Two-Layer Structure Control of an Automatic Mechanical Transmission Clutch During Hill Start for Heavy-Duty Vehicles

The engagement control of an automatic mechanical transmission (AMT) clutch during the hill start of a heavy-duty vehicle has a significant impact on the comfort, safety and service life of the vehicle. However, the control effect of a traditional control strategy can be easily affected by interference (clutch wear, temperature). Therefore, this paper proposes a two-layer structure control strategy based on an AMT clutch automatic actuator with the clutch engagement speed as the control target. First, the clutch automatic actuator is designed and the governing characteristics of the diesel engine and the control characteristics of the solenoid valve are studied. Second, a logic threshold control method and PID control method are adopted in the proposed two-layer structure control method. Moreover, the robustness of the proposed control algorithm is validated by a co-simulation platform (TruckSim, MATLAB/Simulink). Finally, experimental research under different slopes (13% and 22%) is carried out to verify the simulation results. The experimental results prove that compared with a single-layer control strategy, the two-layer control strategy proposed in this paper can shorten the start time by more than 10%, and reduce the vehicle start-up jerking by approximately 20%, which significantly improves the performance of the vehicle in the hill start process.