Abstract
Most automatic transmission systems are equipped with a lock-up clutch to improve efficiency. However, the use of lock-up in the low-speed range was greatly influenced by unmodeled dynamics and disturbances. In order to suppress such uncertainties, slip control of the lock-up clutch is needed. This paper first explains the modeling of the lock-up clutch as a low-order system within the range of slip control. It then describes a slip control system designed by using a robust control method, which takes into account variations in dynamic characteristics of components. Finally, the results of driving tests are presented to demonstrate the effectiveness of the slip control system.
