  Construction equipment is designed to maintain good traction, even when
operating in difficult off-road conditions. To curb wheel slip, the vehicles
are equipped with differential locks. A driver may engage/disengage the locks
to switch between two distinct operating modes: the closed mode is
characterized by greater off-road passability while the open mode allows better
manoeuvrability. However, many drivers lack the education and experience
required to correctly judge the terrain ahead of the vehicle and therefore
engage/disengage the locks in a suboptimal fashion. An automatic traction
control solution for locking and opening the differentials is hence desirable.
This paper compares three on/off differential lock control algorithms, all
derived from the same kinematic vehicle model but each relying on the
availability of output signals from different sensors. The validity of the
kinematic model and the algorithms' sensitivity to the values assumed by a
couple of unobservable states, the wheel slip angles, is investigated by
comparison to a realistic articulated hauler model in the multibody physics
simulator MSC ADAMS.
