A time-varying saturated synchronous formation controller for nonholonomic mobile robots

In this paper, a new saturated synchronous controller is proposed for multiple nonholonomic wheeled mobile robots to perform a time-varying formation task. Each robot is controlled to track its desired trajectory, while synchronized its motion with the two neighboring robots. A novel dynamic model of the wheeled mobile robot is derived based on Lagrange method. The Lagrange multipliers of the robot are determined based on the input torques and the robot´s velocities. The dynamic model is divided into translational and rotational model. A saturated synchronous translational controller is proposed to guarantee the asymptotic stability of both position and synchronization errors. A rotational controller is developed such that each robot always oriented towards its desired position. A simulation results verified the efficiency of the proposed saturated synchronous controller in the formation tasks.