  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.
