Abstract: Electromechanical brake(EMB) exhibits advantages such as rapid response speed and high control accuracy, making it a crucial development trend in automotive brake-by-wire systems. To address industry challenges of inaccurate clamping force estimation and difficult-to-guarantee tracking control accuracy in EMB systems, this study proposes a clamping force estimation and tracking control strategy based on piecewise affine(PWA) identification. First, the structure and working principle of EMB systems were analyzed, establishing a comprehensive EMB system dynamics model that incorporates driving motor models, motor friction models, and transmission mechanism models, laying the foundation for subsequent clamping force tracking control strategy design. Second, experimental data of EMB clamping force variations with brake pad temperature and motor rotation angle were obtained. Based on this, a PWA identification-based EMB clamping force estimation model was developed, with its accuracy verified through comparative analysis of simulation and experimental data. Third, an EMB clamping force tracking control scheme integrating PID, nonsingular terminal sliding mode, and model predictive control algorithms was formulated, with functional allocation and design procedures determined by leveraging the performance characteristics of different control algorithms. Finally, simulation and experimental validation of the proposed EMB clamping force tracking control strategy were conducted. Results demonstrate that the proposed strategy effectively accelerates system response, reduces steady-state errors, and enhances tracking accuracy.

Key words: automobile, brake-by-wire chassis, electromechanical brake(EMB), clamping force estimation, piecewise affine identification, tracking control