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STRUCTURAL PARAMETERS CALIBRATION BY POSTURE MEASUREMENT ON PARALLEL 6-DOF PLATFORM

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Chinese Journal of Mechanical Engineering 2002年第4期15卷 334-338,343页

作者： Wu Jiangning Li Shilunstate key laboratory of fluid power transmission and control, zhejiang university,hangzhou 31002., china state key laboratory of fluid power transmission and control Zhejiang University Hangzhou 310027 China

Some approaches to measure parallel 6-degree of freedom platform's posturestatically and to calibrate the platform's actual structural parameters by measuring a series of theplatform's varying postures are studied. In the case where high posture accuracy is requiredrelatively, to obtain the platform's actual structural parameters is very important. Threedimensions measurement with 2 theodolites are used to obtain the platform's postures statically andNewton iterative method is adopted to calibrate structural parameters. Some measures taken in themeasurement and the calibration are discussed in detail. And the experiment results of theplatform's posture control before and after the calibration are given. The results show that theplatform's posture control accuracy after the calibration is improved notably.

关键词： parallel 6-DOF platform theodolite posture measurement nonlinearequation group structural parameters calibration

Exact stationary solutions independent of energy for strongly nonlinear stochastic systems of multiple degrees of freedom

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Science china(Technological Sciences) 2009年第8期52卷 2424-2431页

作者： HUANG ZhiLong1,2 & JIN XiaoLing1 1 Department of Mechanics, zhejiang university, hangzhou 31002., china 2 The state key laboratory of fluid power transmission and control, zhejiang university, hangzhou 31002., china Department of Mechanics Zhejiang University Hangzhou 310027 China The state key laboratory of fluid power transmission and control Zhejiang University Hangzhou 310027 China

A new procedure is proposed to construct strongly nonlinear systems of multiple degrees of freedom subjected to parametric and/or external Gaussian white noises, whose exact stationary solutions are independent of energy. Firstly, the equivalent Fokker-Planck-Kolmogorov (FPK) equations are derived by using exterior differentiation. The main difference between the equivalent FPK equation and the original FPK equation lies in the additional arbitrary antisymmetric diffusion matrix. Then the exact stationary solutions and the structures of the original systems can be obtained by using the coefficients of antisymmetric diffusion matrix. The obtained exact stationary solutions, which are generally independent of energy, are for the most general class of strongly nonlinear stochastic systems multiple degrees of freedom (MDOF) so far, and some classes of the known ones dependent on energy belong to the special cases of them.

关键词： exact stationary solution nonlinear stochastic system equivalent system independent of energy

Stochastic stability of quasi-integrable Hamiltonian systems with time delay by using Lyapunov function method

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Science china(Technological Sciences) 2010年第3期53卷 703-712页

作者： LING Quan 1,JIN XiaoLing 1 &HUANG ZhiLong 2 1 Department of Mechanics,zhejiang university,hangzhou 31002.,china 2.state key laboratory of fluid power transmission and control,zhejiang university,hangzhou 31002.,china 1. Department of Mechanics Zhejiang University Hangzhou 310027 China2. State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

The asymptotic Lyapunov stability of one quasi-integrable Hamiltonian system with time-delayed feedback control is studied by using Lyapunov functions and stochastic averaging ***,a quasi-integrable Hamiltonian system with time-delayed feedback control subjected to Gaussian white noise excitation is approximated by a quasi-integrable Hamiltonian system without time ***,stochastic averaging method for quasi-integrable Hamiltonian system is used to reduce the dimension of the original system,and after that the Lyapunov function of the averaged It equation is taken as the optimal linear combination of the corresponding independent first integrals in ***,the stability of the system is determined by using the largest eigenvalue of the linearized *** examples are used to illustrate the proposed procedure and the effects of delayed time on the Lyapunov stability are discussed as well.

关键词： Lyapunov stability Lyapunov function time delay stochastic averaging

SIMULATION OF fluid FLOW IN CHANNEL OF A NOVEL HYDRAULIC SHOCK GENERATOR

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Chinese Journal of Mechanical Engineering 2000年第4期13卷 258-262页

作者： Fu XinYang Huayong (state key laboratory of fluid power transmission and control, zhejiang university) 浙江大学流体传动及控制国家重点实验室浙江杭州

In order to improve the engineering performance of a novel hydraulic shock generator, the fluid flow inside its complex passages is numerically investigated. The effects of the inlet flow velocity upon the turbulence intensity of the jet flow are analyzed. The calculated pressure loss is experimentally verified with the consideration of temperature determined viscosity shifting. The results are used as the reference in the further development of the hydraulic shock generator

关键词： Shock generator Numerical simulation Jet flow Turbulence

Transport and deposition of nanoparticles in bend tube with circular cross-section

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Progress in Natural Science:Materials International 2009年第1期19卷 33-39页

作者： Peifeng Lin a,Jianzhong Lin a,b,a state key laboratory of fluid power transmission and control,zhejiang university,hangzhou 31002.,china b china Jiliang university,hangzhou 310018,china [a]state key laboratory of fluid power transmission and control Zhejiang University Hangzhou 310027 China [b]China Jiliang University Hangzhou 310018 China

Transport and deposition of nanoparticles in bend tube with circular cross-section were simulated numerically for different Reynolds numbers and Dean numbers.A finite-volume code and the SIMPLE scheme were used to solve the *** results show that the distribution of nanoparticle concentration is symmetrical with respect to the top and bottom sides of the *** diameter of the nanoparticles has a weak effect on the distribution of nanoparticle *** maximum and minimum of the deposition enhancement factor occur near the outside and inside walls of the bend tube,*** higher the Reynolds number is,the shorter is the time for nanoparticle *** bend curvature radius has a slight effect on the deposition enhancement factor.

关键词： Nanoparticles Transport Deposition Numerical simulation

STABILITY IN THE CIRCULAR PIPE FLOW OF FIBER SUSPENSIONS

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Journal of Hydrodynamics 2003年第2期15卷 12-18页

作者： You Zhen jiang, Lin Jian zhong Department of Mechanics, state key laboratory of fluid power transmission and control, zhejiang university, hangzhou 31002., china DepartmentofMechanics StateKeyLaboratoryofFluidPowerTransmissionandControlZhejiangUniversityHangzhou310027China

A linear stability analysis on the circular pipe flow of fiber suspensions ispresented. The fiber orientation tensors are used to describe the characteristics of theorientation dislribution of fibers. The constitutive equation for the fiber suspensions is set upand the modified Orr-Sommerfeld stability equation is derived. An improved finite difference methodwith high order accuracy is employed to solve the e-quation. The Newtonian pipe Poiseuille flowcorresponding to H = 0 is also analyzed for comparison. The results reveal that the fiber additiveswill enhance the flow stability, the degree of enhancement becomes high with the increases of theparameter H which accounts for the fiber resistance to the stretching along its axis. Fibersuspensions with large H can suppress the influence of high Reynolds number on the flow ***, fibers give a higher attenuation of the short waves of disturbance.

关键词： flow stability circular pipe flow fiber suspensions numerical simulation

RESEARCH ON EXPERT SYSTEM OF FAULT DETECTION AND DIAGNOSING FOR PNEUMATIC SYSTEM OF AUTOMATIC PRODUCTION LINE

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Chinese Journal of Mechanical Engineering 2002年第2期15卷 136-141页

作者： Wang Xuanyin Gao Lei Tao Guoliangstate key laboratory of fluid power transmission and control, zhejiang university,hangzhou 31002., china *** state key laboratory of fluid power transmission and control Zhejiang University Hangzhou 310027 China

Fault detection and diagnosis for pneumatic system of automatic productionline are studied. An expert system using fuzzy-neural network and pneumatic circuit fault diagnosisinstrument are deigned. The mathematical model of various pneumatic faults and experimental deviceare built. In the end, some experiments are done, which shows that the expert system usingfuzzy-neural network can diagnose fast and truly fault of pneumatic circuit.

关键词： Pneumatic assembly line Fuzzy-neural network fault diagnosis Faultdetection expert system

Stochastic optimal control of partially observable nonlinear quasi-integrable Hamiltonian systems

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Science china(Physics,Mechanics & Astronomy) 2010年第1期53卷 147-154页

作者： FENG Ju, ZHU WeiQiu & YING ZuGuang Department of Mechanics, state key laboratory of fluid power transmission and control, zhejiang university, hangzhou 31002., china 1. Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

The stochastic optimal control of partially observable nonlinear quasi-integrable Hamiltonian systems is investigated. First, the stochastic optimal control problem of a partially observable nonlinear quasi-integrable Hamiltonian system is converted into that of a completely observable linear system based on a theorem due to Charalambous and Elliot. Then, the converted stochastic optimal control problem is solved by applying the stochastic averaging method and the stochastic dynamical programming principle. The response of the controlled quasi Hamiltonian system is predicted by solving the averaged Fokker-Planck-Kolmogorov equation and the Riccati equation for the estimated error of system states. As an example to illustrate the procedure and effectiveness of the proposed method, the stochastic optimal control problem of a partially observable two-degree-of-freedom quasi-integrable Hamiltonian system is worked out in detail.

关键词： quasi-integrable Hamiltonian system partial observation stochastic optimal control

STUDY ON MECHANISM OF HYDRODYNAMIC OSCILLATION IN VORTEX PRECESSION METER USING LARGE EDDY SIMULATION

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Chinese Journal of Mechanical Engineering 2001年第1期14卷 9-11页

作者： Fu Xin Yang Huayong state key laboratory of fluid power transmission and control,zhejiang university 浙江大学流体传动及控制国家重点实验室浙江杭州

In order to improve the anti jamming performance of a vortex precession meter, the disciplinarian of the vortex precession and the mechanism of hydrodynamic oscillation inside the vortex precession meter are numerically investigated by using the large eddy simulation The results show that the periodical eccentric motion of the vortexes initiates a hydrodynamic oscillation inside the vortex precession meter The visualized time dependent flow fields indicate that the pressures at axisymmetric points oscillate with a same intensity and frequency but 180° phase shift By using differential sensing technique,a new prototype of double sensor vortex precession meter,aimed to improve measurement accuracy, is developed

关键词： Flow measurement Vortex precession Hydrodynamic oscillation Flow visualization