Autonomous Robot Digger Constructs Massive Dry Stone Wall from Random Rocks

Autonomous Excavator Constructs Dry-Stone Wall

Researchers at ETH Zurich have achieved a significant milestone in the field of autonomous construction. They have trained an excavator to construct a dry-stone wall using random rocks and building waste. The wall measures 65m in length and 6m in height.

The excavator, known as Heap (hydraulic excavator for an autonomous purpose), is a customised Menzi Muck M545 equipped with various sensors including cameras, lidars, inertial measurement, satellite navigation, and joint angle sensors. These sensors enable the excavator to autonomously create a 3D map of the construction site and identify suitable building blocks and rocks for the wall.

By scanning the stones, the excavator is able to estimate their weight and centre-of-gravity. An algorithm then matches these known stones to the remaining locations on the growing wall. The researchers explained in a paper that their geometric planning algorithm uses a combination of constrained registration and signed-distance-field classification to determine the optimal positioning of the stones for stability and shape.

The excavator's efficiency is impressive, as it can place 20 to 30 stones in a single consignment, which is equivalent to the supply of one delivery. This makes the construction process faster and more streamlined.

The dry-stone wall is part of a digitally planned park that is being built gradually by the autonomous excavator. The wall retains robotically contoured terraces and stands near a 10 x 4 x 1.7m freestanding dry stone that the machine also constructed.

The research paper titled "A framework for robotic excavation and dry stone construction using on-site materials" provides more details on the project. However, only the abstract is available without payment.