The Engineering Meetings Board has approved this paper for publication. 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 or by any means, electronic, mechanical, photocopying, recording, or otherwise, 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.s ae.org Printed in USA 2009-01-1020 Luigi del Re Johannes Kepler University Linz, Austria Copyright © 2009 SAE International ABSTRACT Today’s racing motorcycles can provide engine torques higher than the rear tire can transfer to the road. In motorcycle applications, rear wheel torque control can be critical not only for performance, but also for safety, especially in or out of curves. While most drivers can achieve rather good results in handling this high torque on a straight road, the same is not true during cornering. In this paper we present a strategy for traction control which enforces safety while keeping high acceleration even for large roll angles. The proposed control strategy is tested on a motorcycle simulator and performance could be shown during different demonstrative maneuvers. INTRODUCTION Modern sport motorcycles can often supply an engine power of more than 170 HP, while the mass of these motorcycles is below 200 kg. Professional as well as amateur riders love this amount of power as the freedom on two wheels becomes even more unrestricted and possibilities and attractions of riding a motorbike increase. On the racetrack, performance is often not limited by the available power, but by the driver skills especially under large roll angles. According to [1] most drivers are able to achieve either high acceleration or drive with large roll angles, but only very skilled riders are able to handle both simultaneously. This motivates the interest of traction controllers intended to assist novice and less skilled riders but able to provide additional safety even to the best experts. As breaking on a motorcycle is usually considered more difficult and also more crucial for safety, ABS systems have been used on production motorcycles for about two decades now. Also several publications have been presented on this issue (e.g. [2], [3], [4]). Traction control systems on the other hand are a rather new development, which is mostly done internally by companies (e.g. [5], [6], [7]) with little dissemination (e.g. [8]). For cars, traction control systems have been used for more than a decade. However, as the vehicle dynamics of a car is completely different to the behavior of the motorcycle, the adaptation of these systems for two-wheel-vehicle is difficult. Motorcycle manufacturers have just started to develop and implement specific traction control systems. For operation in curves, two different approaches can be found: on one hand, race track oriented systems, mainly focused on performance and including different mechanisms for adaptation ([5] and [6]) and on the other hand systems intended for general users ([7]) focusing on safety, and by consequence more conservative. Although this paper concentrates on race track systems, the results can also be used for road systems. This paper is structured as follows: An overview on the motorcycle simulator is given in section Simulation Environment . The section C