Comprehensive gear shift schedule of heavy-duty commercial electric trucks based on dual axle driving

A heavy-duty commercial electric truck is equipped with dual axles, with the middle axle driven by an electric motor and a three-speed transmission and the rear axle driven by an electric motor and a two-speed transmission. To consider the dynamics and economic performance of the whole vehicle, as well as the gear distribution characteristics in the vehicle operation, a comprehensive shifting law based on the cross-particle swarm algorithm is proposed. By establishing the longitudinal dynamics model of the truck, the optimal power shift schedule and the optimal economic shift schedule of each of the two transmissions are studied. Under the standard test conditions, an optimal gear control strategy based on the dynamic programming algorithm considering the shift interval is proposed, and the shift schedule for the standard conditions is derived through the hierarchical clustering method. Furthermore, with 100 km acceleration time and specific energy consumption as the objectives, a comprehensive performance shift schedule optimization model is established based on three types of shift schedules, and the comprehensive shift schedule curve is obtained by solving the cross-particle swarm algorithm. MATLAB\Simulink is used for vehicle modeling and simulation test condition design to compare and analyze the power performance and economic performance of the four types of gearshift schedules. The results show that the comprehensive performance shifting schedule can be close to the best-shifting law in terms of power performance while exhibiting good economic performance simultaneously, which can also effectively reduce the frequency of shifting.