Log Loading Automation for Timber-Harvesting Industry

The timber-harvesting industry is lagging its peer industries, such as mining and agriculture, with respect to deployment of robotic, AI and autonomous technologies. In this paper, we tackle automation of a critical task that arises in transporting logs from the forest to the sawmill: the log loading operation. This work is motivated by the acute shortages of human operators and the need to improve the efficiencies of timber-harvesting processes. To this end, we demonstrate the full autonomy pipeline for the log loading operation with a fixed-base manipulator (a.k.a., the crane), starting with perception of logs around the machine, then grasp planning for where to grasp logs, through motion planning and control of the log loading maneuver. Our main contribution is in the full integration of the necessary elements to achieve a completely autonomous loading cycle, where the crane picks up and loads all logs within its reach on a trailer. Notable features of our implementation are a generalizable perception stack, a grasp planner to pick up multiple logs at a time and an extensive experimental campaign conducted outdoors, on a commercial log loader retrofitted for autonomy. Our results demonstrate an overall 87% success rate of the log loading operation, with primary failure cases due to log segmentation errors and deficiencies in the final height adjustment algorithm for grasping logs. We also present detailed timing results of the main parts of the autonomy pipeline, which support the feasibility of deployment in operational environment.

I. Introduction

Interest in applying advances in robotics and AI in the forestry industry and, specifically for forestry operations, has increased significantly over the past few years [1], [2]. Research on automating the operation of timber harvesting machines, in particular, is primarily motivated by the lack of skilled machine operators and the need to increase efficiencies. These factors make the shift from human-operated to automated forestry machines an urgent concern [3], [4]. While forestry operations are numerous and diverse, the log loading operation is critical to the wood supply chain as it is carried out at several points along the supply route, from the forest to the sawmill. Due to the variability in operational scenarios and unstructured nature of the operating environment, it is a challenging task to automate and forms the central focus of this paper.