With the development of the road industry, heavy-duty vehicles now require additional braking power to fulfill their braking requirements. Auxiliary braking systems, which include a hydraulic retarder and an engine brake, can provide additional braking force in nonemergency braking conditions. A water medium retarder is a new type of hydraulic retarder that can convert the kinetic energy of a vehicle into the thermal energy of coolant. This study introduces a novel auxiliary braking system involving a water medium retarder and an engine brake for heavy-duty vehicles. The specific forces of heavy-duty vehicles and the auxiliary braking system are established. The control logic of the novel auxiliary braking system is assigned, and a main controller is designed to dynamically manage the entire braking process. The main controller includes controllers A and B, which handles the engine brake and water medium retarder, respectively. The heavy-duty vehicles dynamic system model is created using MATLAB/Simulink. Upon performance testing, simulation results show that the designed main controller can effectively and rapidly manage the auxiliary braking system, thus satisfying the braking requirements in any nonemergency braking condition. Even when the slope of a road changes, the main controller can extract dynamical forces as well as acceleration parameters and fulfill the braking requirements of vehicles.
Driver Evaluation in Heavy Duty Vehicles Based on Acceleration and Braking Behaviors