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Friction compensation design based on state observer and adaptive law for high-accuracy positioning system

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Progress in Natural Science:Materials International 2006年第2期16卷 147-152页

作者： WANG Ying, XIONG Zhenhua and DING Han (school of mechanical{2., shanghai jiao tong university, shanghai 2.0030, China) [a]school of mechanical{2. Shanghai Jiao Tong University Shangai China

Friction is one of the main factors that affect the positioning accuracy of motion system. Friction compensation based on friction model is usually adopted to eliminate the nonlinear effect of friction. This paper presents a proportional-plus-derivative (PD) feedback controller with a friction compensator based on LuGre friction model. We also design a state observer to observe the unknown state of LuGre friction model, and adopt a parameter adaptive law and off-line approximation to estimate the parameters of LuGre friction model. Comparative experiments are carried out among our proposed controller, PD controller with friction compensation based on classical friction model, and PD controller without friction compensation. Experimental results demonstrate that our proposed controller can achieve better performance, especially higher positioning accuracy.

关键词： friction compensation state observer adaptive law linear motor motion control.

New Receiving Mode of Extinction for Determining Particle Size and Density without Convex Lens

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Chinese Journal of Lasers 2002年第1期11卷 46-51页

作者： WU Weiliang CHEN Hanping (school of Power and Energy engineering,{2., shanghai 2.0030, China) CAI Xiaoshu WANG Naining (school of Power and Energy engineering, university of shanghai for Science and Technology, shanghai 2 school of Power and Energy engineering Shanghai Jiao Tong University 上海 200030 school of Power and Energy engineering University of Shanghai for Science and Technology 上海 200093

In this article a new receiving mode for scattering light by particle is theoretically discussed. Using this receiving mode the convex lens can be omitted during determining the extinction of particle. Therefore the extinction coefficient of sphere particles is redefined by extrapolating the conventional one. In terms of the calculation results of light scattering the definition of near-field extinction coefficient of a swarm particle is depicted. Through the error analysis it is proved that the error coming from the new definition of extinction coefficient is acceptable for engineering application. In addition, a technique for determining the particle size and density is presented in this article and the advantage using this receiving mode is described.

关键词： extinction of particle light scattering fluctuation method particle size particle density

Kinetic theory of self-condensing vinyl polymerization

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Science China Chemistry 2010年第12期53卷 2429-2439页

作者： ZHOU ZhiPing 1 & YAN DeYue 2.1 school of Materials Science and engineering,Jiangsu{2.,Zhenjiang 2.2.13,China 2.school of Chemistry and Chemical engineering,shanghai jiao tong{2.,shanghai 2.02.0,China 1. school of Materials Science and engineering Jiangsu University Zhenjiang 212013 China2. School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China

This review introduces the kinetic theory of self-condensing vinyl polymerization (SCVP),including the SCVP of AB inimers,the SCVP with non-equal reactivity between A and B groups,the SCVP in the presence of a small amount of multifunctional initiators,also the SCVP of both inimers and *** analytical expressions of various molecular parameters for the resulting hyperbranched polymers,such as the molecular size distribution function,the average molecular weight,the polydispersity index and the degree of branching,are reviewed systematically.

关键词： kinetic theory self-condensing vinyl polymerization (SCVP) hyperbranched polymers

Effect of Cold Rolling on Microstructure and mechanical Properties of AISI 301LN Metastable Austenitic Stainless Steels

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Journal of Iron and Steel Research International 2012年第10期19卷 59-63页

作者： HUANG Jun-xia1, YE Xiao-ning1, XU Zhou2.(1. shanghai Baosteel Research Institute, shanghai 2.0431, China 2.{2. of Material Science and engineering, shanghai jiao tong university, shanghai 2.02.0, China) [a] shanghai Baosteel Research Institute Shanghai 200431 China [b] school of Material Science and engineering Shanghai Jiao Tong University Shanghai 200240 China

The microstructure and mechanical properties evolution of AISI 301LN metastable austenitic stainless steels during cold rolling were investigated. A wide range of cold thickness reduction (10%-80%) was carried out in a four-high rolling mill at ambient temperature. The X-ray and Feritscope MP30 were used to identify the strain-induced α′-martensite phase and its volume fraction, respectively. The microstructure was observed by optical micrograph and the mechanical properties were determined by tensile tests and microhardness. The results show that the strain-induced α′-martensite nucleated at the shear bands intersections and the growth of α′-martensite occurred by the repeated nucleation of new embryos. The volume fraction of strain-induced α′-martensite increased with increasing the cold rolling reduction. In addition, the percentage increased in the tensile strength is the same as that of hardness. The ratio between the average tensile strength and the average microhardness was found to range between 2.82.and 3.17.

关键词： metastable austenitic stainless steel cold rolling reduction strength

Phase transition in the Zr_(60)Al_(15)Ni_(2.) bulk metallic glass subjected to rolling at room temperature

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Science China(Technological Sciences) 2006年第6期49卷 655-662页

作者： YAN Zhijie1, 2. LI Jinfu1, ZHOU Yaohe1 & WU Yanqing3 1. State Key Laboratory of Metal Matrix Composites, school of Materials Science and engineering,{2., shanghai 2.0030, China 2. school of Materials Science and engineering, Taiyuan university of Science and Technology, Taiyuan 03002., China 3. school of Environmental Science and engineering,{2., shanghai 2.0030, China State Key Laboratory of Metal Matrix Composites School of Materials Science engineering Shanghai Jiao Tong University Shanghai 200030 China school of Materials Science engineering Taiyuan University of Science Technology Taiyuan 030024 China school of Environmental Science engineering Shanghai Jiao Tong University Shanghai 200030 China

The microstructure evolution of the Zr60Al15Ni2. metallic glass during rolling at room temperature is investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC); high-resolution transmission electron microscopy (HREM). The results show that the values of full width at half maximum (FWHM) of the XRD patterns; exothermic enthalpy ΔH of DSC plots do not monotonically change with the variation of deformation degrees . As is not large than 2.%, the values of FWHM; ΔH are lower than that of the as-cast state. When reaches 30%, the values of FWHM; ΔH become larger than that of the as-cast state, while their values begin to decrease again as reaches about 85%. These results indicate that the reversible transitions between ordered; disordered atomic configurations occur during rolling, which is further verified by the HREM images. The reversible phase transition can be explained by the competition between the diffusion controlled reordering; shear-induced disordering during rolling.

关键词： metallic glasses, plastic deformation, phase transformations, shear bands.

The Effect of Body Pitching on Leg-Spring Behavior in Quadruped Running

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Journal of Bionic engineering 2010年第3期7卷 219-227页

作者： Qi Deng, Shigang Wang, Qinghua Liang, Jinqiu Mo school of mechanical{2., shanghai jiao tong university, shanghai 2.02.0 P. R. China [a] school of mechanical{2. Shanghai Jiao Tong University Shanghai 200240 P. R. China

In this paper we investigated how the running speed would affect the dynamics of body pitching, and whether body inertiais important for animals. Passive trotting of spring-mass model and passive bounding of spring-beam model were studied atdifferent speeds for different sets of body parameters respectively. Furthermore, different body inertias were used in *** found that running speed exerts effect on leg performance by means of centrifugal force. The centrifugal force can be understoodas an enhancement to the natural frequency of the spring-mass system. The disadvantage of body pitching may beoffset by the great increase in centrifugal force at high speed. The results also reveal that body mass distribution might not be themain reason for the difference in maximal running speeds of different animals.

关键词： body pitching leg performance running speed centrifugal force body inertia

Global optimization of tool path for five-axis flank milling with a cylindrical cutter

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Science China(Technological Sciences) 2009年第8期52卷 2449-2459页

作者： DING Han1 & ZHU LiMin2.1 State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong university of Science and Technology, Wuhan 430074, China 2.school of mechanical engineering,{2., shanghai 2.02.0, China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074 China school of mechanical{2. Shanghai Jiao Tong University Shanghai 200240 China

In this paper, optimum positioning of cylindrical cutter for five-axis flank milling of non-developable ruled surface is addressed from the perspective of surface approximation. Based on the developed interchangeability principle, global optimization of the five-axis tool path is modeled as approximation of the tool envelope surface to the data points on the design surface following the minimum zone criterion recommended by ANSI and ISO standards for tolerance evaluation. By using the signed point-to-surface distance function, tool path plannings for semi-finish and finish millings are formulated as two constrained optimization problems in a unified framework. Based on the second order Taylor approximation of the distance function, a sequential approximation algorithm along with a hierarchical algorithmic structure is developed for the optimization. Numerical examples are presented to confirm the validity of the proposed approach.

关键词： five-axis flank milling tool path optimization tool axis trajectory surface surface approximation distance function minimax optimization

Nonlinear analysis of slow drift extreme responses of a compliant offshore structure

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Acta Mechanica Sinica 2009年第5期25卷 651-657页

作者： Yingguang Wang Jiahua Tan school of Naval Architecture, Ocean and Civil engineering,{2. jiao tong university, 2.02.0 {2., China school of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University 200240 Shanghai China

This paper first demonstrates that the accuracy and efficiency of the method of numerical simulation often used is not very high in predicting the slow drift surge extreme responses of a compliant offshore structure. Next, the slow drift surge extreme responses of the structure are analyzed via the path integral solution racy and efficiency of the PIS （PIS） method, and the accumethod is found to be higher than those of the numerical simulation method. A compound PIS （CPIS） method is first proposed in this article to further improve the efficiency of the path integral solution method, and the accuracy and efficiency of the CPIS method is validated.

关键词： Compliant offshore simulation Path integral solution solution structure Numerical Compound path integral

Data fusion for target tracking in wireless sensor networks using quantized innovations and Kalman filtering

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Science China(Information Sciences) 2012年第3期55卷 530-544页

作者： XU Jian1,2., LI JianXun1,2.& XU Sheng3 1Department of Automation, Science and Technology on Avionics Integration Laboratory, shanghai jiao tong university, shanghai 2.02.0, China 2.epartment of Automation, System Control and Information Processing, Ministry of Education of China, shanghai jiao tong university, shanghai 2.02.0, China 3school of mechanical engineering, shanghai jiao tong university, shanghai 2.02.0, China 1. Department of Automation Science and Technology on Avionics Integration Laboratory Shanghai Jiao Tong University Shanghai 200240 China2. Department of Automation System Control and Information Processing Ministry of Education of China Shanghai Jiao Tong University Shanghai 200240 China3. School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China

A novel networked data-fusion method is developed for the target tracking in wireless sensor networks (WSNs). Specifically, this paper investigates data fusion scheme under the communication constraint between the fusion center and each sensor. Such a message constraint is motivated by the bandwidth limitation of the communication links, fusion center, and by the limited power budget of local sensors. In the proposed scheme, each sensor collects one noise-corrupted sample, performs a quantizing operation, and transmits quantized message to the fusion center. Then the fusion center combines the received quantized messages to produce a final estimate. The novel data-fusion method is based on the quantized measurement innovations and decentralized Kalman filtering (DKF) with feedback. For the proposed algorithm, the performance analysis of the estimation precision is provided. Finally, Monte Carlo simulations show the effectiveness of the proposed scheme.

关键词： data fusion target tracking limited bandwidth quantized innovation Kalman filtering