Active variable geometry suspension system development for a small off-road vehicle

In this paper, a non-linear full-vehicle model of a mini Baja off-road vehicle is retrofitted with a series active variable geometry suspension (SAVGS). Small off-road vehicles usually have trouble performing tight cornering maneuvers due to loss of tire normal force generation and grip, leading to poor steering performance. The maneuverability is of paramount importance for race cars, thus increasing the front axle roll stiffness by changing spring forces could lead to oversteer behavior which is desired. The SAVGS can improve the cornering performance of the off-road vehicle. A powerful multibody dynamics model is proposed for vehicle and suspension dynamics behavior simulation. Overly, a configuration of 45 degrees left (outer) link and 150 degrees right (inner) link produced the best results. The proposed SAVGS satisfies the stability in the high LATAC cornering test, contrary to the conventional vehicle, and improves the understeer gradient between 15% to 58% in the other cases.