Study of the positioning accuracy of machine-tractor units for working on slopes

In Ukraine, a precision farming system based on geo-information technologies is used. The quality of technological operations depends on the accuracy of the positioning of the machine-tractor unit. In Ukraine, a large part of agricultural land is located on slopes. When using machine-tractor units equipped with navigation devices without gyroscopes on slopes, the accuracy of positioning depends on the errors caused by both correction signals and the angle of inclination of the working area. In the article, theoretical studies are carried out on the influence of the height of the antenna of the navigation equipment and the angle of transversal inclination of the working area of the field on the positioning error of the unit. It has been found that the positioning error of the unit caused by the transverse inclination of the site increases significantly with the increase in the angle of inclination of the site and the height of the antenna location. To confirm the theoretical data, a multivariate experiment was carried out using the non-composite Box-Behnken plan. The ASN-Agro parallel drive system with ASN-Agro V1.03 software was used to investigate the positioning accuracy of the machine-tractor unit. For the experimental studies, a machine-tractor unit was used, consisting of MTZ1221 tractor, OGN 800/16 sprayer and ASN-Agro parallel drive system. The research was carried out taking into account the following factors: the height of the antenna of the navigation equipment, the angle of the transverse inclination of the working area, the speed of the machine-tractor unit. The height of the antenna of the navigation equipment above the surface of the working area was 1–2.8 m. The transverse tilt angle of the work area was 0–3 degrees. Based on the results of the research, regression equations were obtained and response surfaces were constructed. The analysis of the experimental data shows that the angle of transversal inclination of the field surface and the height of the antenna of the navigation equipment have a significant influence on the accuracy of the positioning of the unit.