Robust exponential regulation of nonholonomic systems with uncertainties

This paper deals with nonholonomic control systems in chained form with strongly nonlinear disturbances and drift terms. The objective is to design a robust nonlinear state and output feedback law which simultaneously solves the global exponential regulation problem for all plants in the class. A switching control strategy is employed to get around the smooth stabilization burden associated with nonholonomic systems. The systematic strategy involves the introduction of a state-scaling technique and the application of the so-called integrator backstepping procedure. For the output feedback case, an interlaced observer/controller scheme is introduced for nonholonomic systems design. While earlier controllers fail to maintain robustness in the face of small disturbances, the simulation results based on some practical examples demonstrate the efficiency and,robust features of the method proposed in this paper. (C) 1999 Elsevier Science Ltd. All rights reserved.