Table of Content

10 January 2010, Volume 21 Issue 1

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Research on Vibration Transmissibility of Vibration Isolation System with Complex Vibration Environment

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

2010, 21(1):  1-5. 

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Based on the analyzing of vibration transmissibility of passive vibration isolation system and active vibration isolation system, the vibration transmissibility of the vibration isolation system under complex vibration environment with the floor disturbance and the direct disturbance is defined. The calculating formulas for the vibration transmissibility of passive vibration isolation system and active vibration isolation system with complex vibration environment are established. The influencing relationships between the vibration transmissibility of the vibration isolation system and the feedback parameters such as acceleration, velocity and displacement are studied systematically.

Hybrid Dynamics of Flexible Multibody System and Real Time Simulation

TIAN Fu-Xiang, TUN Hong-Chao, DIAO Da-Xu, SHAO Bing, WANG Chao-Qun, SHU Jian-Yang

2010, 21(1):  6-12. 

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The hybrid recursive dynamics based on the spatial operator algebra theory and real time simulation of a generalized flexible multibody was presented herein. The generalized flexible multibody was described according to the type of the joints (active or passive); then the generalized articulated inertia-matrix, the residual forces and the generalized acceleration and torque were computed through twice tip-to-base recursive and once base-to-tip recursive; at last the O(N) hybrid dynamics was gained. Next real time solver for the large differential-algebra equation was studied based on the linear multi-step method. Simulation results show that the dynamics modeling and fast integration techniques proposed here are very useful.

Composite Adaptive Control in Work Space of Free-floating Dual-arm Spatial Robot System with Unknown Parameters 

HONG Zhao-Bin, CHEN Li

2010, 21(1):  12-16. 

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A composite adaptive control of free-floating dual-arm sptial robot system with an uncontrolled base was proposed. In order to deal with the problem that the dynamics equations have a nonlinear relationship with the initial parameters, the spatial robot can be modeled as an under-actuated system. And it is shown that the dynamics equations of the system can be linearly parameterized. With the augmentation approach, we demonstrate that the augmented generalized Jacobi matrix can also be linearly parameterized. Based on the results, the composite adaptive control scheme was designed to track the desired trajectory in workspace for dual-arm spatial robot with unknown parameters. The experimental results validate the proposed method.

Analysis on the Performance of Overcoming Obstacles for Internal and External Hybrid Driven Spherical Robots

JIANG Ji, LI Xiao-Feng, LI Qiu-Ji, LIU Wei-Gang

2010, 21(1):  17-21,58. 

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An internal and external hybrid driven spherical robot was designed based on the method of applying the robot-driven force couple caused by offseting the gravity center. Then a prototype of the spherical robot was produced. According to the theory of moment balance, the constraint equations that described the performance of overcoming obstacles for the spherical robot was developed for different drives of the wind driven, internal driven and internal and external driven. With these equations, wind speed, the slope angle of the terrain, the height of obstacles, the counterweight in the sphere and the size and weight of the sphere were determined to be associated each other by some relations. The motion analysis programmes were composed. Finally, motion cases of the robot verify the effectiveness of the overcoming obstacles analysis method.

Application of Marginal Estimation of Distribution Algorithms in Optimization of Turning Parameters

XIE Shu-Tong, GUO Yin-Biao

2010, 21(1):  22-26. 

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In NC turning operations, it is of important and also practical sense to decrease the unit production cost. Unfortunately it is a non-linear optimization problem with high complexity and many constraints, that is to decide how to select a set of turning parameters to save the unit production cost. To deal with it, UMDArp and UMDAp algorithms based on marginal estimation of distribution were proposed. And under a set of practical machining constraints, the reasonable machining parameters (speed, feed rate and depth of cut for both rough and finish machining, and number of rough machining) were obtained by proposed algorithms along with optimization of the rough and finish machining parameters at the same time. Furthermore, the performance of the proposed algorithms was improved through the constraint dealing method combined gene repair strategy and penalty function. Computer simulation shows the UMDArp can achieve more optimal solution than other algorithms proposed previous to reduce the production cost.

Study on Optimization of a Small Hydraulic Device for Blowing Methane in Upper Corner

GU Yong-Xia, ZHOU Zhong-Ning, LI Yi-Min

2010, 21(1):  26-29. 

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In order to improve the tear situation of slipper pair in the outer fringe and low efficiency of the fan, the flow field of lubrication film under the bottom of slipper was analyzed particularly, some regular concaves convergenting along radial in slipper's bottom face were machined; optimization was done for the main flow parts through numerical experiments. The structure of impeller, guide vane, spinner, hub, and rectification object were improved.The results indicate that new concave design improves the wear situation in the outer fringe, the total amount of wear reduces 28.77%, total pressure efficiency of the fan increases from 73.39％ to 77.11％.

Research on Continuous Torsional Vibration Modeling and Simulation of Rotary Machinery

HOU Dong-Xiao, LIU Ban, SHI Pei-Meng

2010, 21(1):  30-34. 

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A novel continuous torsional vibration dynamics model of rotary machinery was established,which was based on the Lagrange equation. And arbitraty shaft's torsional formula of drive system was obtained by transfer function method. Then a nonlinear continuous dynamics model considering clearance of drive system was established. Compared to lumped mass model, the natural frequency of the continuous model is more accurate, and it can decrease the calculational errors which are caused by human factors. A numerical example indicates that the method can reflect more complex characteristics of the torsional vibration, and it provides a new method for analysing torsional vibrations.

Optimization Method for Shape Adjustment of Perimeter-truss Mesh Antenna Reflectors

YANG Dong-Wu, DU Jing-Li, LI Qiu-Ji

2010, 21(1):  35-37. 

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An optimization method for shape adjustment of perimeter-truss mesh antenna reflectors was put forward.With the assumption that only one cable element to be adjusted in once time, and based on the fundamental frequency of mesh structure and the errors of each adjustable nodes, a scheme for choosing the best element to be adjusted in current procedure was firstly proposed. Then, optimization model for only once shape adjustment procedure was developed, with variation of the element length as design variables, root mean square(RMS) error of the adjustable nodes as objective function and element stresses as constraints. The numerical example shows that the proposed method possesses a rapid convergence rate and needs low adjusting workload.

Finite Element Analysis and Parameter Verification of Temperature Field in WEDM

LIU Zhi-dong, CHENG Guo-Zhu, LI Jian-Jun

2010, 21(1):  38-42. 

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Discharge model of single pulse was established on WEDM, and the temperature field of single-pulse discharge condition was analyzed based on finite element method. Discharge caves were engendered in both work-piece and wire electrode under single-pulse discharge conditions, and their geometric features were calculated. The features were contrasted with process indexes such as surface roughness, electrode relative-wear, cutting efficiency. Simulation results were corrected based on processing characteristics of WEDM, and erosion rule was studied for WEDM. Results show: the correction value of simulating single pulse discharge caves can approximately represent the actual surface roughness during continual cutting process; the main reason why relative-wear of the wire electrode is low is because of the discharge channel transfer in wire electrode; considering the actual cutting-related factors, corrections made to theoretical cutting efficiency turn out to be in line with the objective circumstances. 

 

Electro-hydraulic Force Servo System for Simulating Thrust in Reverse of Experimental Systems on the Ground for Airplane

SHI Guang-Lin, PAN Jian

2010, 21(1):  42-45. 

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The electro-hydraulic force servo system was introduced, which was used to give force to a certain kind of airplane during its experiments on the ground.The characteristics and structure of this electro-hydraulic force servo system was analyzed in detail. The control strategy of the system was emphasized on, and the experimental results of stop mode, normal mode and back mode were also given respectively. The experimental results show that the dynamic trace error of this electro-hydraulic force servo system is less than 15%. This is suitable to engineering applications.

Structural Element Library Based Conceptual Design Methodology of MEMS

MA Bing-He, WANG Hui, YU Wei-Zheng

2010, 21(1):  46-50. 

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A new methodology for MEMS conceptual design was introduced to assist the initial stages of design exploration.The methodology utilized past successful MEMS designs and sub-assemblies as building blocks stored in an indexed library. During conceptual design for exploring new MEMS configurations, interrelated elements can be retrieved automatically from the library by behavior matching, and then elements' function and structure of components and the device can be further considered and determined by the designers. Design of shear stress sensor was taken as an example to successfully testify the ability to obtain new designs with high efficiency. 

An Adaptable Optimization Design Method of Machine Tool Structures Based on Unit Structure

MAN Jia, ZHANG Lian-Hong, CHEN Yong-Liang

2010, 21(1):  51-54,66. 

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An optimization design method for NC machine tool structures based on unit structures was proposed. Firstly, the machine tool structures were decomposed into several unit structures, and through the combination of which a modified scheme sets was confirmed. Next, the second are development language of CAD or CAE software was applied to establish the general parametric model of modified scheme sets. Then, comprehensive evaluation function of the structural performance indices based on adaptable design was set up and regarded as objective function. The validity of this method has been proved by the case of column of ring gear milling machine. 

Real-time Diagnosis of Bearing Faults Based on Harmonic Wavelet Singular Entropy

DING Jian-Meng, LIN Jian-Hui, YANG Jiang, NONG Han-Biao

2010, 21(1):  55-58. 

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A new method for real-time diagnosis of bearing faults was proposed based on harmonic wavelet, SVD and entropy. The vibration signals were transformed by using harmonic wavelet to get harmonic wavelet coefficients. The wavelet coefficients were used to construct harmonic wavelet time-frequency distribution matrix, scale for rows and time for columns. The singular values were obtained through time-frequency matrix SVD. The information entropy was computed in the partition criteria of singular values to diagnose bearing faults. A concrete model based on harmonic wavelet singular entropy was presented. Through many inner- outer ring fault experiments, the results show that the method is effective to analyze bearing faults, has high degree in real-time, which achieve real-time diagnosis in less 68kHz sampling frequency, has good applicability.

Segmentation and Extraction of Small Defects in X-ray Images for I Style Weldments

DAN Duan-Hu, GANG Tie, ZHANG Hua-Jun, YANG Gen-Chi

2010, 21(1):  59-62. 

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X-ray real time image system was used to detect I style laser weldments nondestructively, and X-ray detection images were obtained. On the basis of image gray feature analysis,a mathematical morphology method was adopted to simulate background, combining the methods of background subtraction and automated threshold, the small defects were extracted from the detected images. The method of curve fitting and searching the maximum value of subtraction results was put forward to determine the size of structural elements. The experimental results show that the extracted method can achieve the segmentation of small defects well, defects fidelity is high, and the adaptability of algorithm is powerful. In addition, the above algorithm is only carried out in the area of interest, so the speed of image processing will be improved greatly.

Application on De-noise Processing of Wavelet Transform in Free-form Surface Reconstruction

YANG Zheng-Yu, JIA Qiang-Guan, JIU De-Jian

2010, 21(1):  63-66. 

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The application of wavelet transform in surface reconstruction de-noising was presented, and the offset points over the constructed original surface were wavelet-decomposed.Thus the lower frequencies of wavelet were extracted, and de-noise processing of wavelet transform was realized.The surface was reconstructed by NURBS of UG, and the precision and efficiency of the reconstruction was examined. Engineering examples prove that this method of de-noising is valid.

Measurement System for MEMS Microstructures Outofplane Dynamic Deformation with Environmental Control Facility

XIE Yong-Jun, SHI Tie-Lin, LIU Shi-Yuan, TUN Jian-Kang

2010, 21(1):  67-70. 

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A measurement system for MEMS microstructures dynamic deformation with environmental control facility was presented. The system integrated Linnik microscopic interferometry and environmental control technology,thus it was able to measure MEMS microstructures out-of-plane dynamic deformation under variable pressures and/or temperature.The environmental control facility can generate variable pressures in 0.1~0.6MPa and variable temperature in 0~300℃.The experimental work conducted on absolute pressure sensor membranes under variable pressures and micro-printed-circuit-boards under variable temperature confirms that such a measurement system is effective and efficient to characterize MEMS microstructures out-of-plane dynamic deformation.The error of measurement repeatability for the deformation of pressure sensor membranes is less than 20nm.

Program Design for Green Manufacturing Implementation Based on Extension Theory

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

2010, 21(1):  71-75. 

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In order to support enterprises to implement green manufacturing(GM), a GM implementation program design method based on matter-element model and extension theory was proposed, which was oriented to knowledge expression and reuse. The knowledge system of GM program was analyzed, and the GM program knowledge was expressed by matter-element model. Then the GM program design process was presented based on extension theory, in which the most similar GM program was searched in the existing successful cases by the distance method, and the final GM program could be obtained by revising the selected program through extension transformation and logical reasoning. At last, this method was applied to design the GM implementation program in a machine tool works to demonstrate its feasibility and validity. 

Transmission Error Calculation and Noise Experiment on Planetary Gear Trains with Straight Profile Internal Gear

XU Kai, DENG Xiao-Zhong, LIU Geng, YANG Jian-Jun, SU Jian-Xin

2010, 21(1):  76-79. 

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In order to improve the accuracy of internal gears with hard face which is hard to grind after quench carburizing process, a new tooth profile with the straight substitute for the involute one was now presented. The geometric models of planetary gear trains were established, so that the TE of planetary gear trains was calculated by TCA and the Loaded Tooth Contact Analysis(LTCA) as well as the concept of planet gears phase. The contrastive experiments of the noise produced from both the planetary gear trains with the straight tooth profile internal gear and with the involute one were carried out. The TE calculations and experiments demonstrate that the transmission error between the straight profile and the involute one is very close under loading conditions, so the straight tooth profile internal gear is fully applicable in the industrial production.

Research on Strategy of Adaptive Rapid Product Quoting Based on Self-clustering of Case Library

XIAO Gang, ZHANG Li-Ban, GAO Fei

2010, 21(1):  80-84. 

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Case-based product quoting according to request-characteristic parameters is an effective strategy and is meaningful for rapid response of custom demands, and one of the key problems is how the quoting algorithm to adapt the dynamic changes of product cost distribution. First, the problem of product quoting was formalized. Second, the strategy and algorithm of product quoting were investigated. Third, weights of request-characteristic parameters were determined through an optimization model and a self-clustering strategy of case library was also proposed. The proposed methodology demonstrates the effectiveness in an instance of crane quoting.

Application of a SST-DES Turbulence Model for Computation of Cavitating Flows

HUANG Biao, WANG Guo-Yu

2010, 21(1):  85-89. 

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To assess the DES model based on k-ω SST turbulence model, a cloud cavitating flow around a Clark-y hydrofoil and the supercavitation flow around the Hydronautics hydrofoil were numerically simulated. The time evolutions of the shape of cloud cavities have been obtained, and compared with experimental results. It is shown that the DES model can successively predict the characteristics of cavitation and the detail process of the cavitation shedding.

Modeling of Mine Sweeping Plough Using Hierarchical Genetic Neural Networks

ZHANG Yuan, GENG Zong-Xi, GAO Jiang, QIN Yong, GU Li-Min

2010, 21(1):  89-93. 

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 A method for designing a radial basis function neural network was proposed based on the hierarchical genetic algorithm, and the technique was employed to settle the modelling problem of the electrohydraulic system of a certain mine sweeping plough with complex nonlinear characteristics. In the proposed hierarchical genetic algorithm, the control genes with binary code were used to identify the structure of neural networks, i.e. the number of hidden units, and the parameter genes with real code were employed to identify the parameters of neural networks, i.e. the center parameters of hidden units. In order to have a better generalization performance and simpler network structure, the Akaike's information criterion was adopted to evaluate the fitness of individual chromosomes. The experimental results and comparisons with other modeling methods indicate that the proposed approach can be more effectively to construct precise models for the mine sweeping plough.

Requirement Optimization for House of Quality Based on Product Quality Improvement

JING Hong-Yang, ZHANG Li, WEN Bang-Chun

2010, 21(1):  94-99. 

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Quality function deployment (QFD) was investigated herein. According to the general quality of products, customer requirements were collected into 5 groups: quality, time, cost, environment and service, and the customer requirement structure was proposed. Analytical hierarchical process (AHP) was applied to determine the importance of customer requirements. 24 design requirements were identified based on the design quality of products. The relationships among customer requirements and design requirements were analyzed, and the values were determined by the Swing method quantitatively. A case study on linear vibration screen was used to demonstrate and validate the HOQ constructed by the above results.

Research on Lateral Crashworthiness of Rhombus Concept Car Based on C-NCAP

DIAO Min, LIU Di-Hui, ZHONG Zhi-Hua, GAO Hui

2010, 21(1):  99-103. 

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The particular layout of a rhombus concept car had been studied.According to the requirements for the side impact test of C-NCAP(China new car assessment program),the side impact finite element models of the rhombus concept car and a conventional car were built with the same modeling method.The comparisons between the simulation results of the two models indicate that lateral stiffness and crashworthiness of the rhombus car is much better than the latter.

Scheme Design and Optimal Selection for Hybrid Electric Vehicle Planetary Gear Mechanism

SHU Fu-Tang, CHEN,LI,YAN Cheng-Liang, TANG Lin

2010, 21(1):  104-109. 

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More and more planetary gear mechanisms are being used in HEV as multi-power coupling mechanism because of their compact structure, high transmission efficiency and strong load bearing capacity. In order to get all the planetary gear schemes that satisfy the requirements of topological characteristics, and the optimal scheme for hybrid electric vehicle planetary gear coupling mechanism (HEV-PGCM) was selected as the references for the following analysis and structural design. Firstly, a variety of HEV-PGCM schemes with required topological characteristics were produced by using the creative design method. Secondly, according to the design requirements of planetary gear transmission and HEV power coupling mechanism, combined with matrix theory, the scheme evaluation indicators and method for HEV-PGCM were presented and used for scheme analysis and optimal selection. The results indicate that this method is general for common use and it can provide reference schemes for the following structural parametrical design and analysis of HEV-PGCM.

Simulation and Experimental Study for a Micro Hybrid Electric Car with Smart Start-Stop System

LI Zhen-Lei, LIN Yi, GONG Xu

2010, 21(1):  110-114. 

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The structure and main components of powertrain system of the BSG hybrid electric car were compared with the smart start-stop car’s, in addition the operating principles of the start-stop system was introduced. By simulation, the fuel economy of traditional cars and the start-stop system cars under ECE, EUDC and NEDC drive cycle conditions were calculated, and experiments were done to verify the simulation results. The results show that fuel economy and emission of the car with start-stop system are improved significantly.

Research Progresses on Behavior and Mechanism of Edge Chipping for Engineering Ceramics

TANG Xiu-Jian, TIAN Xin-Li, TUN Zhi-Yuan, YANG Dun-Fei, ZHANG Bao-Guo

2010, 21(1):  114-119. 

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Edge chipping is a phenomenon commonly observed during the machining process of ceramic material, and which is one of the key factors deciding the qualities and costs of ceramic components. Traditional ceramic grinding theories are difficult to explain the characteristic phenomenon and regulars of edge chipping for its special geometric location, the research of its behavior and mechanism has become focus work in recent years. Recent research progresses of behavior and mechanism about edge chipping were summarized, and edge spalling model, edge chipping by single indenter and edge chipping by scratch test were introduced, all of the merits and defects of them were evaluated, some issues need to be solved for them and some methods to prevent it taking place were presented.

Research Progresses of Precision Measurement Technique for Micro-cavity

CUI Ji-Wen, TAN Jiu-Ban, SONG Chuan-Xi

2010, 21(1):  120-125. 

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Several precision measurement techniques for micro-cavity dimension were presented to solve the problem in the field of cavity precision measurement, including non-contact, compensated, and aiming and triggering measurement techniques. For each technique, the measurement principles were analyzed, the measurement ranges were obtained through the design, and the measurement performance was discussed. Three aiming and triggering measurement techniques using optical fiber were mainly analyzed, and their performance was compared. And lastly the development direction of precision measurement for micro-cavity was generalized.