October 20, 2011

Column | Korky Koroluk

Swiss Architects, Carnegie Mellon engineers develop robotic construction technologies

An aging workforce has been a worry for the Canadian construction industry for a decade or more, and there doesn’t seem to be any sign of the situation improving.

If young people don’t choose to learn a construction trade, and immigration of skilled tradespeople continues at present levels, a labour crunch in the industry is inevitable. It’s also inevitable that robots of one kind or another will be looked at as a way to help alleviate labour shortages.

People who like working in high-tech fields are almost inevitably drawn to robots. Who could resist a robot that can build a brick wall unattended, or a robotic excavator that can load trucks without human interference? Well, both are closer than you might think.

Robotic construction of walls, or other shapes, is already being done in Switzerland. Fabio Grazmazio and Matthias Kohler are architects who teach at the Institute for Technology at ETH Zurich. Since 2006 they have explored various ways of creating astonishing structures built entirely by robots. They use digital design tools to create novel shapes and patterns that wouldn’t be possible without robots that are extremely precise in their work, and unbeatable at repetition.

They have written several algorithms for their machine, each enabling it to do different jobs. Algorithms, in computer-speak, are sets of rules used for calculations or problem-solving. Designers write the algorithms; programmers convert them to software applications which can be loaded into the machine. Then a tool is attached to the machine’s arm to enable to perform all the gyrations necessary to carry out the assigned task.

Thus, the Swiss machine has been used to build curving brick enclosures. It has been used to mill slabs of concrete into specialized forms that can shape the acoustics in a room or a concert hall. It has been used to build soaring wooden structures made from hundreds of slats which the robot cut and placed.

Now, Grazmazio and Kohler are exploring the idea of robotic fabrication to the design and construction of high-rise buildings.

On this side of the Atlantic, engineers at the National Robotics Engineering Center at Carnegie Mellon University, in Pittsburgh, have designed an autonomous loading system that completely automates the task of loading excavated material into dump trucks.

The excavator uses rangefinders to locate the truck, measure the soil face and detect obstacles. The software decides where to dig and where to dump the excavated soil into the truck. It even modifies both its digging and dumping plans based on soil settling that its sensors might detect.

The system has been demonstrated successfully on a 25-tonne hydraulic excavator, and loaded trucks at about 80 per cent of the speed of an expert human operator. Of course, it doesn’t stop for coffee or lunch breaks, and it doesn’t get tired near the end of the day as human operators do.

The development of the system was funded by Caterpillar, Inc., which is also funding an autonomous haulage system. That system will use large off-highway trucks of the sort used when a lot of earth must be used, as in dam construction, or mining.

The trucks will be able to load and dump earth or ore and navigate a network of haul roads without human intervention, all while operating safely in the vicinity of people and other vehicles and equipment.

Developers have also got robots almost ready for market that crawl through pipes without tethers linking them to the surface. One model takes photos as it moves along; another creates a detailed, three-dimensional map of the pipe’s inner surface.

Robots used to be the stuff of science fiction, But their ability to replace labourers will mean that, before long, we will see them doing a variety of jobs on construction sites.

Korky Koroluk is an Ottawa-based freelance writer. Send comments to editor@dailycommercialnews.com

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