SAE International Gearshift Actuator Dynamics Predictions in a Dual Clutch Transmission 2013-01-9021

Although hybrid variants of Automated Mechanical Transmissions such as the Dual Clutch Transmissions are less affected by driveline torque interrupts, actuator dynamics is very critical in the speed of gear pre-selection and during multiple gear shifts. To avoid torque interrupts, such systems require precise gearshift duration hence the actuators are expected to have fast, stable and predictable responses. However, actuator dynamics and controls remain barriers to attaining the full benefits of such complex systems, demanding precise timing and coordination of the gearshifts alongside the clutches engagement and disengagement. To overcome such challenges, a dynamic model of an electro-hydraulic gearshift actuator, the synchronizer and the shift fork has been developed. The model predicts the gearshift actuator dynamics for a given set of input parameters, which can be correlated against experimental data. The significance of the work is that an efficient and robust means of improving the gearshift quality of a DCT has been devised.