ADAPTIVE COMPLIANT MOTION CONTROL OF MANIPULATORS WITHOUT VELOCITY-MEASUREMENTS

This article presents two adaptive schemes for compliant motion contro l of uncertain manipulators. The first strategy is developed using an adaptive impedance control approach and is appropriate for tasks in wh ich the dynamic character of the end-effector/environment interaction must be controlled, while the second scheme is an adaptive position/fo rce controller and is useful for those applications which require inde pendent control of end-effector position and contact force. The propos ed controllers are very general and computationally efficient, require virtually no information regarding the manipulator dynamic model or t he environment, and are implementable without velocity measurements. I t is shown that the schemes ensure semiglobal boundedness of all signa ls in the presence of bounded disturbances, and that the ultimate size of the system errors can be made arbitrarily small. The capabilities of the proposed control strategies are illustrated through both comput er simulations and laboratory experiments with a 6 degree-of-freedom ( DOF) IMI Zebra Zero manipulator. (C) 1997 John Wiley & Sons, Inc.