Practical stabilization for nonholonomic chained systems with fast convergence, pole-placement and robustness

In this paper, issues of practical stabilization problem for nonholonomic chained systems are discussed. A novel controller that can guarantee a fast convergence, like the exponential convergence, is proposed based on the switching controllers approach. The steady-state error can be specified in advance. Moreover, the convergent rate can be pre-assigned and the transient response can be improved using the pole-placement method. The proposed controller is shown to be robust with respect to some uncertainties in the model. Simulation results for a unicycle-modeled mobile robot that has a small bias in orientation, an unknown radius in the rear wheels and an unknown distance in between them are presented to validate the effectiveness of our approach.