Fuel Consumption vs Pollutant Emission Trade-Off for Hybrid Electric Vehicle: An Application of the Pontryagin's Minimum Principle

Hybrid topologies are now recognized as a good solution to reduce the fuel consumption of vehicles. The topologies and the associated energy management strategies have been long discussed in order to improve the fuel economy. However, the pollutant emission is seldom taken into account, although it can be greater with hybrid vehicles. This paper develops a method to find an optimal strategy of management taking into account two objectives (fuel consumption and pollutant emissions) during the cold start phase. The Pontryagin's minimum principle is applied considering two states variables. Results on a two clutches hybrid vehicle are proposed and discussed regarding the Pareto front and the evolution of the energy management strategy.