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 dynamic and economy performance of the whole vehicle, as well as the gear distribution characteristics in the vehicle operation, a comprehensive shifting schedule 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 economics 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 0-100 km/h acceleration capability and specific energy consumption as the objectives, a comprehensive shift schedule optimization model is established, 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 dynamic performance and economy performance of the four types of gear shift schedules. The results show that the comprehensive shift schedule can be close to the optimal dynamics shift schedule in terms of dynamic performance while exhibiting good economy performance simultaneously, which can also run in real-time without relying on the overall operating conditions.