PLANNING OF MECHANICAL SYSTEM

Ge Xinsheng

(Department of Basic Science Courses, Beijing Institute of Machinery, Beijing 100085)

Chen Liqun

(Department of Mechanics, Shanghai University, Shanghai 200072)

LÜ Jie

(Department of Machinery Engineering, Beijing Institute of Machinery, Beijing 100085)

Abstract: Nonholonomicity arises in many mechanical systems subject to nonintegrable velocity constraints or nonintegrable conservation laws. Due to nonholonomic constraints, the motion planning and control of a nonholonomic mechanical system is much more difficult than that of a conventional system. When the total angular momentum is zero, the dynamics of a mechanical system is described in the form of differential equations of first order. According to such equations, the control problem of system can be converted to the motion planning problem for a driftless control system. The equation of dynamics of space robot with free floating is obtained by using the momentum theorem. The control technique and wavelet analysis method are made use of and an numerical algorithm for nonholonomic motion planning is proposed. The wavelet approximation is used to optimal control and to generate a feasible trajectory for a nonholonomic system. The effectiveness of the numerical algorithm is demonstrated by numerical simulation.

Key words: Mechanical system  Nonholonomic constraint  Motion planning  Optimal control  Wavelet

CLC No: TP242

国家自然科学基金资助项目(No.10372014，10272008). Received 20030806, received in revised form 20040330