Governments and private corporates are trying to prevent work-related musculoskeletal disorders in static high-precision work or dynamic heavy lifting.
Musculoskeletal disorders are injuries or pain in the human musculoskeletal system, including the joints, muscles, nerves, and structures that support limbs, neck and back. They can become acute or chronic as well. The treatment, unfortunately, is very expensive and not simple.
A wearable robot, which involves physical hardware for assisting with human motion, could be a helping hand in this kind of situation. It might be easy for us to picture cool humanoid robots or fictional military robots in sci-fi movies when someone says ‘robot’, but sadly those robots that would make our lives way better haven’t been invented yet. But, we do have wearable robots right now, and they are already distributed among workers in North America. Hyundai and Kia debuted their wearable robots for industrial use, for the first time in automotive industry.
After Hyundai and Kia debuted CEX (Chairless Exoskeleton) to give knee support to sedentary assembly workers back in October 2018, they are planning for its mass-production.
The investigational VEX(Vest EXoskeleton) is a follow-up exoskeleton designed for neck and shoulder support, and will be deployed by the end of the year.
The robotics team (Head Researcher Dong Jin Hyun, Sang In Pak, Senior Researcher Gyu Jung Kim, and Senior Researcher Ki Hyun Bae) shares the whole story below:
Q. ‘The robotics team’ does not really sound familiar to us. What is it?
Hyun: Hyundai Motor Group selected Robot-Artificial Intelligence as one of five areas of future innovation growth. The company established a designated robotics team in its strategic technology headquarters to focus on the development of related tech. The CEX and the VEX we unveiled last year are also a part of many projects we are working on right now.
Q. Why did you develop the CEX and the VEX?
Kim: Many of the workers in any industry are older than ever, and such wearable robots can boost load support and mobility, and prevent work-related musculoskeletal disorders.
Wearable robots for industrial use are widely distributed in North American region already, so it might not be the first time you have seen these. But the CEX and the VEX are created by the automaker that has its own car factories, and for this reason we know exactly what the workers need. We are expecting our creations to be very handy in so many other industries, such as construction, or retail and distribution industry.
Hyundai and Kia are about to use our wearable robots at their plants in North American factory.
Q. Any feedback on VEX?
Pak: We ran two pilot programs at US production plants, and the workers with musculoskeletal disorders or old workers were satisfied the most. They ‘felt the exoskeleton boosting load support and mobility by huge’, and some of them ‘felt like turning into something akin to Iron Man’.
The reason we conducted a blind experiment was to gain objective feedbacks from the workers who were already aware of other competitors’ creations, so that we could compare the two thoroughly.
Q. Do other automakers use similar robots in their plants?
Bae: Ford, BMW, and Toyota are running pilots starting from their North American Factories, but the thing is, they bought the robots from other industrial robotics manufacturers. Hyundai and Kia is the first to debut its own version.
Q. What is the difference between the two?
Kim: It is not about the performance. I think it will be safe to say that we have a better understanding of how workers actually work on assembly lines. The CEX and the VEX are created by the automaker that has its own car factories, and for this reason we knew exactly what the workers needed.
Q. Tell us about the CEX and the VEX briefly.
Pak: The CEX, the group’s first industrial wearable robot, is to give knee support to sedentary assembly workers. It weighs only 1.8 kg but is endurable enough to buttress a body weight of up to 150kg. It can be easily equipped and adjusted to the user’s height, and it features three different angle settings (85/70/55). The best part is that it can reduce the user’s back and lower body muscle activity by 40%, indicating that it could prevent work-related musculoskeletal disorders and improve work efficiency.
Bae: The VEX is a follow-up exoskeleton designed to support workers who lift their arms for a long time in overhead-task environment to assemble a car. When a worker raises his hand, the robot provides lift assist, helping prevent musculoskeletal disorders and increase job efficiency. It can be worn as a vest and is intended to support the activities under heavy load.
Q. By how much do you think the VEX could prevent musculoskeletal disorders?
Hyun: We need to collect actual data for a better answer, but we have assessed the health of muscles and the nerve cells that control them through Electromyographic Nerve Tests (EMG) before. The result showed that the VEX decreased muscle exercise by 30 per cent, which means it reduces fatigue of workers for sure.
Q. By how much does the VEX increase efficiency?
Kim: It really depends on how fast the user can adapt to the VEX, because it is quite obvious that first-timers will need some time to use the VEX in a right way. After then, we are expecting that it would increase efficiency by 10 per cent. This number may look small, but the users say that it feels like they reduced fatigue by half with the VEX.
Q. Doesn’t the VEX become another burden to bear?
Pak: The VEX weighs only 2.5kg, compared to competing products weighing 3-4 kg.
The user places their arms through the shoulder straps of the vest, then fastens the chest and waist buckles. The back section can adjust in length by up to 18 cm to fit a variety of body sizes, while the other products only allows by 12 or 16 cm. It also features a wide range of angle settings (70 – 100 degrees), compared to its competitors featuring 45 to 90 degrees. All the VEX users became very loyal to it.
Q. How did you make it lighter?
Hyun: Using a lighter material does not always help when you want to make the product lighter. Losing 10% of a 1,000 kg-car is huge, but losing 10% of a 2.5 kg-VEX is not. 250g does not really make a difference for workers. It is not zero, but there will be a price increase as well.
So we tried to make the structure as simple as possible, making the VEX weigh up to 42% less than competing products.
Q. Is the polycentric axis used in the VEX really a breakthrough?
Kim: The polycentric axis design is for a wearable exoskeleton that mimics shoulder movements and aids in lifting the user’s arms.
When you watch your shoulder move from above, you will see its movement is elliptical. Other products only feature single-axis, which is not really helpful for the users. The VEX, on the other hand, has multiple pivot points with 4-link assistance, making it move much more like a human shoulder.
Bae: Multi-link muscular assistance is an important feature the VEX houses. The inherent flexibility of the compensators allows to absorb movements in multiple directions. The multilink joints can resolve tension forces much better than other competitors using only Cams and Wires. Multilink joints also have better durability than wires do.
Q. How can users determine the power the VEX possesses?
Pak: A kilogram-force (kgf) is a gravitational metric unit of force. It is equal to the force exerted by one kilogram of mass in a standard gravitational field. The VEX can offer up to 5.5 kilogram-force in support. In other words, an 80 kg man wearing the VEX can lift a 3kg tool without doing anything. The amount of force assistance can be adjusted to six different levels, depending on the work environment.
Q. Can VEX become more powerful with other assistance mechanisms?
Kim: We designed the degree of force assistance to be adjusted up to as much as 5.5 kgf, considering the work environment. And of course we can stretch it further. The most important part here is whether it can be more powerful, while being lighter. So far we have made ours 40 percent lighter than similar products, and just as powerful.
Q. Will such wearable robots be distributed widely?
Hyun: Though the VEX costs much lower than existing products, which usually cost around $5,000, still we can’t say it is cheap. The price will get lower, once the market gets bigger. Government can also accelerate the change. They are already working on assessing the social cost to reduce treatment costs, for example. When they are sure these wearable robots can actually prevent various disorders, we will be able to make it widely distributed.
Q. The VEX is about to be mass-produced by the end of this year. Do you have further plans?
Bae: We are thinking of adjusting it for other industrial uses other than automotive industry, construction for instance. Because all workers are required to wear protective equipments on construction sites, we are planning to make the VEX certified as a Personal Protective Equipment (PPE) for construction.
Q. What is your ultimate goal?
Hyun: Currently, wearable robots can merely assist workers, but we want to develop much more powerful and advanced wearable robots that can actively read the users’ intention. We will keep working on it until the day comes.