A survey-based type-2 fuzzy logic system for energy management in hybrid electrical vehicles

Hybrid electrical vehicles combine two or more energy sources (at least one electrical) to benefit from their different characteristics regarding autonomy, reversibility and dynamic response. Energy management consists in discovering an energy distribution between the different energy sources whilst meeting different design requirements such as comfort or energy consumption minimization. This paper aims to design a fuzzy logic controller to manage the energy in a hybrid electrical vehicle equipped with three different energy sources: batteries, a supercapacitors system and a fuel cell system. We use human expertise to design the fuzzy logic controller. A survey using linguistic labels was conducted among experts in hybrid electrical vehicles. As each expert has defined different fuzzy sets and rules we use type-2 fuzzy sets, that permit to combine the knowledge from the experts handling the uncertainty associated with the meaning of the words. The proposed fuzzy logic controller is evaluated by computer simulation. (C) 2011 Elsevier Inc. All rights reserved.