Technical requirements and challenges of driving:
As the main handling equipment in the production workshop of steel mills, the safety and reliability of cranes are very important, and their operating efficiency will directly affect production capacity. The complex ground conditions bring many safety problems to the operation of the equipment. Every year, due to problems in the operation of the vehicle, accidents of different degrees are caused, such as damage to the ground unit equipment, and even personal safety issues. As a part of the traffic control architecture, the communication network plays a vital role, especially in the unmanned garage area management system. It not only relates to the flexibility of the system architecture, but also determines the stability and safety of the entire project.
Based on such requirements, the communication network for unmanned driving applications in steel plants has certain technical requirements and challenges:
One is the priority configuration or isolation of control signals. Based on the traditional industrial Wi-Fi solution, considering the safety and reliability of unmanned driving, two sets of Wi-Fi will be deployed, one for automation control and the other for CCTV (Closed-Circuit Television) remote monitoring. This method isolates the control and monitoring channels, and avoids the occupation of the network channel and affects the real-time performance of the control signal.
The second is the high reliability and low latency of wireless communication. As a special production equipment, driving vehicles have higher requirements on the quality of wireless networks. When the slabs are moved by cranes, the unstable network will cause the cranes to stop suddenly and cause great safety hazards. At the same time, before a sudden safety accident on the ground, it is necessary to quickly suspend the driving operation in the warehouse area or the central control room to ensure that the driving operation is stopped before the accident occurs and avoid more accidents. Based on such business requirements, the communication delay between the PLC in the central control room and the on-vehicle PLC should be less than 50ms, the consecutive packet loss should be less than 3, and the average packet loss rate should be less than 1%. The time delay between the emergency brake IO and the safety PLC in the central control room requires 10ms.
The third is a higher uplink rate requirement. There are usually 2 to 4 driving video cameras, which are used for remote control under special circumstances. Therefore, the uplink bandwidth rate of a single unmanned driving vehicle is required to reach more than 10Mbps.