Fuel Optimal Control of Parallel Hybrid Electric Vehicles

A mathematic model of fuel economy optimal control and its corresponding dynamic programming(DP) recursive equation were established for an existing parallel hybrid electric vehicle(HEV).Two augmented cost functions for shifting and engine starting were proposed to prevent frequent gear shifting and engine stop-starting.To overcome the curse of dimensionality of numerical DP,an algorithm of restricting the exploring region was proposed which largely reduces the computational complexity.The system model is converted into real-time simulation code by using MATLAB/RTW to improve the computation efficiency.Comparison between the results of chassis dynamometer test,simulation and DP was(performed.) It proves that the proposed method is capable of computing the performance limit of the HEV within acceptable time and can be used to evaluate and optimize the control strategy.