A failure-to-safety “Kyozon” system with simple contactdetection and stop capabilities for safe human-autonomous robotcoexistence

摘要

In this paper, we discuss a method to achieve safe autonomousrobot system coexistence (or Kyozon in Japanese). First, we clarifyhuman pain tolerance and point out that a robot working next to anoperator should be covered with a soft material. Thus, we propose aconcept and a design method of covering a robot with a viscoelasticmaterial to achieve both impact force attenuation and contactsensitivity, keeping within the human pain tolerance limit. We stressthe necessity of a simple robot system from the viewpoint ofreliability. We provide a method of sensing contact force without anyforce sensors by monitoring the direct drive motor current and velocityof the robot. Finally, we covered a two-link arm manipulator with theoptimum soft covering material, and applied the developed manipulatorsystem to practical coexistence tasks