Research On The Coordinated Control For Regenerative Braking System And Hydraulic Braking System

Regenerative braking system is one of the core techniques of hybrid electric vehicle, it can recover and reuse the braking energy. Regenerative braking system can realize vehicle brake and increase the driving range. Therefore, energy utilization ratio can be improved and environmental pollution can be reduced.To make full use of regenerative braking system and hydraulic braking system, compound brake system is used in hybrid electric vehicle. Researches on the hybrid braking system mainly includes two aspects: coordinated control strategy and coordinated control device. The coordinated control system for regenerative braking and hydraulic braking need to realize coordinated control function, give a good pedal feeling to the driver and ensure good braking performance.The main content of this paper is about research on the coordinated control between regenerative braking system and hydraulic braking system. The scheme of coordinated control and braking control strategy are designed and simulation model is constructed. The crucial parameters are optimized by simulation analysis, which can provide a convenient reference for further research. The following contents are mainly included in the paper:(1) The requirement of the braking control system is analyzed, the coordinated control hardware for regenerative braking system and hydraulic braking system is designed and the control strategy of the braking control system is put forward. The control strategy includes braking strength division, braking demand calculation, the strategy of braking force distribution and the control of the braking system.(2) According to working principles of brake master cylinder, vacuum booster, vehicle brake and ABS in hydraulic braking system, the conventional braking system model is constructed. The curial parameters that affect braking performance and brake pedal feeling are analyzed in the traditional braking system. Though simulation analysis, the pedal characteristic curve and the relationship curve of brake pedal force and pressure from master cylinder are obtained.(3) The key parameters and the structure of brake feeling simulator are designed and its model is built in AMESim. Criteria for selection are determined by service conditions and working environment of components, and components selection is completed. The structure of operation mode switching valve is designed.(4) The model of the coordinated control for regenerative braking system and hydraulic braking system is constructed. Simulation results of brake pedal feeling and braking performance are analyzed by using simulation conditions and evaluation index. The results proved that the maximum energy recovery can be realized in the situation of guaranteeing the braking stability. These research results provide the theory instruction and hardware support for the coordinated control optimization.