A Proactive Strategy for Safe Human-Robot Collaboration based on a Simplified Risk Analysis

• Published in: Modeling, identification and control Vol. 36; no. 1; pp. 11 - 21
• Main Authors: Sanderud, Audun, Thomessen, Trygve, Osumi, Hisashi, Niitsuma, Mihoko
• Format: Journal Article
• Language: English
• Published: Kristiansand Norsk Forening for Automatisering (NFA) 2015; Norwegian Society of Automatic Control
• Subjects: Risk Analysis; Risk Field; Safe Human-Robot Collaboration
• ISSN: 0332-7353; 1890-1328
• DOI: 10.4173/mic.2015.1.2

In an increasing demand for human-robot collaboration systems, the need for safe robots is crucial. This paper presents a proactive strategy to enable an awareness of the current risk for the robot. The awareness is based upon a map of historically occupied space by the operator. The map is built based on a risk evaluation of each pose presented by the operator. The risk evaluation results in a risk field that can be used to evaluate the risk of a collaborative task. Based on this risk field, a control algorithm that constantly reduces the current risk within its task constraints was developed. Kinematic redundancy was exploited for simultaneous task performance within task constraints, and risk minimization. Sphere-based geometric models were used both for the human and robot. The strategy was tested in simulation, and implemented and experimentally tested on a NACHI MR20 7-axes industrial robot.