Control strategies and optimization analyses of front-mounted parallel system

In order to recover and use the vehicle’s own braking energy as much as possible to improve fuel economy, reducing greenhouse gas emissions, this paper analyzes the braking characteristics of a certain type of heavy vehicle in the driving condition of the city, according to the structure characteristics of hydraulic hybrid system, the control strategies and processes of three working modes are proposed. By establishing the vehicle dynamic model, the simulation model was established on AMESim software, and the effect of control strategies on the performance of the whole machine were analyzed and optimized. The hardware and software system of the controller based on MATLAB/Simulink and dSPACE were developed, and the correctness of the control strategies and simulation analyses were verified by the road condition tests on the experimental prototype vehicle which was converted from a primitive heavy vehicle. Simulation and experimental results show that the proposed control policy parameters are reasonable. The hydraulic regenerative braking control strategies can reasonably distribute the ratio of hydraulic regenerative braking torque and the traditional friction torques, under the premise to ensure braking safety, the kinetic energy of the brake can be recovered and utilized efficiently, and it has good ride comfort.