An approach to regulation of contact force and position in flexible-link constrained robots

Abstract

We consider a flexible-link robotic manipulator with its end-effector in contact with a rigid work surface. The robot performs contact tasks on the work surface which requires control of the contact force exerted by the robot on the work surface as well as position control of the robot end-effector on the work surface. We design a control law for local regulation of contact force and position vectors to desired constant vectors. The design is based on the assumption that the links of the robot arm are very stiff, which allows the use of singular perturbation methods for control design. The control design procedure is based on a general model of a flexible-link robot manipulator which includes effects of actuator dynamics and joint flexibility. The control design method is illustrated using an example and it is shown that local regulation of contact force and position is achieved.