Abstract: A method and a system for regulating, while the vehicle is in motion, the linear position of a fifth wheel of a vehicle combination which comprises a tractor unit and a semi-trailer, which linear position of the fifth wheel is regulated automatically on the basis of the vehicle speed. Forward movement of the fifth wheel ordered in response to an increase in the vehicle speed, in order to reduce the distance between the driving cab and the semi-trailer, is effected at a faster rate of movement of the fifth wheel at times when the tractor unit is performing a gear change operation than at times when the tractor unit is not performing a gear change operation. When a rearward movement of the fifth wheel to increase the distance between the driving cab and the semi-trailer has to be effected in response to a decrease in the vehicle speed, braking of the semi-trailer relative to the tractor unit is ordered, in order thereby to facilitate the rearward movement of the fifth wheel.

Abstract: A method and a system for regulating, while the vehicle is in motion, the linear position of a fifth wheel (4) of a vehicle combination which comprises a tractor unit (1) and a semi-trailer (2), which linear position of the fifth wheel is regulated automatically on the basis of the vehicle speed. Forward movement of the fifth wheel ordered in response to an increase in the vehicle speed, in order to reduce the distance between the driving cab (3) and the semi-trailer, is effected at a faster rate of movement of the fifth wheel at times when the tractor unit is performing a gear change operation than at times when the tractor unit is not performing a gear change operation. When a rearward movement of the fifth wheel to increase the distance between the driving cab and the semi-trailer has to be effected in response to a decrease in the vehicle speed, braking of the semi-trailer relative to the tractor unit is ordered, in order thereby to facilitate the rearward movement of the fifth wheel.

Abstract: A method and a system for regulating, while the vehicle is in motion, the linear position of a fifth wheel (4) of a vehicle combination which comprises a tractor unit (1) and a semi-trailer (2), which linear position of the fifth wheel is regulated automatically on the basis of the vehicle speed. Forward movement of the fifth wheel ordered in response to an increase in the vehicle speed, in order to reduce the distance between the driving cab (3) and the semi-trailer, is effected at a faster rate of movement of the fifth wheel at times when the tractor unit is performing a gear change operation than at times when the tractor unit is not performing a gear change operation. When a rearward movement of the fifth wheel to increase the distance between the driving cab and the semi-trailer has to be effected in response to a decrease in the vehicle speed, braking of the semi-trailer relative to the tractor unit is ordered, in order thereby to facilitate the rearward movement of the fifth wheel.