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 2007-01-1313 Clutch-to-Clutch Transmission Control Strategy John E. Marano, St even P. Moorman, Matthew D. Whitton and Robert L. Williams General Motors Powertrain Reprinted From: Tr ansmissions & Drivelines (SP-2134) 2007 World Congress Detroit, Michigan April 16-19, 2007 Downloaded from SAE International by University of Minnesota, Tuesday, July 31, 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 Minnesota, Tuesday, July 31, 2018Copyright © 2007 SAE International ABSTRACT An automatic transmission cont rol system for clutch-to- clutch shifting systems has been developed. This enables the new General Motors Powertrain families of rear- and front-wheel drive transmissions to meet stringent cost, mass, and packaging reqiurements, while providing driveability and fuel economy improvements over the four- and five-speed transmissions that they replace. The design team utilized several new technologies and methods to robustly engineer a control system that allowed excellent first time capability and reduced calibration intensity. I nnovative technical approaches were developed in several key mechatronics areas. INTRODUCTION The GMPT portfolio of six-speed clutch-to-clutch automatic transmissions was launched with the introduction of the 6L80-E rear-wheel drive automatic transmission in the 2006 model year Chevrolet Corvette. Additional applications have been introduced since, with different torque capacity variants (6L45-E, 6L90-E) and a front-wheel drive architecture (6T70-E, 6T75-E) introduced for the 2007 model year. The transmission families and variants all share a common clutch-to-clutch controls architecture, utilizing a common software set and similar hydraulic and electromechanical components. A total-system approach was taken in the design of the control architecture. Integration of a math-based control algorithm strategy with an electohydraulic and mechanical system of accurate and predictable responses allows precise cont rol of shift quality. Key product performance enablers included introduction of a characterization of transmission physical component and subsystem parameters, a math-based feed-forward clutch control algorithm architecture, and a powerful shift adaptive scheme. A unique regulating valve design and a pressue switch-based clutch fill detection system was developed. A control strategy to manage multiple gear step power on downshift transitions was developed to provi