Study on ride comfort in post-braking phase based on brake-by-wire system

Abstract

This paper focuses on both brake safety and ride comfort improvement in the postbraking phase. First, a complete vehicle model is established together with the design of a safety control strategy for the longitudinal deceleration control method. Information on driver behavior and vehicle signals is collected to ensure braking safety, including vehicle speed, vehicle deceleration, steering wheel angle, accelerator opening degree, and ABS status. Second, a methodology for longitudinal deceleration control is proposed using a sliding mode control algorithm, aiming to improve ride comfort in the postbraking phase under the prerequisite of a reduced braking distance. Finally, co-simulation, based on Simulink and CarSim, and vehicle tests are carried out. The results show that when the braking distance is constant, the longitudinal deceleration vibration and vertical pitch vibration in the postbraking phase are well suppressed. The peak overshot of longitudinal deceleration and the amplitude of vertical vibration in the postbraking phase decrease. The vibration period of the vehicle is shortened. The braking process of the vehicle is smoother. Thus, the ride comfort is improved in the postbraking phase while maintaining braking safety.