Classification of collaborative applications and key variability factors to support the first step of risk assessment when integrating cobots

Risk assessment in collaborative robotics is a challenge. This is one reason why safety is a barrier to the adoption of cobotics. To overcome this challenge, this paper proposes five classes of collaborative applications and variability factors to launch the first step of risk assessment: determination of the use, space and time limits of the application, as per ISO 10218-2:2011. The five classes are Direct alternating collaboration, Direct-assistance collaboration, Indirect sequential collaboration, Indirect parallel collaboration, and Occasional workspace sharing without collaboration. The variability factors to consider when designing a collaborative application relate to the interaction between the cobot(s), human(s) and equipment involved and their characteristics within a space throughout the application's life cycle. The factors are concrete examples that help fulfill the standard's requirements regarding those limits. Since robots are partly completed machinery, one must consider the collaborative application as a whole, and not only the human-robot interaction.