Jerks and Neutral-Gear Wait Eliminated Cooperative Control Strategy for Non-Synchronizer Electric-Drive Mechanical Transmission

Non-synchronizer electric-drive mechanical transmissions (NEMTs) are a good choice for heavy-duty commercial vehicle powertrains due to their simplicity and low cost. However, long power interruptions and jerks are two issues that need to be addressed during the gear-shifting process. To that end, we propose a fast cooperative control strategy aligning the angle difference to avoid jerks and eliminating the neutral-gear wait to reduce power interruption time. First, a dynamic model for the NEMT considering the drive motor torque response and vehicle drag is built. A time-optimal control law for the drive motor is formulated to align speed and angle differences, thereby avoiding jerks. A cooperative control strategy without the neutral-gear wait for the drive and shift motors is proposed to reduce power interruption time. Subsequently, the effect of disturbances from vehicle drag is analyzed. A dual PID model tracking control strategy is designed to enhance the antidisturbance capacity. Finally, the proposed control strategy is validated on the test bench. The experimental results demonstrate that the whole gear-shifting process takes only 210 ms without jerks transmitted to the vehicle. Compared to traditional methods, it can shorten the power-interruption time by 45% and reduce 75.22% of impacts between the sleeve and gear ring.