Towards Autonomous Robotic Precision Harvesting: Mapping, Localization, Planning and Control for a Legged Tree Harvester

TL;DR

This paper introduces an integrated autonomous system for precision harvesting with a legged tree harvester, capable of mapping, localization, planning, and control in GPS-denied forest environments, demonstrated in real-world tests.

Contribution

It presents a novel fully autonomous harvesting system combining mapping, localization, planning, and control for a legged tree harvester in challenging environments.

Findings

Successful autonomous navigation and tree grabbing in natural forests.

First demonstration of full autonomy on a full-size hydraulic machine in realistic conditions.

Effective integration of mapping, planning, and control for precision harvesting.

Abstract

This paper presents an integrated system for performing precision harvesting missions using a legged harvester. Our harvester performs a challenging task of autonomous navigation and tree grabbing in a confined, GPS denied forest environment. Strategies for mapping, localization, planning, and control are proposed and integrated into a fully autonomous system. The mission starts with a human mapping the area of interest using a custom-made sensor module. Subsequently, a human expert selects the trees for harvesting. The sensor module is then mounted on the machine and used for localization within the given map. A planning algorithm searches for both an approach pose and a path in a single path planning problem. We design a path following controller leveraging the legged harvester's capabilities for negotiating rough terrain. Upon reaching the approach pose, the machine grabs a tree with a general-purpose gripper. This process repeats for all the trees selected by the operator. Our system has been tested on a testing field with tree trunks and in a natural forest. To the best of our knowledge, this is the first time this level of autonomy has been shown on a full-size hydraulic machine operating in a realistic environment.