Adaptive sliding mode control of nonholonomic systems in chained form with unknown control direction and uncertainties
by
Antonella Ferrara
Department of Computer Engineering and Systems Science - University of Pavia - Pavia, Italy
Coauthors: Luisa Giacomini, Claudio Vecchio - Department of Computer Engineering and Systems Science - University of Pavia - Pavia, Italy

An adaptive sliding mode control scheme capable of solving the problem

of stabilizing a class of nonholonomic systems in chained form with

unknown control direction is proposed. The problem is further complicated

by the fact that the considered systems are assumed to be

affected by uncertain nonlinear drift term and parametric uncertainties.

The crucial point is the necessity of reformulating the system model so as to make the

uncertain terms appear in matched form. The system model transformation

proposed in this work is based on a discontinuous state scaling and a

backstepping based procedure. It can be shown that, relying on the

new system state, it is possible to design an appropriate parameter

adaptation mechanism and a suitable sliding manifold. The control

scheme which is the object of the proposal is designed so as to be able to enforce a sliding mode on the selected

manifold without the necessity of knowing the sign of the control gain.

The adaptive nature of the control law and its robustness features make

it applicable to nonholonomic systems with unknown control

direction also in presence of a significant class of uncertainties.

Date received: March 17, 2008

Copyright © 2008 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cawz-62.