A basic requirement for long-lasting, healthy trees is regular and professional pruning. According to Germany’s University of Hohenheim, about 80% of fruit trees in Germany are not pruned regularly, despite the fact that this makes them structurally stronger and more resistant to disease. As a result, the trees become sick or die.
Now, a project by the University of Hohenheim in Stuttgart wants to provide support with the help of artificial intelligence. The engineers are working on the development of an autonomous robot that will largely take over tree pruning independently in the future so that they grow old healthy.
The autonomous robot, named Phoenix, is being developed by the Hohenheim agricultural technician Dr. Reiser, together with the Ph.D. student Jonas Straub and the research assistant Jonas Boysen in the field of process engineering in plant production.
The scientists have mounted an additional robotic arm on an existing mobile prototype. This articulated arm robot can move freely in all directions so that any point within its range can be controlled. The arm is also equipped with special sensors that help navigate and recognize the trees and their structures.
The pruning robot is slated to begin each pruning mission by first driving around the tree, performing 3D scans using the built-in LiDAR scanner and an optical camera. The integrated computer will then use the scanned data to create a tree model showing the three-dimensional structure of its crown. The AI-based software will then analyze this structure, determining which branches need to be cut to keep the crown in optimal shape.
Finally, the Phoenix will proceed to automatically perform the actual pruning with the help of a small saw at the end of the articulated arm to remove the problematic branches.
“We are currently working on teaching the computer where the robot should place the saw,” says Dr. Reiser. “Tree pruning is a science in itself, and you could almost speak of philosophy.”
The current pruning robot prototype still has to be controlled manually to the individual trees and interfaces. In the future, however, Phoenix will be able to autonomously navigate through orchards using a combination of its onboard sensors and a navigation system and cut branches up to a height of seven meters.