Lateral sway motion of vehicle and trailer

In everyday life, the joint movement of a vehicle and trailer is widespread. Accordingly, when towing a trailer, due to road irregularities, potholes and the influence of side wind, a lateral swaying movement may occur. Under certain conditions, the swinging movement can increase, even ending with the overturning of a vehicle or a trailer. It is influenced by the mass of the vehicle and the trailer, as well as the initial conditions for the movement. This article discusses how to prevent such unwanted motion modes with active motion control. Movement on a horizontal road of the vehicle and trailer mutually connected with a non-deformable coupling is studied. The case is analysed when the towing vehicle moves without slipping, but the trailer can start to slide sideways. Using the technique of classical mechanics, the differential equations of the system motion were drawn up, in which a combined model of sliding and rolling resistance was used. The equations also include adaptive control of sway damping. One of the adaptive sway damping models is created as a moment of internal forces in the coupling joint. This torque control is programmed as a function with feedback from the trailer turning angle and angular velocity. The turning on of the control moment takes place against the direction of the angular velocity, observing the turning off in the range of relatively small turning angles. The second sway damping control model was created as a supplement to the towing car drive power. Also in this model, the feedback reacts to high values of the trailer turning angle and angular velocity. The motions of the vehicle and the trailer are analysed by computer simulation, in which the sway motion is induced by crosswind interaction. For all studied cases, computer simulation results are presented graphically in the form of time histories and phase diagrams. In general, the results obtained can be used in some other similar dynamic applications.