MODEL-BASED ADAPTIVE HYBRID CONTROL FOR MANIPULATORS WITH GEOMETRIC END-POINT CONSTRAINT

A model-based adaptive controller for robot manipulators under geometr ic endpoint constraint is proposed on the basis of joint-space orthogo nalization of feedback signals. The adaptive law is devised by referri ng to the basic properties of robot dynamics, which are (1) passivity of robot dynamics, (2) use of feedback of residual error velocity and position signals that are projected to the tangent plane in joint spac e and orthogonal to the joint force vector caused by the contact (this is called 'joint-space orthogonalization'), and (3) use of the fact t hat important but uncertain physical parameters enter linearly in the equation of motion of robots. The convergence of tracking errors on th e surface is proved under an appropriate initial condition and the smo othness of the surface. In addition, the convergence of force error is proved provided that the endpoint is kept to in contact with the surf ace.