Robust control of a constrained robot arm

In this paper, the problem of designing a robust control for trajectory tracking of the end effector on a constrained surface with specified constraint force is considered. The loss of degree of freedom of the constrained robot, leads to a reduced dynamical model suitable for motion and force control. The authors consider here a perturbed system due to the presence of system modeling uncertainties and disturbances which satisfy some matching conditions. Under these conditions, using input-output linearization, both motion and force control loops will be linearized and decoupled. Because of its robustness, a sliding mode controller (SMC) will be introduced to deal with these uncertainties