In this paper, a new tracking controller that integrates a kinematic controller (KC) with a new integral sliding mode dynamic controller (NISMC) is designed for an omnidirectional mobile robot (OMR) to track a desired trajectory at a desired velocity. First, a posture tracking error vector is defined, and kinematic controller (KC) is chosen to make the posture tracking error vector go to zero asymptotically. Second, an integral sliding surface vector is defined based on the angular velocity tracking error vector and its integral term. A new integral sliding mode dynamic controller (NISMC) is designed to make the integral sliding surface vector and the angular velocity tracking error vector go to zero asymptotically. The above controllers are obtained based on Lyapunov stability theory. The simulation results are presented to illustrate effectiveness of the proposed tracking controller.

Abstract. This paper proposes a new nonlinear controller that makes the combination of a kinematic controller (KC) and an integral sliding mode controller (ISMC) for a welding mobile robot (WMR) to track a desired welding path with a constant velocity. First, the kinematic controller is designed to make the position error vector go to zero asymptotically. Second, the integral sliding mode controller is designed to make velocity error vector also go to zero asymptotically. The stability of system is proved based on the Lyapunov stability theory. The simulation results are shown to illustrate effectiveness of the proposed nonlinear controller.