Simulation Study on Hydraulic Braking Control of Engine Motor of Hybrid Electric Vehicle

Abstract

Taking the hybrid electric vehicle as the research object, under the premise of ensuring the braking safety, aiming at maximizing the use of motor regenerative braking force and improving the coordination performance of motor hydraulic braking, a simulation study of motor hydraulic braking control based on hybrid electric vehicle engine is proposed. According to the dynamic model and ideal braking force distribution curve of hybrid electric vehicle, combined with the common idea of electro-hydraulic compound braking force distribution, a three-layer braking control structure of hybrid electric vehicle is constructed. The management determines the braking intention through the driver's pedal action, calculates the expected torque, and the control layer obtains the target braking force distribution relationship through the logic gate limit control method based on the expected torque. According to the actual motor torque signal fed back by the executive layer and the wheel cylinder pressure signal of the hydraulic braking system, the braking force and regenerative braking force of the hydraulic system are dynamically coordinated and controlled to ensure that the state switching of each component can be rapid, stable and timely, and the control instruction is transmitted to the motor hydraulic braking system of the executive layer through the vehicle controller to complete the motor hydraulic braking of the hybrid electric vehicle engine. The experimental results show that this method can realize the reasonable distribution of motor hydraulic braking under different braking intensity, different initial braking speed and different pedal dip amplitude, which makes the reaction speed of hybrid electric vehicle in the braking process faster, the braking switching more stable and safe, effectively improves the energy utilization rate of hybrid electric vehicle, and ensures the economy and safety of braking control of hybrid electric vehicle.