Design Of Acoustic Emission Monitoring System For Coal And Rock Based On STM32F407

When the coal and rock mass is acted by force,it will produce deformation or failure,release the elastic wave expressed in the form of pulse,such as the acoustic emission phenomenon of coal and rock.The acoustic emission signal of coal and rock can provide very valuable information for the prediction of coal mine dynamic disaster.The acquisition and analysis of coal rock acoustic emission signal is of great significance for judging the arrival of coal mine power disaster and doing well in advance.In this Thesis,a high performance cost-effective acoustic emission monitoring system for coal and rock is designed by using the latest high-end embedded processor chip STM32F407 of STMicroelectronics.The system can realize the collection and preprocessing of acoustic emission signals of coal and rock,and transmit data through Ethernet to PC.The work of this Thesis is focused on the design of the coal and rock acoustic emission monitoring system substation.The main points of the work are as follows:(1)The STM32F407 minimum system module is designed.The microcontroller chip uses STM32F407ZGT6 chip with Cortex-M4 core and 168MHz frequency.(2)In view of the large dynamic range of AE signal,a high-resolution data acquisition module is designed.The AD converter uses ADS1278 to achieve 24 bit resolution and 8 channels synchronous acquisition.(3)In view of the large amount of data of acoustic emission signal,SD card is used to achieve large capacity storage function.STM32F407 supports data cache of Acoustic Emission signals up to 64GB.Data is managed efficiently by the FATFS file system.(4)The display module of monitoring sub-station is designed by using ILI9341 driver chip and 4.3 inch LCD color screen.Display resolution up to 480*800,real-time display of current acoustic emission event waveforms and parameters.(5)The Ethernet communication module is designed by making full use of the combination of Ethernet MAC and external expansion PHY built in STM32F407 chip.Using Ethernet DMA to transmit data,the system has high transmission speed.(6)The software system of monitoring substation is designed based on ?C/OS operating system.The ?C/OS-? operating system is transplanted,and the special DMA transmission for Ethernet communication is designed based on the ?C/OS-?system.In the aspect of data transmission in each module,the powerful DMA on STM32F407 chip is used to complete the data transmission,which improves the speed of data transmission.In the aspect of digital signal processing,a large amount of redundant data is eliminated from the 8 channels of collected signal.The complete coal and rock acoustic emission monitoring system is composed of the designed monitoring station and the MEMS acoustic emission sensor(bandwidth 22kHz)previously developed by the project group,and the comprehensive test is carried out,and the design requirements are achieved.