Long shifts spent standing in one space – lifting, stretching, and adjusting workpieces – can lead to fatigue, stressing employees and potentially lowering build quality toward the end of a shift. It’s a common problem for many industries and a particularly acute one for automakers.
At BMW’s plant in Spartanburg, South Carolina, workers are using Levitate Technologies Inc.’s Airframe, a lightweight, backpack-like exoskeleton that supports workers arms when lifting or working over their heads.
“During the initial testing and review period at BMW, I received very positive feedback from the users,” says Joseph Zawaideh, vice president of marketing and business development at Levitate Technologies. “They embraced the Airframe quickly and mentioned they don’t want to go back to working without it. They liked that the Airframe was very low profile, lightweight, and did not restrict motion.”
BMW officials say the Airframe has outperformed other systems, giving workers relief in their factories. BMW manufacturing uses 66 airframes in the Spartanburg factory, where the automaker produces X-series sport utility vehicles (SUVs) for the U.S. and worldwide export. Four other BMW plants, including Munich, Germany, are testing the exoskeletons as are several competitors.
“We get follow-up orders – this is the best feedback industry can give us,” Airframe inventor Mark Doyle says. “We’re excited to make the workers happy with the wearable Airframe.”
The Airframe exoskeleton supports the arms of professionals and skilled trade workers who perform repetitive arm motions and/or stationary arm elevation (working at shoulder level or above the head). It transfers the weight of the user’s arms from the shoulders, neck, and upper and lower back to the core through pads that rest on the outside of the hips. Doyle developed the exoskeleton in his garage in 2011 and founded Levitate Technologies in 2013. In 2015, Levitate hired Pathway, a design company, for production optimization. The Airframe is now produced at D&K engineering.
“The Airframe relieves the muscles and supports the movement sequences,” Doyle explains. “This prevents tension in the neck, shoulder, and upper and lower back.”
Since the Airframe is designed like a backpack, it can be adjusted to almost any body size with adjustable straps.
Assistance systems cannot interfere with workflow, so wearable frames must be light, comfortable, and functional. Doyle collaborated with engineers at motion plastics company igus to minimize weight in the Airframe’s design, opting for 32 plastic bushings in the exoskeleton rather than metal ones.
“The igus products are practical, robust, configurable, and the material is appropriate,” Doyle says. “It’s really easy to work with igus, their support is great. The igus bushings are great quality, operate smoothly, and have a long service life.”
Another advantage of the plastic components is self-lubrication. Greases or oils aren’t acceptable in wearable applications because they could leak onto workers’ clothes. With the exoskeleton projected to last at least 1 million movement cycles, Doyle says he expects the igus bearings to support long product lifespans.
In 2015, when Pathway joined the project, designer Arthur Deptala and others improved the Airframe, overcoming force control and adaptability challenges.
“We tested various possibilities for the design of all the rotary mechanics and have found out that igus offers us the ideal bushing solution,” Deptala says.
Inspiration for wearbles
Although BMW and others in the auto industry have begun using Airframe to alleviate muscle fatigue and allow employees to continue working over their heads for longer shifts, automotive wasn’t Doyle’s intended market. The concept came from talks with surgeons who suffered from fatigue and pain during and after long surgeries. Doctors wanted a system to relieve the stress on arms and shoulders during long and repetitive movements, such as in endoscopic and laparoscopic operations.
Surgeons who used the wearable frame during testing confirmed its positive effect on their work. An Internal Review Board (IRB) approved study demonstrated 50% reductions in fatigue in operations after 12 minutes, and 25% reduction in pain rates.
Early interest came from doctors and automakers, but other industries have gained benefits as well. Insurance claims showed hairdressers who often work with their hands above shoulder level while tilted forward, experienced high numbers of musculoskeletal injuries. An international agricultural equipment manufacturer studied use of the Airframe for painters and welders. During the study, the number of painted parts increased by more than 50%, and the number of welded joints increased by as much as 86%. The quality and duration of the work also improved.
Made in California
Due to positive Airframe feedback, Levitate officials are anticipating an increase in orders. The exoskeletons are produced for Levitate at the D&K site in San Diego, California. Production levels, measured in systems per month, are in the hundreds and in the process of transitioning to the thousands. A group of employees assembles the individual parts.
To avoid long lead times, Levitate and D&K are testing systems to increase production by 5x. Based on initial demand, the planning department estimates that thousands may have to be produced every month to keep up. When large companies complete their tests, a wave of orders could potentially arrive all at once.
A BMW employee in Spartanburg, South Carolina, uses a Levitate Technologies' Airframe exoskeleton to install underbody components on an X-series sport utility vehicle. Using dozens of plastic bearings from German supplier igus, the Airframe supports arms and shoulders, allowing employees to comfortably work over their heads for long time periods.
In 2015, the International Federation of Robotics (IFR) estimated that more than 350 exoskeletons were sold that year but expected more than 6,500 exoskeletons to be sold by 2019.D&K Engineering