Synchronization strategy for differentially driven mobile robots: Discrete-time approach

Based on a discrete-time approach, this paper considers the synchronization problem of a group of n differentially driven mobile robots. A discrete-time model, obtained by the exact discretization of the original continuous-time kinematic model is considered. The synchronization problem considers the formation of a group of robots together with the tracking of a desired trajectory. To solve the problem, an approximate state feedback is proposed which is based on a one step retarded time. Also, it is formally proven that, for the resultant closed-loop system, the involved error signals exponentially converge to a neighbourhood of the origin. The performance of the synchronization strategy is evaluated by real-time experiments with the help of a group of three mobile robots and an indoor absolute localization system based on artificial vision.