Electromechanical Brake Modeling and Control: From PI to MPC

The electromechanical brake (EMB) force control problem has been approached in prior work using cascaded proportional-integral (PI) control with embedded feedback loops to regulate clamp force, motor velocity, and motor current/torque. However, this is shown to provide limited performance for an EMB when faced with the challenges of actuator saturation, load-dependent friction, and nonlinear stiffness. There is a significant margin for improvement, and a modified control architecture is proposed using techniques of gain scheduling, friction compensation, and feedback linearization. A further improvement is then achieved by incorporating a model predictive control that better utilizes the available motor torque. Simulation and experimental results are presented to demonstrate the improvement in performance.