What is an exoskeleton? The boring official definition of an exoskeleton in nature is “a hard outer layer that covers, supports, and protects the body of an invertebrate animal such as an insect or crustacean,“ as opposed to the internal skeleton (endoskeleton) that we humans have.
However, here we’re talking about the idea of an artificial external skeleton, more akin to those used by Marvel Comics’ Iron Man or Sigourney Weaver in Aliens. Of course, their custom-built, powered suits of armour and the accompanying complement of weapons and hi-tech gizmos are to help them defeat the baddies, whereas we’re more interested in how an exoskeleton might help you on a building site.
Exoskeletons are starting to be used in a wide variety of areas, from engineering and construction to medicine and rehab. In rehab, they are especially useful for those injured in war, from motor or industrial accidents or from strokes or other illnesses that prevent people using their limbs properly. We start to see articles about their use in construction from around 2015, but as this article from Wired magazine explains, battery powered exoskeletons don’t generate sufficient power for long enough to make them practical. However, industrial exoskeletons don’t need power, “relying instead on counterweights and a standard, sprung arm used on image-stabilizing steadicams. The trick is the carbon fiber harness and metal-tube frame running down a user’s legs. It translates the weight of whatever’s on the end of the arm down through the suit and into the ground.”
In practical terms, this means that a construction worker using an exoskeleton can lift items weighing far more than a single man could ordinarily move. The benefits are obvious, although, like most such developments in construction there is a concomitant concern that this will lead to fewer workers needing to be employed on building sites of the future.
I find this a fascinating subject. I recently attended the first ever Digit Expo conference in Scotland, where one of the presentations was from Sethu Vijayakumar, Professor of Robotics at the University of Edinburgh. Professor Vijayakumar described how robotics research is moving on from repetitive tasks to developing equipment that allows humans and robots to co-manipulate heavy objects (as described above) and, ultimately, to the development of fully autonomous robots.
He explained how robotics engineers have had to develop “compliant actuator design and stiffness control,” by which he means that “limbs” on a robot must “give” when they interact with a human. In the longer term, Professor Vijayakumar sees humans doing the “high level stuff” while the robots do the more mundane, heavy lifting or otherwise dangerous work. Ever bigger and more complex buildings and bridges (we already have the 34 mile long Hong Kong-Zhuhai bridge over the sea) will mean that it will be far safer to get robots to do checks and maintenance.
Finally, for those worried that the fully autonomous robots are going to take over the entire building site, Professor Vijayakumar had some words of comfort. Apparently, it’s difficult to get robots to walk successfully on an uneven surface (like, for example, the average site), although “learning is the new wave of robotics” and they are getting smarter each time they “walk their walk.” But be reassured - if you look carefully at the video of the robot on the uneven surface you’ll see that is has two safety ropes to hold it upright in case it falls. At a cost of £2million for the robot, if it trips that’s an expensive breach of health and safety.
Chris Peace, MD, Peace Recruitment