Research on Brake Pitch Comfort Control for Distributed-drive Electric Vehicles Based on Brake-by-wire System

The changes in pitch angle of the vehicle body during braking, especially the “braking nodding” phenomenon before absolute stop, are a significant factor for the compromised ride comfort. In this paper, a comfort control strategy based on brake-by-wire system for distributed drive electric vehicles is proposed. Firstly, the braking intention is determined based on driver input and vehicle speed. Then, the braking mode switching is designed based on the driver's braking intention and vehicle parameters. Under non-emergency braking conditions, a predictive model control method is designed for the front and rear axle braking force distribution. In addition, a smooth switching control algorithm with double closed-loop feedback is presented for smoothing the electro-hydraulic compound braking force. Finally, the proposed strategy is evaluated under various brake scenarios in Simulink-Carsim joint simulation. Finally, the proposed strategy is examined under various brake scenarios in Simulink-Carsim joint simulation. The results show that the proposed scheme can significantly reduce the changes in pitch angle and pitch rate during braking under the premise of ensuring braking performance, only resulting in a braking distance increase of up to 20 cm. © 2024 Chinese Mechanical Engineering Society. All rights reserved.