Motion dynamics and path tracking control problem of a dual-unit articulated vehicle

A particular class of vehicles, consisting of two units of single axle half vehicles (or two-wheeled trailer) pivoted together in the middle, is used for ore transportation in underground mines. Steering of this vehicle is performed by changing the angle between the two units through an actuator. Automated motion of this relatively low-speed vehicle is of interest. In this paper, the dynamics of motion of this type of vehicle are studied and the equations governing the motion and the tracking error dynamics are formulated. The objective is to see how the dynamic forces can affect the vehicle behaviour in path tracking. The system inputs are the traction forces on the front and rear wheels and the articulation actuator effort. These equations can be used for formulation of the path tracking control problem and synthesis of a control policy for automated guidance of the vehicle.