Embedding obstacle avoidance in the control of a flexible multi-robot formation

This work proposes a way to make a group of mobile robots which are navigating as a formation to avoid obstacles in their paths. A trajectory tracking controller is proposed to guide the robots during the navigation, to which an obstacle deviation subsystem is added. Such subsystem is implemented in each robot in the formation, whereas the proposed controller is applicable to subsets of three robots. The obstacle deviation is based on virtual forces, which are considered to change the velocities of the individual robots. A proof of the stability of the control system implemented with the proposed controller, including control signal saturation to avoid the saturation of the actuators, is presented, based on the theory of Lyapunov. Simulated and experimental results are also presented, which validate the proposal.