Hybrid Electric Vehicle Energy Management Based On Cruise Speed Optimization

Energy crisis and environmental pollution present are increasingly serious, in order to alleviate the pressure of energy saving, hybrid electric vehicles become the main trend in the development stage for the automobile industry since the high efficiency and low emissions. Compared to traditional vehicles, the control problem of hybrid electric vehicles are more complicated. In order to satisfy the growing demand for safety and fuel economy,reasonable energy management strategies(energy management mode and shift schedule)are needed to solve the problem of the torque split between the power source, so that we can improve the efficiency of the hybrid vehicle power source. With cruise control system widely available in various vehicles, it is also one of the issues to optimize the vehicle cruising speed and realize economy cruising at this stage. In order to improve hybrid vehicle fuel economy on cruise control, energy management strategies are studied in this paper.In order to facilitate energy management strategy, this paper build the vehicle model hybrid vehicle based on Simulink environment, and design rule-based energy management strategy to carry out functional simulation of the model. Then speed optimization of hybrid vehicle on cruise control and energy management strategy optimized are designed In order to improve hybrid vehicle fuel economy on cruise control, this paper optimizes the vehicle cruising speed trajectory and energy management strategy separately. As for cruising speed trajectory, we collect the front vehicle speed with the help of navigation systems, and optimize the speed trajectory with the various constraints such as driving safety case, realize the economy cruising purposes. As for energy management strategy,based on optimal speed trajectory and vehicle status information, we get optimal energy management strategies using dynamic programming algorithm. And we realize rolling optimization with the help of Model Predictive Control(MPC), Finally, we carry out the simulation to verify the correction of energy management strategy. Simulation results show that fuel economy has improved 4.23%, the operating point of engine and motor basic falls in the high efficiency area of the energy consumption curve, and improve the efficiency of the engine and the motor obviously, and the feasibility of the optimization method has been proved.