me Engineering Society For Advancing Mobility and sea Air and Space, INTERNATIONAL- 400 COMMONWEALTH DRIVE, WARRENDALE, PA 15096-0001 U.S.A. Development of ABS and Traction Control Computer Susumu Masutomi and Kiyotaka Ise Toyota Motor Corp. Kimio Tamura Nippon Denso Co., Ltd. Passenger Car Meeting and Exposition Dearborn, Michigan September 17-20,1990 Downloaded from SAE International by North Carolina State Univ, Sunday, September 16, 2018The appearance of the ISSN code at the bottom of this page indicates SAE's consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on the condition, however, that the copier pay a$5.00 per article copy fee through the Copyright Clearance Center, lnc.. Operations Center. 27 Congress St., Salem, MA 01 970f0r copying beyondthat permitted by Sections 107or 108ofthe U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAE Customer Service Department. To obtain quantity reprint rates, permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior writ- ten permission of the publisher. ISSN 0148-7191 Copyright 1990 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the Persons wishing to submit papers to be considered for presen- author(s) and not necessarily those of SAE. The author issolely tation or publication through SAE should send the manuscript responsible for the content of the paper. A process is available or a 300 word abstract of a proposed manuscript to: Secretary. by which discussions will be printed with the paper if it is Engineering Activity Board, SAE. published in SAE Transactions. For permission to publish this paper in full or in part, contact the SAE Publications Division. Printed in USA Downloaded from SAE International by North Carolina State Univ, Sunday, September 16, 2018Development of ABS and Traction Control Computer Susurnu Masutomi and Kiyotaka Ise Toyota Motor Corp. Kimio Tamura Nipwn Denso Co., Ltd. ABSTRACT A new ABS and Traction control system (TRAC system) has been developed and put into mass production in a new model LEXUS LS400. The TRAC system controls Sub-Throttle Valve and brake hydraulic pressure independently for left and right wheels. To realize the ABS and TRAC systemlit is necessary for the Electronic Control Unit (ECU) to process complex algorithm and high speed calculation. The ABS and TRAC ECU far LEXUS LS4OO is constructed by 3 TOYOTA custom 8-bit single chip microcomputers. Each CPU performs wheel speed calculationtABS control and TRAC contro1,sharing the common data through high speed serial communication. This paper describes the function of each CPU,the method of CPU communication and fail safe function in the ECU. INTRODUCTION An advanced ABS and Traction Control (TRAC) system has been developed in ' 90 model LEXUS LS400. Recently,more vehicles have been equipped with ABS on demand for safety. ABS operates efficiently to shorten stopping distance and improve stability and steerability in braking. On the other hand,TRAC system operates in starting or accelerating a vehicle to pull out proper traction force and lateral force according to the road surface condition. Therefore TRAC system improves the acceleratioh performance and prevents vehicle from sliding sideways on slippery road. Some TRAC system has been proposed and mass-produced by some automobile suppliers. [I], [21 The TRAC system in LEXUS L