ADAPTIVE TASK-SPACE CONTROL OF FLEXIBLE-JOINT MANIPULATORS

This paper considers the motion control and compliance control problem s for uncertain rigid-link, flexible-joint manipulators, and presents new adaptive task-space controllers as solutions to these problems. Th e motion control strategy is simple and computationally efficient, req uires little information concerning either the manipulator or actuator /transmission models, and ensures uniform boundedness of all signals a nd arbitrarily accurate task-space trajectory tracking. The proposed c ompliant motion controllers include an adaptive impedance control sche me, which is appropriate for tasks in which the dynamic character of t he end-effector/environment interaction must be controlled, and an ada ptive position/force controller, which is useful for those application s that require independent control of end-effector position and contac t force. The compliance control strategies retain the simplicity and m odel independence of the trajectory tracking scheme upon which they ar e based, and are shown to ensure uniform boundedness of all signals an d arbitrarily accurate realization of the given compliance control obj ectives. The capabilities of the proposed control strategies are illus trated through computer simulations with a robot manipulator possessin g very flexible joints.