The goal of the PowerGrasp project was the development and evaluation of a wearable soft-robotic assistance system for arm, shoulder and hand support.
Despite the modernisation of work processes and the use of new technologies, a large number of musculoskeletal disorders can be traced back to occupational activities. The aim of the project was to reduce the physical strain of assembly workers by means of power assistance, thus preventing possible consequential damage and preserve the workers’ health.
The video gives a brief insight into the development process and the final result of the project.
Within the design process, several participatory workshops were conducted with potential users and experts, to learn about their thoughts, needs and visions regarding a possible assistive system. The participants were asked to visualize their ideas and suggestions prototypically on their own bodies with the help of a toolkit specifically designed for this purpose. Throughout the process, participants were asked to perform workplace-related movements to take into account possible constraints and to think about how they would like to interact with the system.
The analysis of the workshops led to a concise collection of requirements for a body worn support system in the fields of use, design and construction, interaction and feedback. Based on these findings, we started to build first low-cost prototypes and experimented with different techniques and materials to move different parts of the body. These early prototypes helped us to understand concepts and functionalities, to transfer them to new situations and to identify problems early in the process.
In several iterations, two components of a wearable and soft assistance system were developed:
1) An elbow-component for arm-support that is made from silicon and can be actuated with air. Several experiments with different shore hardnesses and wall thicknesses as well as exterior shapes of the actuator and shapes for air chambers finally led to a version that is able to lift the arm.
2) A system for shoulder-support that can be worn as a jacket and consists of several integrated air-chambers that provide support to the body and the shoulder. In this phase of the project an air pump was used to inflate the chambers.
Later in the project and in cooperation with the involved partners, a working demonstrator of the assistive soft-robotic system was build. Therefore, additional components such as a control unit, valves, power supply and compressed air storage had to be attached to the system. A big challenge in this phase was the placement of the technical components without restricting the user or creating an unpleasant wearing sensation. In several iterations the components were attached to the body in various constellations to find the most suitable solution. In a workshop with assembly workers the system was evaluated in terms of wearing comfort and the experience of use.