Research on the Gearshift Control in Dual Motor Hybrid System

This paper delineates a shift control approach for a dual motor structure incorporating a drum-type shift lever in a parallel mode, which can be approximately categorized into five stages. In the first stage, the torque of the dual motor and ICE engine is interchanged, and the engine side torque is reverted to zero within the capacity range, with the P3 motor compensating for the torque loss on the engine side. In the second stage, the VCU transmits a request for series connection to the PCM and dispatches a request for the ICE gear position to be in neutral to the PCM. The PCM enters the sequence for the transition from parallel to series and undertakes the action of unloading the C0 clutch torque. Once the C0 clutch torque is completely disengaged, the actual mode is fed back as parallel, and the actual engine gear position is fed back as neutral. In the third stage, upon the PCM's feedback of the actual series connection, the VCU internally conducts a CAN delay judgment and subsequently requests a return to parallel, which is dispatched to the PCM. Simultaneously, the new engine gear position is sent to the PCM. The engine gear position at this juncture is the target gear position for parallel connection and is continuously updated. The actual engine gear position fed back by the PCM is neutral, and the gear actuator commences to disengage the gear and engage the new one. In the fourth stage, the PCM continues to provide feedback that the actual ICE gear position is in the N position, and the PCM governs the gear actuator to engage the new gear until the engagement is accomplished. In the fifth stage, after the PCM finalizes the gear engagement and the gear actuator, it increments the C0 clutch torque and aligns the C0 clutch. The outcomes of the on-vehicle verification substantiate that it assumes a vital role in enhancing driving performance.