Integrated control system of primary retarder charging and discharging oil and its dynamic response characteristics analysis

In view of the shortcomings of traditional hydrodynamic retarder (HR), such as low braking power density, large axial installation space, and complex oil circuit layout, the study takes the primary retarder with more technical advantages as the research object. In the study, the integrated design of the primary retarder and the hydrodynamic torque converter (HTC) is carried out. The cooperative control of the lock-up clutch and the retarder valve is used to realize the fast function switching between the long downhill braking condition and the driving condition. The study employed the aviation oil tank model to equivalently model the filling and discharging oil model of the HR, and builds a dynamic filling and discharging oil integrated control system of the HR on the AMEsim platform. In this paper, the effects of different filling rates and rotational speeds on the braking performance of the HR are discussed from the perspective of simulation and test. At the same time, the oil filling and discharging characteristics and braking characteristics of the HR oil chamber under long downhill braking and driving conditions are analyzed. The simulation and experimental results show that the maximum prediction error of the braking torque of the primary retarder is 5.834%, and the average error is 4.583%. When the vehicle is operating in the long downhill braking condition, the filling time of the HR under the condition of full filling rate is 1.78 s; When the vehicle is operating in the driving condition, the time for the HR to empty the oil chamber is 3.84 s. The modeling idea and simulation control method in the study can provide reference for the precise control and rapid response research of HR filling and discharging oil.