Formation motion control for multiple mobile robots based on switching control between two reference points

A model of formation is developed by considering the relative position and the orientation between two robots. On the basis of the traditional leader-following schema, the idea of switching control is introduced into the formation control for multiple mobile robots. There are three controllers between the leading robot and the following robots. Two motion sub-controllers, which control the relative position and the orientation between the leading robot and the following robots, are designed corresponding to two reference points on the axis of the following robot chassis. The switching condition of the two sub-controllers is based on the sign of the linear speed of the following robot when the system reaches the state of equilibrium. Therefore, the queue constituted by multiple mobile robots can converge to the desired formation. The results of simulation show that the queue constituted by multiple mobile robots performs the desirable uniform movements, and the formation of the queue is performed smoothly in the course of movement.