Requirements for Safe Robots: Measurements, Analysis and New Insights

TLDR

Human–robot interaction is increasingly important, yet robots must never pose a threat to humans, and prior collision tests have sought to improve safety. The study provides a systematic evaluation of safety in human–robot interaction, focusing on key injury mechanisms. We quantified injury risk by conducting impact tests with the DLR‑Lightweight Robot III in standard crash test facilities, evaluated several industrial robots of varying mass and velocity, and examined both constrained environments and quasi‑static impacts to assess their effects on human injury. The study found that non‑constrained impact tests only partially capture human‑robot safety, and it presents a systematic classification of injuries relevant to robotics.

Abstract

Physical human—robot interaction and cooperation has become a topic of increasing importance and of major focus in robotics research. An essential requirement of a robot designed for high mobility and direct interaction with human users or uncertain environments is that it must in no case pose a threat to the human. Until recently, quite a few attempts were made to investigate real-world threats via collision tests and use the outcome to considerably improve safety during physical human—robot interaction. In this paper, we give an overview of our systematic evaluation of safety in human—robot interaction, covering various aspects of the most significant injury mechanisms. In order to quantify the potential injury risk emanating from such a manipulator, impact tests with the DLR-Lightweight Robot III were carried out using standard automobile crash test facilities at the German Automobile Club (ADAC). Based on these tests, several industrial robots of different weight have been evaluated and the influence of the robot mass and velocity have been investigated. The evaluated non-constrained impacts would only partially capture the nature of human—robot safety. A possibly constrained environment and its effect on the resulting human injuries are discussed and evaluated from different perspectives. As well as such impact tests and simulations, we have analyzed the problem of the quasi-static constrained impact, which could pose a serious threat to the human even for low-inertia robots under certain circumstances. Finally, possible injuries relevant in robotics are summarized and systematically classified.