The role of the robot mass and velocity in physical human-robot interaction - Part II: Constrained blunt impacts

Accidents occurring with classical industrial robots often lead to fatal injuries. Presumably, this is to a great extent caused by the possibility of clamping the human in the confined workspace of the robot. Before generally allowing physical cooperation of humans and robots in future applications it is therefore absolutely crucial to analyze this extremely dangerous situation. In this paper we will investigate many aspects relevant to this sort of injury mechanisms and discuss the importance to domestic environments or production assistants. Since clamped impacts are intrinsically more dangerous than free ones it is fundamental to discuss and evaluate metrics to ensure safe interaction if clamping is possible. We compare various robots with respect to their injury potential leading to a main safety requirement of robot design: Reduce the intrinsic injury potential of a robot by reducing its weight.