Development of technology for automatic detection of forwarder loading platform and log loading position

Abstract

A method for the automatic detection of a forwarder’s position and orientation using 3D LiDAR has been developed, along with a system to determine the appropriate loading position based on the loading conditions of the platform. The accuracy of the forwarder detection and the validity of the determined loading position were investigated, and their relationship with measurement conditions was evaluated. The forwarder’s position and orientation were estimated by placing five markers with reflective tape wrapped around a pole on the loading platform, which were then measured using 3D LiDAR and aligned with model points. The log loading position was calculated by analyzing the surface point clouds on the loading platform and identifying valleys formed by the logs. Experiments were conducted by varying the number of point clouds, number of loaded logs on the loading platform, and forwarder angle. When five markers were detected, the forwarder position estimation error was 0.052 m, with orientation estimation errors of 0.51° in roll, −0.25° in pitch, and −0.08° in yaw. For the log loading position estimation, the error increased with the forwarder angle. The two-dimensional error in the cross-section of the loading platform was 0.049 m when four logs were loaded at a forwarder angle of 0°, 0.041 m with seven logs, and 0.058 m with ten logs, , indicating that forwarder detection and loading position determination could be performed within practical limits.