2018 Vol. 44, No. 4

Display Method:
Developing trend and key technologies of network technology of mine Internet of things
ZHAO Xiaohu, ZHANG Kai, ZHAO Zhikai, HUO Yu
2018, 44(4): 1-7. doi: 10.13272/j.issn.1671-251x.17324
Abstract:
The current status of mine network was summarized. According to development goal of mine Internet of things and changing trend of information processing modes in future mine, developing requirements and trend of mine network were analyzed form aspects of network capacity, manageability, dense access, real-time performance, intelligentization, emergency communication after disaster, etc. Design principles of network of mine Internet of things were proposed including flattening, intelligentization, resource abstraction, etc. The application and developing requirements of key technologies in mine Internet of things were introduced such as wireless transmission coding, software-defined network, flow offloading, edge computation, network function virtualization, cognitive radio, energy capture, semantic network and so on.
Calculation method of joint elongation of steel cord conveyor belt
LI Xianguo, ZHANG Can, ZHANG Lei, SHEN Lifang, JIANG Hangqi
2018, 44(4): 8-13. doi: 10.13272/j.issn.1627-251x.2017110052
Abstract:
In view of problems of single determination way and high computational complexity of joint elongation of steel cord conveyor belt, a calculation method of joint elongation of steel cord conveyor belt based on X-ray image was proposed. Histogram equalization and mean filter are used to pretreat image for improving image contrast and effectively solving the problem of uneven grayscale image of the steel cord conveyor belt. Sobel operators are used for joint edge detection and dynamic threshold process to extract upper and lower joints. Slope of fitting straight line of the upper and lower joints is used to determine whether the joint of the image to be checked is the same with the reference joint, so as to judge whether the joint is elongated or not. Outermost length on the left and right ends of the joint and average length of the joint are calculated according to the end points and the fitting lines of the upper and lower joints. The experimental results show that the method is computationally fast, efficient and can calculate the joint elongation easily and accurately.
Development of automatic test platform of electro-hydraulic control system of hydraulic support
LI Junshi
2018, 44(4): 13-19. doi: 10.13272/j.issn.1627-251x.2017110051
Abstract:
In view of problems of high cost, low test efficiency and unable to record test data automatically of functional test methods of existing electro-hydraulic control system of hydraulic support, and in order to verify adaptability of control logic of the electro-hydraulic control system of hydraulic support to working condition of fully mechanized coal mining face, an automatic test platform of electro-hydraulic control system of hydraulic support was developed by taking SAC hydraulic support electro-hydraulic control system as research object. The test platform uses a test management platform to coordinate multiple test devices to execute test cases collaboratively, adopts simulation technology to simulate data changing process of various sensors, and uses multiple communication networks to real timely collect test data, uses switching of multiple relays to realize multi-function complex. The test platform can realize automatic configuration and management of port function of detection device according to the specific application of fully mechanized coal mining face, and can realize single function test, group function test, automatic following function test and automation adaptability test of working condition of fully mechanized coal mining face, which improves test efficiency and test accuracy, provides an effective means to study adaptability of the electro-hydraulic control system under complex working conditions such as roof caving and floor bump on fully mechanized mining face.
Detection method of instantaneous coal quantity of belt conveyor based on laser scanning
GUAN Binghuo
2018, 44(4): 20-24. doi: 10.13272/j.issn.1627-251x.17302
Abstract:
In view of problem that existing coal quantity detection method with laser instrument does not propose a clear method for laser line extraction, a detection method of instantaneous coal quantity of belt conveyor based on laser scanning was proposed. Image of loose coal on belt conveyor is obtained by digital camera and laser instrument, and laser line profile is extracted by using characteristics of Ohta color space, then laser line thinning and connection processing based on index table are performed. According to offline acquired baseline and laser line acquired in real time, cross-sectional area of coal is calculated using trapezoidal area cumulative method, and instantaneous coal quantity of belt conveyor is obtained real-timely. Test results show that coal quantity detection result of the method matches actual coal quantity, and the method has high accuracy and good real-time performance.
Research on volume measurement method of coal on belt conveying based on machine visio
LI Ping, REN Anxiang
2018, 44(4): 24-29. doi: 10.13272/j.issn.1627-251x.2017110027
Abstract:
Through analyzing characteristics and application status of current dynamic measurement methods of coal on belt conveying, a volume measurement method of coal on belt conveying based on machine vision was proposed in view of problem of lower precision of laser belt scale. Firstly, a volume measurement model was established based on principle of trigonometric distance measurement, and a set of image acquisition device suitable for coal mine environment was used to collect images. And then fast skeleton extraction algorithm based on gradient optimization was used to get center of line laser stripe, the interpolation method based on distance threshold was adopted to repair break line. Finally, according to the volume measurement model, the volume measurement of coal was realized by calculating the center offset of the laser stripe. Test results show that volume measurement error of the method is lower than that of the common laser belt scale, which is more suitable for dynamic measurement of coal on belt conveying.
Research on mine personnel positioning method based on time range
SUN Zhexing
2018, 44(4): 30-33. doi: 10.13272/j.issn.1671-251x.17297
Abstract:
Four kinds of mine personnel positioning methods based on time range were researched, namely TOA, TWR, SDS-TWR and TDOA positioning methods, they are less influenced by roadway environment and suitable for mine personnel precise positioning.TOA positioning method requires time of transmitting device and receiving device must be strictly and accurately synchronized, clock accuracy requirement of transmitting device and receiving device is very high with synchronous calibration, so its positioning card and substation cost high. TWR positioning method does not need to strictly synchronize in clock of signal transmitting device and receiving device, so complexity and cost of its positioning system is reduced, but its positioning precision is affected by clock error of positioning card and substations, positioning card and substation cost high. SDS-TWR positioning method does not need to strictly synchronize in clock of signal transmitting device and receiving device, so influence of clock error of its positioning substation and card on positioning precision is reduced, but its positioning precision is affected by clock error of positioning card and substations , positioning card and substation cost high. TDOA positioning method requires time between positioning substations must be strictly and accurately synchronized, and clock accuracy requirement of positioning substations is very high with synchronous calibration, positioning card cost lower and positioning substation cost higher.
Application prospect analysis of new technologies of mine-used belt conveyor
XIAO Huaming, SUN Shijiao, CAO Lianmin
2018, 44(4): 34-39. doi: 10.13272/j.issn.1627-251x.20171120049
Abstract:
Introduction and application prospect of new technologies were discussed such as centralized control and unattended intelligent control of conveyor belt, anti-tearing of conveyor belt, new technology of energy saving and reduction, rapid installation and withdrawal technology. The realization of unattended monitoring was described from three aspects of vision function, hearing function and touch function. A new longitudinal tearing recognition device for mine conveyor belt was introduced, it uses camera video recognition technology to identify and judge damage of conveyor belt real timely. It is analyzed that application of new rubber conveyor belt with aramid as the skeleton material, the intelligent technology of video recognition, and low-resistance stainless steel roller can effectively save energy and reduce consumption. A non-foundation fixing method for rapid installation and withdrawal of belt conveyor was introduced. The application of the new technologies of mine-used belt conveyor will gradually realize the functions of high intelligence centralized automatic control, quick and efficient installation and withdrawal of belt conveyor, and lay a solid foundation for safe, high yield and high efficiency of coal mine.
Research on equipments cooperative advancing control technology on fully-mechanized coal mining face and two-roadways
WANG Feng
2018, 44(4): 39-43. doi: 10.13272/j.issn.1671-251x.2017100026
Abstract:
For problems of low automation level and poor cooperative control of equipments on fully-mechanized coal mining face and two-roadways, a scheme of equipments cooperative advancing control technology on fully-mechanized coal mining face and two-roadways was proposed, which took self-advancing control technology of support, transportation and auxiliary equipments on two-roadways as basis, industrial Ethernet based on Ethernet/IP communication protocol as cooperative control communication platform, and cooperative advancing control process as decision-making basis. The scheme can realize equipments cooperative advancing control on fully-mechanized coal mining face and two-roadways, which effectively reduces number of operators and meets requirements of rapid and high efficient advancing.
Analysis of electric field distribution at air gap defect and its influencing factors in mine-used high-voltage cable insulatio
YANG Shuo, GENG Pulong, QU Bingni, SONG Jiancheng, LIU Jucai, TIAN Min
2018, 44(4): 44-51. doi: 10.13272/j.issn.1627-251x.2017110050
Abstract:
In order to know influence factors and laws of electric field distribution with air gap defects in cable insulation, taking mine-used high-voltage XLPE cable as research object, ANSYS finite element software was used to establish cable structure model contained air gap defect. Influence of shape, size and location of the air gap and thickness of the insulating layer on electric field distribution in the air gap was simulated and studied based on theoretical analysis of relationship between shape, size and electric field strength of air gap in insulation. Results show that electric field intensity of elliptic cylinder air gap defect is the largest of four different shapes of air gap, and the larger the air gap length in direction of insulation perpendicular to the field strength, the greater the field strength in the air gap. For size of the air gap, the larger the r value, the greater the field strength at the air gap, and change of the air gap size has little influence on the field strength at the air gap. For different radius size of the air gap, the maximum electric field strength at the air gap increases first and then decreases with increasing of distance between the air gap and the conductor shield. For a given size of the air gap, the field strength in the air gap and the insulation increase accordingly with decreasing of thickness of the insulation. These conclusions lay foundation for partial discharge of air gap defects, and also provide technical guidance for cable operation and maintenance.
Reliability analysis of traction unit of electrical haulage shearer
GE Hongbing
2018, 44(4): 51-56. doi: 10.13272/j.issn.1671-251x.17306
Abstract:
For the problem that traditional manual reliability analysis method for traction unit of electrical haulage shearer could not find hidden fault real-timely, a reliability analysis method of traction unit of electrical haulage shearer was proposed which was based on fault tree analysis and fuzzy logic theory. Non-traction fault tree of the traction unit is built firstly, and failure degree of basic events in the fault tree is graded. Then membership degree of each basic event belonging to corresponding fault grade is calculated by use of fuzzy synthetic discrimination method, so as to get the fault form and fault rate of the traction unit in each working stage. The method can realize reliability analysis and health management of the traction unit of electrical haulage shearer.
Research on over-discharge hydraulic buffer system for hydraulic driven hoist
TANG Youliang, ZHANG Ji
2018, 44(4): 57-61. doi: 10.13272/j.issn.1627-251x.2017120069
Abstract:
Working principle of hydraulic buffer system of hydraulic driven hoist and its main influencing factors were analyzed. System simulation model was established based on AMEsim, and influence law of overload valve diameter, overload valve opening pressure, engine swept volume, bucket weight and operating speed to bucket displacement and engine inlet pressure were simulated and analyzed. The analysis results can provide theoretical guidance for further optimization of design of the over-discharging buffer system.
Texture feature extraction of coal-rock image based on variogram and local variance image
HUANG Lei, GUO Chaoya
2018, 44(4): 62-68. doi: 10.13272/j.issn.1627-251x.17311
Abstract:
In view of problems of low classification accuracy and algorithmic running efficiency and poor robust property of rotation texture recognition existed in local binary patterns for texture feature extraction of coal-rock, a texture feature extraction algorithm of coal-rock image based on variogram and local variance image was proposed. Firstly, local variance image was got by calculating local variance with pixel by pixel in theoretic framework of local binary patterns. Then, the variogram vectors with different direction were calculated by variogram in local variance image. Finally, combination variogram vectors were taken as the texture feature, classification and recognition of texture of coal-rock was realized combining the texture feature and local binary patterns feature. Experiment results show that the algorithm can effectively extract spatial distribution information of the local variance image, realize information reuse missed by local binary patterns, and its classification results are better than other algorithms of texture extraction based on local binary patterns, the classification precision reaches 86%.
Research on formation process of arc grounding over-voltage in mine power supply system
LIU Jucai, GENG Pulong, QU Bingni, SONG Jiancheng
2018, 44(4): 69-74. doi: 10.13272/j.issn.1671-251x.2017080063
Abstract:
For comprehensive research on formation process of arc grounding over-voltage in mine power supply system, a mine power supply system model and an intermittent arc grounding model were built by use of real time digital simulator, and over-voltages in processes of power frequency arc extinction, high frequency arc extinction and hybrid arc extinction were simulated. The simulation results show that the maximum transient over-voltage under condition of power frequency arc extinction theory is slightly lower than historical measured value; the maximum transient over-voltage under condition of high frequency arc extinction theory increases with the increase of arc re-ignition times, which is larger than the historical measured value; in the case of hybrid arc extinction, the more times high frequency arc extinction occurs and occurs continuously, the larger the maximum transient over-voltage is; when arc grounding fault occurs in mine power supply system, power frequency arc extinction and high frequency arc extinction alternately occurs, and probability is very low that high frequency arc extinction continuously occurs more than three times.
Mine personnel fusion location system
WU Jingran, CUI Ran, ZHAO Zhikai, YOU Peng, ZHANG Lei
2018, 44(4): 74-79. doi: 10.13272/j.issn.1671-251x.17296
Abstract:
For problems that mine personnel location system based on traditional received signal strength indication (RSSI) fingerprint location algorithm had heavy workload in fingerprint database collection during off-line stage and was easily influenced by underground environment, and the location system based on pedestrian dead reckoning (PDR) algorithm had accumulative error, a mine personnel fusion location system was proposed which was based on an improved RSSI fingerprint location algorithm and PDR algorithm. The system uses intelligent terminals consisting of GS1011 controller and MPU9150 inertial sensor to send the data of inertial sensor, RSSI and timestamp to location server on the ground through underground WiFi network. The location server fuses location information of RSSI fingerprinting location algorithm and PDR algorithm by use of extended Kalman filter, so as to realize underground personnel location. The test result shows that the average location error of the system is 1.79 m and smaller than the one of RSSI fingerprint location algorithm or PDR algorithm, and location accuracy satisfies underground personnel location requirement.
Stable sensorless control for permanent magnet synchronous motor of mine-used electric locomotive at low speed stage
ZHU Longji, HUANG Qi
2018, 44(4): 80-85. doi: 10.13272/j.issn.1671-251x.17300
Abstract:
In order to improve stability of sensorless control for interior permanent magnet synchronous motor of mine-used electric locomotive at low speed stage, an improved pulsating high-frequency voltage injection method was proposed. High-frequency sinusoidal voltage signal is injected into direct axis of estimated synchronous rotating coordinate, and high-frequency current of quadrature axis is processed through low pass filter, so as to obtain signal containing estimation error of rotor position angle. The signal is input into Luenberger observer to calculate estimated rotor position. The simulation and experimental results show that the method can estimate rotor position angle and speed accurately at low speed stage, so that electric locomotive can realize smooth starting, operation and stopping at low speed stage.
Location and recognition method of digital tube of digital display instrument under complex environment
ZHANG Li, LIU Bin, GUI Junguo, JIN Yunyu, ZHANG Cheng, DU Bing, LIU Bo
2018, 44(4): 85-89. doi: 10.13272/j.issn.1671-251x.2017100053
Abstract:
For problem that digital tube of digital display instrument is difficult to locate and accurately recognize in robot inspection system of mine equipment high-voltage distribution room, a location and recognition method of digital tube of digital display instrument under complex environment was proposed. In aspect of digital tube location, feature graph and mark-based watershed algorithm are used to roughly locate digital tube. Then binary image is obtained by use of Otsu threshold method and mark-based watershed algorithm and split by projection, so as to get digital tube character. Non-digital tube area is excluded by local binary pattern feature and support vector machine classification algorithm, which can improve location accuracy of digital tube. In aspect of digital tube character recognition, self-adaptive Canny algorithm is used to extract edge of digital tube character. Then Radon transform is adopted to estimate tilt angle of digital tube character, and filter template is used to remove noise. Finally, threading method is introduced to recognize digital tube character. The experimental results show that the method has high location and recognition accuracy, which can adapt to different lighting, digital tube size and tilt angle.
Construction and implementation of platform for intelligent mine
QUE Jianli
2018, 44(4): 90-94. doi: 10.13272/j.issn.1627-251x.17317
Abstract:
In view of problems of small anount of acquisition of basic parameter, low value of comprehensive utilization of integrated data, single data applications and analysis existed in construction of current digital mine, content of intelligent mine platform was discussed, architecture design of the intelligent mine platform was put forward, key technologies in the platform implementation was introduced.The platform uses perception technology and high reliability control technology to realize omni-directional perception and Internet of thngs control for environment, staff, equipment, and intelligent monitoring for overall production process; uses big data processing technology to build a unified data operation and maintenance layer, and can realize unified management, utilization of mine master data, real-time monitoring data, geographic measurement data, operation management data, and improve utilization rate of the data; uses big data and deep learning technology to gather and classify collected, input and extracted data, which realizes comprehensive utilization of the data, and improves capacity of mine control and management.
Classification and calculation of the best escape route of coal mine based on Dijkstra algorithm
TONG Xing, YUAN Shuaiqi, FANG Weipeng, MA Jinyu
2018, 44(4): 94-99. doi: 10.13272/j.issn.1627-251x.17314
Abstract:
In order to make mine escape route have better applicability, the method of classification and calculation of the best escape route when the mine is facing different types of disaster risk was discussed. According to characteristics of different disasters, mine disasters are classified into three categories: water inrush disaster, roof fall accident, and a category including coal and gas outburst, gas or coal dust explosion, mine fires. Feasible topological maps for the three types of disasters are plotted, and equivalent length of each roadway is calculated. The equivalent length of the roadway is taken into the topological map as weight of each side of the feasible route, and the shortest path algorithm Dijkstra algorithm is used to solve the best escape route of each topology. Analysis result shows that the method expands selection of escape routes and make capacity of roadway system be fully developed with more refugees.
Training system for coal mine full-hydraulic drilling rig based on virtual reality technology
WANG Tianlong, QIAO Jie, PENG Tao, YAO Yafeng, LIU Ruiquan
2018, 44(4): 100-104. doi: 10.13272/j.issn.1671-251x.2017120016
Abstract:
In view of problem of unsatisfactory effect of traditional training for coal mine full-hydraulic drilling rig, a training system for coal mine full-hydraulic drilling rig based on virtual reality technology was developed. The system is consisted of lower computer and upper computer, and communication between the lower computer and the upper computer is realized through FX2N series PLC programming interface. The lower computer uses PLC to collect and process control instruction of drilling rig virtual console. The upper computer applies Quest3D virtual software to realize virtual drilling rig and scene setting, key parts virtual disassembly and virtual drilling rig operation programming. The system shortens training period and reduces training cost with good human-computer interaction performance and simple operation.
Improved differential evolution algorithm for solving open-pit mine transportation problem
PENG Cheng, SUI Xiaomei, WANG Huiju
2018, 44(4): 104-108. doi: 10.13272/j.issn.1671-251x.2017100044
Abstract:
Aiming at open-pit mine transportation problem, a mathematical model of the open-pit mine transportation problem was established which took production and transportation capacity of open-pit mine as constraint conditions and the minimum transportation cost as objective function. In view of problem that intelligent optimization algorithm for solving the open-pit mine transportation problem was easily getting trapped in local optimal solution, an improved differential evolution algorithm was proposed. Normalization is introduced into differential evolution algorithm which makes equality constraint in the transportation problem can be satisfied automatically and is advantageous to jump out of local optimal solution. The application results show that the algorithm has good repeatability, and transportation cost is significantly reduced by use of the algorithm to optimize the open-pit mine transportation problem.