Study of the controlled motion process of an agricultural wide span vehicle fitted with an automatic driving device

The aim of research is to analyse the process of the wide span vehicle motion on the treads of the permanent process track with the use of the traction method of turn. The completed studies have proved that the plane-parallel motion of a wide span vehicle solely with the use of the traction method of turn on the treads of the permanent process track requires a significantly smaller difference between the moments applied to the wheels on the right side and on the left side of the vehicle, as compared to that of a crawler tractor. This difference is in proportion to the width of its wheel base that has a relatively smaller length. It has been established that the use of solely traction-based turn does not provide for the adjustment of the motion trajectory through the lateral (plane-parallel) displacement of the fore-and-aft axis of the agricultural wide span vehicle. The oscillations in the lateral displacement of the agricultural wide span vehicle in the process of its motion are low-frequency ones. The main variance spectrum of these oscillations is concentrated within the range of frequencies of 0-2 s-1. At the same time, the maximum transverse displacement of the agricultural wide span vehicle equal to 1.3 10-5 m N-1, occurs also at low frequencies. In view of the fact that the main variance spectrum of the oscillations of the tangential forces applied to the wheels on the left and right sides of the agricultural wide span vehicle is concentrated exactly within a low frequency range, only the high accuracy of the system using a laser beam can ensure its satisfactory steerability.