Robust tracking control for constrained robots actuated by DC motors without velocity measurements

A dynamic feedback control design is proposed to treat the trajectory tracking control for constrained robots actuated by brushed DC motors. Only measurements of both angular motor position and motor armature current are required to construct the hybrid position/force control law. It is shown that for any preassigned attraction region all the variables of the closed-loop system are bounded and different robustness performance is achieved with respect to different uncertain signals. The attraction region can not only be arbitrarily enlarged but also explicitly constructed. Moreover, the proposed control algorithm can be employed directly to treat the tracking control of electrically driven unconstrained robots, and, consequently, both simple linear time-varying as well as linear time-invariant controllers are constructed. Finally, simulation examples are given to demonstrate the effectiveness of our proposed control algorithms.