Ride Quality and Handling Characteristics of a Vehicle with Active Anti-Roll Bar Suspension

Ride quality is one of the important properties of an off-road vehicle limiting the speed-made-good on rough terrain. Anti-roll bars are used to limit the sprung mass roll angle and generate under-steer characteristics, improving the stability of a vehicle. However, anti-roll bars may have a negative influence on ride quality, particularly on natural terrain with random roughness. In this study, a multi-body dynamics model of an off-road vehicle having an independent suspension is used to investigate the effects of front anti-roll bar stiffness on ride quality using synthetically generated roughness profiles. The simulated results revealed that while the anti-roll bar does not influence the ride quality on symmetric roughness profiles, significantly higher seat base accelerations are observed with stiffer anti-roll bars on asymmetric profiles, particularly in the lateral axis. Based on these results an active anti-roll bar control algorithm, operating in a co-simulation environment, is proposed to reduce the seat base accelerations while maintaining the desired handling characteristics. Handling characteristics of the vehicle are investigated using various transient tests such as double-lane-change and J-turn. It is found that the ride quality of an off-road vehicle traversing over a natural terrain can be significantly improved using active anti-roll control without compromising the cornering characteristics.