Terminal sliding mode formation control of uncertain multiple robots

Abstract

The formation control problem of multiple non-holonomic two-wheeled robots is considered in this paper. Since the terminal sliding mode (TSM) control approach can eliminate the reaching phase, such an approach is characterised as a novel option to cope with the mismatched uncertainties rooted in the robots. Taking the uncertain factors into accounts, such as parameter fluctuations in practice, skidding as well as slipping triggered by hostile environment, a complete dynamic model is established primarily. Combined with the leader-follower-based formation mechanism, a TSM controller is developed to guarantee the system stability in the sliding-mode stage according to the Lyapunov direct method. A sufficient condition is also proven to make the stable tracking errors converge to zero in finite time. To verify the validity and robustness of the presented TSM controller, a simulation platform composed of three robots in the presence of mismatched uncertainties is built up. The simulation results by the platform illustrate the TSM controller can form up and maintain the multi-robot system in a predefined trajectory while resisting the mismatched uncertainties.