Vision-based exponential stabilization of mobile robots

A new smooth closed loop time invariant control law is proposed for the exponential stabilization of mobile robots with nonholonomic motion constraints. The control scheme relies solely on visual information and includes an observer for the system state estimation by means of the essential matrix. The problem of model degeneracies due to short baseline is solved with the definition of a virtual target that provides a stable estimation of the essential matrix. The novelty of this paper lies in the new vision-based control scheme with state observer which is robust, ensuring convergence to the target location. The stability of the system under the proposed control law is demonstrated and experimental results show the goodness of the approach. Keywords—Visual control, Essential matrix, Nonholonomic mobile robots.