Safety of interactive robotics: Learning from accidents

Finland is ranked rather high in international robot density statistics. In Finland, robots are typically used in applications where they operate in close proximity to humans. The research described in this paper, sourced from Finnish databases, identified 25 severe accidents which can be attributed to robots. The current accident data can provide an insight into the type of accidents associated with future human-robot interaction (HRI) applications. Accident statistics indicate that most of the severe robot-related accidents involved crushing a person against a rigid object. As crushing hazards currently dominate accident statistics, and with HRI applications becoming increasingly common, humans are expected to be exposed to more crushing hazards in the future. The close proximity of the robots means that there is very little time to escape from crushing hazard. The prevention of collisions between robots and humans is paramount to reducing the amount of accidents. Actions to diminish the effects of any subsequent collision are also important. The control after a collision, however, needs to be very quick in order to minimise the damage caused by an impact. Current practice demands that upon detection of a collision, active movements are typically not allowed without a human supervision. Moving a robot away to a safe position and releasing any pressure against a person may save lives, but would entail some adjustments or new interpretations of the current safety requirements.