Abstract
In a passenger car automatic transmission, the duty pattern of pressure control solenoid valve is predetermined for various cases of gear ratio change. There are some control parameters in a duty pattern and it is very important to determine proper values of them for better shift quality. In this study, with the dynamic model and simulation of a passenger car power train, the dynamic characteristics of an automatic transmission during gear ratio change are examined. And the effect of the duty control parameters are investigated by parameter study. The objective function is established considering the constraints and the optimal values of the control parameters are determined by optimization process.