Strategy research on vehicle constant speed downhill control based on hydraulic retarder

It is of great significance for achieving constant speed downhill control to improve efficiency and safety of vehicle transport. The vehicle hydraulic retarder is an auxiliary braking device that brakes the vehicle and keeps the vehicle speed stable without using main brake or using fewer main brake. This study aims at constant speed downhill control for heavy truck, the process of vehicle downhill baking is analyzed in detail, the vehicle downhill dynamic model is established in the Matlab/Simulink. The constant speed controller is designed and a new constant speed control strategy is designed to adjust the liquid filling ratio with the change of vehicle speed. The correctness of the constant speed control strategy is verified by setting different initial velocity in simulation environment. It shows that the control strategy can realizes the vehicle constant speed downhill control. The constant speed controller has the characteristic of fast response and the characteristic of simple controller structure.