Design and Development of a Roaming Wireless Safety Emergency Stop

TL;DR

This paper presents a wireless emergency stop system with roaming capabilities for automated manufacturing, enhancing safety, flexibility, and security in dynamic production environments through a secure, portable switch and a robust communication protocol.

Contribution

It introduces a novel wireless emergency stop system with seamless roaming, combining IO-Link Wireless and IO-Link Safety, and demonstrates its effectiveness through experimental validation.

Findings

Effective handover mechanism confirmed by experiments

System improves flexibility and safety in manufacturing environments

Potential for AI-based radio signal evaluation for future enhancements

Abstract

Modern manufacturing is characterized by a high degree of automation, with autonomous systems also frequently being used. In such environments human intervention in the event of malfunctions or maintenance becomes a rare but also necessary task. When human workers are no longer an integral part of the production process, but only intervene when necessary, e.g., in the case of unexpected machine behavior, appropriate safety solutions will become even more important. This work describes a wireless communication system enabling a flexible and safe emergency stop function for multiple automation cells. A portable emergency stop switch allows seamless transition between different wireless cells, ensuring functional safety. The communication protocol combines IO-Link Wireless features with the safety requirements already implemented in IO-Link Safety. Security requirements are fulfilled through encryption and authentication. The IO-Link Wireless roaming functionality is used to extend the system across several manufacturing cells. An experimental setup confirms the suitability of the system for various applications. The results demonstrate the effectiveness of the handover mechanism and evaluate the potential of the system to improve flexibility, availability and security in dynamic production environments. Future extensions could include the use of AI based evaluation of the radio signals for an intelligent cell handover.