Design of kinematic coupling of the rear wheels of a road trailer

Abstract

This paper discusses the design of the kinematic coupling for the passage of an articulated vehicle combination through a bend. A lorry (tractor unit) and a semi-trailer as a trailer are used as an articulated vehicle combination. In the standard design of an articulated vehicle combination, the track of the wheels of the tractor unit wheels and the semi-trailer differs when passing through a bend. As a result, the track of the articulated vehicle combination (lane width) is increased when a bend is negotiated compared to when driving in a straight line. This situation restricts the handling of the vehicle in a limited space, such as city streets and lower-class roads. A mathematical relationship defining the steering angle of the steerable wheels on the axles of the semi-trailer is presented in the paper. It outcome is a set of kinematic equations indicating the partial steering angles of the steerable wheels of the semi-trailer, ensuring that these wheels copy the steering path of the tractor unit while simultaneously rolling smoothly on the road. The theoretical approach is also applied to a real interaction tractor unit and semi-trailer. The use of steerable wheels on a semi-trailer will significantly improve the handling of the entire articulated vehicle combination. A key benefit of this work is its relevance to autonomous vehicle control, where a smaller number of sensors monitoring the vehicle’s surroundings – while maintaining a high degree of safety – is fully sufficient for a semi-trailer.