Control strategy optimization for hybrid electric vehicle based on DIRECT algorithm

A new method based on DIRECT algorithm was presented for parametric optimization of control strategy for hybrid electric vehicles. A logic threshold control strategy (LTCS) implemented in an existing hybrid vehicle was considered. A set of parameters was adopted in the LTCS to command the operation of the vehicle. The optimal adjustment of these parameters was formulated as a constrained nonlinear programming problem with an objective function minimizing fuel consumption. A DIRECT algorithm was proposed and applied to find the optimal set of parameters. Simulation results demonstrate effectiveness of the proposed method which can be used for off-line parametric optimization and thus shorten the time of controller calibration in the real vehicle.