Title: Closed-loop controller for post-impact vehicle dynamics using individual wheel braking and front axle steering

Authors: Derong Yang; Bengt Jacobson; Mats Jonasson; Tim J. Gordon

Addresses: Department of Applied Mechanics, Chalmers University of Technology, SE-41296 Gothenburg, Sweden ' Department of Applied Mechanics, Chalmers University of Technology, SE-41296 Gothenburg, Sweden ' Department of Vehicle Dynamics and Active Safety, Volvo Car Corporation, SE-40531 Gothenburg, Sweden ' Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA

Abstract: This paper presents a vehicle path controller for reducing the maximum lateral deviation (Y_max) after an initial impact in a traffic accident. In previous research, a Quasi-Linear Optimal Controller (QLOC) was proposed and applied to a simple vehicle model with individually controlled brake actuators. QLOC uses non-linear optimal control theory to provide a semi-explicit approximation for optimal post-impact path control, and in principle can be applied to an arbitrary number of actuators. The current work extends and further validates the control method by analysing the effects of adding an active front axle steering actuator at different post-impact kinematics, as well as increasing the fidelity of the vehicle model in the closed-loop controlled system. The controller performance is compared with the results from open-loop numerical optimisation which uses the same vehicle model. The inherent robustness properties of the QLOC algorithm are demonstrated by its direct application to an independent high-fidelity multi-body vehicle model. Towards real-time implementation, the algorithm is further simplified so that the computational efficiency is enhanced, whereas the performance is shown not to be degraded.

Keywords: collision avoidance; active safety; post-impact kinematics; path control; vehicle dynamics; vehicle braking; vehicle steering; optimal control; controller design; individual wheel braking; front axle steering; lateral deviation; vehicle accidents; vehicle safety; multi-body dynamics; dynamic modelling.

DOI: 10.1504/IJVAS.2014.060114

International Journal of Vehicle Autonomous Systems, 2014 Vol.12 No.2, pp.158 - 179

Received: 06 Mar 2013
Accepted: 12 Oct 2013
Published online: 27 Oct 2014 *

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