Human-Robot Collaboration Safety In Flexible Manufacturing Environments: A Review Of Safety Strategies, Risk Assessment, And Emerging Sensor-Based Assurance Mechanisms

Abstract

While integrating humans and robots in shared workspaces is much easier and more intuitive than in traditional manufacturing, the physical, cognitive, and organizational security of human operators has become a major engineering and managerial challenge as flexible manufacturing grows increasingly common, balancing the need for mass customization with productivity requirements. This manuscript draws on approaches to safety through control, motion planning, and prediction, as well as psychological and ergonomic considerations in shared workspaces, to synthesize existing knowledge on human-robot collaboration (HRC) safety. The study adopts a structured narrative review approach, using 20 peer-reviewed articles published by MDPI (MDPI Global Journal on Human and Robot Interaction) and Taylor & Francis, focusing on stop categories rated for safety, detection sensor technologies, and quantitative measures of collaboration quality and risk. The results reveal that single-modality systems cannot achieve the same safety benefits as hybrid safety architectures that combine power- and force-limiting with vision-based and proximity-sensing systems to reduce incidents without impacting productivity, and that there remains a significant disparity in stakeholder perceptions of risk, regardless of whether they are operators, developers, or managers. The discussion places these results in the context of the transition from Industry 4.0 to 5.0, where human-centric design features are increasingly present in safety-assurance frameworks. Relevant standardization gaps, data availability, and the generalizability of risk models derived from laboratory settings are highlighted, and directions for further research are suggested, developed in parallel with the digital twin and generative artificial intelligence. The study concludes that safety in a flexible manufacturing environment should be established by combining technical, procedural, and human factors approaches, as no single approach is sufficient to ensure safe production.