Model-Based Torque Shaping for Smooth Acceleration Response in Hybrid Electric Vehicles*

Model-based design approaches can be used to help reduce the development time and cost associated with developing advanced hybrid vehicles in the automotive industry. This approach allows engineers to design more of the vehicle’s control system in a virtual environment, before hardware is available to test the control software. The research presented here describes the development of a model-based approach of shaping the driver’s torque request to prevent a vehicle’s energy management strategy from receiving discontinuous torque request trajectories. The energy management strategy must always meet the driver’s torque request, even if that torque request will cause drive quality problems during tip-in and tip-out maneuvers. Thus smoothing the torque request helps prevent the energy management strategy from receiving torque requests that have the potential to cause drive quality problems in the vehicle. A numerical model-based approach to shaping the driver’s torque request is proposed here that has the capacity to handle the non-linear and discontinuous aspects of the vehicle powertrain.