Improving Vehicle Roll Stability by LQR Active Anti-roll Bar Control

Today there are over 1.3 billion vehicles in use all over the world and vehicle rollover is a serious safety problem, which can result in large financial and environmental consequences. In order to improve the roll stability, most modern vehicles are equipped with the passive anti-roll bar system to reduce roll motion during cornering or riding on uneven roads. However, the passive anti-roll bar does not meet the required stability when the vehicle is in an emergency. This paper introduces the active anti-roll bar control which is designed by finding an optimal control, based on a Linear Quadratic Regulator (LQR). A four-degree-of-freedom half roll model that captures the essential vehicle dynamics associated with rollover phenomenon is presented. The obtained results of comparison of performance between a passive and an LQR active anti-roll bar show the significant effectiveness of the active anti-roll bar control in various maneuver situations.