Sensor range sensitivity of predictive energy management in plug-in hybrid vehicles

The fuel saving potential of passenger plug-in hybrid vehicles (PHEVs) is presented as a function of sensor prediction range. The route is assumed to be given, while the upcoming vehicle speed is uncertain and requires prediction. The proposed prediction method uses up-to-date sensor information inside the prediction horizon and rough estimations through road inclination and speed limits beyond that prediction horizon. The entire route is thus considered in the optimization process. A deterministic Dynamic Programming algorithm then uses the speed- and acceleration-related power demand estimation to find the optimal torque-split control signals for the hybrid powertrain - the vehicle speed is not affected. The research results show that achieving significant fuel saving potential is relatively insensitive to the prediction range. Even relatively short prediction ranges within radar sensor range enable fuel economy very close to the global-optimal solution. The simulation results are compared with a simple charge-depleting strategy using the same amount of electrical energy to show the fuel saving potential.