Determining the theoretical trajectory of the centre of tractor’s mass when turning in a combined way

Abstract

Abstract One of the ways to increase the stability of movement and improve the manoeuvrability and controllability of a wheeled universal row-crop tractor in curvilinear motion is the choice of a rational turning method. To solve the tasks, the authors proposed a combined method of turning the tractor, which consists in crabbing in the entry into the rotation, after which the rear wheels automatically return to the neutral position and then the direction of movement in the established rotation and exit from the rotation uses front steering wheels. The article developed a methodology for determining the theoretical trajectory of the centre of mass of a wheeled tractor with a combined method of rotation for the three distinct sections of the movement included in it. Based on the conditions of smoothness and continuity, we glued together three characteristic sections of the curvilinear trajectory of the centre of mass and obtained a continuous non-linear piecewise smooth function of the investigated combined rotation method. It is possible to apply the research results for theoretical calculations of the parameters for the curvilinear motion of tractors, as well as other wheeled vehicles, that allows choosing rational laws to change the speed and control modes of turning the wheels, to identify the patterns of change for ensuring the necessary stability, manoeuvrability and controllability and confirming effectiveness in comparison with known and previously investigated laws.