Approximate Dynamic Programming Real-Time Control Design for Plug-In Hybrid Electric Vehicles

A real-time control is proposed for Plug-in Hybrid Electric Vehicles (PHEVs) based on the optimal Dynamic Programming (DP) trajectories in this study. Firstly, the DP is used to solve the Driving Cycle to obtain the optimal trajectories and controls, and the Model-Based Calibration tool (MBC) is used to generate the optimal Maps for the given optimal trajectories. Secondly, a Feedback Energy Management System (FMES) is built with State of Charge (SoC) as the feedback variable, which takes into account the Charge and Discharge Reaction (CDR) of the battery. In order to make full use of the energy stored in the battery, combined with the Charge Deplete-Charge Sustain strategy (CDCS), then the reference SoC is introduced; Finally, a comparative simulation on this real-time controller is conducted against DP, the results show that the fuel consumption of the real-time controller is close to the fuel consumption using DP, and when the driving distance is not known, the controller can maintain the SoC within the desired range, and when the driving distance is known, the SoC can follow the reference SoC well to make full use of the energy stored in the battery.