Development and validation of guidelines for safety in human-robot collaborative assembly systems

TLDR

Industrial collaborative robotics promises significant benefits for assembly, yet safety concerns from unexpected human‑robot contacts remain a major barrier and there is a lack of practical design tools. The study develops and classifies guidelines for designing safe human‑robot collaborative assembly systems, focusing on system‑wide features. The guidelines were validated through a laboratory case study and a digital twin, demonstrating that non‑expert manufacturing engineers can autonomously apply them to reduce mechanical risk. Results show that the guidelines effectively aid non‑experts in developing and improving collaborative assembly systems from a safety perspective.

Abstract

Industrial collaborative robotics is one of the most promising technologies of Industry 4.0. In particular, human-robot collaboration in assembly will be particularly interesting for manufacturing companies. In this context, the interaction between humans and robots opens new possibilities but also challenges. A major problem is related to safety: unwanted and unexpected contacts between the human and the robotic system may cause injuries and therefore limit the potential for collaboration. Nowadays, there is a lack of simple and practical tools for helping system designers in overcoming such limiting conditions. In this work, guidelines for the design of safe human-robot collaborative assembly are developed and classified, particularly focusing on the features characterizing the entire system. These are validated by means of a laboratory case study and a digital twin. The validation process is based on the assumption that a team of manufacturing engineers (not-experts in occupational health and safety) should be able to autonomously and gradually apply the given guidelines reducing the mechanical risk in a collaborative assembly system. The proposed solutions have been virtually modelled allowing the evaluation of their effectiveness. According to the results, the proposed guidelines effectively help non-expert users in the development and improvement of collaborative assembly systems from the safety perspective.