A novel adaptive controller for two-degree of freedom polar robot with unknown perturbations

In industrial applications, the performance of robot manipulators is always affected due to the presence of uncertainties and disturbances. This paper proposes a novel adaptive control scheme for robust control of robotic manipulators perturbed by unknown uncertainties and disturbances. First, an active sliding mode controller is designed and a sufficient condition is obtained guarantying reachability of the states to hit the sliding surface in finite time. Then, based on a Lyapunov function candidate an adaptive switching gain is derived which make the controller capable to bring the tracking error to zero without any disturbance exerted upon the stability. By virtue of this controller it can be shown that the controller can track the desired trajectories even in the presence of unknown perturbations. For the problem of determining the control parameters Particle Swarm Optimization (PSO) algorithm has been employed. Our theoretic achievements are verified by numerical simulations.

► A simple active sliding mode controller is proposed.
► A novel adaptation law is derived for the switching gains of the controller.
► By the virtue of the adaptation law, there is no need for the knowledge of upper bounds of uncertainties and disturbances.
► Stability proofs are presented based on Lyapunov theory.
► Particle Swarm Optimization is employed for the problem of determining appropriate values of the controller.