Automatic shift adjustment in passenger cars with automatic transmissions

The shift behaviour of modem passenger cars with automatic transmissions is controlled by the shift strategy and the parameter based shift algorithms stored in the (e) under bar lectronic (c) under bar ontrol (u) under bar nit (ECU). The driver has no influence on the quality (in terms of comfort) of the gear change. Therefore the parameters for the gear changes in an automatic drive train are set in a way, that an optimum in subjective shift comfort is achieved for every possible shifting operation, throttle position and vehicle speed. The paper shows the development stages leading to a system for the automated tuning of the shift behaviour of an automatic transmission on a roller dynamometer.