# 3507 / Determination of the tractive forces of a tractor based on the reconstruction of... Title: Determination of the tractive forces of a tractor based on the reconstruction of tire – soil contact surface obtained by means of photogrammetry Authors: Jaroslaw Pytka, Tomasz Śliczniak, Leszek Gardyński, Aleksander Czajka, and Sławomir Tarkowski Abstract: The aim of the work was to develop a method for determining tractive forces based on a three-dimensional reconstruction of the tire - soil contact surface. The photogrammetry method was used to reconstruct the contact surface between the tractor tire and the soil, further the traction forces were determined using the Bekker model. The value of the contact pressure was determined on the basis of the three-dimensional model of the contact surface. The tow test method was used to measure traction forces as part of verification tests. Field measurements were carried out for different wheel load values, on two soils, sandy and loamy, at different moisture. It was found that the obtained values of the drawbar pull force, determined analytically using photogrammetry, show small discrepancies in relation to the values measured in field tests using a dynamometer. In the case of loamy soil, it was noticed that with increasing moisture, the sinkage of the wheel (rut depth) as well as the horizontal displacement of the soil was smaller. Order the full paper: ISTVS members: receive three papers per year as part of your membership via the ISTVS Member Portal: --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://2023.istvs.org/submissions/papers/3507.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.