ISO/TS 15066: How Different Interpretations Affect Risk Assessment

TL;DR

This paper examines how differing interpretations of ISO/TS 15066:2016(E) impact risk assessment in human-robot interaction, highlighting inconsistencies and proposing tools for clearer, more reliable safety evaluations.

Contribution

It identifies conflicting definitions in ISO/TS 15066:2016(E), demonstrates their effects through experiments, and proposes decision trees and collision force maps for unambiguous risk assessment.

Findings

Different interpretations lead to inconsistent risk classifications.

Incorrect application of the standard can compromise safety.

Proposed tools improve clarity and consistency in risk assessment.

Abstract

The current technical specification ISO/TS15066:2016(E) for safe human-robot interaction contains logically conflicting definitions for the contact between human and robot. This may result in different interpretations for the contact classification and thus no unique outcome can be expected, which may even cause a risk to the human. In previous work, we showed a first set of implications. This paper addresses the possible interpretations of a collision scenario as a result of the varying interpretations for a risk assessment. With an experiment including four commercially available robot systems we demonstrate the procedure of the risk assessment following the different interpretations of the TS. The results indicate possible incorrect use of the technical specification, which we believe needs to be resolved in future revisions. For this, we suggest tools in form of a decision tree and constrained collision force maps, which enable a simple, unambiguous risk assessment for HRI.