Heavy vehicle fuel economy improvement using ultracapacitor power assist and preview-based MPC energy management

Abstract

A heavy hybrid vehicle is considered in which an electric motor and ultracapacitor energy storage are used in a parallel hybrid configuration as a power assist to improve fuel economy. The ultracapacitor's high power capabilities make it a good choice for this application. The optimal control technique of Dynamic Programming (DP) is applied to obtain the "best possible" fuel economy for the vehicle over the driving cycle under pointwise-in-time hard system constraints. Attainable fuel economy improvements are illustrated using a real-time implementable Model Predictive Control (MPC) method using a simple model for predicting future torque demands. The incorporation of simulated telematic future information is also investigated to further improve the the fuel economy of the MPC method close to the DP-calculated maximum.