Comparative Evaluation of Electro-Mechanical Brake Clamping Force Estimation and Sensor Compensation Control Method for High-Speed-Train

Abstract

Recently, with the emergence of electro-mechanical brake (EMB) devices, a control method for an electric motor to replace the existing pneumatic actuator has been studied. The clamping force estimation control method (ECM) from the rotor position of the motor is primarily used because sensor installation is difficult owing to the temperature increase of the friction surface of the brake disk. However, to accurately control the clamping force according to the change in the friction surface and hysteresis characteristics of the motor, it is necessary to consider the installation of a force sensor. This study deals with the installation of force sensors and the sensor compensation control method (SCCM) for the clamping force of an EMB for high-speed train applications. To evaluate the proposed method, that is, the SCCM of the EMB, static control with the wheel in the non-rotating state and dynamic control with the wheel in the rotating state were performed. In addition, static control performance evaluation was performed under the maximum clamping force reference and continuous step reference input. Comparing the two control methods, the error rate of the SCCM was improved by up to 5%. The results of evaluating the dynamic braking performance with the wheels rotating at 300 km/h showed that the SCCM had an improved deceleration pattern, and the braking speed was more than 3 s faster than that of the pneumatic braking system and ECM of the EMB.

Keywords

• Brake-by-wire
• electro-mechanical-brake
• sensor compensation control
• estimation control
• clamping force control
• emergency brake