An exoskeleton, as the name suggests, is an external frame that can be worn to support the body. In the animal kingdom, some invertebrates, such as lobsters, scorpions and crabs, have an exoskeleton (a rigid external covering for the body) for the attachment of muscles, helping with movement as well as providing protection from the environment. We humans on the other hand, along with other mammals and fish, have an endoskeleton (an internal support structure).
In recent years, exoskeleton development has also taken off across industry (see box out for some other providers). These devices have been designed to aid operators by providing support to the body, including the back, shoulders, waist and thighs, and assist with movement, such as repetitive tasks and lifting and holding heavy items.
One provider is advanced industrial automation specialist Comau. Its wearable exoskeleton called ‘Mate’ aims to improve work quality in an efficient and ergonomic manner by providing consistent and advanced movement assistance during repetitive, as well as daily, tasks (www.is.gd/eyojuc). The Mate Fit for Workers exoskeleton uses a spring-based passive structure and aims to deliver lightweight, breathable and effective postural support without the need for batteries or motors.
As reported by Engineering Designer magazine last autumn, the device does not increase the strength of workers, but instead helps to compensate the weight of the arm by a mechanical chain that discharges its weight not to the shoulder, but directly to the pelvis bones. It weighs less than 4kg and consists of three elements: a passive mechanism called the ‘active box’ to provide adjustable gravity compensation; a mechanical chain, including linear and rotational guides, to naturally follow the body’s motion; and the surfaces of the device that actually attach to the body. Furthermore, it comes in two sizes: small/medium and large, with each able to adjust in width at the shoulder, in height, and at the belly.
Mate has recently been introduced to the operators on a minibus production line at vehicle maker Iveco’s (Industrial Vehicle Corporation) Brescia, Italy plant. The move was born out of a desire to preserve the health of employees while also improving their comfort and, consequently, the quality of their work. Here, Iveco explains its reasoning behind adopting the device and the subsequent results to operators.
Among the production lines at the factory is the Eurocargo line. Plant manager Marco Colonna says: “The production of Eurocargo makes us proud, because its huge range of configurations allows us to offer our customers about 13,000 different versions. In other words, it’s very rare that two identical vehicles are delivered at the same time.
“Obviously, keeping high production efficiency with such significant product variability is not simple, and requires a structured logistics organisation because many materials are delivered to the various stations on a just-in-time basis and according to the production cycle. Consequently, the flow of information must be managed correctly as well, in order to ensure that everyone knows what to do at any given time and has all the necessary tools available for their tasks.”
Such accurate and efficient organisation is the result of the application of a ‘World Class Manufacturing (WCM) philosophy’ (www.is.gd/xuxafo), a strategy that incorporates the methodologies of total productive maintenance (TPM), lean manufacturing and total quality management. Paolo Gozzoli, WCM plant support of Iveco, says: “WCM is a production approach that involves the company at every level and function, from production to safety, logistics and maintenance activities. The goal is to achieve efficiency in every department in an integrated way by means of tests and designed tools to manage specific inefficiencies.”
A natural consequence of the application of WCM was the redeployment of some of employees to the interior construction of minibuses with Daily engines. Gozzoli explains: “The aspects examined also include the working conditions of our operators. This department features many activities that must be carried out while lifting the arms. A demanding condition in itself, which requires even more attention, considering that the average age of Iveco employees is around 49 years.
“For this reason, in the search for solutions that could make the work on minibuses the least burdensome possible, we started a collaboration with the Ideal Production System (IPS) division, whose task is to search for new ideas and tools in an Industry 4.0 perspective to guarantee the best operating conditions at every time for the people and the plant as a whole.”
The company completed its research into possible solutions in 2018 at the same time that the Automatica fair in Munich, Germany, was taking place, and where subsequently Comau’s Mate exoskeleton was shown. Gozzoli says: “During the event, we considered different types of exoskeletons, but Comau’s Mate immediately stood out as the ideal solution for our needs. First of all, we required a tool that could help our operators in activities involving the upper limbs without reducing their mobility due to its structure or size. Another crucial feature for us was our conviction that a wearable device should be easy to wear and lightweight, also considering summer heat as a detrimental factor in terms of comfort.”
Iveco has since introduced the Mate exoskeleton to some of the operators involved in the construction of the minibuses.
In one specific station, operators are assisted by the device during the placement of reinforcements and accessories in the upper part of the minibus. For these tasks, the workers have to keep their arms raised overhead, resulting in trapezius-deltoid muscle fatigue, which is said to have been immediately reduced with the introduction of the exoskeleton.
Antonio Maccarinelli, team leader of section one of the minibus line, explains: “I have used the Mate exoskeleton for a few months now, and I must say that I immediately found relief, especially for my shoulders.
“When mounting the reinforcements in the upper part of the vehicle, I have to keep my arms raised for a long time, often while I’m holding the tools [that] I need to mount the various components. Even though they are all light objects, at the end of my shift, I always noticed that this apparently minimal effort has taken a toll on my body. Now, my shoulders are in an excellent condition.
“Moreover, I must say that the device is really easy to wear. It’s like carrying a backpack, and just needs a few initial settings to be immediately operational. Adjusting the shoulder straps is also quick and easy, which is really important, because I share Mate with other operators. Each of us has a slightly different build, but we can easily adapt it and feel comfortable.”
Box out: Other exoskeleton designs
Ekso Bionics is a developer of exoskeleton solutions that aim to amplify human potential for medical and industrial uses (www.is.gd/adavur). One device is produces is the EksoVest, an upper body exoskeleton that is said to elevate and support arms to assist with tasks ranging from chest height to overhead. It uses compressed gas springs to provide 5-15lbs (2.3-6.8kg) of force per arm, according to Engineering Designer.
Swiss design company Auxivo has also developed an exoskeleton called the LifeSuit that is said to weigh less than 1 kg and aims to reduce workload, muscle fatigue and exhaustion (www.is.gd/pukose). According to the company, the device supports back and hip muscles when lifting objects from below hip level, or when working in a forward-leaning position. Its website states: “As of Q2 - 2020, you can rent the LiftSuit to test it, and we are offering a limited amounts of LiftSuits to selected customers and partners in Switzerland and Europe.”