Wireless sensor networks and safe protocols for user tracking in human-robot cooperative workspaces

Workers protection in collaborative industrial robotics application represents the predominant aspect of robot safety in production systems. Flexible production systems and multimodal human-robot interactions often encompass cooperative tasks that are performed in fenceless configurations. Collaborative open workspaces enable, in fact, a workflow of continuously interchangeable tasks done by operators or by robot at close distance or using hand-guided modes. Layout and workflow optimization may, in fact, require a co-presence in some shared spaces whose safeguarding (e.g. robot speed limitations, distances) is conservatively restricted by the current standards. In such scenarios, the tracking of operators is mandatory for the overall assessment of the system safety. In this work, a combination of wireless sensing technologies, highly robust wireless protocols and safe computation over a standard ethernet IP (black channel) concur to improve the functional safety of a cooperative robotic system. The system architecture and data framework are in particular discussed with reference to the properties of the communication protocols implementing the safety layer.