Experimental results for a robust position and force controller implemented on a direct drive robot

Abstract

SummaryIn this paper we present the results obtained from the implementation of a robust position/force controller on a two-degree-of-freedom direct drive robot. The controller is based on the theoretical work presented in references 1 & 2, which guarantees Globally Uniformly Ultimately Bounded (GUUB) position tracking error and bounded force tracking error. The controller accomplishes this stability result in spite of robot model uncertainty and only requires; joint position and velocity measurements, end-effector force measurements, and bounds on the model parameters. Experimental results described in this paper serve to verify the theoretical claims.

Experimental evaluation of a variable structure controller for constrained robots

“…By introducing a nonlinear transformation from the joint space to a new set of coordinates, the dynamic model of the system was reduced to a diOE erential equation that describes an unconstrained robot motion along the constraint manifold, and an algebraic equation that describes the relation between the constraint force and the unconstrained robot motion. Bridges et al (1995) designed and implemented a robust position± force controller for constrained robots using the reduced-order model method. An adaptive controller was developed for the reduced order robot system by Yu et al (1993).…”