400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-0790 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2007-01-1311 Toyota AA80E 8-Speed Automatic Transmission with Novel Powertrain Control System Masami Kondo, Yoshio Hasegawa, Yoji Takanami, Kenji Arai, Masaharu Tanaka and Masafumi Kinoshita Takeshi Ootsuki, Tetsuya Ya m aguchi and Akira Fukatsu Reprinted Fr om: Tr ansmissions & Drivelines (SP-2134) 2007 World Congress Detroit, Michigan April 16-19, 2007 Toyota Motor Corp. Aisin AW Co., Ltd. Downloaded from SAE International by University of Liverpool, Sunday, August 12, 2018By mandate of the Engin eering Meetings Board, th is paper has been approved for SAE publication upon completion of a peer review process by a minimum of three (3) industry experts under the supervision of the session organizer. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise,without the prior written permission of SAE. For permission and licensing requests contact: SAE Permissions 400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: [email protected]: 724-776-3036Tel: 724-772-4028 For multiple print copies contact: SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-0790Email: Customer [email protected] ISSN 0148-7191Copyright © 2007 SAE InternationalPositions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE.The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the pap er if it is publishe d in SAE Transactions. Persons wishing to submit papers to be considered for presentation or publication by SAE should send themanuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USADownloaded from SAE International by University of Liverpool, Sunday, August 12, 2018 Copyright © 2007 SAE International ABSTRACT Toyota has developed the world’s first 8-speed automatic transmission (AA80E) for RWD automobiles. The transmission will first be used in the all-new Lexus LS460. In addition, a novel control system has been developed to maximize the predictability, response, efficiency, and initial quality of the powertrain while utilizing the high number of gear steps. INTRODUCTION Mounting concern over high carbon dioxide emissions and the growing costs of crude oil continue to drive Toyota Motor Corporation to develop increasingly fuel efficient automobiles. On the other hand, in the luxury vehicle market, high dynamic performance is still one of the most significant factors of attraction. In the development of the LS460, the goal was to not only improve fuel economy and over all refinement, but also to realize a major improvement in drivability and dynamic performance. The present paper will provide an overview of the function and integration of the primary components that make up the AA80E, as well as the new powertrain control system behind it, which have contributed to the improvement in the above stated areas. KEY DEVELOPMENTS Several new and improved control elements applied to the AA80E distinguish it from previous systems: 1. A quantitative index of acceleration and deceleration, used to provide objective targets for smooth and stable acceleration with respect to accelerator operation. 2. A driving response and acceleration management system that de termines a drive power target based on accelerator input. To meet the drive power target, the most suitable gear stage and engine torque level is calculated, while also taking into consideration drive power requirements from other vehicle systems. 3. A dual clutch-to-clutch shift control, in which two friction elements engage a