Implementation of Wireless Synchronous Robotic Control in 5G and Edge-Cloud Environments

5G and Edge-Cloud computing play pivotal roles in fostering the flexibility and intelligence required by Industry 4.0 for modern production systems. This paper presents our investigation into deploying the control logic of two UR5e robotic arms on the Edge Cloud, utilizing 5G for communication and establishing a soft Programmable Logic Controller (PLC). Leveraging the Message Queue Telemetry Transport (MQTT) and Network Time Protocol (NTP), the soft PLC coordinates the two robotic arms synchronously, mitigating the impact of the network latency variance. In the context of a concurrent delay-sensitive use case, our measurements reveal that, compared to Ethernet, wireless 5G results in 12 ms and 9 ms increases in the 99.9th percentiles of uplink times and downlink times, respectively. However, the NTP-based coordination mechanism in our implemented solution demonstrates a 77 % reduction in behavior inconsistencies caused by the 5G network latency variance in 99.98 % of cases.