Many jobs in the construction industry fall under the “dull, dirty, and dangerous” category said to be ripe for automation — but only a few can actually be taken on with today’s technology. One such job is the crucial but repetitive task of rebar tying, which a startup called SkyMul aims to completely automate using fleets of drones.
Unless you’ve put together reinforced concrete at some point in your life, you may not know what rebar tying is. The steel rebar that provides strength to concrete floors, walls, and other structures is held during the pouring process by tying it to the additional rebar where the rods cross. This can easily be thousands of ties for a good-size building or bridge, and the process is generally done manually.
Rodbusters (as rebar tying specialists are called, or so I’m told) are masters of the art of looping a short length of plastic or wire around an intersection between two pieces of rebar, then twisting and tying it tightly so that the rods are secured in multiple directions. It must be done precisely and efficiently, and so it is — but it’s backbreaking repetitive work. Though any professional must feel pride in what they do, I doubt anyone cherishes the chronic pain they get from doing that task thousands of times in an hour. As you might expect, rodbusters have high injury rates and develop chronic issues.
Automation of rebar tying is tricky because it happens in so many different circumstances. A prominent semi-robotic solution is the TyBot, a sort of rail-mounted gantry that suspends itself over the surface — but while this makes sense for a bridge, it makes far less for the 20th floor of an office building.
Enter SkyMul, a startup still in the very early stages but with a compelling pitch: rebar tying done by a fleet of drones. When you consider that the tying process doesn’t involve too much force and that computer vision has gotten more than good enough to locate the spots that need work… it starts sounding kind of obvious.
CEO and co-founder Eohan George said that they evaluated several different robotic solutions but that drones are the only ones that make sense. The only legged robots with the dexterity to pick their way through the rebar are too expensive, and treads and wheels are too likely to move the unsecured rebar. The sky system was developed after early research into the area done at Georgia Tech’s robotics lab.