Determination of the characteristics of the soil flow formed by a forest fire truck using optical recognition and optical measurement methods

Conducting field experimental research is an integral part of the development and research of agricultural and forestry tools. Ground-throwing equipment used to extinguish and prevent forest ground fires is undergoing a number of theoretical and laboratory-field studies. From the moment of separation by the milling working body until the moment it meets the edge of the forest ground fire, the soil is in flight in the form of fragments moving in the air under the influence of the laws of aerodynamics and opposing forces. A significant increase in the computing power of computers, the development of the modeling process, as well as the improvement of algorithms provided an opportunity to increase progress in the application of computer vision and optical measurement methods in scientific research. The purpose of the work is to determine the characteristics of the movement of the soil flow in the air by the methods of optical recognition and optical measurement from the video sequence. To achieve the goal of the study, it is necessary to identify the most effective method of optical recognition, which makes it possible to separate the flow of soil from the background with high reliability and develop a mathematical apparatus that allows, for each frame of the video recording of the field experiment, to determine the characteristics of the flow of soil formed by forest fire ground-throwing equipment. In the course of scientific research, we have tested five main methods of optical recognition by video sequence to determine the most effective method for separating the image of the soil flow from background images (trees, branches, grass, etc.): separation by color, separation by brightness, combination methods by colors and brightness, determining the background image (preliminary or by averaging a set of video frames) and separating moving objects on a video frame from the background, highlighting areas of frames blurred in motion. Analysis of the methods showed that the combined color-brightness method is the most effective for achieving the goal set in the work. Based on the shape of the trajectory of the soil flow, it was found that the forest fire soil thrower delivers the soil flow at an angle of 35º to the horizon with an initial speed of 14 m/s, while the distance of throwing the soil is 11 m. As the soil flow moves, the speed first decreases from 14 m/s to 6 m/s due to the flight of the soil upwards and the transition of kinetic energy into potential energy, then increases from 6 m/s to 8 m/s as the soil falls to the surface due to the transition of potential energy into kinetic energy. The angle of subsidence of soil particles on the surface is about 73° to the horizon, which favors extinguishing the edge of a forest ground fire.