Longitudinal control design and experiment for heavy-duty trucks

This paper addresses a model-based longitudinal control design and experimental work for heavy-duty vehicles. The engine braking effect, which is caused by the mismatch between engine speed and wheel speed when the fuel is released and drive-line is engaged, is united with Jake brake in a single model. A transmission retarder model is presented. Based on these models and the models proposed by the authors in previous work, the longitudinal control design has been carried out. The structure of the controller can be divided into upper level control and lower level control. The upper level control uses the sliding mode control to generate the desired engine/brake torque from the desired vehicle acceleration. The lower level control is divided into two branches: (1) engine control - from a positive desired torque to a desired fuel rate (engine control) using the static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; and (2) the brake control is to generate, from a negative desired torque, to the Jake brake ON time period, applied pneumatic brake pressure, and applied voltage of the transmission retarder. Test results are also reported.