Dynamic analysis of shift quality for clutch to clutch controlled automatic transmission

Dynamic characteristics of a shift quality are investigated for a clutch to clutch controlled automatic transmission. Dynamic models of the hydraulic control system and the geartrains are obtained using Bondgraph. Based on the dynamic models, a simulation tool is developed to evaluate the shift quality. Using the simulation tool, shift performances for a 1-2 upshift and a 4-2 downshift are investigated and are compared with test results. It is found that the simulation tool is able to predict the pressure profiles of the clutch and brake, output torque, and turbine speed for a given input duty signal. It is expected that the simulation tool developed in this work can be used to improve the shift quality for the clutch to clutch controlled automatic transmission by saving time and cost in the tests.