Experimental Investigation of Interconnected Hydraulic Suspensions with Different Configurations to Soften Warp Mode for Improving Off-Road Vehicle Trafficability

Hydraulic suspension systems with different interconnected configurations can decouple suspension mode and improve performance of a particular mode. In this paper, two types of interconnected suspensions are compared for off-road vehicle trafficability. Traditionally, anti-roll bar, a mechanically interconnected suspension system, connecting left and right suspension, decouples roll mode from the bounce mode and results in a stiff roll mode and a soft bounce mode, which is desired. However, anti-roll bars fail to connect the front wheel motions with the rear wheels', thus the wheels' motions in the warp mode are affected by anti-roll bars and it results an undesired stiffened warp mode. A stiffened warp mode limits the wheel-ground contact and may cause one wheel lift up especially during off-road drive. In contrast with anti-roll bars, two types of hydraulic suspensions which interconnect four wheels (for two-axis vehicles) can further decouple articulation mode from other modes. Based on previous researches, the mass-spring-damper method is used in modeling a sport utility vehicle, the full-car transient modeling approach is utilized for modeling two hydraulic suspensions. An experimental vehicle fitted with these systems has been tested on different type of terrains under the same condition, and the comparison of the experimental results is presented.