In the automated warehouse project of an international household company in Fengxian District, Shanghai, the automated stereoscopic warehouse covers an area of nearly 2000 m2, with 18 30m ultra-high speed stackers, 2 high-speed RGV,351 stations with different types of transportation equipment, 25 PLC control systems, 1 MFC monitoring and dispatching system, 5 mobile HMI operating screens, nearly 500 network communication nodes, and up to 3000 sets of daily entry and exit turnover operations. At the same time, each device needs to communicate with the control layer in real time to inform the running status of the equipment, and the MFC control layer carries on a lot of communication with each system. Thread real-time communication to ensure the real-time and accuracy of information between each system. Therefore, the automatic three-dimensional warehouse system needs more stable industrial communication network, larger network communication bandwidth and farther network communication distance. The traditional industrial bus communication technology can not meet the network communication requirements of the system. Therefore, the project adopts industrial Ethernet technology, combined with optical fiber communication cable, wireless communication local area network and router isolated transmission technology to construct stereoscopic library network to realize stable signal transmission between subsystems and devices in the system.

Features of the industrial Ethernet architecture of the project:

The main results are as follows: 1) When the equipment layer builds the network, the optical fiber and the industrial shielded network line are combined to route the network, which ensures the accuracy of long-distance information transmission.

2) Two dual hot standby routers are set up in the equipment layer. The network nodes in different network segments of the equipment layer communicate with the upper computer of the control layer through the router relay function, so as to avoid the redundant loss of data information and improve the accuracy and stability of information transmission.

3) The communication between mobile devices and network nodes in device layer adopts wireless local area network technology, the signal is transmitted by industrial wireless router, and the router adopts 5G band, which avoids the interference caused by the mixing of many kinds of communication in the field. According to the field working area and signal coverage, the wireless router measures the position of AP, sets up 7 AP to broadcast the field signal, and ensures the mobile device to carry on the high quality data communication. At the same time, the mobile HMI operation screen provides convenience for the device maintenance personnel to view the equipment status and close operation equipment on the spot, so that the user experience has been greatly improved.

4) The field equipment is directly connected to the system network. In the high-speed communication line, the equipment state is fed back to the superior network node in real time, which is convenient for the user to control the running state of the field equipment in real time, find and deal with the problems in time, improve the response speed of equipment fault treatment, and indirectly improve the efficiency of the system.

The project is the largest logistics center in the world for an international home group. The effective running time of the system is nearly 20 000 hours, the equipment failure rate is less than 0.5%, and the communication failure rate is less than 0.01%. The stable system communication provides a guarantee for the efficient operation of the automated three-dimensional warehouse.