Determination of Verified Thresholds for Safe Human-Robot Collaboration
Humans and robots will be sharing work areas more and more frequently in the near future and often working together hand-in-hand. Generally, the biomechanical load on humans in the event of contact must be safely limited to a tolerable level. Humans may not be injured.
The institutions for statutory accident insurance and prevention as well as users of human-robot collaboration and robot manufacturers are agreed that the maximum load for humans in the event of human error or technical malfunctions may not exceed a harmless minor injury, e.g. slight swelling or hematomas but no injury of the epidermis such as a slight abrasion. Moderately severe pain is defined as another threshold. No verified thresholds that can be used to demonstrate a tolerable load on humans in the case of a collision with a robot are available for occupational safety.
The Fraunhofer IFF has developed a test setup with a pendulum, which has been approved by an ethics commission. It allows collision tests with human subjects for the first time to determine maximum load. In close collaboration with physicians from Otto von Guericke University Hospital, select areas of the human subject’s bodies are struck systematically with varying energy. The pendulum mass, the collision speed and the impactor’s geometry are varied during tests with human subjects. Every test is concluded the moment one of the loads classified as tolerable or moderately severe pain occurs.
The maximum loads such as force, pressure or impact energy ascertained during the tests with human subjects can be used subsequently to define verified thresholds. Thus, the Fraunhofer IFF is making an important contribution to defining verified maximum loads, the future benefits of which will go far beyond human-robot collaboration.
The findings will be incorporated in internationally relevant standards and define maximum loads in human-robot collaboration.