A distributed proximity sensor for safe human-robot interaction

The industrial state of the art prescribes a physical separation of robotic manipulators and human workers by means of safety barriers, in order to prevent risks of collisions. This separation has a clear negative influence on the widespread use of robotic technology in shopfloors. On the other hand, the removal of protective barriers gives rise to safety issues, that can be addressed with a combination of approaches, e.g. with a reactive control based on exteroceptive sensors measurements. In this work we developed a distributed distance sensor prototype, that can be mounted on an industrial manipulator in order to detect humans in the robot workspace. The optimal placement of such sensor “spots” is discussed, taking into account detection capabilities and safety enhancement. Experiments exploiting an ABB IRB 140 robot and off-the-shelf distance sensors as spots are presented, integrating the prototype in a control scheme aimed at enhancing human safety.