Table of Content

10 November 2007, Volume 18 Issue 21

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Dynamics Analysis of the Main-plate of Stepping-scanning Lithography and Optimization

Chen Xuedong, Guo Hezhong, Yan Tianhong, Yu Xianzhong

2007, 18(21):  2524-2527. 

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The main-plate of the high-resolution stepping-scanning lithography was studied. Using the finite element analysis theory and modal analysis theory, dynamic characteristics of the main-plate were analyzed, and it proves the structural design is reasonable. Using modal test, the finite element model was validated. Using the finite element model, we carried out sensitive analysis, and implemented the optimization design.

Research on the Kinematic Characteristics of Bionic Kangaroo-Hopping Robot during Flight Phase

Ge Wenjie, Huang Jie, Yang Fang

2007, 18(21):  2521-2524. 

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Based on the body configuration and kinematics characteristics of kangaroo in its flight phase, a new method to analyse the torque characteristics was presented.A model to simulate the kangaroo robot in the flight phase was also founded using
D-H method. The equations of the model were derived using Lagrange method and the model was simulated by Matlab at last. The results show that, the hip and knee joints play the most important role in tuning the configuration of kangaroo hopping robot in flight phase,which is the basis for the experimental research and choosing driving actuators.

Influences of Wear Resistance of Tool Electrode and Different Electrorheological Fluids on the Electrorheological Effect of Abrasive Slurry

Yan Qiusheng, Feng Jianhua, Lu Jiabin, Gao Weiqiang

2007, 18(21):  2528-2531. 

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Experiments were conducted to reveal the effects of electrode materials with different wear resistance,such as chilled steel electrode, stainless steel electrode, brass electrode and graphite electrode,and ER fluids with different components on the material removal efficiency of common glass. The processing mechanism was also studied. Experimental results indicate that higher efficiency of material removal can be achieved using chilled steel electrode tools and stainless steel electrode tools, thus, the material removal efficiency will enlarge with the increase of the wear resistance of the cone-electrode tool.Furthermore,a greater material removal efficiency can be obtained using the zeolite particle-ER fluid than that using the SiO₂ particles-ER fluid.The reasons are that the wear resistance of cone-electrode material dominates the stability of the working gap between the needle-like tool and workpiece,and that different ER fluids can obviously influence the strength of ER effects,which determines the polishing pressure on the workpiece surface and directly influences the polishing performance of the tiny-grinding wheel.

Research on the Dynamics Characteristics of Inner Planetary Gear Reducer with Three Axes

Zhang Suohuai, Zhang Jiangfeng, Li Lei

2007, 18(21):  2532-2534. 

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Considering the meshing stiffness and damping of the gear pairs and stiffness of the bearings, the dynamics governing equations of an inner planetary gear reducer with three axes were established based on the lumped mass method. According to the different constructions, which have different numbers of inner planetary gears, the natural frequency and mass unbalance response of the reducer were investigated. It is found that the natural frequency of the reducer with different numbers of inner planetary gears has almost the same frequency value. Mass unbalance force can result in bending vibrations and twisting vibrations. When the reducer has three inner planetary gears, its dynamics characteristics will be improved.

Research on Capacitance Measurement Instrument for Inner Diameter of Deep Holes

Zhou Xinglin, Yu Zhanguo, Zheng Yizhong

2007, 18(21):  2535-2538. 

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A system, which used the capacitance sensor to measure the aperture of small blind holes, was studied. A capacitance probe with small diameter was used as the sensor. The capacitance instrument converted the change of the aperture in to the change of voltage signals which can be inputted into a computer through the USB interface to get processed. The working principle of the capacitance sensor and the electronic circuits of the capacitance instrument were discussed. The design scheme was also disserted as the system using the capacitance sensor to measure the aperture of small holes. The calibration of the sensor was done on the small blind holes with 3mm and 7mm aperture. From the analyzed experimental data, the resolution is 005μm, and the standard deviation of the experiments is within 05μm. 

An On-chip Micro-tribotester and Its Micro-fabrication

Guo Zhanshe, Jiang Chunfu, Zhang Yuxiao, Zheng Dezhi

2007, 18(21):  2539-2542. 

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An on-chip micro-tribotester was designed and fabricated to simulate the tribolgical properties for the lateral contact surfaces of MEMS devices. The loading structure, testing part and force sensors were all integrated on a single chip by bulk silicon technology and bonding process. It is verified from the tested results that the static frictional coefficient between the contact pairs is 0.9 and dynamic frictional coefficient varies with normal force.

Cutting Forces in High Speed Milling of Hardened Steel P20 and 45

Pang Junzhong, Wang Minjie, Duan Chunzheng, Yang Yu

2007, 18(21):  2543-2546. 

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Using solid carbide ball end mills with TiAlN coating, the experiments of high speed milling of hardened steels were performed. Workpiece materials tested included 45 steel at 52HRC, 48HRC, 42HRC, and P20 steel at 41HRC, 33HRC, respectively. Based on flow stress equation at material formation and shear angle theory, the effects of cutting speed, workpiece hardness, material performance on cutting forces were investigated. The cutting parameters involved were: cutting speeds in the range of 156 to 816 m/min, feed rate of 0.1 mm/tooth, axial depth of cut of 3mm, and radial width of cut of 1mm. The results show that saw-tooth chips are formed during the high speed milling of hardened steels, and the influences of cutting speed, workpiece hardness on milling forces are significant. 

A Study of Nano-precision Synergistic Process Integrated ELID-grinding and MRF for CVD-SiC

Yin Shaohui, Chen Fengjun, Sheng Xiaomin, Ohmori Hitoshi, Lin Weimin, Uehara Yoshihiro

2007, 18(21):  2547-2550. 

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A new ultra-precision synergistic process integrated electrolytic in-process dressing (ELID) grinding and magnetorheological finishing (MRF) was applied to nano-precision finishing for CVD-SiC. ELID grinding, as pre-finishing, was employed to shape rapidly, and obtain a relatively good surface smoothness and form accuracy in high efficiency. Furthermore, MRF, as the final finishing, was used to decrease sub-surface damage and improve form accuracy. Several sets of plane finishing experiments for CVD-SiC have been performed, and micro-surface roughness Rq=2.4nm and from accuracy 21.2nm have been obtained. Furthermore, characteristics of the generated surface resulting from ELID grinding & magneto-rheological finishing were compared and analyzed.

Relative Speed Analysis for Spherical Contour Lapping

Ma Yongtao, Chen Wuyi

2007, 18(21):  2551-2555. 

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Contour lapping method which was driven by two axes was studied. By using auxiliary triangle method, analytic result for the relative speed on four quadrants of the sphere and the computer program were brought out, then 3D curved faces were plotted to illustrate the speed distribution. With the help of computer program, zero speed point was searched. The results show that the zero speed point is located on the arc between two absolute speed zero points of rotation axes, and the necessity of relative speed zero point is demonstrated. From the location of speed zero point, some useful conclusions can be drawn. For some special parts, the speed zero point can be put out of the parts by adjusting speed ratio and tilt angle of two axes. So the adverse effects of zero point can be eliminated.

Implementation of a Multiple Automatic Focusing Algorithm for Video Measuring System

Wang Pingjiang, Chen Dejun, Wu Mengliang, Chen Jihong

2007, 18(21):  2555-2560. 

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Three common evaluation functions for automatic focusing were introduced. They were deviations function, gradient function and frequency-spectra function, the later two were optimized. Their merits and deficits in delicacy, stability and velocity were analyzed. And a multiple automatic focusing algorithm based on three-stages was proposed herein. It performs well in the video measuring system and can focus exactly and rapidly.

Research on Management of Design Knowledge Based on Ontology in the Integrated Product Development

Huang Weidong, Wang Youyuan, Xie Qiang, Ding Qiulin

2007, 18(21):  2566-2569. 

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On the basis of knowledge sharing and knowledge reusing in IPD, the paper used ontology theory to study the expression of product design knowledge base on semantics, to analyze the background of the knowledge demands and personal characteristics, to set up the knowledge management frame of product design, to propose the method of knowledge retrieval on the basis of the concept feedback. Through comparing and analyzing recall ratio and accuracy ratio of knowledge retrieval,the practicability and validity of this research results were verified.

STEP-NC Manufacture Feature Reconstructive Mechanism Based on Dictionary Entity

Zhou Gang, Wu Yijie, Pan Xiaohong

2007, 18(21):  2561-2565. 

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Manufacture feature reconstruction is a key technology in STEP-NC machining program extraction. First of all, entities in STEP-NC data model were coded, then raw node data and dictionary entity data were constructed. Node-entity data was constructed by matching node data and dictionary entity data. According to the geometry, entity was divided into five classes, there were feature, profile, curve, point and placement. In the course of reconstruction, node’s attribute content construction in upper class was completed by its entity reconstruction function in lower class. In the same class, node’s geometry was constructed from above to below according to inherit relationship between entities. In such a way, a test prototype was developed and verified by program in STEP-NC FDIS, and the reconstructive mechanism is proved by the result.

Research on Key Technologies of Web Services Mobile Control CNC System

Wang Zhisen, Gao Rong, Dong Bolin, Huang Xiaofeng, Zhang Jianke

2007, 18(21):  2570-2675. 

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Web Services Mobile control CNC（WS-mCNC） was proposed, which was composed of two parts: one was the CNC mobile controller, the other was the CNC device controller installed on the CNC machine. They communicated via Bluetooth protocol and interface, a Man-Machine-Cooperative mode was formed. The concept and characteristics of WS-mCNC were provided .Architectures of WS-mCNC hardware and software were emphasized ,relation and process of Web Services requester and provider were illustrated. Process and program of mobile controller were established. Integration of motion control card involved standard interface and CNC were studied,the concept of Version Space was provided，and how to shorten Version Space was very important, Finally,Bluetooth communication protocol was established,and Bluetooth communication experiment was accomplished.So problem is solved that different platforms and limits of resources that digital machines result in difficulty of information integration for shop floor. 

Modeling and Simulation of Single-row Layout Based on Logistics Routing

Suo Xiaohong, Liu Zhanqiang

2007, 18(21):  2576-2579. 

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Based on analyzing the advantages and disadvantages of single-row layout, models of material handling costs, area utilization rate and production cycle were established for the wide applications of single-row layout in FMS, GT cell and factories using JIT. Taking the No.117 piston production line as the example, three types of single-row layout, including straight line layout, U-shape layout and semi-circular layout were modeled and simulated on platform of QUEST. The simulation data for these three models were collected and analyzed. Parameters selected are the same for the three types of single-row layout. The simulation results show that: ① material handling costs of semi-circular layout are the lowest；②the production cycle of semi-circular layout is the shortest；③the area utilization rate of U-shape layout is the highest.

Calculating Atomic Scale Frictional Force with Composite Oscillator Model

Xu Zhongming, Huang Ping

2007, 18(21):  2592-2596. 

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A method to calculate interfacial friction force with composite oscillator model was discussed, and the formulas used in calculation were derived. Some experiments with an atomic force microscopy were carried out to testify the method. The experimental results are in accord with the numerical analysis ones of the proposed method. This indicates the method is feasible. The research shows that the frictional force increases linearly as the contact area increases, but decreases with increase of the lateral stiffness of the macro oscillator. Therefore, it is possible to develop a new method to control friction because the lateral stiffness of the macro oscillator can be changed by modifying the geometry of the frictional surfaces.

A Diagnosis Method for Aero Engine Wear Fault Based on Rough Sets Theory and Integrated Neural Network

Wen Zhenhua, Zuo Hongfu

2007, 18(21):  2580-2584. 

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Rough sets theory combined with Neural Network was applied to intelligent diagnosis system, based on the importance of attribute and the consistency of decision table, SOM(self-organizing map) neural network was employed to discretize continuous data. Then rough sets theory was applied to reduce attribute and extract the primary feature which will be the foundation of structuring the sub-network. The final conclusions are reached by combing the results of sub-networks based on D-S(dempster-shafer) evidence theory. The method was applied to diagnosis the aero engine wear fault.Example shows the validity of the method proposed.

Part Family Coding Analysis Based on FCM Algorithm

Zhang Taihua, Gu Xinjian

2007, 18(21):  2585-2588. 

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A fuzzy c-means(FCM) model of part family clustering was provided. Part family clustering was analyzed by a FCM algorithm. The method considered fuzzy relations of part family object characteristics and distances among clustering centers,it is unnecessary to design power coefficients. The clustering results were compared with that from the fuzzy clustering  algorithm and the k-means algorithm through an example that proves the algorithm is validity and corresponding conclusion was presented.

Dynamic Assessment for Noise of Rolling Bearing Using Grey Bootstrap

Xia Xintao, Chen Xiaoyang, Zhang Yongzhen, Wang Zhongyu

2007, 18(21):  2588-2591. 

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Based on grey prediction and bootstrap resampling, a model of dynamic assessment was proposed to evaluate noise of rolling bearings. The model characterized completely noise of rolling bearings by developing six parameters viz. dynamic uncertainty, estimated interval, estimated true-value, mean uncertainty, mean true value, and trend measure. Computer simulation and engineering experiments show that the model can effectively separate trends with a minimum of the mean uncertainty, without any requirements for both the probability distribution of random variables and the type of trends. Reliability of assessment is proved to be 100%.

Phase Reconstruction and Chaotic Properties Analysis of Signal Time Series of Current during Spot Welding

Liu Pengfei, Shan Ping, Luo Zhen, Deng Huan, Gao Zhanjiao

2007, 18(21):  2596-2599. 

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Chaotic theory and phase reconstruction were used to analyse signal time series of current during spot welding, and some indexes such as optimal delay time τ, correlation dimension D, embedding dimension m, and Lyapunov exponent were obtained, and chaotic properties were verified in this series sometimes. And the number of influencing factor was discussed. At last, the largest forecasting scale on the signal series time of spot welding current was estimated. And it gives a reference to the research of quality detection and controlling system.

Flow Features of Synthetic Jet from Slot Nozzle Actuator Driven by Piezoelectric Membrane

Tan Xiaoming, Zhang Jingzhou

2007, 18(21):  2600-2604. 

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Experimental study and numerical simulation were used to study the flow characteristics of a synthetic jet. The results show that: near the slot exit, pairs of vortexes are generated, broken down and merged together periodically, forming the continue jet at one normal distance near the slot nozzle. And during the development, the synthetic jet spreads rapidly in the short axis direction, this means the weaker strain of the side synthetic jet. Comparing with the constant jet, the velocity profiles of the synthetic jet is self-similar in the short axis direction, While in the long axis direction, the synthetic jet contracts firstly and then spreads slowly. Near the nozzle, the velocity distribution on the slot length is like a saddle while with the distance far away it disappeares.

Kinematic Modeling and Analysis of Intelligent Forklift with Variable Load under the Condition of Considering Sideslip Factor

Ma Binliang, Huang Yumei, Shi Enxiu, Shangguan Wangyi

2007, 18(21):  2604-2607. 

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The change of the load’s mass and position was transformed into change of the intelligent forklift’s mass and centroid position,and kinematic model of the circular motion based on the sideslip was established with variable load by the coordinate transformation, and effect of the load’s mass and position was analyzed on trace of intelligent forklift by simulation. It shows that the change of the load’s mass and position can result in different degrees of oversteer.

NURBS Interpolation and Feedrate Adaptive Control Based on de Boor Algorithm

Wang Tianmiao, Cao Yunan, Chen Youdong, Wei Hongxing

2007, 18(21):  2608-2613. 

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Since NURBS has its own particularities,a NURBS curve feedrate model was constructed based on de Boor algorithm. This model consisted two parts-feedrate adaptive control and pre-interpolation acceleration/deceleration(acc/dec).The chord error, shear acceleration and normal acceleration of whole interpolation period were monitored and controlled based on de Boor algorithm. In order to calculate the distance of deceleration zone of the NURBS curve, a concept of NURBS reverse interpolation was introduced,which was illustrated by linear acc/dec.This model feasibility has already been proved in real CNC system.

Optimization of Variable Binder Force in Sheet Metal Forming Using the Micro Multi-objective Genetic Algorithm

Liu Guiping, Han Xu, Jiang Chao

2007, 18(21):  2614-2617. 

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A multi-objective optimization method for the optimization of variable binder force in sheet metal forming was suggested. The objectives were to minimize the forming shortcomings and the characteristic parameters of the variable binder force curve were selected as the design variables. The micro multi-objective genetic algorithm with high efficiency was adopted. An approximation model based on the neural network was also used to improve the efficiency. As an examples, a 2D draw bending problem of NUMISHEET’93 and a shoe plate of the front floor of a car stamping problem were solved using the presented method. Eventually, several variable binder force curves which could fulfill different needs are acquired efficiency.

Experimental Study on the Differential Capability of Motorized Wheels Driving Vehicles

Jin Liqiang, Wang Qingnian, Zhang Huanhuan

2007, 18(21):  2632-2636. 

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The differential of motorized wheels driving vehicles was discussed. And then the self-regulation method to realized the electric differential by controlling the torque of the motor and freeing the speed of the wheels was brought out. The control strategy was demonstrated with experiments on the re-equipped motorized wheels driving vehicles under the turning mode, the uneven road condition and the different tire radius modes. It shows that the differential capability of the experimental vehicle is good.

Finite Element Simulation for the Temperature Field in Multi-layer Thin-wall Metal Part Formed by DMLS

Zhou Jianzhong, Guo Huafeng, Xu Dapeng, Ji Xia

2007, 18(21):  2618-2623. 

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In order to acquire the heating-cooling process of laser molten pool and the mutual effect of sintering layers in multi-layer powder sintering, factors such as heat conduction, heat radiation, heat convecting and changeable thermophysical property parameters were taken into account comprehensively, the 3D transient state FEM of the temperature field of multi-layer thin-wall metal parts formed by DMLS was established based on ANSYS. The APDL (ANSYS Parametric Design Language) was used to carry out thermal resource moving and the technique of birth/death for element was used to simulate the process of material addition. The simulation results show that with the present process parameters ,sintering depth is over 0.15mm,sintering width is about 0.61mm, sintered part is jointed tight with substrate and within the inter-layers; the thermal gradient along z direction within the sintered part is absolutely predominant compared with that along x direction, so heat dissipates mainly along z direction during cooling process. At last the sintering experiment was carried out, it indicates that experimental result agrees with the previous simulation result well.

Development of a Kind of Ultrahigh Pressure Integration Device for Hydro-bulging in the Common Press

Wang Liandong, Zhang Wei, Cheng Jia, Ma Lei, Wang Jianguo, Cui Yaping

2007, 18(21):  2624-2627. 

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A kind of ultrahigh pressure hydro-forming device was developed. The device integrated the supercharger and the filler within the sliding bulging die, utilizing the interference fit sealing and combination sealing, being of the functions of filling tube quickly, producing the changed ultrahigh pressure, filtrating liquid in cycles and controlling tube-bulging automatically. Through the hydro-forming tests under the given load steps in the common press, the designed sample of automobile axle housings was manufactured. It is proved by a great deal of trial-produce and the ultrahigh pressure test after the die closed that the device realizes the designed functions, the capacity being stable and the sealing being credible. The research of the device contributes to simplifying the bulging equipment , reducing energy and extending the hydro-forming technology.

Modeling and Dynamic Analysis of a Metal Elastic Wheel

Guan Xin, Wang Peng, Zhan Jun, Dong Yiliang, Wu Jungang

2007, 18(21):  2637-2640. 

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Based on the research of contact theory, a new contact model between the metal elastic wheel and rigid ground was proposed. In modeling process, the elastic characteristics between rim and outside-wheel were considered and the friction solution algorithm under slip and stick conditions was developed. According to the subroutine interfaces, the contact model was embedded in ADAMS software. The simulation results show that this model can simulate the contact relations between metal elastic wheel and rigid ground and has high accuracy. It overcomes the defects of the contact model in ADAMS.

Research on Inverse Dynamics of Vehicle Minimum Time Maneuver Problem

Zhang Lixia, Zhao Youqun, Song Guixia, Wu Jie

2007, 18(21):  2628-2632. 

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A simulation research method for vehicle handling inverse dynamics was proposed. Based on optimal control theory, the steering angle input and the traction/brake force imposed by driver were the control variables, the minimum time required to complete the double lane change was the control object. By using the improved direct multiple shooting method , the optimal control problem was converted into a nonlinear programming problem that was then solved by means of the sequential quadratic programming. The simulation results show that the proposed method can solve the vehicle minimum time maneuver problem,can compare the maneuverability of two different vehicles that complete double lane change with the minimum time and the results fit that of ADAMS/Car virtual experiment.

Adaptive Neuron Control Strategy for Multivariable Active Suspension System

Jin Yao, Yu Dejie, Du Xiaojin

2007, 18(21):  2641-2645. 

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This paper investigated the adaptive control of vehicle active suspension, in which multivariable and uncertainty problems were involved. A novel multivariable neuron controller was proposed. An integrated error concept was firstly given, then a new neuron controller combining integrated error with traditional neuron controller was formed. It can directly control the multi-output variables of controlled plant simultaneously. The control scheme was applied for controlling a quarter-car active suspension, and the optimum parameters of the corresponding controller were obtained by means of minimization of the quadratic performance index. The self-adaptability of the controller was investigated in various vehicle parameters and random road conditions. Extension comparisons with an equivalent passive suspension and an active suspension using traditional neuron control were also performed. Simulation results demonstrate the proposed controller is a simple, effective and robust adaptive controller which can achieve better vehicle overall performance, especially in ride comfort. In addition, the newly-proposed neuron scheme provides a concise yet efficient new possibility to the control of a class of uncertain multivariable systems similar to vehicle active suspension.