Work has been performed in several directions to ensure the development of the different technologies relevant to the DigiForest objectives for the first year.
As a first step, the members of the consortium have worked in enabling field autonomy of the different robot platforms which will be leveraged in the project. During the first year, the semi-autonomous harvester has received several hardware upgrades to perform chassis balancing and to be able to perform position control of the hydraulic manipulator.
For the ANYmal and the different drones, state-estimation frameworks have been developed to allow for precise odometry in challenging, unstructured environments such as a forest. The state-estimation frameworks rely on LiDAR-IMU sensors or visual-inertial sensors. Also, approaches leveraging submaps for scalable mapping have been developed.
To ensure safe navigation, traversability-aware navigation methods have been developed based either on geometric information or on semantics and geometric information for the different ground-robots. Path planning, based either on submaps or monolithic maps, has been developed for the drones. Also, reactive planning is being studied, to avoid trees and branches of the forest while flying through it, which will allow for autonomous navigation of the drones without the requirement of a prior map.
The BLK laser scanner family from Leica as part of their drone (BLK2FLY) and as handheld carriers (BLK2GO) has also been integrated on the ANYmal. These will be used for high precision measurements of the forests.
A map server interface has been defined to allow for a common representation of the maps generated by the different platforms. These maps will be used to generate the valuable properties related to the forest, after being mapped by the robotic platforms. During this period, work on semantic and object-level mapping in an offline fashion has been done, by post-processing the map information from the map server. Also, geometric modelling is performed on these offline maps to compute estimate the tree trunk via cylindrical primitives.
Two filed trials have been conducted during this period, one in Switzerland and another, more extensive one, in Finland. In these, the different members of the consortium have tested their developments in a real-world scenario and also collected data to continue with their development. With the data collected in these trials, initial work on the development of an individual tree inventory has started and initial efforts on the decision support system development have been performed. Also, a logging planner and interface to allow for the harvester to perform path planning has been developed.
