Development of Economic Velocity Planning Algorithm for Plug-in Hybrid Electric Vehicle

The energy consumption of a plug-in hybrid electric vehicle (PHEV) is directly related to its velocity. Considering the influence of road condition information such as traffic velocity, road speed limit and slope on the energy economy of PHEV, the economic velocity planning algorithm is designed in this study. Firstly, based on the actual vehicle test data, the polynomial fitting energy consumption models with the input parameters of vehicle speed and acceleration for charging of depleting mode and charging of sustaining mode are developed. The economic velocity planning model based on traffic flow velocity and road speed limit on flat roads is established adopting the Pontryagin's minimum principle (PMP). Afterwards, the road gradient information is introduced into the economic velocity planning algorithm based on the equivalent acceleration. Finally, the planned economic velocity and traffic flow speed are compared by the hardware-in-the-loop energy consumption tests. The results show that compared with the traffic flow speed, the economic velocity improves the vehicle energy economy by more than 4%, and the output torques of the engine and driving motor are more stable, which are more conducive to the energy economy of the vehicle. The designed economic velocity planning algorithm based on road information for PHEV improves the adaptability of PHEV control strategy to actual road conditions, and expands the optimization dimension of energy-saving driving. Thus, it has high practical application value.

Automated summary

This study proposed an economic velocity planning algorithm based on road information for PHEV, which can improve the energy economy of the vehicle and make the output torques of the engine and driving motor more stable, contributing to the energy economy of the vehicle.