Robust position tracking control for rigid-link flexible-joint robots subjected to constraints

The purpose of this paper is to present a robust position/velocity tracking controller for rigid-link flexible joint (RLFJ) robots operating either on or off a constraining surface. The controller explcits aspects of the dynamic and kinematic models to provide a global uniform ultimately bounded (GUUB) stability result despite the presence of parametric uncertainty, joint flexibility, and mechanical actuator dynamics. The controller delivers the GUUB result for both position and velocity error. Is addition, the controller maintains bounded contact forces while the manipulator is on the constraint surfaces. Finally, it should be noted that the controller described in this development only requires position and velocity measurements from the motors and links.