The MRAC based clamping force control of the electro-mechanical braking device

A novel precise control method of clamping force is proposed for a new type of braking device, which is composed of a motor servo system and a mechanical transmission. Because of machining error, assembling error and friction force of mechanical transmission, a great deal of error exists in force transfer, which makes the champing force of the electromechanical braking device to be uncontrollable under open-loop control. In this research, the model-reference adaptive control (referred to below as MRAC) based on MIT law was first applied for control the braking device, and a hardware-in-the-loop experiment was carried out. The experimental results showed that this control method could control small clamping force accurately, but not suitable for large clamping force. Therefore, system identification of reference model and normalization of control law were applied for the algorithm improvement, and the clamping force is finally accurately controlled in all ranges.