Brake pedal feel plays an important role in the driver's comprehensive subjective feeling when braking, which directly affects the active safety and riding comfort of passenger car.
A systematical mathematical model of the vehicle brake system is built in according with the structure and system characteristics of hydraulic servo brake system. A complete hydraulic servo brake system simulation model composed of brake pedal, vacuum booster, brake master cylinder, brake pipe, brake wheel cylinders, brake calipers is established in AMESim. The effects of rubber reaction plate stiffness, rubber valve opening, brake master cylinder piston, brake caliper, brake pipe deformation and friction liner deformation on brake pedal feel are considered in this model. The accuracy of this model is verified by real road vehicle tests under static and dynamic two different conditions. The influence of six structural parameters of vacuum booster, brake pipe and brake caliper on brake pedal feel are analyzed in detail. Finally, based on the evaluation system of BFI, the influence degree of different factors in different levels on the brake pedal feel are discussed through the orthogonal experiment design. The optimal scheme of brake pedal feel is put forward based on the sensitivity of various factors and validated by experiment.
This study can serve as important reference for obtaining the best brake pedal feel, and also provides the theoretical basis for pedal simulator design and braking intention recognition in Brake-by-wire.