TRACKING CONTROL FOR END-EFFECTOR POSITION AND ORIENTATION OF STRUCTURALLY FLEXIBLE MANIPULATORS

A simple and effective feedback control strategy is presented for end-effector position and orientation tracking of structurally flexible manipulators free of external forces as in space applications. The fully feedback-driven approach employs an augmented dynamical description in which derivatives of the control inputs are included in the state. This ensures smooth control inputs to the manipulator joints. The feedback law uses gain scheduling of a series of steady-state regulators derived by considering the manipulator at intermediate (nominally rigid and stationary) configurations along the desired trajectory. The performance of the control method is demonstrated in simulations of a planar three-link manipulator system. Examples show that the controller can be applied successfully in discrete-time, and that spillover does not appear to be a problem. (C) 1993 John Wiley & Sons, Inc.