Swerve correction of heavy-duty articulated lorries

The trailers of heavy-duty articulated lorries are usually linked to the tractors by auxiliary dollies to improve the manoeuvrability along curved paths. Connecting the dolly to the tractor by a four-bar linkage, some performance improvement may be achieved in comparison with the conventional single pin. The correct path along a road curve may be obtained exerting control moments on the horizontal plane by means of differential braking of the wheels. The results of the analysis show that the forward-converging and the crossing bar quadrilaterals are mostly yaw-stable, whereas the farther backward-converging bars prove to be inherently unstable.