Research On Key Technologies Of Cable And Cableless Hybrid Cross-station Based On Multimode Communication

In the large-scale seismic data acquisition work,two-dimensional seismic exploration has been unable to meet the production requirements of high density and high resolution.Three-dimensional seismic exploration can clearly see the three-dimensional imaging map of underground space,and it has gradually become the mainstream exploration method.Seismic data acquisition systems for three-dimensional seismic exploration have also come out one after another.According to the communication method,they can be divided into cabled and cableless acquisition systems.Although the two acquisition systems have their own advantages,seismic data acquisition systems that have both cabled and cableless communication in the published data have not been widely used.Focusing on the actual needs of three-dimensional seismic exploration,this paper studies the key technologies of cabled and cableless hybrid cross-stations based on multi-mode communication,and develops a physical prototype of cabled and cableless hybrid cross-stations to accelerate the development of three-dimensional seismic exploration.First,through analyzing the data transmission requirements of the cabled and cableless hybrid communication system and comparing the communication technologies widely used in seismic data acquisition system,the cabled and cableless hybrid cross-stations in the hybrid communication system are determined to use the hybrid communication method of Ethernet,RS-485 and Wi-Fi.Then the seismic data transmission network consisting of the host,the cable and cableless hybrid cross-stations,the cabled acquisition stations,the cableless acquisition stations and the cable is divided into a cabled acquisition network,a cableless acquisition network,a backbone network,and an extended network through a cabled and cableless hybrid cross-station.Finally,the overall design scheme of the cabled and cableless hybrid cross-station is determined.In the development of physical prototypes,the core board with NXP I.MX6 Q microprocessor as the core processor was selected as the main control module to achieve centralized control of the seismic acquisition system.By integrating Ethernet,RS-485 and Wi-Fi communication chip,hybrid communication module is designed and it realizes the mixed communication function of coexistence of wired communication and wireless communication.At the same time,this paper describes the circuit design of power module,SD card memory module and debugging module in detail.In terms of control software design,this article uses Linux operating platform to study the data transmission method of hybrid cross-station based on multi-media hybrid communication technology.It mainly includes: relay Ethernet data transmission method based on TCP/IP,data transmission method of bus topology structure based on RS-485 and seismic data transmission method based on Wi-Fi technology.It implements the protocol design of networking and data recovery of the cabled and cableless hybrid cross-station in a hybrid communication system.Finally,this paper tests the data transfer rate and stability of the hybrid communication module with cable and cableless hybrid cross-station.After testing,the Ethernet module can meet the relay communication requirements and the transmission rate is higher than 90 Mbps.In complex electromagnetic environment,the communication rate of the Wi-Fi module is higher than 8Mbps,and it has good stability.The RS-485 module meets the communication requirements when the communication distance is less than 50 m,and has good real-time performance.