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Abstract Understanding how a race car driver controls a vehicle at its friction limits can provide insights into the development of vehicle safety systems. In this paper, a race car driver's behaviour inspires the design of an autonomous racing controller. The resulting controller uses the vehicle's centre of percussion (COP) to design feedforward and feedback steering. At the COP, the effects of rotation and translation from the rear tire force cancel each other out; consequently, the feedforward steering command is robust to the disturbances from the rear tire force. Using the COP also simplifies the equations of motion, as the vehicle's lateral motion is decoupled from the vehicle's yaw motion and highlights the challenge of controlling a vehicle when the rear tires are highly saturated. The resulting dynamics can be controlled with a linear state feedback based on a lane-keeping system with additional yaw damping. Utilising Lyapunov theory, the closed-loop system is shown to remain stable even when the rear tires are highly saturated. The experimental results demonstrate that an autonomous vehicle can operate at its limits while maintaining a minimal lateral error. Keywords: autonomous racingvehicle control at the limits of handlingstate-space steering controllercentre of percussionstability at the limits of handlingLyapunov function Acknowledgements This material is based upon the work supported by Audi of America, the Volkswagen Automotive Innovation Lab (VAIL), and the Electronics Research Laboratory of Volkswagen of America (ERL), with additional support from a Fulbright Science and Technology Fellowship. The authors thank Kirstin Talvala and Guido Koch for their valuable comments on this paper, Infineon Raceway and the Santa Clara County Fairgrounds for their assistance with testing, OmniSTAR, Inc. for its DGPS service, and B. Huhnke, B. Mueller-Bessler, M. Hernandez, G. Stanek, R. Simpson, R. MacLellan, D. Langer, F. Weidner, P. Marx, M. Duigou, I. Tarasov, S. A. Beiker, J. Rahn, R. Hindiyeh, P. Theodosis, and J. Funke for their assistance with the research project. Notes Although using a small angle approximation introduces some error, note that even at 30° rear tire slip, this approximation produces less than 5% error. In addition, the experimental results described in Section 5.1 demonstrate system's stability even when the rear tires have high slip angle.
Kritayakirana et al. (Sun,) studied this question.