Leader-follower formation control of nonholonomic robots with fuzzy logic based approach for obstacle avoidance

In this paper we investigate the leader follower motion coordination of multiple nonholonomic mobile robots. A combination of the virtual vehicle and trajectory tracking approach is used to derive the formation architecture. A virtual vehicle is steered in such a way it stabilizes to a shifted reference position/heading defined by the leader, the velocity of the virtual vehicle is then provided for further use in designing control law for the follower independent from the measurement of leader´s velocity. Position tracking control is then constructed for the follower to track the virtual vehicle using the backstepping and Lyapunov direct design technique. Furthermore and to ensure the safety of robots while moving in a dynamic environment, obstacle avoidance scheme based on sensing the relative distance between follower robots and obstacles is introduced using fuzzy logic. Simulations are provided to show the effectiveness of the proposed approach.