The Engineering Meetings Board has approved this paper for publicat ion. It has successfully completed SAE’s peer review process under the supervision of the session organizer. This process requires a minimum of three (3 ) reviews by industry experts. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form o r by any means, electronic, mechanical, photocopying, recording, or otherwi se, without the prior written permission of SAE. ISSN 0148-7191 Positions 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. SAE Customer Service: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: [email protected] SAE Web Address: http://www.sae.org Printed in USA Copyright © 2009 SAE International ABSTRACT The Advanced Engineering (AE) group within General Motors Powertrain (GMPT) develops next generation engines and transmissions for automotive and marine products. As a research organization, AE needs to prototype design ideas quickly and inexpensively. To this end, AE has embraced model-based development techniques and is currently in vestigating the benefits of software in-the-loop (SIL) testing. The underlying obstacle faced in developing a practical SIL system lays in the ability to integrate a plant model with sufficient fidelity together with target application software. ChiasTek worked with AE utilizing their CosiMate tool chain to eliminate these barriers and delivered a flexible SIL system simulation solution. INTRODUCTION Automotive embedded powertrain software monitors and controls electrical, hydr aulic, and mechanical loads hundreds of times per second in harsh dynamic environment over years of operation. To insure robust operation over all these conditions, intensive testing must be performed on the software “in-the-loop” with the powertrain system. Many industry solutions exist for “hardware in the loop” (HIL) testing, where embedded software is run on a target electronic controller, which is then interfaced with a mix of physical and simulated loads. This method is effective; however it requires developing physical loads or real time simulated loads, both of which can be expensive and available only late in a development cycle. An alternative to this method is known as “software in the loop” (SIL); an approach where all of the loads are completely simulated. Since the target software is linked virtually to the plant, no special hardware is required, allowing this type of evaluation to be performed earlier in a development cycle and with considerably less cost. The barrier commonly limiting the use of this approach is the complexity in interfacing control algorithms with high fidelity plant models. This barrier compounds in magnitude for powertrain system s due to the fact that they frequently contain subsystems across several engineering domains; embedded software, electronics, hydraulics, and mechanics. These different domains are typically modeled in different simulation tools developed by independent suppliers. The Advanced Engineering (AE) group within General Motors Powertrain (GMPT) researches and develops next generation powertrain technologies. Methods to more efficiently evaluate, develop, and test these systems are of critical interest to AE in their pursuit to provide their customers wi th robust, market-leading technologies. The AE team, already experienced in *9-2009-01-0520*2009-01-0520 Using a Co-simulation Framework to Enable Software-in-the-Loop Powertrain System Development Kurt J. Mitts and Keith Lang General Motors Corporation Thierry Roudier and Daniel L. Kiskis ChiasTek, Inc. Downloa