Research On Multi-node Micro-seismic Data Acquisition And Transmission Technology Based On PTP

In coal mining, there will inevitably lead to a series of geological disasters phenomena due to human or natural factors, such as the roof collapsed, gas outburst, rock burst, etc. All of the geological disasters once occur, which will cause huge losses for the people and the country. Therefore, in order to avoid casualties and reduce property damage, it is very necessary and essential for us to take measures to reduce and prevent the occurrence of such geological disasters. According to scientific studies show that the coal and rock will cause a weak tremor that we call it micro-seismic signals before the roof collapse and gas outburst and other disasters occurred in the coal mine. As long as these micro-seismic signals can be monitored in real time and effectively, then locate the micro-seismic source of the position through processing and analyzing these signals be monitored. Once the source and the near region are judged to be the danger zone, measures must be taken to protect the area and prevent the disasters. Therefore, it is very necessary and urgent for coal mining enterprises to build a comprehensive micro-seismic monitoring system.Principle of micro-seismic monitoring technology:under the action of certain factors, the subsurface rock burst and will produce seismic waves spread to the surrounding, use the detector distributed installation in the surrounding rock collect the micro-seismic signal detector, and then take a certain algorithm to deal with the collected data, and finally determine the location of the rupture of the rock and identify possible security risks of the region by analyzing the results of the data processing, thereby eliminate the risk of disasters. The technology is good or bad depends on the integrity of the micro-seismic data, so the collection and transmission of micro-seismic signals is the key.In this paper, based on the Ethernet communication technology, we adopt PTP(Precision Time Protocol) clock synchronization technology to realizing the micro-seismic data synchronization acquisition and efficient transmission in the circumstances of multi-nodes. We focuses on micro-seismic signal acquisition and transfer done in-depth research in coal micro-seismic monitoring system, key technologies involved in this paper as follows:(1) Design of micro-seismic geophone. Micro-seismic geophone include a MEMS (Micro-electromechanical Systems) sensors, tri-axial electronic compass, micro-seismic signal conditioning circuit, micro-seismic signal processing circuit and micro-seismic data transmission circuit as one unit. Use three MEMS sensors to orthogonal consist the X Y Z rectangular axes, the purpose of design is to improve the ability of the detector seismometer. Relative to the traditional moving coil analog receivers, the advantage of this detector is that the effective and timely processing micro-seismic signal, avoiding the signal loss in the transmission process.(2) Research on multi-node synchronization acquisition technology. In micro-seismic monitoring system, each geophone is a distributed installation and there is a certain distance between each geophone, with the expansion of the scope of monitoring, the node is also increasing, in order to improve the positioning accuracy of micro-seismic events, it is critical for each collection node to realize synchronization between nodes. In view of the micro-seismic monitoring system, we set up the local area network (LAN) for the acquisition node, and use PTP network clock synchronization for each collection synchronized clock correction nodes, so as to enable each node synchronization acquisition.(3) Design of the data transfer station. Due to the limited number of monitoring host network interface, so each node of the data cannot be directly transmitted to the monitoring host, the data of all nodes uniform to a transfer station point for storage in advance, and then the transfer station aggregated data processing nodes each collection. Finally, the transfer station will have all nodes data transmit to the monitoring host, to achieve a combination of data transmission.