Table of Content

25 December 2008, Volume 20 Issue 24

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Theory and Method of Key Stiffness Identification on a Machine Tool Based on Analyzing the Sensitive Distortion 

HUANG Jiang, ZHANG Gen-Bao

2009, 20(24):  2899-2902. 

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To distribute the stiffness on a machine tool reasonably or find out the

optimization target of component stiffness,a way was proposed to identify the distortion sensitivity of the machine component during design.The first work was to build an error model of target machine tool by combining the multi-body system theory and homogeneous coordinate transform.Then,it was supposed that each component produced respectively the unit distortion of six freedoms,and their action value and direction on final execution component were calculated with aforesaid error model.To compare these results, the

influence degree of each component stiffness on the final export precision will be realized. 

Research on Basic Characteristics of Bending Joint Based on Flexible Pneumatic Actuator 

JIAN Shao-Meng, YANG Qiang-Hua, BAO Guan-Jun, WANG Zhi-Heng, ZHANG Li-Ban

2009, 20(24):  2903-2907. 

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Based on FPA,a type of flexible pneumatic bending joint was proposed,the bending joint can be used for designing robot dexterous multi-fingered hand.When inflating the FPA with

compressed air,the pneumatic bending joint turned with an angle.

The force equilibrium equation of the FPA end was established.The static model about angle and force of the bending joint was obtained.Experiments were carried out to verify the static model.It is concluded from theoretical and experimental results that the experimental curve matches with the simulated curve.Then the experiments on dynamic performances of the bending join

were carried out. Experimental results show that the angle step response time of the joint is about 1s,and that the force step response time of the joint is about 0.5s.The accurate angle can be obtained based on PI feedback control and feed forward compensation.

Dynamics Analysis and Control of 1P5R Flexible Joint Manipulator

PENG Wei, FANG Chen-Wei, LIU Xiao-Beng

2009, 20(24):  2907-2911,2916. 

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A dynamics model coupled rigid and flexible system of a 6DOF flexible joint manipulator was established,and the feedback linearization control of manipulators including 1 prismatic joint and 5 revolute

joints was discussed detailedly.Then trajectory was designed in workspace of the system,and tracking control methods considering two different motions at the same route were simulated numerically with MATLAB.The results show that the trajectory tracking having the startup and braking phases are more effective.The flexibility of joints affects the shaft position of the revolute joint directly which absorbs the oscillations, and the more flexible,the larger of the difference between the shaft position and joint position.However,the flexibility of joints has little effect in the shaft position of the prismatic joint.

Optimization of Feedback Parameters of Active Vibration Control System with Genetic Algorithm

ZHANG Chun-Liang, MEI De-Qiang, CHEN Zi-Chen

2009, 20(24):  2912-2916. 

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The feedback parameters of an active vibration control system with harmonic disturbance were optimized by means of genetic algorithm. Aiming at the disturbance over wide frequency area, the integral of the vibration transmissibility in range of

frequency for the active vibration control was used as optimization objective function, and genetic algorithm was used to optimize the feedback parameters of the active vibration control system. The optimized results show that relative acceleration, relative velocity and relative displacement should not be used for the feedback signals in the active vibration control system with the disturbance over wide frequency area.

Research on New Techniques of Superfine Grinding for Superhard Powder by High Vibration Intensity

YANG Xiao-Lan, LIU Ji-Feng, JU Jing-Chao, JIAN Zhi-Gang, CHAN Chang-Qun

2009, 20(24):  2917-2921. 

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To solve the problem that ultrafine grinding of super-hard powder particles are not thin and easy to unify,etc.,effects of vibration intensity K on the fineness of powder were analyzed.High vibration intensity crushing technologies with K between 10～18 was applied.In order to solve various types of faults caused by the application of the high vibration technology engineering,the following steps were taken:building a two-body vibration structure,using a nonlinear vibrating system,applying two-vibrant self-synchronization technology,near sub-resonance technology and converter technique.

Vibration test was carried out with a kind of prototype testing and sampling powder detection and analysing particle size.The experiments have found that particle size refinement to the nano-scale trends.Finally progress in crushing fineness is made;the average input of

diamond superhard powder is 10μm and the output under 0.195μm is about 50%.

Structural Optimization Design and Manufacture of Super High-speed Point Grinding Wheel

CHOU Jian, GONG E-Dong, LIU Ru-Meng, XIU Shi-Chao

2009, 20(24):  2922-2927. 

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It was designed as 42CrMo matrix vitrified CBN wheel with a special abrasive layer which contained a decline face on the leading edge and

it was helpful for point grinding. After studying on the connection between inner micro-

unit’s displacement and stress of wheel matrix, the distribution of stress and displacement of wheel matrix can be seen. Models for strength check were also established.

It is found the displacement and stress quadratic increase with wheel speed increasing. In addition,a finite element analysis (FEA) method was applied to optimize wheel structure.In the end,the optimized super high-speed point grinding wheel was obtained. 

Matching Method of Wheel Loader Permanent Magnet Synchronous Motor Drive System

BIAN Yong-Meng, GE Feng-Long, JIN Xiao-Lin

2009, 20(24):  2927-2931,2937. 

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In order to reform electric wheel-drive system from mechanical

hydraulic drive system on a 1.5t wheel loader,the reasonable matching was calculated according to the design and dynamic performance parameters of the whole wheel loader,including power matching,speed matching,torque matching.With the characteristic curve of permanent magnet synchronous motor,torque control strategy and computer simulation software MATLAB/Simulink,the model of electric drive system on the whole wheel loader

was built.Through the analysis of the drive characteristics in all kind of conditions and the test results,it is verified that the matching theory and the torque control strategy is reasonable.

Green Manufacturing Operation Model for Machine Tool Industry Oriented to Product Life Cycle

LI Cong-Bei, LIU Fei, WANG Qiu-Lian, CAO Hua-Jun, CAO Le

2009, 20(24):  2932-2937. 

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In order to implement GM effectively,a product design main-line and life cycle main-line based GM operation

model for machine tool industry was presented oriented to the product life

cycle.The key submodels of the model were discussed in detail, in which the green design submodel focused on design process,objectives and green design methods;the green production submodel focused on manufacturing

process,environmental emissions and clean measures;remanufacturing submodel

focused on parts and machine remanufacturing.Finally,the GM operation model was applied in a machine tool enterprise,which has achieved good application results. 

Grid Task Reliability Analysis of Manufacturing Resources Based on Monte Carlo Simulation

GUO Su-Chang, HUANG Hong-Zhong

2009, 20(24):  2938-2942. 

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To describe the impact of local task arrivals and failures on grid

task execution,a state analysis of manufacturing resources based on deterministic and stochastic Petri net was discussed and the formula of grid task reliability without considering local task arrival was given.In order to describe the influence of local task arrival,

research on grid task reliability based on the Monte Carlo simulation was studied and the influence of local task arrival rate and local task execution rate on grid task reliability was analyzed.The simulation results can provide some information to grid resource management so as to make grid task scheduling better.

Flow-style Scheduling Technology under Job Shop Discrete Manufacturing Environment

DING Lei, WANG Ai-Min, NING Ru-Xin

2009, 20(24):  2943-2948. 

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To reduce the manufacturing make-span and improve the production quality consistency level, flow-style scheduling technology under Job Shop discrete manufacturing environment was proposed. By analyzing the flow-style working pattern，the technical mechanism integrated with production step balance, manufacturing resource group construction, dynamic production priority was presented. Manufacturing resource group allocating algorithm was put forward, which can smooth the requirement differences among the procedures. Computational method of the number of work-in-progress between the procedures with different processing time was constructed. The dynamic algorithm of selecting priority of part and machine was built. And a scheduling system was built which was authenticated with realistic case. The new flow-style continuous production pattern under Job Shop discrete manufacturing environment was derived.

A Generating Algorithm of Multi-axis NC Machining Tool-path for Triangular Mesh Surface Model

SUN Dian-Zhu, CUI Chuan-Hui, LIU Jian, LI Yan-Rui

2009, 20(24):  2949-2953. 

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A generating algorithm of multi-axis NC machining tool-path for triangular mesh surface model was proposed,which had five steps:first,the special index structure of triangular mesh surface model was established based on the R*-tree;second,section data were computed through intersecting between the mesh model and the tool-path section according to the special index structure; third,the transient processing area was obtained;forth,the cutter location points were generated by means of the relevant computing modes;fifth,the cutter location points were sorted with the minimum spanning tree algorithm.It is proved that it can generate multi-axis NC machining tool-path for all kinds of triangular mesh surface models accurately and efficiently.

Research on Concurrent Control of a Coordination Conceptual Design System

ZHANG Li, XU Juan, DIAO Wen-Chao, LIU Zheng-Yu, ZHANG Jian-Jun

2009, 20(24):  2954-2958. 

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On the analyses of each existing concurrent control methods in

the coordination conceptual design,in order to solve the problem of concurrency and

in real-time which could not be taken into account simultaneously in concurrency control mechanism, and the problem of the complexity in the concurrent algorithm development,

the real-time control factor and the safety control factor were used and a concurrent control model was proposed which was based on the high priority of two sections of lock’s. Through the experiments the paper verifies that this model can effectively reduce concurrent conflict in the coordination conceptual design,and proves the security and timeliness of this model.

Research on Maturity-driven Design Activity Overlapping Model

ZHANG Ding-Hua, FENG Chao, CHEN Bing, WANG Gang

2009, 20(24):  2958-2962. 

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Aiming at the activity overlapping by releasing preliminary

information in concurrent product development process,product maturity was presented.According to the activity overlapping degrees,the algorithm based on maturity for calculating the rework caused by activity overlapping was presented.Based on those,the rework caused by activity overlapping was calculated toward coupled and uncoupled activities,and

the activity overlapping model driven by product maturity was constructed.Then the time optimal model of product development process was obtained by analyzing and transforming the overlapping model. Finally, the validity and the optimization of the model with an instance were proved, and it shows that product maturity has a great advantage in describing and controlling the activity overlapping.

Study on Output Waveforms of an Electro-hydraulic Vibration Exciter under Actions of Typical Waveforms

LIN Yan, RUAN Jian

2009, 20(24):  2963-2968,3023. 

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Based on the theory of an electro-hydraulic dynamic system and a nonlinear relation between pressure and flow,a mathematical model of the electro-hydraulic vibration exciter was established first.The analytic solutions to excited waveforms were given under the actions of two typical waveforms,such as sine wave and triangle wave.Then the calculations of the waveform distortion rate were carried out.Finally,the theoretical analysis results were validated by the vibration experiments.The experimental results reveal that the vibration wave peak moves to lateral side and the wave trough moves to medial side under the actions of triangle wave.This is mainly because of the changes of the direction of elastic load.The extent of deviation depends on the throttling areas of the valve.When it reaches to a certain threshold,the pick of the load pressure and system pressure equal and excited waveforms are in a critical saturation.When it descends below the critical value, the waveforms tend to symmetries.When it ascends above this point,waveforms tend to square wave.The waveforms under sine wave are basically identical with the waveforms under triangle wave.Waveform distortions follow a linear law with the valve port area,but

the distortions are in a certain range and progressive the border.

Deployment-style Reliability Modeling Approach and a Four-parameter Statistics Model

XIE Li-Yang

2009, 20(24):  2969-2973. 

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Traditional reliability theory and method are still far from perfect since the embodiment and characterization on the reliability controlling factors such as load, strength,structural feature, and time as well are incomplete.Based on appropriate expression to the time-dependent property (i.e. load history effect and strength degradation effect),load uncertainty in both macro- and micro- aspects, the dependence between component failures in a system or the dependence between multi-susceptible locations on a structure,this paper presented the characterization method for complex load history,

reliability modeling method for different systems,highlighted the effect of load uncertainty

on system reliability-component reliabilities relationship,discussed time-dependent reliability property and the controlling factors.Finally,through system-level probability analysis/modeling methodology and multiple-level statistics theory,the paper developed uniformal reliability model for both component and system,built uniformal reliability model for both static failure and fatigue.

Research on Workspace of a Spherical 2-DOF Parallel Manipulator with Actuation Redundancy

ZHANG Li-Jie, NIU Ti-Wei, LI Yong-Quan

2009, 20(24):  2974-2978. 

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A kind of spherical 2-DOF parallel manipulator with

actuation redundancy was investigated herein.Based on the geometric parameter design spaces and constraint conditions,the relationship between geometric design parameters and the reachable workspace was studied in detail by using geometric methodology.The shapes of reachable workspace was expressed on the plane by using conformal transformation.

These results will be very useful for designers to understand and grasp the

performances of this manipulator’s workspace. 

Maintainability Evaluation Model Based on Fuzzy Multiple Attribute Decision Making Theory for Virtual Products

LIU Zhong, SUN Wei-Chao

2009, 20(24):  2978-2983. 

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Maintainability design attributes of product are determined by analysis of maintainability influencing factors;and the calculation method of each attribute was proposed by means of maintenance task virtual simulation,rapid upper limb assessment and maintainability checklist.In terms of multiple attribute decision-making theory,the normalization methods of maintainability attributes were proposed, and the comprehensive maintainability evaluation model of products was established based on fuzzy theory and multiple attribute decision making method.At last,a comprehensive evaluation instance, combined with two different types of nose landing gear system’s virtual mock-ups,was given to illustrate the effectiveness of the model.

An Error Controllable Modeling Method of Complicated Roller Gear Cam Spatial Contour Surface Based on Ruled Surface Theory 

CAO Ju-Jiang, LI Yan, MA Xiao-Qin

2009, 20(24):  2984-2987. 

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According to the deficiencies of current roller gear cam surface modeling method in data relativity and error controllability, this paper discussed the ruled surface feature of roller gear cam surface and the error control method of constructed developable

 surface.An error controllable roller gear cam surface was constructed based on the directrix and generatrix family in UG FreeForm environment.

Study on the ZCPA-auditory-model-based Method of Feature Extraction for Mechanical Faults Diagnosis

LI Yuan-Gong, ZHANG Jin-Ping, DAI Li, ZHANG Tie-Yi, LIU Jie

2009, 20(24):  2988-2992. 

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An auditory model,ZCPA model,was introduced to the feature extraction for mechanical fault diagnosis.The basic principles of ZCPA model were introduced.According to the characteristics of vibration signal analysis in mechanical fault diagnosis, ZCPA model was adjusted. The first adjustment was to replace logarithm

 function by S function for modeling the inner hair cells in cochlea,and the other was distributing frequency bins on frequency axis with the width of frequency bin proportionably increasing.Furthermore,the basilar membrane was modeled by Gammatone filterbank.To test the performance of ZCPA model in feature extraction,the experiments of four kinds of rotor faults were carried out and the measured vibration signals were processed by ZCPA model.The outputs of ZCPA model,the results of feature extraction,show that the ZCPA model can represent different faults only using a few numbers of value(16 values here),

and the stability and coherence for same type faults are satisfactory. Then it is quite possible that ZCPA model or some other auditory models may be applied to engineering practice.

FE Analysis of the Extrusion and Welding Process in Porthole Die for an Aluminum Alloy Square Tube

LIN Gao-Yong, FENG Di, LIU Jian, JU Yan-Meng

2009, 20(24):  2993-2998. 

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A detailed analysis of metal flow into

a porthole die to produce a square aluminum alloy tube by means of three-dimensional FE simulation was performed.An insight into the metal flow rules and the

longitudinal weld seam formation were orchestrated subsequently.Corresponding to the variable-section-porthole of die,the process includes five distinctive stages of upsetting,

dividing,filling the clearance of portholes,solid welding and steady extruding.

The commonly observed defects on the extrudate surfaces are due to the entrapped air between porthole and work-piece during the stage of filing the clearance of portholes.The results also show, that solid welding first starts at the mid-height of welding room while the upper part is the last as a result of friction ,which also makes little air entrapped under the bridge in the upper part of the welding room causing poor welding quality at the beginning of an extrusion cycle.Finally, an improving project was proposed for the porthole design of “regular section” in order to avoid surface defects.

Investigation of Ultra-fine Grained Copper Fabricated by Multi-axial Compression Process

DAN Feng-Jian, WANG Lei-Gang, HU Sheng

2009, 20(24):  2998-3001. 

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Microstructure evolution and mechanical property of pure copper after multi-axial compression were investigated.Microstructure

evolution with the number of compressions was examined by scanning electron microscopy.The microhardness variation and distribution were investigated by measuring the Vickers microhardness on the middle section.The results show that dislocation division is the main mechanism of grain refinement.The subgrain misorientation increases by dislocation absorption and rearrangement with the increase of dislocation density and the rotation of compression axis,which leads to the grain refinement gradually.The ultra-fine grains are obtained in the most regions after 12 compressions.The microhardness is improved obviously, while its distribution on the middle plane is ununiform due to the friction between the billet and anvils, higher at the centeral portion and lower at the circumambience.

Research on Integrated Strength Ratio and Its Dynamic Variation Law of Laser Tailor-welded Blanks

SUN Dong-Ji, LIN Jian-Beng, LIU Rui-Tong, HU Qiao-Qing

2009, 20(24):  3002-3007. 

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During the tailor-welded blanks(TWBs) forming process,the change of thickness and hardening ability of sheet metal are becoming different in the deformation process,which will result in the dynamic variation of strength difference of base metals.Based on comprehensive consideration of the influence of these two factors on the strength difference of base metals,a theoretical model of integrated strength ratio of laser TWBs was proposed,and its explicit expression was established.On the basis of theoretical research on the constitutive relation of laser TWBs in plane strain state,

the dynamic changing law of the integrated strength ratio of laser TWBs with different thickness and strain state of the weak base metal was studied under

three typical straining states.And the influencing law of thickness ratio of

TWBs on the strength difference of base metals was obtained, which

will provide theoretical reference for the further researches of the formability of TWBs.



HEV Operating Mode and Simulation Based on Electromagnetic Continuously Variable Transmission 

LUO Yu-Chao, TANG Gao-Cheng, FU Xin-Feng

2009, 20(24):  3008-3012. 

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HEV(hybrid electric vehicle) transmission structure with EMCVT system and its mathematic model were pointed out herein.The partial efficiency,electromagnetic power,stator current,

rotor current,drive ratio and rotary speed difference of whole electrical variable transmission system were analyzed by simulating ECE（economic commission for Europe) and EDUC(extra urban driving cycle) operating mode.The results of simulation were compared and could be helpful for the theoretic research and design after

the actual operating mode of EMCVT system had analyzed.It is showed that the whole EMCVT system can run in high efficiency regions under reasonable control strategy.

Study on Influence Factors for Crush Intrusion in Passenger Vehicle Front-to-side Impact

TANG You-Ming, CAO Li-Bei, Mohan Pradeep, Kan Steve

2009, 20(24):  3013-3019. 

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Making the side crush intrusion of the 5th generation Taurus made in Ford Automotive Company in USA as the objective function of research,the relationship among variables was studied when the

delta velocity of its side was 28km/h,to the crush intrusion of the left side of struck vehicle.Research variables included the two vehicle weight ratio,primary

energy absorbing structure relative position,and approach velocity and

contact area of striking vehicle.In order to make sure the effectiveness of influence factors of side impact, the results comparing testing of US New Car

Assessment Program and simulation were analyzed,under the condition of

impact of Federal Motor Vehicle Safety Standard(FMVSS),validated the FE model for side impact of target Taurus and other FE models for front impact of a series of passenger vehicle.With the data of statistic analysis accidents of

real world,analyzed the influence of crush intrusion on the passenger abbreviate injury

scale (AIS) value.

Modeling and Simulation of a Pretension Safety Belt Installed with New Clutch Using MADYMO

JU Jie-Hui, LIU Qiu-Cheng

2009, 20(24):  3020-3023. 

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A new clutch used for pretensioner of safety belt

 was metioned here.Based on the clutch and the mechanical structure of belt Tokai-Rika 85PT,a new safety belt was developed.Then,a MADYMO frontal impact model was built and used to compare the occupant protection effectiveness of the belt restraint systems in terms of simulating occupant kinematics,chest and head injury responses.The results show that the new safety belt can significantly reduce the injury responses and has better protection performance.