Dynamic modeling and tracking control of a four wheeled nonholonomic mobile robot

This paper presents methodologies for kinematic/dynamic modeling and trajectory tracking for a four wheeled nonholonomic mobile robot. The vehicle with two front (steering) and two rear (driving) wheels is considered. The complete dynamic model of such a wheeled mobile robot is established using the Euler’s Lagrange equation and MATHEMATICA. Then a dynamical extension that makes possible the integration of a kinematic controller and a torque controller is presented .A combined kinematic/torque control law is developed using backstepping approach and asymptotic stability is guaranteed by Lyapunov theory. The mobile robot is modeled as a non holonomic system subject to pure rolling, no side slipping constraints. Simulation results are performed to illustrate the efficacy of the proposed control strategy.