Reverse Dynamics Structure Factors for Lumped-parameter Model in Vehicle Front-to-side Impact
    TANG You-Ming-1, 2, HUANG Gong-Wu-1, 2, CAO Li-Bei-3
    2012, 23(18):  2252-2257. 
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    The lumped-parameter model has been used widely to analyze the vehicle safety in front-to-side impact.There are two methods that full-scale vehicle quasi-static test and finite element simulation impact to obtain the factors of lumped-parameter model.Based on the two methods,a new method titled nonlinear reverse was developed.The least square function of piecewise parameter approximation  was used to fit the test data of front-to-side impact according to the rules of China.Inputting the results a lumped-parameter model of nonlinear dynamic system in vehicle front-to-side impact was built by using MATLAB software.Then the rigidity characteristics of the lumped-parameter model,and the structure components of dummy were reversed,and the results were compared with that of testing and linear methods.The rigidity characteristics reversed present nonlinear which are more close to truth values.

    Modification of Cab Suspension System Based on Pitch Angular Acceleration
    ZHANG Jun-Feng, HE Yan-Song, YANG Hai-Wei, HUANG Yong
    2012, 23(18):  2258-2262. 
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    A multi-body dynamics model based on flexible suspension cab was built.The excitation and validation signals were acquired through road-test.The accuracy of the model was investigated in three ways by
    degree of freedom,acceleration RMS and system mode shapes.Taking weighted pitch angular acceleration RMS as the evaluation target,the orthogonal test for matching parameters of the cab suspension was conducted in the frequency domain,the driver's seat weighted pitch angular acceleration RMS is reduced by 9% on average at various speeds,the weighted vertical acceleration RMS is reduced by 14% on average and reduction of the dynamic deflection of cab suspension is as 18%.Finally,the cab
    suspension springs were redesigned according to the calculation results.

    Continuous Curvature Trajectory Planning Method for Intelligent Vehicle Considering No Slip Constraints
    CHEN Huan, LING Dui, LI Shun-Ming
    2012, 23(18):  2263-2267. 
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    Given the status of starting and ending points,this paper focused on a method of feasible trajectory generation considering the no slip constraints.Based on the model of front wheel steering,a 7D nonlinear vehicle dynamic model was established.According to the no slip hypothesis,a no slip expression of the steering wheel angle and its rate were derived.Based on the Modified Nicolas-Comstock(MNC) tire/road model,the dynamic constraints were obtained,which was employed to calculate the valid velocity profile.The optimized motion trajectory was generated by using the closed-loop driving stability evaluation indexes.The simulation results validate the effectiveness of  the proposed method.