Abstract: To eliminate the busy-shift when the vehicle travels on the upslope and to make use of the engine’s brake capability when the vehicle travels on the downslope, the vehicle’s longitudinal dynamics is discussed. A slope recognition method based on the vehicle’s acceleration is proposed. This method has many merits, such as simplicity, utility, etc. It is very significant to improve the slope travelling performance of conventional automatic transmission.

Key words: Automatic shift strategy, Automatic transmission, Longitudinal dynamics, Slope recognition