Direct Model Reference Adaptive Tracking Control of Wheeled Mobile Robot

This paper presents a model reference adaptive control (MRAC) scheme for trajectory tracking of a nonholonomic wheeled mobile robot (WMR) in presence of parametric uncertainty in its dynamic model. The integration of a kinematic controller and a dynamic controller for the dynamic model of a nonholonomic mobile robot has been presented. First, feedback velocity control inputs are designed for the kinematic steering system to make the position error asymtotically stable. Second, a feedback velocity-following control law is designed such that the mobile robot's velocities converge asymtotically to the given velocity inputs. The adaptive controller designed based on the dynamic model provides the voltages of the robot actuators for yielding the required velocities. This means point stabilization. Simulations also demonstrate the good performance of the proposed control scheme under the presence of the dynamic parameter uncertainties.