2018 Vol. 44, No. 8

Display Method:
Diagnosis and recognition of vibration interference in distributed laser methane detection system
GUO Qinghua
2018, 44(8): 1-6. doi: 10.13272/j.issn.1671-251x.2018030088
Abstract:
In order to eliminate influences of external vibration on distributed laser methane detection system, based on analysis of frequency characteristics of vibration waveform and influences of vibration on physical properties of fiber and methane detection, a vibration waveform recognition algorithm based on real-time sampling signal and set frequency signal was proposed. The algorithm can effectively identify external vibration waveforms with different frequencies by steps including Fourier transform, cross-correlation operation, maximum similarity coefficient judgment and methane concentration calculation, and then the vibration waveform can be accurately deleted and the influences of external vibration on methane concentration measurement can be eliminated. The laboratory test and industrial test results show that the algorithm can effectively identify the vibration interference with different frequencies and avoid measurement error introduced by vibration signal.
Design of panoramic image acquisition system in coal mine underground
YIN Dafa
2018, 44(8): 6-9. doi: 10.13272/j.issn.1671-251x.17331
Abstract:
For problems of large size of existing panoramic image acquisition devices which did not apply to coal mine underground and collected image with uneven illumination caused by pointolite in the devices, a panoramic image acquisition system in coal mine underground was designed. Synchronous control process of image acquisition of the system was introduced in detail as well as design schemes of key hardware including intrinsically safe type LED lighting device, intrinsically safe type panoramic image acquisition device, intelligent vehicle loaded mileage recorder and image acquisition synchronization controller, etc. The test result shows that the system can quickly and conveniently acquire panoramic image of coal mine underground with good image quality.
Application prospect analysis of augmented reality technology in mine ventilation system
CHENG Donghao, HUN Baoju, JIN Kai
2018, 44(8): 10-14. doi: 10.13272/j.issn.1671-251x.2018010021
Abstract:
Basic concept and features of augmented reality technology were introduced, idea of applying augmented reality technology to mine ventilation system was proposed combining with development trend of smart mines in China. Application prospect of augmented reality technology in mine ventilation system was analyzed from three aspects, namely 3D visualization of data model, orientation recognition and guidance and realistic enhancement of ventilation tunnel. The analysis results show that using augmented reality technology can realize visualization of the ventilation tunnel data, and obtain real-time information of roadway environment, orientation recognition and guidance are more precise and humanized, which provides a new technical means for intelligent management of mine ventilation system.
Construction of enterprise HSE control platform based on public clouds
HAN An
2018, 44(8): 15-19. doi: 10.13272/j.issn.1671-251x.17333
Abstract:
In view of problems that there was no standard for security management and supervision method was backward in terms of safety control, occupational health and environmental protection in current enterprises, construction plan of enterprise health, safety and environment (HSE) control platform based on public clouds was proposed. Physical architecture and functional architecture design of the platform were introduced, and key points, key technologies of platform construction and platform advantages were analyzed. Planning, execution, inspection, and action (PDCA) management and control system are used to combine real-time dynamic monitoring with daily static business management, event/accident drive is applied to achieve rapid response, and emergency management and emergency response are adopted to achieve auxiliary emergency rescue under catastrophic conditions. Continuous optimization of HSE overall dynamic assessment and control indicators and implementation process is achieved by convergence of indicator plan, implementation efficiency, control effects, and other factors, then strength and depth of management and control are improved. The platform fully utilizes technical advantages and operation and maintenance modes of cloud computing and the Internet of things, reduces construction cost and operation and maintenance difficulty of the HSE project, and improves regulatory efficiency and supervision depth.
Regional gas control scheme and effect analysis
HU Zhifang
2018, 44(8): 19-23. doi: 10.13272/j.issn.1671-251x.2018020043
Abstract:
In view of problems of high gas pressure and poor permeability of outburst coal seam, unsatisfactory of outburst elimination effect of regional gas control, slow speed of coal roadway excavation and tension of working face replacement caused by deep mining on 15-17220 working face in the Twelfth Coal Mine of Pingdingshan Tia'an Coal Mining Co., Ltd., a regional gas control scheme of "crossing boreholes + hydraulic punching" was proposed, and the regional gas control effect was tested and verified. The following conclusions are obtained: residual gas content and pressure are reduced to 5.57 m3/t and 0.40 MPa, they are lower than threshold of outburst prevention regulation, which achieve outburst prevention standard for coal mine safety mining; drilling cuttings and borehole gas emission initial velocity respectively are reduced to 3.5 kg/m and 2.18 L/min, the indicators are not overweight, so as to eliminate outburst danger of coal seam; coal roadway excavation footage is risen every month steady with 10%, and effectively relieves problem of tension of working face replacement. The control results validate rationality of the regional gas control scheme.
Research on improving measurement stability of mine-used X-ray nuclear scale
REN Fengguo, LIU Xuehong, REN Anxiang, WANG Wenqing
2018, 44(8): 24-27. doi: 10.13272/j.issn.1671-251x.2018010058
Abstract:
In order to improve measurement stability of mine-used X-ray nuclear scale, specific methods were given from two aspects of explosion-proof X-ray source and measurement zero point. Energy and intensity of X-ray which are output from X-ray source are monitored by X-ray detector, and the monitored X-ray parameters are received by monitoring network module which is installed in X-ray source. By comparing the monitored X-ray parameters with the set X-ray parameters, tube voltage and tube current of the explosion-proof X-ray source are controlled to keep stable of X-ray parameters. Source intensity zero point is defined by average value of the tube voltage and the tube current of the explosion-proof X-ray source. X-ray parameters are collected in real time through the X-ray detector and compared with measurement zero point and the source intensity zero point, so as to adjust the measurement zero point and the source intensity zero point to overcome influence of conveyor condition change and X-ray tube aging on the measurement zero point. The test result shows that the methods can effectively improve X-ray stability and ensure measurement stability of mine-used X-ray nuclear scale.
Status and prospect of microcomputer protection device for mine-used high-voltage explosion-proof switch
LU Donggui, RONG Xiang, ZENG Ke
2018, 44(8): 28-31. doi: 10.13272/j.issn.1671-251x.2018050038
Abstract:
Status of microcomputer protection device for mine-used high-voltage explosion-proof switch was introduced from aspects of hardware structure and basic functions. Some problems of the microcomputer protection device for mine-used high-voltage explosion-proof switch were pointed out, such as lack of uniform standards, low accuracy of selective leakage protection, uncomprehensive performance of anti-override trip, lack of fault diagnosis function and poor communication reliability. Development trends of the microcomputer protection device for mine-used high-voltage explosion-proof switch were proposed, which included unified technical standards, selective leakage protection based on multi-criteria fusion, anti-override trip based on intelligent substation, fault diagnosis of mine-used high-voltage explosion-proof switch and combination of multiple communication modes.
Weighted centroid localization algorithm based on node cooperation in coal mine underground
ZHAO Tong, LI Xiansheng, ZHANG Lei, DING Enjie, HU Yanjun
2018, 44(8): 32-38. doi: 10.13272/j.issn.1671-251x.2018010007
Abstract:
In view of problems of large attenuation error and low positioning accuracy of personnel positioning signal in underground long-distance roadway, a weighted centroid localization algorithm based on node cooperation was proposed. Under the ZigBee communication environment, the algorithm selects virtual reference node (unknown node that has been located) at a close distance to cooperate localization with reference node in long-distance roadway, and uses improved small-area triangle weighted centroid localization algorithm to locate the unknown node, uses coordinate correction method to determine position of unknown node. The simulation and experimental results show that the localization of reference nodes and virtual reference nodes can reduce use of long-distance reference nodes, which can solve the problem of large signal attenuation caused by long distance and improve the accuracy and stability of underground personnel positioning. The average positioning error of the algorithm is 1.5 m, which meets requirements of personnel location precision in underground long-distance roadway.
Wireless accurate location algorithm based on node cooperation in underground coal mine
GAO Li, HU Yanjun, ZHANG Lei, ZHAO Tong
2018, 44(8): 39-45. doi: 10.13272/j.issn.1671-251x.2018030086
Abstract:
In view of problems that existing multilateral location algorithms had low location accuracy and poor robustness in the case of sparse location base station, a wireless accurate location algorithm based on node cooperation was proposed. Weighted non-convex location model with the minimum error sum of unknown nodes, and corresponding non-iterative location algorithm was proposed. The simulation and experimental results show that average location error of unknown nodes obtained by the proposed algorithm decreases with the increasing of the number of nodes in typical roadway location arrangement and uniform random nodes, and downward trend slows down as the number of nodes increases. The location algorithm can achieve overall improvement of location robustness and location accuracy, which is at the cost of lowering the location accuracy of individual nodes and increasing the complexity of location time.
Analysis of influence regularity of cutting head load to roadheader's deviation angle
ZONG Kai, FU Shichen, LI Yiming, ZHANG Minjun, WANG Pengjiang, WANG Zhilong
2018, 44(8): 46-51. doi: 10.13272/j.issn.1671-251x.2018030002
Abstract:
In order to obtain influence regularity of cutting head load to deviation angle of boom-type roadheader during cutting process, a dynamical model of roadheader's deviation angle was established. According to input problem solved by the model, a calculation method of the cutting head load was proposed, and relationship between the cutting head load and pressure of driving cylinders and cutting position of cutting arm was obtained by simulating calculation. The variation of roadheader's deviation angle during cutting process was simulated and analyzed, and influence regularity of the cutting head load to the deviation angle in different cutting conditions and different cutting positions of the cutting arm were obtained: In horizontal cutting condition, the deviation angle increases with increasing of the cutting head load , and it reaches to the maximum when the horizontal angle of the cutting arm is 14°; in vertical cutting condition, the deviation angle decreases with increasing of the cutting head load, and the larger vertical angle of the cutting arm is, the smaller the deviation angle is.
Horizontal shape detection method for scraper conveyor
QIAO Chunguang, WANG Xuewen, XIE Jiacheng, LI Xiang, YANG Zhaojian
2018, 44(8): 52-57. doi: 10.13272/j.issn.1671-251x.2018060004
Abstract:
Aiming at problem of inaccurate measurement results of existing horizontal shape detection methods for scraper conveyor, a horizontal shape detection method for scraper conveyor was proposed which was based on cooperative position and attitude calculation of shearer and scraper conveyor. Firstly, information of strapdown inertial navigation system was calculated by use of Rodrigues parameter method according to coupling relationship between shearer and scraper conveyor in running process, so as to obtain position and attitude information of shearer when running on scraper conveyor. Then the calculated position and attitude information of shearer and the known heading angle of middle trough of scraper conveyor were substituted into mathematical model of horizontal shape detection for scraper conveyor, thus each heading angle of middle trough of scraper conveyor was calculated, so as to obtain horizontal shape of scraper conveyor. The test results show that detection error of the method is 0-1.5° to heading angle of middle trough of scraper conveyor, and the maximum detection error of horizontal shape of scraper conveyor is 30.70 mm, which meets horizontal shape detection requirements of scraper conveyor.
A residual life prediction method of mine-used cable
LI Lei, MA Xianmin, FAN Wenling
2018, 44(8): 57-62. doi: 10.13272/j.issn.1671-251x.2018010044
Abstract:
For problems of complex modeling, difficult invalid data collection and low prediction precision of existing residual life prediction methods of mine-used cable, a residual life prediction method of mine-used cable was proposed which was based on gray prediction and multi-scale quantum harmonic oscillator algorithm(MQHOA). Dielectric dissipation factors and aging time under different temperature are collected firstly in accelerated hygrothermal aging test. Then residual life prediction model of mine-used cable is established by use of gray prediction GM(1,1) model and the collected data, which takes dielectric dissipation factor of 5% as ending criterion of cable life. Finally, MQHOA is used to optimize parameter of the GM(1,1) model to improve prediction precision. The test result shows that the method has short test time and higher correctness.
Vision measurement system for cutting head attitude of mine-used boom-type roadheader
ZHANG Xuhui, LIU Yongwei, YANG Wenjuan, MAO Qinghua, WANG Dongman, ZHOU Ying
2018, 44(8): 63-67. doi: 10.13272/j.issn.1671-251x.2018010067
Abstract:
For problems that current vision measurement methods for cutting head attitude of boom-type roadheader needed to change roadheader structure with low measurement stability, a vision measurement system for cutting head attitude of mine-used boom-type roadheader was designed by use of monocular vision measurement technology. Firstly, multi-point infrared light source is used to form a square on infrared target installed on cutting arm near rotary table, and the infrared target image is regularly collected by camera. Then, center of light spot is extracted to calculate coordinate of the square vertices in pixel coordinate system, and coordinate of the infrared target in camera coordinate system is obtained by use of pesprctive-4-point method. Finally, attitude angle of cutting head is calculated by use of attitude measurement model of cutting head. The experimental results show that vertical swing angle error of the system is within ±0.8° and horizontal swing angle is within ±0.5°.
Region discretization mine target positioning method based on compressed sensing
XU Zhiming, TIAN Zijian, WANG Wenqing, LIU Zhenzhen, LIU Ting, HUANG Lei
2018, 44(8): 67-70. doi: 10.13272/j.issn.1671-251x.2018020005
Abstract:
For problems of low positioning accuracy of electromagnetic wave ranging positioning method due to underground electromagnetic interference and continuous measurement and storage of massive offline data in offline construction of fingerprint feature database by fingerprint positioning method, a region discretization mine target positioning method based on compressed sensing was proposed. Firstly, positioning area is divided into grids for discretization, and fingerprint feature database is constructed by offline measuring signal strength at the grid. Then, sparse position matrix containing target position information is obtained by compressed sensing with a small amount of signal strength sampled online, so as to estimate possible position of the target. Finally, the target is accurately positioned by grid centroid method. The experimental results show that the method achieves accurate positioning of mine target with higher positioning accuracy and less positioning time.
Study on thin bedrock deformation and strata behavior in coal seam mining under ultra-thick unconsolidated strata
ZHAI Xinxian, LYU Chao, TANG Shijie, YU Chunsheng
2018, 44(8): 71-75. doi: 10.13272/j.issn.1671-251x.2018020007
Abstract:
Taking No.12051 fully-mechanized coal face of Zhaogu No.1 Coal Mine as research object, thin bedrock deformation and strata behavior in coal seam mining under ultra-thick unconsolidated strata were studied by use of UDEC numerical simulation software. The results show that the first weighting interval and periodical weighting interval of the coal face is 55 m and 15 m respectively. Caving zone and fractured zone appear in overlying strata after mining. The height of caving zone and fractured zone is 12.4 m and 36.7 m respectively. Ratio of caving zone height to mining height is 3.54 and ratio of fractured zone height to mining height is 10.48. Affected zone range of front abutment pressure, peak of front abutment pressure and plastic zone range increase with increase of coal face advancing distance. The front abutment pressure is stable after the first weighting at basic roof, which manifests in the maximum stress concentration factor and plastic zone range basically remain unchanged. The research results can provide basis for surrounding rock stability control of fully-mechanized coal face under the similar geological condition.
Fault diagnosis of rigid cage guide based on wavelet packet and BP neural network
MA Tianbing, WANG Xiaodong, DU Fei, CHEN Nanna
2018, 44(8): 76-80. doi: 10.13272/j.issn.1671-251x.2018010051
Abstract:
In view of problems that existing fault diagnosis methods of rigid cage guide could not eliminate influences of environmental factors and low recognition rate of joint faults, a method of fault diagnosis of rigid cage guide based on wavelet packet and BP neural network was proposed in order to improve accuracy of identification of fault types of rigid cage guide. Experimental platform of lifting system of vertical shaft was set up to simulate two typical fault types of rigid cage guide including step protrusion and joint failure, and vibration acceleration signal of lifting vessel was collected. Wavelet packet decomposition was applied to carry out energy analysis and extract fault characteristic parameters. The fault characteristic parameters were taken as input of BP neural network, and a new test sample was selected to detect diagnostic effect of the neural network. The experimental results show that the method has high accuracy of fault identification, and the confidence level reaches to 0.91.
Research on rotor-side frequency conversion speed regulation technology for high voltage wound-rotor motor
CHENG Guodong, WANG Huaping, XIA Jingjing
2018, 44(8): 81-86. doi: 10.13272/j.issn.1671-251x.17330
Abstract:
In view of problems of technical difficulties, high cost and high voltage requirements for power electronic components in current high voltage wound-rotor motor using stator-side high voltage inverter for frequency conversion speed regulation, a rotor-side frequency conversion speed regulation technology for high voltage wound-rotor motor was proposed. The technology transfered power transformation from stator side to rotor side taking advantage of low voltage level on rotor side, frequency conversion speed regulation of high voltage wound-rotor motor was realized through general frequency converter. Mathematical model of vector control system for rotor-side frequency conversion was deduced, and adaptive full-order state stator flux linkage observer was designed. Speed identification was realized according to stator flux linkage observation. Matlab simulation and experimental results verify the correctness and feasibility of rotor-side frequency conversion speed regulation technology.
Design of personnel positioning system in coal mine underground based on MEMS sensor
ZHAO Yue, LAN Ying, QU Xian
2018, 44(8): 87-91. doi: 10.13272/j.issn.1671-251x.17326
Abstract:
For problems of low positioning accuracy and high cost existed in current underground personnel positioning system, a personnel positioning system in coal mine underground based on MEMS sensor was designed. The system uses MPU9150 inertial sensor to obtain measurement data and takes CC2530 as the main control chip to collect and process data. It combines with pedestrian dead reckoning (PDR) algorithm and through existing underground WiFi base station to realize accurate positioning for underground personnel: it uses an expression that combined the variance of the walking frequency and acceleration to determine step length, and uses the quaternion method to estimated pedestrian orientation angle, uses extended Kalman filter to correct the original data, so as to obtain specific location of underground personnels. The experimental results show that the positioning error of the system is less than 2.2 m in 100 m, which can achieve high accuracy of personnel positioning in coal mine underground.
Design of separation system of coal and gangue
YANG Huigang, QIAO Zhimin, GAO Huiyan, LIU Yu, ZHAO Yiding
2018, 44(8): 91-95. doi: 10.13272/j.issn.1671-251x.2018020004
Abstract:
In view of problems of high cost, high consumption of natural resources and serious environmental pollution existed in common coal preparation methods and X-ray coal preparation method was easy to occur identification errors for different thickness of coal and gangue, a separation system of coal and gangue based on X-ray and optical fiber sensor was designed. Firstly, X-ray images of coal and gangue are obtained by X-ray scanning, which are processed to get gray value of the images. Then thickness of coal and gangue are measured by optical fiber sensor. Finally, identification threshold value of coal and gangue is determined by integrating gray value and thickness, so as to realize separation of coal and gangue. The experimental result shows that the system can identify coal and gangue effectively through the identification threshold value of coal and gangue.
Research on wearable devices for safety of underground mine personnel
MA Yujing, BAI Dongmei, LIU Yutian, MA Chengran, WU Mingzhe
2018, 44(8): 96-99. doi: 10.13272/j.issn.1671-251x.2018030079
Abstract:
In view of problems of low positioning accuracy of underground personnel positioning system and incomplete functions of underground personnel vital signs monitoring system, a wearable device with functions of personnel positioning, falling or lying posture monitoring and heart rate monitoring was studied. The device adopts combination of RSSI ranging and step calculation to improve positioning accuracy of underground personnel. Three-axis acceleration sensor is used to detect abnormal movement of person, and heart rate sensor is used to obtain heart rate data. The test results show that the device can achieve accurate positioning of underground personnel, can accurately determine falling or lying posture of underground personnel, and alarm abnormal state.
.Design of acquisition system of multi-channel microseismic signal
CAI Jianxian, MIAO Jie, YAO Zhenjing, LI Yanan, HAN Zhiming
2018, 44(8): 100-104. doi: 10.13272/j.issn.1671-251x.2018010002
Abstract:
In view of problems of high cost and low universality existed in current acquisition systems of mine microseismic signal, an acquisition system of multi-channel microseismic signal was designed. The system adopts seismometer to collect microseismic signals, uses acquisition circuit to implement amplification for microseismic signals, analog-to-digital conversion and digital filter, and uses STM32 to real-timely send filtered signals to PC for analysis by USART. The test results show that the system can accurately collect and record 3-channel microseismic signals collected by seismometer with good stability, high reliability and low cost.