THE CONTROL OF A MECHANICAL SYSTEM WITH UNKNOWN-PARAMETERS BY A BOUNDED FORCE

A mechanical system whose dynamics can be described by Lagrange's equa tions of the second kind is considered. It is assumed that the kinetic energy matrix of the system is unknown and the system is subject to u ncontrollable bounded external forces (such a situation occurs, for ex ample, if the load carried by a manipulator remains unknown). A contro l law is constructed which enables the system to be transferred from a n arbitrary initial state to a given final state in a finite time usin g a force of bounded modulus. In the algorithm proposed linear feedbac k is used with piecewise-constant coefficients: the coefficients incre ase as the system approaches the final state. The algorithm rests on t he second Lyapunov method. The results of a numerical model of the dyn amics of a double-link unit are presented. (C) 1997 Elsevier Science L td. All rights reserved.