Path-tracking for articulated vehicles with off-axle hitching

A technique that complements path-tracking controller design procedures based on exact linearization is proposed. The objective is to make these procedures applicable to vehicles whose kinematic model is not necessarily exactly linearizable (as a tractor-trailer with off-axle hitching or a load-haul-dump mining vehicle). A key element of our approach is to control a inexactly linearizable vehicle by associating to it an auxiliary (ghost) vehicle whose model can be exactly linearized and whose behavior satisfies certain compatibility conditions. Main features of this approach are illustrated by considering articulated vehicles with off-axle hitching (which are not exactly-linearizable), and by focusing attention to a geometric path-tracking design procedure recently developed by Sampei et al. (1993, 1995)