Trajectory Tracking Control for Wheeled Mobile Robots Based on a Cascaded System Control Method

Abstract

In this paper, the trajectory tracking control problem is studied for wheeled mobile robots (WMRs) in the cases without and with kinematic disturbances. In the case without kinematic disturbances, a tracking controller based on cascaded system theory is designed, which guarantees asymptotic tracking for the WMR to the reference trajectory. In the case with kinematic disturbances, two kinds of controllers are designed. At first, a PID tracking controller is proposed. Secondly, after designing some generalized proportional-integral observers (GPIOs) to estimate the kinematic disturbances, a GPIO-based composite tracking controller is derived by combining the disturbance estimates with the tracking controller designed for the case without disturbances. Some comparison simulations are given, by which it is demonstrated with the GPIOs' accurate disturbance estimations and compensations, the GPIO-based composite controller has the best performance among the three kinds of controllers on the trajectory tracking for WMRs with kinematic disturbances.