ROBUST CONTROL FOR ROBOT WITH FRICTION

ZHOU Jinglei  ZHANG Weihai

(College of Information & Electrical Engineering, Shandong University of Science and Technology, Qingdao 266510)

Abstract: According to the characteristic of friction in machine system, the friction force result in scalar case is extended to the vector space case, which makes the control problem of the external stochastic disturbance in robotic systems embodied. First, the robotic dynamical model based on Lagrange equation is transformed into a linear state equation via feedback control technique. Then, based on the linear state equation together with the Lyapunov stability theory, the robust compensated controller corresponding to the general trait of friction is designed to attenuate the effect coming from the unexpected friction force of robotic control systems. The aim is that the actual movement trace can converge to the desired position asymptotically in global sense. The designed controller exhibits some merits such as clear theory, easy design, and good robusteness and so on. Moreover, a completed theory proof is given. Finally, the simulation test results are given by taking a two-joint robot as an example. From the comparison between the two different simulation results which are obtained by using different controller, it can be seen that the presented robust controller performs well in application.

Key words: Robot Friction Robust control Global asymptotic stability

CLC No: TP242

国家自然科学基金(60474013)和山东省优秀中青年科学家科研奖励基金(2004BS01010)资助项目. Received 20060706, received in revised form 20070412