Trajectory Control of a Car-Like Wheeled Robot

Abstract

This paper proposes a trajectory control method for a carlike four-wheeled mobile robot. First, a kinematic control scheme is designed based on the nonholonomic kinematic constraints of a mobile robot, in which reference driving speed and steering angle are computed for a given desired trajectory of the robot. This kinematic control scheme, generating the reference speed and steering angle, can be applied to unmanned vehicle control with a robot driver. Second, a new backstepping trajectory control scheme is designed based on the robot dynamics subject to the nonholonomic kinematic constraints, in which the desired driving force and steering torque are computed for a given desired trajectory. In this study, the Lyapunov stability theorem is used as a mathematical design tool. The proposed control guarantees asymptotic stability of the trajectory control while keeping all internal signals bounded. Finally, the validity of the theoretical results is shown by realistic computer simulations with one sampling delay in the control loop.