Design and Control of Active Brake Pedal Simulator with Brake Feel Index-Based Optimization

Brake-by-wire systems eliminate the mechanical linkage between the brake pedal and wheel actuators, resulting in the loss of the natural and familiar braking feel perceived by the driver. To address this issue, this study proposes an active brake pedal simulator based on a linear motor and springs, aiming to simulate the adaptive pedal feel and ensure safety performance. Firstly, this paper established a structural model of the pedal simulator and designed a force compensation strategy to reproduce the target pedal characteristic curve of the traditional hydraulic braking system. Subsequently, the system was verified through Adams simulation and real vehicle experiments under slow, normal, and emergency braking conditions. The experimental results show that the initial design exhibited a relatively “soft” pedal feel, with a brake feel index score of 62.31. By optimizing the spring stiffness and feedback force composition, the brake feel index score was significantly improved to 92.21. The optimized pedal simulator is capable of achieving precise pedal force tracking and adaptive adjustment of pedal feel, and still providing basic and reliable pedal force feedback, even in the event of motor failure. Therefore, the designed pedal simulator provides a practical and effective solution for improving the pedal feel of the brake-by-wire system, demonstrating strong application potential.