Trajectory tracking for wheeled mobile robots via model predictive control with softening constraints

In this study, model predictive control with softening constraints is applied to a non-holonomic wheeled mobile robot for trajectory tracking in the presence of external disturbances. In order to improve real-time robustness of the wheeled mobile robot, a linearised tracking error model is used to predict system behaviours. The proposed control scheme contains a feedforward controller and a feedback controller, in which both control constraints and control increment constraints are considered to achieve trajectory tracking smoothly. Finally, numerical simulations demonstrate the performances of the control scheme.