Safety Assessment of Human-robot Systems : 1st Report, Hazard Identification Based on the Action-changes and the Action-chains Models

Abstract

The purpose of this work is to develop systematic methodology to improve the safety of robot systems both at present and in future, ranging from their design stage to practical use. In this paper, the Action-Changes and Action-Chains Models, which can be applied to any type of man-machine systems, are proposed to clarify the concept of "hazards" and the production process. In the models, actions between system elements are divided into six types according to the characteristics, and the action chains produced among system elements are divided into five types according to the relations of two selected elements and the others in the chain. The hazards of a robot to a human are, then, effectively identified by enumerating the actions between the elements and changes, the action chains among the elements, and the injuries to a human by utilizing the models.