Model-Based Transmission Control

Abstract

Abstract This article presents an overview of model-based transmission control. The transmission is an integral part of the automotive powertrain and connects the engine to the vehicle via the driveline. Just as for the internal combustion engine, traditional transmission control has been conducted with extensive calibrations. This is mainly due to the lack of precise models and low cost sensors that can enable real-time model-based feedback control. However the calibration-based approach is facing more challenges as the recent trend in transmission systems has driven up the time and cost associated with the calibration process. Recently, eight and nine speed transmissions have been introduced. The increasing number of different types of transmissions and the gear ratios can drastically increase the burden for control calibration. This calls for control-oriented model development and model-based control. Transmission control is mainly concerned with the transmission shift scheduling and gear ratio shift control. This shift scheduling determines when to shift and which gear to shift.