A testing campaign at ADAC testing ground in Kempten, compared the performance of three predictive braking control algorithms for the ROboMObil’s hybrid braking actuators, composed of friction brakes and electric motors.
First, a cascaded controller consisting of a scheduling wheel slip controller and a subordinate model predictive control allocation was tested. Second, a model predictive control method was developed to centralize the cascaded controller to a single-loop controller. Third, a robust model predictive control method was applied, which additionally handles plant disturbances relying on the constraint tightening approach. It was shown that the single-loop controller can improve the tracking performance compared to the cascaded controller under nominal and disturbed (µ-step) braking scenarios at the limit of tire adhesion. The video above demonstrates the difference between a system with model predictive control and an uncontrolled system on a low friction and a split friction surface.