Title: A study of the shifting transients of a torque converter equipped vehicle

Authors: Han-Sang Jo, Weon-Sig Lim, Yeong-Il Park, Jang-Moo Lee

Addresses: Institute of Advanced Machinery and Design, Seoul National University, Seoul, Korea. ' Department of Automotive Engineering, Seoul National Polytechnic University, Seoul, Korea. ' Department of Mechanical Design, Seoul National Polytechnic University, Seoul, Korea. ' Department of Mechanical Design and Production Engineering, Seoul National University, Seoul, Korea

Abstract: A torque converter, the major component of an automatic transmission, is a hydrodynamic device that has a great influence on the transient characteristics of a vehicle during gear shifting. To predict accurately the vehicle characteristics, detailed analysis of the torque converter is required. In this study, the classical one-dimensional modelling of the torque converter, based on the concept of the mean flow path, is used to analyse the shifting transients. It is proved that the equivalent parameters included in the modelling can be determined from the experimental results by using nonlinear optimisation methods. Dynamic modelling of power transmission components, such as clutches and planetary gear systems, are also considered. The clutch engagement condition, which determines the degree of freedom of the system during shifting, is proposed. In the modelling of the power transmission system, the stiffness of the shaft and various control logics are included. Using the developed simulation method, the effects of the design variables and the control conditions are evaluated. Finally, the results of the driving simulation are compared with those of the dynamometer-based experiments.

Keywords: automatic transmission; driving simulation; dynamic modelling; dynamometer testing; shifting transients; torque converter; gear shifting; mean flow path; power transmission; clutch modeling; planetary gear systems; clutch engagement.

DOI: 10.1504/IJHVS.2000.005254

International Journal of Heavy Vehicle Systems, 2000 Vol.7 No.4, pp.264 - 280

Published online: 16 Sep 2004 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article