Fixed-time Tracking Control Approach Design for Nonholonomic Mobile Robot

In this paper, fixed-time control problem is addressed for nonholonomic mobile robot. By using cascaded control design method, the error dynamics of a mobile robot are divided into a first-order subsystem and a second-order subsystem. Firstly, in order to stabilize the angle error system of mobile robots, a fixed-time control law is designed. Secondly, a new fixed-time control algorithm is designed for forward velocity error system by proposing a new integral terminal sliding mode surface. Compared with many existing finite-time control results, in which the convergence time grows unboundedly when the system initial conditions grow, the fixed-time control method proposed in this paper provides faster convergence rate by using high-degree terms. Moreover, the settling time is independent of the system initial conditions and only determined by the controller parameters. Finally, the proposed control algorithm is applied to the mobile robots, and the simulation results demonstrate the effectiveness of the proposed control scheme.