Real-time Synchronous Monitoring System For Electromagnetic Radiation And Micro-seismic Signals Of Coal Fractures

Rock burst and coal and gas outburst are typical coal,rock and power disasters which seriously threaten the safety of coal mining companies and the property and life safety of mine workers.With the extensive use and excavation of coal mine resources by modern people,a series of sudden coal and rock power disasters have continued to occur and increase.At present,there is a single instrument for rock micro-seismic and electromagnetic radiation on the market,but some of the existing monitoring instruments only use a single prediction index to predict and warn coal and rock dynamic disasters.There is a problem of low monitoring accuracy.How to integrate The use of multi-parameter comprehensive diagnosis of rock faults is an urgent engineering issue.In the process of coal rock rupture,it will be accompanied by the generation of micro-seismic and electromagnetic radiation signals.Such signals have the advantages of continuous and non-contact.In order to solve the problems existing in the current instrument design,this paper has designed a signal that uses electromagnetic radiation and micro-seismic signals.Real-time synchronous monitoring system for two kinds of parameter indexes.The system uses two monitoring indexes to carry out safety monitoring on the surrounding environment of the mine and tunnel construction,so as to improve the accuracy and real-time of predicting and early warning of coal-rock dynamic disaster events.In the process of system design and development,the following work was mainly completed:1.Based on the electromagnetic field theory,fracture mechanics theory and damage theory,this paper analyzes the mechanism and process of coal rock breaking,the generation mechanism of electromagnetic radiation and micro-seismic signals,and summarizes the relevant parameters of electromagnetic signals and micro-seismic signals.The method of signal analysis provides a theoretical basis for the design and implementation of the system.2.This article completes the real-time monitoring data collection,analysis and management of electromagnetic radiation and micro-seismic signals.Among them,the hardware circuit is mainly divided into two parts: front-end data acquisition module and main control module.The front-end data acquisition module includes an A/D acquisition circuit and two signal conditioning circuits.The corresponding signals are converted into electrical signals through two sensors and input to the signal conditioning circuit for processing.Then,the ADS8556 chip is used to perform A/D conversion into digital signals.And passed to the main control module.The main control module is composed of the smallest unit circuit of the microprocessor and some peripheral circuits.The microprocessor selects the STM32F407 chip with ARM Cortex-M4 as the core for circuit design to realize signal processing,storage,result output and alarm.The software part includes data acquisition design,micro-processing software design,liquid crystal display design and data storage design,and is mainly written on the Keil uvision5 platform.The microprocessor software includes four parts: system clock configuration,pulse counting,interrupt configuration and timer configuration.Data analysis and processing adopts multiple analysis directions on the MATLAB platform,including frequency spectrum,correlation and the proposal of criteria.3.This article tests and experiments the designed system.First,test the signal conditioning circuit to verify that the designed circuit can well complete the amplification and filtering functions,and use the data acquisition part to take a voltage with a large dynamic range to verify the accuracy and reliability of the data acquisition and display module.In the last experimental part,after the whole system was tested by the experiment of loading coal samples until breaking,and according to the experimental results,two sets of experimental results were selected for spectrum analysis.At the same time,the electromagnetic signal and the micro-seismic signal were combined to make the correlation between the two.The analysis found that the crosscorrelation function of the electromagnetic signal and the micro-seismic signal in terms of energy and energy cumulative value is the maximum near the value of 0,so it is considered that the electromagnetic signal and the micro-seismic signal have good correlation and synchronization,and also The effectiveness and accuracy of coal-rock dynamic prediction and early warning combined with multiple detection methods of this system are verified.