(CN) — 3D printing may sometimes be presented as a novelty for creating fun gadgets, but recent advances have made it useful for everything from food production to medical applications. Researchers look toward additive manufacturing for constructing structures large enough to live and work in.
Proposed by Mirko Kovac, director of the Aerial Robotics Laboratory at Imperial College London, and his colleagues Wednesday in the journal Nature, a new method for construction 3D printing looks to compensate for what ground-based robot construction cannot do. The new design, inspired by the builders of the animal kingdom, would consist of a team of drones that could fly to remote or hostile environments and construct collectively and autonomously without constraint to the scale and height of the project.
As in many instances where robots have been drafted into work, 3D printing — also known in the industry as additive manufacturing — is frequently utilized in situations where it may be difficult or dangerous for humans to access. Already, ground-based versions of additive manufacturing machines are used to build entire houses and even bridges.
The use of robotics in construction has been endorsed for the high level of flexibility it grants to designers, while also being an eco-friendly process that can reduce material waste and increase workplace safety. Construction businesses have also appreciated the potential for increased efficiency and lower production costs with the reduced amount of human involvement in the process.
But researchers point out that there are limitations to the ground-based, large-scale additive manufacturing machines that are in use.
“These technologies, however, necessitate scaling-up robot hardware to a larger dimension than the desired manufacturing envelope, rendering parallel operation or occupation of a building site by people or other machinery difficult and dangerous,” the study explained.
According to the research, these robots are usually tied to a stationary power source and require human intervention to set up in the first place, which may render them impractical for hard to access or treacherous locations, where it would be difficult to assemble and maintain the machines. Although some prior projects have investigated the use of a team of smaller robots, they were still constrained by operational height and the robots’ range of motion.
The aerial method proposed by Kovac and colleagues would instead allow for an “autonomous, scalable and flexible approach” to construction 3D printing. The method works as a network among two kinds of drone platforms: a “BuilDrone” outfitted with a nozzle to deposit the building material and a “ScanDrone” that supervises and assesses the BuilDrones’ work.
The drones would synchronously while in the air with “real-time trajectory adaptation and material extrusion by the BuilDrones and print verification through the ScanDrone and a human supervisor.”
The study cites natural builders, such as barn swallows, as influence for the multi-drone system. The birds cannot carry much material at once while constructing their nests, so they adjust by making multiple trips to compensate.
The researchers also looked toward social insects like wasps and termites, who work collectively to build their nests, working around each other and adapting to different landscapes. The researchers identify path optimization as a point of interest in developing the pattern of the drones.
The aerial system was then designed be able to build structures without constraints the structure’s height or location. Researchers needed to be able to accomplish this while offsetting the drones’ relatively small size and the limited amount of material that could be carried.
Researchers tested the system of robots by directing the drones to build several simple structures with foam and a cement-like material to demonstrate the system’s ability to build without height or payload constraints. One BuildDrone could construct a six-foot-tall tube of foam, while two could work cooperatively, going back and forth between depositing the cement material and refilling at a ground station.
The study also explores the system’s need for a more specialized cement, explaining that, “A cementitious Aerial-AM [additive manufacturing] material must be lightweight and less dense than traditional and ground-based AM study mortars, with higher water/binder ratios and lower fine aggregate/binder ratios required,” else they won’t be able to work successfully with the drones.
Simulations showed the potential to construct even larger and more complete structure with more than three robots in play at once.
Researchers intend to continue trials with the system before it is really able to begin full-scale construction.
“Scaling-up of the manufacturing volume will require automation of material and battery replenishment, and further means of assessment are needed to evaluate the efficiency of distributed manufacturing relative to the scale of the manufactured object and the robot platforms used,” the study reads.
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