Robust Finite-Time Formation Tracking Control of Multiple Nonholonomic Mobile Robots With Constraints on Velocities and Control Torques

In this article, a distributed control protocol is proposed for finite-time (FinT) formation tracking control of multiple nonholonomic mobile robots with constraints on velocities and control torques. To tackle the inability of some followers in the group to communicate directly with the leader, a practical predefined-time leader-state observer is devised. By applying the nonlinear transformation technique and a smooth input saturation model, the multiple constraint issue is converted into a bounded problem of the transformed states and the model input. Then, a distributed robust FinT formation tracking control scheme is proposed, based on the backstepping method, the robust control approach, and the adaptive control technique. The theoretical analysis demonstrates that the controller designed in this article is able to guarantee all errors of formation tracking to converge to a neighborhood of zero within finite time and all robots can achieve the desired formation under multiple constraints. Finally, the effectiveness of the proposed FinT formation tracking controller is verified by simulation results.