2017 Vol. 43, No. 10

Display Method:
Framework and key technologies of Internet of things for precision coal mining
YUAN Liang
2017, 43(10): 1-6. doi: 10.13272/j.issn.1671-251x.2017.10.001
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Abstract:
On the basis of analyzing existing problems of coal mine production logistics system, concept and connotation of Internet of things(IoT) for precision coal mining were proposed and five key technologies were condensed by summarizing scientific conception of precision coal mining and development of mine IoT, which were intelligent perception of multi-source information, multi-network fusion transmission, multi-parameter information analysis and processing, disaster monitoring and early warning based on cloud technology and mine disaster emergency rescue. It was pointed out that precision coal mining based on transparent earth and intelligent perception based on IoT were two major technical systems to realize future unmanned mining, precision coal mining was technology core, and IoT was technical guarantee. Taking IoT for dynamic disaster precision early warning of coal mine as an example, its system framework was expounded including perception layer, network layer, application layer and public technology, and its engineering application was introduced, which directed technology route for precision coal mining.
Design of on-line monitoring system for self-excited deduster
WANG Dongxue, LI Xiaochuan, WEI Tao, HU Haibin, XIANG Wu
2017, 43(10): 7-13. doi: 10.13272/j.issn.1671-251x.2017.10.002
Abstract:
Due to unobservable operating environment, gas-liquid mixing state of self-excited deduster can not be observed in real time, so it is difficult to avoid dust escape caused by fluctuation of liquid surface and intermittent excitation of traps in gas fluid coupling process, and determining of operating parameters (liquid level, wind speed, etc) of the deduster lacks of scientific basis, so it is difficult to guarantee removal efficiency of the deduster. In order to solve the above problems, an on-line monitoring system for self-excited deduster was designed. The system uses five characteristics parameters as the important identification basis of flow pattern to identify the gas-liquid flow pattern inside the deduster quantitatively, including resistance parameter, liquid level parameter, power spectral density value, relative power spectral density value and frequency characteristic segment of pressure signal. The system can adjust operating parameters of the deduster, and realizes on-line monitoring of gas-liquid mixing state in the self-excited deduster.Test results show that the system can realize real-time and precise recognition for gas-liquid flow pattern of deduster with 95.6% recognition rate.
Application of symmetrical component method in protection system of bolter-miner
JIAO Xiaofeng
2017, 43(10): 14-17. doi: 10.13272/j.issn.1671-251x.2017.10.003
Abstract:
In view of problems of low reliability and accuracy of fault diagnosis of asynchronous motor in bolter-miner, symmetrical component method was purposed to apply in protection system of bolter-miner to realize asymmetry over-current fault diagnosis. Three-phase voltage is decomposed into positive sequence component, negative sequence component and zero sequence component, then active phase shifting circuit and phase sequence judgment circuit are used to judge phase sequence of main circuit, and the negative sequence voltage is obtained by negative sequence component acquisition circuit and is used to judge fault and its type. Industrial test results show that application of the symmetrical component method improves sensitivity, reliability, accuracy and intelligence level of the protection system of bolter-miner, reduces system maintenance cost, and improves service life of asynchronous motor and excavation speed on working face.
Development trend of mine frequency converter
ZHU Yongping, XU Xiaojian
2017, 43(10): 18-23. doi: 10.13272/j.issn.1671-251x.2017.10.004
Abstract:
Main problems of mine-used frequency converter were analyzed that input of research and development is insufficient, value exploration is inadequate, pollution to power net is heavy, and use and maintenance is relatively difficult. Development trends of the mine-used frequency converter were expounded in term of explosion-proof technology, variable frequency drive technology and application technology, namely explosion-proof and intrinsically safe is still mainstream of explosion-proof type for the mine-used frequency converter in the future, explosion-proof research of the mine-used frequency converter will focused on optimization design of shell, internal environment control of shell, innovation of heat dissipation technology. Research focuses of the mine-used frequency converter are application of middle and high pressure and high-power inverter, new technologies and devices in the future, clean utilization and energy saving of frequency converter.
Research status and prospect of shearer positioning technology on fully mechanized coal mining face
XIA Ting, LI Wei, WANG Chao, LI Yuche
2017, 43(10): 24-28. doi: 10.13272/j.issn.1671-251x.2017.10.008
Abstract:
On the basis of development status of shearer positioning technology on fully mechanized coal mining face at home and abroad, characteristics of conventional shearer positioning technology, shearer positioning technology based on strapdown inertial navigation, shearer positioning error compensation technology based on strapdown inertial navigation, and shearer positioning technology based on combination of strapdown inertial navigation and other methods were analyzed. Development trends of shearer positioning technology were pointed out, which were researching positioning calculation strategy of strapdown inertial navigation, exploring tight coupling fusion strategy between wireless sensor network and strapdown inertial navigation, and studying shearer spatial positioning technology under complex vibration and multipath effect.
Status and development direction of key technologies of gas telemetry
HUO Yuehua, FAN Weiqiang, SUN Yanyu
2017, 43(10): 29-33. doi: 10.13272/j.issn.1671-251x.2017.10.005
Abstract:
Application status of key technologies of gas telemetry based on tunable diode laser absorption spectroscopy were introduced including tunable diode laser technology, signal noise reduction technology and trace gas detection technology. Some problems of the key technologies of gas telemetry were pointed out, such as unstable performance of tunable diode laser, short distance of gas telemetry, poor signal noise reduction effect and big error of trace gas detection. Development directions of the key technologies of gas telemetry were proposed, which were developing tunable diode laser with high performance, studying nonlinear and unstable signal noise reduction algorithm, and designing digital lock-in amplifier for underground.
Application analysis of LoRa technology in mine wireless communicatio
HUO Zhenlong
2017, 43(10): 34-37. doi: 10.13272/j.issn.1671-251x.2017.10.006
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Abstract:
For status that existing mine wireless communication systems had poor application effect in areas with severe environment and low-speed requirement of data transmission such as top corner, a scheme of applying LoRa technology in mine wireless communication was proposed through analyzing its technical characteristics. Application architecture of LoRa technology in coal mine was analyzed, and application situations were discussed. LoRa technology can wirelessly transmit equipment operation status data and environmental parameters in working face, multi-sensor data in mine pressure monitoring system, gas sensor data in top corner of working face, temperature sensor data in goaf, monitoring data of mine-used electromechanical equipment, etc.
Roof stability analysis in No.3 coal seam of Panxie peripheral
ZHANG Yutong, LIU Qimeng, CAI Mengya, ZHAO Jin, YE Mei, ZHANG Danda
2017, 43(10): 37-42. doi: 10.13272/j.issn.1671-251x.2017.10.007
Abstract:
In view of problems of poor accuracy and weak maneuverability existed in roof stability evaluation methods, the extension theory was applied to stability analysis of coal seam roof. For problem of roof stability of No.3 coal seam of Panxie peripheral, fault fractal value, hard-rock ratio, strength coefficient of immediate roof and number of layers in the statistical thickness were used as evaluation factors. And classification standard of each factor was determined by quartering and mathematical statistics analysis. Finally, the grey relation method and the extension matter-element model were used to evaluate roof stability. The evaluation results show that stable region has a large area in Panxie peripheral, mid-stable zone is scattered, unstable and extreme unstable areas are located in the central of peripheral and the vicinity of F66 fault and magmatic intrusive area; the overall roof stability in the south is better, while roof stability in the northern and southern parts is poor, which mainly related to magmatic erosion; from northwest to southeast, the influence of F66 fault on roof stability of nearby coal seam decreases gradually.
Variability modeling of coal mine safety monitoring and control field
YUAN Yaru, XIE Binhong, PAN Lihu, ZHANG Yingjun
2017, 43(10): 43-47. doi: 10.13272/j.issn.1671-251x.2017.10.009
Abstract:
Traditional software development methods rarely can reuse accumulated development experiments when developed same system, and cause vast repetitive work. In view of the problem, development method of software product line was proposed and applied into the software development for coal mine safety monitoring and control system. On the basis of analysis of product line of the system, relationships among characteristics of the system were discussed according to commonality and variability characteristics of the system, variability model of the coal mine safety monitoring and control field based on feature modeling method of variability was built. The model can effectively manage variability of the system, and can quickly complete requirements analysis of specific customized monitoring and control system under guidance of the characteristics dependency rules at the same time, which lays foundation for following realization of reusable framework in the coal mine safety monitoring and control field.
Theory and key technologies research on adaptive multi-antenna in coal mine tunnel
C, ZHANG Yi, XU Zhao, GAO Min
2017, 43(10): 48-52. doi: 10.13272/j.issn.1671-251x.2017.10.010
Abstract:
Characteristics of wireless communication environment and multi-antenna radiation in coal mine tunnel were analyzed. An adaptive multi-antenna technology was proposed on basis of tunnel waveguide theory and adaptive array antenna technology. Basic composition and principle of the adaptive multi-antenna in coal mine tunnel were introduced. Meanwhile, key technologies needed to be further studied were discussed. The adaptive multi-antenna in coal mine tunnel can selectively control number, type and intensity of guided wave modes according to channel characteristics, so as to improve underground status of wireless communication coverage from the source and performance of coal mine wireless communication system.
Mine TOA ranging method based on re-spread spectrum to WiFi signal
SUN Jiping, JIANG Ensong
2017, 43(10): 53-58. doi: 10.13272/j.issn.1671-251x.2017.10.011
Abstract:
TOA ranging method requests high precision time measurement while existing mine WiFi systems can not provide high temporal resolution timer. In order to resolve the above technical problems, a TOA ranging method using re-spread spectrum technology to WiFi signal to obtain high resolution was proposed. Multi-carrier spread spectrum modulator is integrated into WiFi mobile station which is used to spread spectrum for ranging WiFi signal. Correspondingly, multi-carrier spread spectrum demodulator is integrated into WiFi base station, and a spread spectrum code capture algorithm with high speed digital matched filter designed by FPGA is used to capture ranging signal sent by the WiFi mobile station in sub-chip level, thus, the signal propagation delay time with high resolution is obtained. The test results show that the proposed method can provide reliable ranging data with mean-error of 1.92 m for TOA positioning of WiFi communication system.
Research on coal-bed image fractures identification based on fracture shape characteristics
LIU Yong, CUI Hongqing
2017, 43(10): 59-64. doi: 10.13272/j.issn.1671-251x.2017.10.012
Abstract:
In view of problems that existing coal-bed image fractures identification method does not take good account of shape characteristics of the fractures or overall information of the fractures is not well obtained, by analyzing coal-bed image and shape characteristics of the fractures in binary image under different gray thresholds, determination coefficient of the coal-bed fractures was defined, and regio's length, width and the ratio of length to width in the coal-bed binary image were defined as shape parameters. At the same time, a method of the coal-bed image fractures identification based on fracture shape characteristics was proposed. Under condition of the given shape parameters, travel a given gray scale threshold range and identify fracture regions in every coal-bed binary image, then merge all the identified fracture regions as the last coal-bed fractures identification result. Finally, an example was given to demonstrate effectiveness of the method. It is concluded that information of the coal-bed image fractures can be acquired to the maximum extent by traveling a certain gray scale threshold range and identify the coal-bed image fractures, and it can effectively improve accuracy of the coal-bed fracture identification by selecting reasonable thresholds of the shape parameters of the fracture determining coefficient.
Research of distributed multi-point laser methane detection system
TAN Kai, GUO Qinghua, ZHANG Yuanzheng, GOU Yi
2017, 43(10): 65-69. doi: 10.13272/j.issn.1671-251x.2017.10.013
Abstract:
For problems of being easily affected by environment, low detection decision and poor stability in traditional methane detection system, a distributed multi-point laser methane detection system was designed based on tunable diode laser absorption spectroscopy technology and space division multiplexing technology. The system adopts distributed feedback semiconductor laser with wavelength of 1 653.7 nm as light source, uses ratio of the second harmonic and the first harmonic gotten by harmonic detection to invert methane concentration, and employs 1/8 beam splitter and reference air chamber to realize real-time multi-point methane concentration detection. The system has been tested in laboratory. The test results show that the system has high accuracy and good stability, can realize monitoring points within 10 km effectively covered, and measurement error is less than 2% when methane concentration is 2.00%-85.0%.
Coal content recognition method of coal-rock mixture based on phase difference detectio
HAN Nannan, CHENG Yuanxin, LIU Xiaowen, ZHAO Duan, WANG Xin
2017, 43(10): 69-73. doi: 10.13272/j.issn.1671-251x.2017.10.014
Abstract:
In view of problems of long measuring time and big error existed in current coal content recognition methods of coal-rock mixture, a coal content recognition method of coal-rock mixture based on phase difference detection was proposed. Relationship between coal content of coal-rock mixture and capacitance was gotten through experiment, parameters of phase difference detection circuit were chosen reasonably, and relationship between phase difference and the coal content was analyzed through numerical simulation and circuit simulation. The results show that coal content is lower than the minimum coal content threshold of coal mining when phase difference is positive, and coal content is higher than the minimum coal content threshold of coal mining when phase difference is negative, which indicate whether coal content achieves the minimum coal content threshold of coal mining can be judged accurately through detecting positive or negative of phase difference.
Design of closed-loop control system for hydraulic cylinder position of roadway support
WANG Fan, ZHAO Jiyu
2017, 43(10): 74-77. doi: 10.13272/j.issn.1671-251x.2017.10.015
Abstract:
For requirements of high precision control and energy saving of hydraulic cylinder position of support in coal mine roadway, a closed-loop control system for hydraulic cylinder position of roadway support was designed based on load sensing principle. Working principle of the system was analyzed, mathematical model of the system was established and simulation model of the system was built by use of AMESim software. The simulation results show that outlet pressure of load sensing variable pump can stably adapt to the maximum load pressure to realize energy saving, and actual hydraulic cylinder displacement can quickly and smoothly track given displacement within 0.6 mm error, which meet high precision control requirement of hydraulic cylinder position of support in coal mine roadway.
Modeling and simulation of drum height adjusting system of shearer
CHEN Jinguo, LIU Chunsheng, FAN Jianhong, ZHANG Yanjun, WAN Feng
2017, 43(10): 78-82. doi: 10.13272/j.issn.1671-251x.2017.10.016
Abstract:
In order to improve dynamic performance and tracking reliability of drum height adjusting system of shearer, mathematical models of drum height and hydraulic cylinder displacement were established by analyzing work principle of the drum height adjusting system and relationship of geometric parameters of hydraulic mechanism. Combining fuzzy adaptive PID controller, simulation models of open loop controlled and closed loop controlled drum height adjusting systems based on electric-hydraulic proportional direction valve controlling hydraulic cylinder were established in Automation Studio software. Speed response and location tracking characteristics of the systems were studied under no-load and load conditions separately. The simulation results show that the systems have fast response speed and better goodness of fit of drum location tracking, and performance of the closed loop controlled drum height adjusting system is better than the open loop controlled one.
Shearer position and attitude adjustment based on strapdown inertial navigation system
ZHANG Qing, WANG Xuewen, XIE Jiacheng, PANG Xinyu, YANG Zhaojian
2017, 43(10): 83-89. doi: 10.13272/j.issn.1671-251x.2017.10.017
Abstract:
For problems of inaccurate shearer position and attitude adjustment, a shearer position and attitude adjustment method based on strapdown inertial navigation system was researched on the ground with slowly varied angle. Firstly, shearer position technology was introduced, namely strapdown inertial navigation system obtained motion parameters of shearer for further processing by Euler angle method, so as to complete attitude solution and real-time position of shearer. Then, an attitude adjustment method based on strapdown inertial navigation system was introduced by taking cutting height adjustment of shearer as an example, and relation between cutting height and body dip angle of shearer was derived under different shearer cutting conditions. Finally, shearer position and cutting height adjustment experiments were carried out by use of a shearer model. The experimental results show that the shearer position and attitude adjustment method based on strapdown inertial navigation system can effectively improve position and attitude adjustment accuracy of shearer.
Residual life estimation of components of hydraulic support in service
ZHAO Dongbo, LU Jingui, YAO Lingling, WANG Jingtao
2017, 43(10): 89-93. doi: 10.13272/j.issn.1671-251x.2017.10.018
Abstract:
In view of problem that existing hydraulic support life estimation method rarely consider continuous performance decline of hydraulic support in use process and leads to great error, a residual life estimation method of components of hydraulic support in service was proposed. Components S -N curve was obtained by correcting material S -N curve through introduction of surface coefficient, structural size coefficient and welding impact coefficient. Then the components S -N curve was used for life estimation according to cumulative damage theory, residual damage capacity and stress spectrum. Multi-level fuzzy evaluation method was used to evaluate the state of hydraulic support roof beam, and overall life coefficient was multiplied by the estimated life to get the residual life of the components of hydraulic support in service. The experimental results show that the estimation error of the proposed method is 3.52% and the precision is high.
Application of travelling bogie ivane n welding station of spiral drill pipe
LAN Fei, WU Zhifeng
2017, 43(10): 94-96. doi: 10.13272/j.issn.1671-251x.2017.10.019
Abstract:
In view of problem that drill pipe transportation depends on manual operation in vane welding process of spiral drill pipe, travelling bogie was applied to vane welding station of spiral drill pipe, which realized transportation of drill pipes between loading and unloading stations and two welding stations. Control program of the travelling bogie was programmed by PLC-FX3U to achieve joint coordination between the travelling bogie and welding station. Application results show that transport time of the entire drill pipe transport process was shortened by nearly half and the efficiency was increased by about 43% after use of the travelling bogie.
Design of self-adaptive echo canceller
C, WANG Xiaohui, SUN Xiaoye
2017, 43(10): 97-100.. doi: 10.13272/j.issn.1671-251x.2017.10.020
Abstract:
In view of problem of echo interference in voice communication of rescue communication system, a self-adaptive echo canceller was designed based on self-adaptive filter using normalized least mean square and voice detection module. Working principle and design scheme of the self-adaptive echo canceller were introduced. The test results show that the self-adaptive echo canceller has rapid convergence speed, which can converge to below -30 dB within 1 s, and basically eliminate audio signal echo.