Stabilization of an Over-constrainedWheeled Mobile Robot

In this paper we describe the development of a nonlinear control law to drive a multi-degree-of-freedom (MDOF) mobile robot to a final configuration, following an asymptotically stable path. By reconfiguring their steering centered wheels, the MDOF mobile robots can negotiate tight turns and travel sideways. Nevertheless, these robots are overconstrained systems, very difficult to control. By this reason, these robots are limited to simple tasks, like follow a guide-wire. In order to obtain an autonomous behavior, we propose the use of a non linear control law, based on a new set of error parameters, leading the robot to the final position and orientation. Numerical results illustrating the effectiveness of the control law are also included.