A Study on Clutch Actuation System(CAS) Program Development using Hysteresis Method

For commercial vehicles with a manual transmission, the transfer torque from the clutch pedal to the clutch-cover is very large. Therefore, the pneumatic and fluid pressure servo-device is widely used for transmitting such big torque. However, the pneumatic and fluid pressure servo-devices usually result in non-linear variation of foot-efforts, also variation of foot-efforts have the non-linear character and such non-linear variation tend to increase physical fatigue of drivers who drive commercial vehicles for a long time. To improve the pedal feeling and the design optimally with the clutch disk wear variation, vehicle manufacturers consider the hysteresis loops in the Clutch Actuation System (CAS) design when a new vehicle model is being developed. Generally, the former work to deal with such hysteresis loops were focused on the experimental method and the experimental method is time-consumed and non-cost effective. In this study, we numerically simulate the hysteresis loops for predictable CAS design, and the experimental results confirm the simulation results.