Powertrain control parameter optimisation using HIL simulations of a heavy-duty vehicle

This paper studies the potential fuel economy improvement that can be achieved by optimising powertrain control parameters without modifying its hardware. A real-time powertrain model was developed and implemented in Simulink. It consists of a simple diesel engine model, an automatic transmission (AT) model with a torque converter, a vehicle dynamic model, and an integrated controller for both the engine and transmission. In particular, a dynamic gearshift clutch model was developed for the AT gearbox. A hardware-in-the-loop (HIL) simulation environment was also established to simulate the developed real-time powertrain model, along with a simplified vehicle model under the federal test procedure (FTP), US06, and urban driving cycles. To evaluate the proposed control parameter optimisation process for a heavy-duty vehicle, the fuel consumptions of the FTP, US06, and urban driving cycles were used as the evaluation criterion, based upon different gear shifting control parameters and throttle slope angle. The HIL simulation results show that about 2% fuel economy can be gained by optimising the throttle slope angle; and simulation results also demonstrated that the optimised gearshift schedule provides the fuel economy improvement between 2.11% and 7.6% over the traditional gearshift schedule, where the most significant improvement was obtained for the urban driving cycle.