Trajectory segmentation for the autonomous control of backward motion for truck and trailer

For logistics centers the disposition and dispatch of goods has reached a high standard of automation. However, the trucks and trailers bringing and taking the goods are driven manually. This can at least be improved for the non-public traffic in the scope of logistics centers by autonomous forward and backward motion control for standard transportation vehicles. By an experimental system it has been shown that truck and trailer can be maneuvered autonomously at a high degree of precision. For purposes of safety it is necessary to guarantee that at any instant of time the vehicle is within some predefined area. Therefore this paper introduces the principle of safe cover segments which are never left by the vehicle in motion and defines rules for the connection of such segments forming a safe corridor.

I. Inroduction

The control theory distinguishes between different classes of vehicles with respect to their kinematics. The most easy class of vehicles is called holonomic and allows any change of direction. In contrast nonholonomic vehicles have a limited freedom of motion. This is already given for a single truck, also called standard 1-trailer [1]. The freedom of motion for standard -trailers which are composed of a truck and one-axle trailers, are described by chain-form differential equations and are investigated with regard to their controliability (see e.g. [2], [3], [4]). However their approach is based on the geometric condition that the coupling device between truck and trailer is exactly above the backward axis of the truck. In contrast, for standard transportation vehicles, as for truck and trailer or as for semitrailers, there is a distance between these two positions. This is expressed with the notation of a general n-trailer [5] leading to a control problem which is even more challenging.