Model Based Automated Calibration for Shift Control of Automatic Transmission

In order to improve shift characteristics of an automatic transmission (AT), it is necessary to control and optimize the hydraulic pressure profile of a clutch. More than 8 speed ATs have been developed recently; thus, considerable time and human resource are required to calibrate the parameters. Herein, we propose a model-based automatic calibration method of clutch hydraulic pressure for an AT. The automated calibration method proposed in this study aims to develop a process that can automatically perform the base tuning of clutch control parameters for shift control, which is performed by experts now at the stage of transmission development. The proposed calibration method consists of a simulation model including an AT, analysis algorithm for vehicle simulation, and automated calibration algorithm based on an optimization process, in which iterative simulations and analysis processes are conducted. This study focuses on the power-on shift, and the simulation results show that the base mapping of the hydraulic pressure profile of a clutch can be successfully and effectively performed.