Nonlinear control design for implementation of specific pedal feeling in brake-by-wire car design concepts

Brake-by-wire means that the direct mechanical link between brake pedal and braking cylinder is completely replaced by an electromechanical braking system. This concept, originally used for aircraft and military only, has massive advantages for implementing in new car designs. As a consequence, the pedal movement can be generated arbitrarily. Ideally, the pedal could behave like a conventional brake. In the paper, a simplified model for the desired dynamical behavior of the pedal unit is presented, which can be tuned for specific requirements like pedal force, and pedal movement. Its numerical solution leads, due to the pedal force, to the desired time-indexed trajectory of the pedal. Secondly, there is presented a closed loop control strategy for a hydraulic driven pedal consisting of an electric pump, servo valve and a differential cylinder in order to track the reference trajectory. Experimental results show the efficiency of the presented controller for the movement of brake pedals in brake-by-wire car design concepts as pedal simulator.