Coordinated Control of Steering and Anti-Roll Bars to Alter Vehicle Rollover Tendencies

Abstract

A Variable Dynamic Testbed Vehicle is presently being built for the National Highway Traffic Safety Administration. It will have four-wheel steering, front and rear active antiroll bar systems, four adjustable dampers, and other active controls. Using these active devices, we can alter the vehicle’s understeer coefficient, front/rear load transfer distribution in high-g lateral maneuvers, and roll mode frequency and damping. This study investigates how these active systems could be controlled to alter the vehicle rollover tendencies. In particular, we study how an increased front antiroll bar stiffness, in conjunction with an increased front damper rate and out-of-phase rear steering could improve vehicle rollover resistance and enhance vehicle safety. Similar but “reverse” algorithms could be used to artificially degrade the rollover resistance of a vehicle. Rollover-related accidents could then be studied using such a vehicle. Results obtained could also provide guidelines for the safe operation of the variable dynamic vehicle in limit lateral maneuvers.

Derivation and validation of nonlinear governing equations for an analysis of vehicle handling

“…[Unit] (Buffalo, 2003) (Lee, 1998) RWD bias ply FWD radial FWD radial (2003), K a s for two tires are 0.2 and 0.05 ** In the reference of Buffalo (2003), µ 0 of two tires is 0.85. ※ In the reference of Lee (1998), no data.…”

Integration of vehicle yaw stabilisation and rollover prevention through nonlinear hierarchical control allocation

“…Control systems have been successfully designed to mitigate rollover by using brakes, [5][6][7] steering, [8,9] anti-roll bars, [10,11] or a combination of different actuators. [12][13][14] The majority of approaches quantifies the rollover threat by an appropriate index and switches the control authority to a roll stabilising controller when indicated. To mitigate rollover without affecting the yaw rate, Rajamani and Piyabongkarn [15] propose to counter-steer the vehicle into the negative roll angle equilibrium during cornering.…”

Control Methods for Roll Instability of Articulated Steering Vehicles

“…These achievements offer great reference value to the study on the active safety technology of the rollover protection of off-highway vehicles. According to relevant literature, the active control measures of vehicles' rollover protection include active steering [5][6][7], active braking [8,9], active and semiactive suspension control [10,11], active roll bars [12,13], and integrated control [14][15][16].…”