RESEARCH ON THE OPTIMIZATION METHOD OF CLUTCH ENGAGEMENT TRAJECTORY IN THE TRACTOR POWER SHIFT PROCESS

To address the issue of reduced comfort and operational accuracy in tractors caused by the clutch engagement process in combination with automatic transmissions, dual-clutch transmissions, and hybrid power tractors, a new method is proposed that considers both the slipping process and synchronous instantaneous control at the moment of engagement. In this method, the optimal engagement process model of the clutch considering the clutch sliding process and synchronous instantaneous control was established, and the optimal trajectory of the clutch engagement process was solved based on the pseudo-spectral method. Then, the optimization results were compared with those obtained without considering the synchronous instantaneous. The results show that the proposed method considering the sliding process and synchronous instantaneous constraint can reduce the frictional loss of the clutch by 9%, and suppress the impact to below 10 m/s³. Finally, this method was applied to the control of tractor starting up, gear shifting and hybrid power mode switching processes. Simulation results demonstrate that this method can be effectively applied to these three operating conditions.