Coordination Control Strategy of Electric Vehicle Hybrid Brake System in Transient Conditions

The control of brake systems in transient conditions when switching between hydraulic brake and regenerative brake takes place is a key technical issue in electric vehicle hybrid brake systems, which affects the braking feel and comfort directly. A coordination control system is proposed in this work, including a brake force distribution correction module and a motor force compensation module. The former modifies the brake force distribution results in hydraulic brake force intervention condition, hydraulic brake force evacuation condition and regenerative brake force low speed evacuation condition. The latter exploits fast and accurate response of the motor to compensate the hydraulic system, thereby improving the response of hybrid system. Simulation results in transient conditions show that the coordination control strategy can effectively reduce the fluctuation and deviation of total brake force and improve braking feel and comfort.