Abstract: Devices are for compensating for the roll of a fifth-wheel coupling, such as on a prime mover towing a semi-trailer. An automated compensation system for a fifth-wheel coupling mounted on a towing vehicle unit includes a first pivoting support to support one lateral side of the fifth-wheel coupling; a second pivoting support to support an opposite lateral side of the fifth-wheel coupling; an actuator configured to cause movement of the first and second pivoting supports; a sensor to sense a parameter relevant to determining whether roll compensation is required for the vehicle; a controller configured to receive a sensor output of the sensor and to determine whether roll compensation is required based on the sensor output, the controller being further configured to issue a control signal to cause the actuator to move the first and second pivoting supports when the controller determines that roll compensation is required.

Abstract: A method of controlling the sideways motion of a trailer forming part of a combination vehicle, such as a road train, for road transport of heavy goods. The vehicle has a trailer including a semi-trailer body and a dolly mounted beneath the front of the semi-trailer body. The method includes steering at least some of the wheels on said axle sets relative to the dolly frame such that at high speeds, as the vehicle turns towards one side, steering the dolly wheels to induce the dolly to move towards that side and, at low speeds, as said vehicle turns towards that side, steering the dolly wheels to induce the dolly to move towards the opposite side.

Abstract: A method of controlling a combination vehicle for road transport of heavy goods, said vehicle comprising a motor vehicle at the front and a trailer attached so as to be towed behind the motor vehicle, said trailer comprising: (a) a semi-trailer body adapted to carry goods, (b) a dolly mounted beneath the front of the semi-trailer body and connected to the semi-trailer body by a pivoting connection, said dolly comprising road wheels attached in one or more axle sets to a dolly frame, each axle set extending across the dolly frame, and (c) a drawbar assembly connecting the dolly frame to a preceding vehicle unit by means of a trailer coupling assembly, wherein: (i) the drawbar assembly defines an instant centre of rotation for the dolly which is located forwards of said trailer coupling assembly while the vehicle is moving forwards at high road speeds, and (ii) the drawbar assembly defines an instant centre of rotation for the dolly which is located at least substantially at the trailer coupling assembly while

Abstract: A method of controlling the sideways motion of a trailer forming part of a combination vehicle, such as a road train, for road transport of heavy goods. The vehicle has a trailer including a semi-trailer body and a dolly mounted beneath the front of the semi-trailer body. The method includes steering at least some of the wheels on said axle sets relative to the dolly frame such that at high speeds, as the vehicle turns towards one side, steering the dolly wheels to induce the dolly to move towards that side and, at low speeds, as said vehicle turns towards that side, steering the dolly wheels to induce the dolly to move towards the opposite side.