In this paper, the energy management strategy between the internal combustion engine and the electric motor in parallel hybrid vehicles is investigated using an improved and innovative online approach. The proposed method is based on fuzzy systems which can provide online strategy, specifically Takagi-Sugeno fuzzy models, which offer several advantages due to their quasi-linear nature. These advantages include lower computational complexity compared to Mamdani fuzzy systems, simplicity in the design phase, lower implementation costs, and high accuracy in simulation results. The key innovation in this study is the reduction of the number of inputs to the fuzzy system. Instead of using both speed and torque as inputs for energy management, only power is utilized as the primary input. This approach ensures that the internal combustion engine operates at maximum efficiency while satisfying constraints such as driving cycle requirements. The results of the simulation provide evidence of improved vehicle performance and reduced fuel consumption, which are presented in detail in the following sections.
Hokmabad et al. (Wed,) studied this question.