Time-of-flight imaging for assessing soil deformations and improving forestry vehicle tracking accuracy

Abstract

ABSTRACT Automatically collected forest environment data is essential when developing more accurate and efficient forestry operations. Reliable position-based data enables efficient wood procurement operations and helps to avoid damage to the forest floor. A modern forestry vehicle with extensive sensing capabilities could measure environmental parameters, such as soil type, topography or weather conditions, while carrying out other wood procurement tasks. Furthermore, methods to improve positioning accuracy are also called for when the positioning is based on global satellite navigation systems (GNSS), whose signals are often blocked by the forest canopy. In this article, data is collected automatically with two of Microsoft’s Kinect v2 time-of-flight sensors during field tests in a forest environment in Southern Finland. The aim of the article is to propose methods which will improve positioning accuracy by enabling the movement of the forwarder to be detected and also to provide reliable measurements of any soil deformations caused by the vehicle in real time. The results show that Kinect v2 technology enables tracking of the vehicle’s movements over short distances with sub-meter accuracy, thus supporting the GNSS positioning during the short periods of unavailable satellite visibility. Kinect v2 technology has also been shown to be able to measure the depth of ruts as accurately as conventional manual measurements.