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Autonomous excavator constructs a 6-meter-high dry-stone wall

November 22, 2023
ETH Zurich
Researchers taught an autonomous excavator to construct dry stone walls itself using boulders weighing several tons and demolition debris.

Until today, dry stone wall construction has involved vast amounts of manual labour. A multidisciplinary team of ETH Zurich researchers developed a method of using an autonomous excavator to construct a dry-​stone wall that is six metres high and sixty-​five metres long. Dry stone walls are resource efficient as they use locally sourced materials, such as concrete slabs that are low in embodied energy.

ETH Zurich researchers deployed an autonomous excavator, called HEAP, to build a six metre-high and sixty-five-metre-long dry-stone wall. The wall is embedded in a digitally planned and autonomously excavated landscape and park.

The team of researchers included: Gramazio Kohler Research, the Robotics Systems Lab, Vision for Robotics Lab, and the Chair of Landscape Architecture. They developed this innovative design application as part of the National Centre of Competence in Research for Digital Fabrication (NCCR dfab).

Using sensors, the excavator can autonomously draw a 3D map of the construction site and localise existing building blocks and stones for the wall's construction. Specifically designed tools and machine vision approaches enable the excavator to scan and grab large stones in its immediate environment. It can also register their approximate weight as well as their centre of gravity.

An algorithm determines the best position for each stone, and the excavator then conducts the task itself by placing the stones in the desired location. The autonomous machine can place 20 to 30 stones in a single consignment -- about as many as one delivery could supply.

Story Source:

Materials provided by ETH Zurich. Original written by Michael Walther. Note: Content may be edited for style and length.

Journal Reference:

  1. Ryan Luke Johns, Martin Wermelinger, Ruben Mascaro, Dominic Jud, Ilmar Hurkxkens, Lauren Vasey, Margarita Chli, Fabio Gramazio, Matthias Kohler, Marco Hutter. A framework for robotic excavation and dry stone construction using on-site materials. Science Robotics, 2023; 8 (84) DOI: 10.1126/scirobotics.abp9758

Cite This Page:

ETH Zurich. "Autonomous excavator constructs a 6-meter-high dry-stone wall." ScienceDaily. ScienceDaily, 22 November 2023. <>.
ETH Zurich. (2023, November 22). Autonomous excavator constructs a 6-meter-high dry-stone wall. ScienceDaily. Retrieved March 2, 2024 from
ETH Zurich. "Autonomous excavator constructs a 6-meter-high dry-stone wall." ScienceDaily. (accessed March 2, 2024).

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