Research on Shifting Strategy of Hybrid Electric Vehicle Based on Dynamic Programming Algorithm

In this paper, for a hybrid power transmission system composed of a planetary gear mechanism and an improved DCT transmission, the vehicle dynamics model, energy management strategy and torque distribution strategy are established through MATLAB, and two-parameter optimal economical shifting law is obtained by analytical method. By constructing a global optimization problem and solving it through a dynamic programming algorithm, the shifting sequence under the WLTC driving cycle is also obtained. The optimal economic shifting law and the shifting law obtained by the dynamic programming algorithm are verified in MATLAB by running the WLTC driving cycle. The shifting law obtained by the dynamic programming algorithm can make the engine work in a more efficient working range, so that the hybrid vehicle achieves a better fuel economy.