Method and device for determining the total length of a trailer

The method involves determining the trailer-side axis coupling ratio. The motion vector (v) of the movement of rear end (9) of the trailer (3) is determined at a constant or quasi-constant circular drive, in which the motion vector represents the direction and speed of the rear end of trailer relative to the road surface. The trailer-side axis-rear distance (IU) is determined in dependence on the direction and the speed. The overall length is determined as the sum of trailer side axle-clutch-distance (lA) and the trailer side axis-rear distance. An independent claim is included for device for determining total length of trailer of vehicle combination.