Sliding-Mode Clamping Force Control of Electromechanical Brake System Based on Enhanced Reaching Law

Abstract

The control of clamping force has a significant influence on the braking performance of low-floor trams. However, the load torque variations, strong nonlinearity and complex structure of electromechanical brake (EMB) systems present challenging the clamping force control issues. In this paper, an EMB system mathematical model is established. Then, an enhanced sliding-mode reaching law (ESMRL) is investigated to address these issues. In addition, novel gap distance elimination and adjustment strategies are proposed to improve the response quality and adjust the gap distance in a simple and low-cost way. Taking advantages of minimal chattering and short reaching times, the proposed ESMRL enhances the dynamic performance and tracking accuracy of the clamping force control. Finally, simulation and experimental results are offered to validate the effectiveness and superiority of the proposed control strategy.