Motion control with minimization of a boundary off-track for non-Standard N-trailers along forward-followed paths

When a multi-body tractor-trailers (N-trailer) vehicle has to follow a varying-curvature reference path, the unavoidable effect of a non-zero off-track occurs for most of the vehicle segments. The boundary off-track determines a minimal width of an envelope around the path which must be kept obstacle-free to ensure safe motion of a vehicle. The cascade-like control strategy presented by the author in his previous works is generalized here to enable minimization of the envelope width by introducing and utilizing the so-called virtual guidance point of a vehicle being a linear weighted combination of postures of all the vehicle segments. Application of the proposed control strategy with appropriately chosen weights allows reducing the boundary off-track for the N-trailers equipped with off-axle hitches. Exemplary simulation results show efficacy and utility of the method for a vehicle with three trailers and mixed signs of hitching offsets.