Separation of Transmission and Driveline Imbalances and Its Application

Imbalances of an automatic transmission have a direct impact on NVH. To measure those imbalances, one needs to overcome two hurdles: (1) Phase uncertainty of individual component imbalance due to clutch indexing; (2) Imbalance separation of transmission from other systems, such as driveshaft and engine crank, connected to the transmission.

To attack those issues, an algorithm has been developed which can deal with the phase issue caused by clutch engagement, and separate transmission imbalance at the system level without individually measuring other system imbalances. The method has been verified with several vehicle programs in both vehicle and dynamometer tests.