Clamping force control of Sensor-less Electro-Mechanical brake actuator

摘要

The brake system plays an important role in vehicles. As the X-by-wire technology develops, Electro-Mechanical Braking system (EMB) can realize individual control of braking force on each wheel; which makes it very suitable for electric vehicles. This paper aims to investigate the clamping force control method for EMB actuator without force sensor. The existing control methods are first analyzed. The modified clamping force control architecture is then proposed. In this paper, the Direct-Torque-Control technology (DTC) is applied for the precise torque control of a permanent magnet motor. In the sensor-less clamping force estimation section, an experiment-based approach is proposed. To verify the performance of the braking force control system, an EMB test-rig is established. Experimental results indicate that the clamping force of EMB actuator is well controlled under the proposed method, and the potential of EMB system for automobile application is also proved.