Exoskeletons in industrial workplaces

Exoskeletons for physical support

Exoskeletons are technical systems that are worn on the human body. In industrial applications, their aim is to support specific movements or stabilize body regions in constrained postures. In order to be effective, it is essential that they are tailored to the person and the context. This requires consideration of the interaction between the person, activity and technology. Most commercially available exoskeletons focus on back or shoulder support. System design usually follows approaches that use either rigid structures or textile-based materials. While the former have a higher force potential, the latter offer advantages in terms of fit. In terms of support, a basic distinction is made between active, semi-active and passive exoskeletons. Active systems have an external energy source and use electric or pneumatic drives to generate support, while passive systems use elements such as springs or elastic bands to mechanically store and release energy. Semi-active systems combine the corresponding features. Passive exoskeletons are currently more widely used for industrial applications.

Findings from studies with exoskeletons

According to the hierarchy of occupational health and safety measures, exoskeletons are a possible personal initiative that may be suitable if technical and organizational measures have been exhausted or are not appropriate. Studies show direct support effects from exoskeletons. Both objectively measurable effects and subjective perceptions must be taken into account. For assembly activities at and above head height, for example, a reduction in muscular activity and a delayed onset of muscle fatigue were observed. The studies also showed that exoskeletons only provide support in the addressed body areas and in certain movement sequences and areas. The achievable support is usually only partial and varies depending on the type of exoskeleton, support situation and application context. With regard to the functional principle, it has been shown that active exoskeletons are particularly suitable for activities with high variance and high load weight due to their ability to provide differentiated support, while passive systems have a particular effect on movements with low variance and constant load weight.

The key factor for possible support from an exoskeleton is that it provides suitable support properties for the activity. In order to ensure acceptance and usability, the main and secondary activities in the work process, PPE requirements, the fit of the system and its functionality for the respective application context should all be taken into account. Based on the findings of the study, recommendations for the selection, use and evaluation of exoskeletons were derived to assist those responsible in companies with the introduction and use of exoskeletons. Recommendations for use in operational practice are described in more detail in a guideline.

The application knowledge also flows into other initiatives such as standardization activities on exoskeletons, the creation of a DGUV publication on exoskeletons in the workplace and training programmes for companies. The latter initiative aims to qualify those responsible in companies for the use of exoskeletons at manual workstations. The program comprises four modules aimed at assessing workplaces and workloads, understanding various support approaches and technologies, implementing and evaluating the use of exoskeletons and their practical application in pilot studies.