2018 Vol. 44, No. 6

Display Method:
Design of cooperative management and control system for production equipments in mine Internet of things
LI Xue'en, YOU Bo, CHEN Qing, WANG Hongxing
2018, 44(6): 1-5. doi: 10.13272/j.issn.1671-251x.17335
Abstract:
For characteristics of large-scale, strict timing constraint and decentralized control of cooperative management and control for production equipments in mine Internet of things(IoT), a multi-level cooperative management and control model for production equipments in mine IoT was established combing with architecture of a cooperative management and control system. A cooperative management and control method for production equipments in mine IoT was proposed which was based on data-driven and knowledge-driven, and task allocation and collaboration mechanism among subsystems and their equipments at all levels was described. Thus a cooperative management and control system for production equipments in mine IoT based on parallel management was established. The system can realize distributed collaborative data processing and cooperative management and control of production equipments of mine IoT, which can reduce human intervention and improve production efficiency.
Research status and prospect of vacuum degree detection methods for vacuum circuit breaker
WU Mengze, SONG Jiancheng, GAO Yunguang, CHEN Shushu
2018, 44(6): 6-10. doi: 10.13272/j.issn.1671-251x.2017120019
Abstract:
Research status of vacuum degree detection methods for vacuum circuit breaker was introduced including off-line detection methods such as observation method, power frequency withstand voltage method, pulsed magnetron discharge method and shield potential method, and on-line detection methods such as coupling capacitance method, partial discharge method, rotary electric field probe method, X ray method and built-in sensor method. Though analyzing detection principle, characteristics and application of each method, it indicated that pulsed magnetron discharge method and power frequency withstand voltage method in off-line detection methods were the most widely applied because of low cost, simple detection and good repeatability, but regular stopping to check vacuum degree became the most important factor to restrict development of the off-line detection methods, and on-line detection methods could detect vacuum degree in real time and find deterioration of vacuum degree, but the methods were not widely applied because of low accuracy, high cost and poor anti-interference and stability. Development trends of vacuum degree detection method for vacuum circuit breaker were proposed, which were improving accuracy of on-line vacuum degree detection method and integrating multiple vacuum degree detection methods.
Research on a robust positioning algorithm for mine proximity detectio
CHEN Kang, BAO Jianjun, WANG Wei
2018, 44(6): 11-15. doi: 10.13272/j.issn.1671-251x.17321
Abstract:
In view of problems of existing positioning algorithms for mine proximity detection that ranging error is large due to non-line-of-sight and other factors, and solution of ranging equation set does not converge under complex conditions, a robust positioning algorithm for mine proximity detection was proposed, namely weighted LM algorithm, which combines Gauss-Newton algorithm, weighted least square algorithm and Levenberg-Marquardt algorithm. The algorithm adds ranging error information to nonlinear iterative solution by adding weight, and adds damping coefficient in iterative process, which greatly improves positioning stability and robustness under precondition of ensuring convergence speed of iteration. Test results show that the weighted LM algorithm has high positioning efficiency and accuracy.
Key technologies and management collaborative architecture of construction of coal big data platform
TAN Zhanglu, MA Yingying, YUAN Hui
2018, 44(6): 16-20. doi: 10.13272/j.issn.1671-251x.2018010014
Abstract:
Application status and needs of coal big data platform were analyzed. Key technologies of construction of coal big data platform were explained in detail from five aspects of fine-grained and wide-range data acquisition, flexible and scalable data storage, multimodal data processing, professional data visualization and high-quality data management, the foundation for collection,storage,analysis and management of coal big data was provided. Collaborative architecture of coal big data management was put forward, suggestions for the construction of coal big data platform was provided from two aspects of technology and management, and ideas for top-level design of big data management was provided.
Testing and selection of ad hoc protocol for proximity vehicle test in open-pit coal mine
WANG Yin , SHI Yanfeng, HU Shengbo
2018, 44(6): 21-26. doi: 10.13272/j.issn.1671-251x.2018020051
Abstract:
The paper pointed out that GPS integrated wireless communication technology is most suitable for application of proximity vehicle detection in open-pit coal mine on the basis of analyzing existing proximity vehicle testing technologies, such as ultrasonic sensing technology, pulse radar and laser detection technology, computer vision technology, RFID and electronic tag technology, GPS technology. It put forward a wireless communication system for proximity vehicle testing with GPS integrating ad hoc in open-pit coal mine: as long as the proximity vehicles are in communication distance range, it can adopt IEEE 802.11 agreement between vehicles, and exchange GPS positioning data by single-hop or multiple-hop method. Taking the system as research object, the real scene of open-pit coal mine was simulated, the received signal strength and the effective communication distance for IEEE 802.11a/b/p were tested and analyzed under the following conditions of line of sight, non line of sight, the receiver at bottom of slope, and receiver at top of slope. The testing results show that protocol packet reception rate of IEEE 802.11b is higher, effective communication distance is farther compared with IEEE 802.11a/p , and is more suitable for proximity vehicle testing in open-pit coal mine.
Research on automatic drawing control system on fully-mechanized coal face with sublevel caving
NIU Jianfeng
2018, 44(6): 27-30. doi: 10.13272/j.issn.1671-251x.2018020020
Abstract:
In view of problem of low production efficiency of artificial drawing method on fully-mechanized coal face with sublevel caving, an automatic drawing control system was studied.Sonic sensors, vibrating sensors and ash sensors are installed on hydraulic supports. Through artificial demonstration operation and machine learning to memory sensor signals, sensor signal characteristic waveform during the end of drawing process is determined, and the similarity between collected vibration sensing signal, sound sensing signal and the characteristic signal is compared; the ash sensor is used to effectively identify inclusion rate of caved top coal. According to the similarity and inclusion rate, the system execute early warning or direct control to realize automatic drawing control which taking sensor-based sensing control as main control, time control as protection value, and remote intervention control as auxiliary control. The system improves automation level and production efficiency of fully-mechanized coal face with sublevel caving.
Influence of offset angle of coil on wireless power transmission characteristics
KANG Huifeng
2018, 44(6): 31-35. doi: 10.13272/j.issn.1671-251x.2018030093
Abstract:
Formulas of relation between magnetic coupling resonant wireless power transmission efficiency and offset angle of coil and transmission distance were derived according to magnetic coupled resonant wireless power transmission model with two coils. Effect of transmission distance and offset angle on transmission efficiency were studied, and conclusions were obtained as follows: as transmission distance increases, impact of offset angle on wireless transmission efficiency becomes smaller and smaller; When offset angle is small, its effect on transmission efficiency is not significant; when offset angle is greater than 75°, the transmission efficiency decreases sharply with increase of offset angle; as the transmission distance increases, decreasing trend of wireless power transmission efficiency is more and more gentle.Correctness of theoretical analysis was verified by Matlab simulation and experiment.
Research on roof stability assessment method of coal roadway
GENG Yue, DUAN Yingjuan, REN Jiami
2018, 44(6): 35-39. doi: 10.13272/j.issn.1671-251x.2017110060
Abstract:
Existing roof stability assessment methods of coal roadway were summarized and analyzed, which included single index method and compound index method in classic methods and supervised learning method and unsupervised learning method in machine learning methods. It was pointed out that the classic methods assessed roof by single index or for a certain type of coal rock so that assessment result is incomplete or unreliable, and the machine learning method needed a large number of hand-crafted labeling of roof monitoring data with large workload and poor actual application effect. A new roof stability assessment mode of coal roadway based on generative adversarial network in deep learning was proposed according to advantage of extracting features from roof monitoring data automatically of the deep learningmethod, so as to decrease labor workload.
Research on whole life cycle service system of shearer
CAO Xiangang, DI Hang, DU Qingqing, XU Boyuan, ZHOU Zhan, XIA Huguo
2018, 44(6): 40-45. doi: 10.13272/j.issn.1671-251x.2018020024
Abstract:
In view of problems that current shearer life cycle management has low real-time performance and low accuracy of information collection, and unable to uniquely identify shearer, a design scheme of RFID-based whole life cycle service system of shearer was proposed. The system encodes a unified electronic product code (EPC) code into an RFID tag, and uses the RFID tag to accurately identify identity information of shearer; it achieves real time collection of status and position information of shearer through cooperation of RFID reader and tag, and uses EPCIS event to describe status information change of device corresponding to EPC, and data integration and data mining were carried out on service platform. The system can realize information exchange and data sharing among enterprises at each node of industrial chain of whole life cycle of shearer, and provide real-time dynamic information and decision support for whole life cycle management of shearer.
Performance analysis of shearer driven by motor and hydraulic torque converter
WU Senfeng
2018, 44(6): 46-51. doi: 10.13272/j.issn.1671-251x.2017090044
Abstract:
Currently shearer is mainly driven by motor and frequency converter, and it is difficult to meet requirement of larger output torque when cutting complex coal seam at low speed. In view of the problem, performance of shearer driven by motor and hydraulic torque converter was analyzed. Reasonable matching between motor and hydraulic torque converter was analyzed and calculating model was developed. MG750/1860-WD type shearer was taken as an example for matching analysis, and results are as follows: driving mode of motor and hydraulic torque converter can realize stepless speed change of shearer traction within a certain speed range and cutting traction of shearer under different conditions; compared with frequency-convention traction, at the same cutting speed, cutting traction with hydraulic torque converter can increase output torque which increases with reducing of traction speed, and the maximum output torque of hydraulic torque converter greatly exceeds that of frequency converter; and under the condition of low speed cutting traction, cutting traction with hydraulic torque converter can increase output torque of walking wheel and increase traction capacity of shearer, which has important significance for cutting of thin seam and coal seam with large resistance.
Analysis of water-filling process in goaf of closed mine
BI Yaoshan, WU Jiwen, WANG Guangtao, ZHAI Xiaorong, ZHANG Hongmei, HUANG Kai
2018, 44(6): 52-56. doi: 10.13272/j.issn.1671-251x.2017110056
Abstract:
In order to research water-filling problem in goaf of closed mine, taking Daihe Coal Mine as research object, mining space method was used to calculate water-filling volume in goaf of the closed mine according to geological and hydrogeological conditions of the coal mine as well as exploration and drainage data of previous working face goaf, and water-filling process in goaf of the closed mine was analyzed. The analysis results are as follows: ① Total water-filling volume in goaf after Daihe Coal Mine being closed is 6 208 267.20 m3, which includes 4 808 923.58 m3 in working face goaf and 1 399 343.62 m3 in abandoned roadways. If water bursting speed is 80 m3/h, then the closed coal mine will fully filled with water after 3 233.47 days. ② Relationship expressionbetween water-filling height (H) and time (td) is H=2×10-8t3d-7×10-5t2d+0.131 7td-415.29.
Simulation research on zero-module characteristics of single-phase grounding fault in mine power supply system
LUO Chao, GENG Pulong, QU Bingni, SONG Jiancheng, LIU Jucai, DU Zhili, YUAN Leiming
2018, 44(6): 57-63. doi: 10.13272/j.issn.1671-251x.2017070011
Abstract:
For poor actual protection effect of existing line selection methods based on characteristic quantity of single-phase grounding fault, a simulation model of mine power supply system was established in RTDS/RSCAD real-time digital simulation system taking an actual mine power supply system as research object. Fault characteristics laws of zero-module current and zero-module voltage of lines were analyzed under operation modes of ungrounded neutral and arc suppression coil grounded neutral. Influences of different fault location, initial phase angle of fault and grounding resistance on time domain characteristics of zero-module current were also researched under single-phase grounding fault of mine power supply system. The research results are as follows: ① Influences of neutral point operation mode on zero-module current of non-fault line and zero-module voltage of bus can be ignored, but influence on zero-module current of fault line is greater. Polarities of the first half wave of zero-module current in fault line and non-fault line are opposite under the two operation modes. ② The farther fault location away from the bus, the smaller impact value of transient zero-module current is. Fault location has less influence on steady-state zero-module current. ③ The larger of the initial phase angle of fault, the larger the impact value of transient zero-module current is, the slower the impact value grows, and the shorter time reaching steady-state of transient zero-module current of fault line is. The initial phase angle of fault has no influence on amplitude of steady-state zero-module current, which only affects initial phase angle. ④ The larger grounding resistance, the smaller impact value and its attenuation rate of transient zero-module current and amplitude of steady-state zero-module current are.
Speed regulation energy saving method of belt conveyor based on preview control
HAN Dongsheng, DU Yonggui, PANG Yusong, QIAO Tiezhu, YAN Gaowei
2018, 44(6): 64-68. doi: 10.13272/j.issn.1671-251x.2017120006
Abstract:
Current speed regulation energy saving methods all regulate speed of belt conveyor in short time, and speed mutation is easy to cause tear and slipping of belt conveyor. In view of above problem, a speed regulation energy saving method of belt conveyor based on preview control was proposed. According to material carrying capacity of preceding belt conveyor, speed which makes succeeding belt conveyor run at rated carrying capacity is calculated, and running speed of the succeeding belt conveyor is adjusted through preview control. Aiming at negative influence of noise on speed regulation effect, Kalman filter is used to estimate state of the controlled belt conveyor in the process of preview control, which can weaken noise interference and smooth speed regulation process. The simulation results show that the method can fully utilize carrying capacity of belt conveyor, reduce power consumption of belt conveyor, and achieve purpose of speed regulation and energy saving on the basis of ensuring safe operation of belt conveyor.
Research on synchronous control strategy of dual-motor drive for mine-used belt conveyor
WANG Huaping
2018, 44(6): 69-73. doi: 10.13272/j.issn.1671-251x.17329
Abstract:
In view of problems of asynchrony of torque and speed existed in traditional synchronous control strategy of dual-motor drive based on current differential closed-loop as well as mechanical torsional vibration caused by load disturbance is not considered, a synchronous control strategy of dual-motor drive for mine-used belt conveyor based on speed differential closed loop was put forward taking dual-motor drive system of mine-used belt conveyor as research object. The current signals of dual-motors were compensated by using rotate speed error between dual motors, if the rotate speed error of dual motors was produced, the rotate speeds were adjusted by adjusting currents (torque) of dual motors, so as to keep the rotate speeds in synchronization. For torsional angle of mechanical axis caused by load disturbance, a torsional vibration suppression strategy was proposed: torsional angle equation was allocated rationally to attenuate the torsional angle rapidly, so as to achieve good suppression effect for torsional vibration. Matlab/Simulink simulation results demonstrate reliability of the control strategy.
Wear fault analysis of centrifugal pump impeller based on multi-source signal fusio
GUO Wenqi, TIAN Muqin, SONG Jiancheng, GENG Pulong, YAO Yu
2018, 44(6): 74-79. doi: 10.13272/j.issn.1671-251x.2018020029
Abstract:
In view of problems that fault signal of centrifugal pump is easily submerged by noise and data analysis is difficult, a wear fault analysis method of centrifugal pump impeller based on multi-source signal fusion was proposed. Three vibration signals of volute, outlet and base of centrifugal pump, and electrical signals of prime mover terminal are collected when centrifugal pump impeller is in normal condition and wear state. Wavelet packet decomposition is used to extract characteristic frequency bands of the vibration signals, it is determined that the base can be used as the best detection point by laterally comparing energy values of each frequency band, and frequency analysis range is narrowed by longitudinally comparing the energy values of each frequency band. Based on narrowed frequency analysis range, chirp Z transform is used to analyze electrical signals of prime mover terminal and separate fault characteristics frequency and the third harmonic frequency, so as to extract fault characteristic frequency accurately. Test result verifies effectiveness of the method.
Research on secondary explosion characteristic of coal dust
LIU Haoxiong, LIU Zhentang, QIAN Jifa, HONG Sen, QIU Liming, ZHANG Rui
2018, 44(6): 80-86. doi: 10.13272/j.issn.1671-251x.2017100056
Abstract:
Influence of concentration, particle size and ignition energy of coal dust on secondary explosion characteristic of coal dust were studied by use of 20 L spherical explosion device, and the secondary explosion characteristic of coal dust was compared with the first explosion characteristic of coal dust. The results show that with the increase of coal dust concentration, the maximum pressure and the maximum rising rate of pressure of secondary explosion of coal dust increase firstly and then decrease, the maximum pressure difference between the first explosion and secondary explosion decreases firstly and then increases, and the maximum rising rate difference of pressure between the first explosion and secondary explosion decreases firstly, then increases and decreases lastly; with the decrease of coal dust particle size, the maximum pressure and the maximum rising rate of pressure of secondary explosion of coal dust gradually increase, the maximum pressure difference and the maximum rising rate difference of pressure between the first explosion and secondary explosion increase firstly and then decrease; with the increase of ignition energy, the maximum pressure and the maximum rising rate of pressure of secondary explosion of coal dust, and the maximum pressure difference and the maximum rising rate difference of pressure between the first explosion and secondary explosion increase; the maximum pressure and the maximum rising rate of pressure of secondary explosion of coal dust is smaller than that of the first explosion; coal dust concentration is the main influence factor on the characteristic difference between secondary explosion and the first explosion of coal dust.
Transient dynamics and modal analysis of rocker shell of shearer
LI Lei, WANG Yiliang, YANG Zhaojian
2018, 44(6): 86-89. doi: 10.13272/j.issn.1671-251x.2017100041
Abstract:
In order to study mechanical characteristics of rocker shell in shearer walking process under instantaneous load, transient dynamics and modal analysis of rocker shell of shearer were carried out in combination with actual working condition of a certain type shearer. The results show that stress at intersection of gear transmission box and motor box, and intersection of planetary head and gear transmission box on the rocker shell is larger, which exceeds yield limit of rocker shell material, so the two intersections are weak parts of the rocker shell. In the first 6-order modal shape, the maximum amplitude occurs at the planetary head. The analysis results can provide theoretical basis for optimal design of the rocker shell.
On-line detection method of operating state of vibrating screen based on binocular visio
YANG Shuo, TONG Jiannan
2018, 44(6): 90-95. doi: 10.13272/j.issn.1671-251x.2018020036
Abstract:
In view of problems that existing detection methods of operating state of vibrating screen can only detect local operating state of vibrating screen, and has shortcomings such as low precision and poor timeliness, an on-line detection method of whole operating state of vibrating screen based on binocular vision technology was put forward. Firstly, the method uses binocular vision detection device to capture movement images of the vibrating screen. Then it makes graying processing for the images, uses multi-scale Harris corner detection algorithm to obtain the feature points of the images, and introducing image pyramid theory to improve Lucas-Kanade optical flow estimation algorithm, so as to enhance on-line tracking ability of motion track for feature points. Finally, BP neural network classifier is designed to complete analysis and identification of motion trajectory of the feature points, so as to realize detection of whole running condition of vibrating screen. Test results show that the detection method has high accuracy and good timeliness, which can realize on-line detection and analysis of whole running state of vibrating screen with omni-directional and multi-angle tracking and identification for the trajectory of vibrating screen. Accuracy of the method respectively reached 97.917%, 90.667%, 96.431% and 93.181% when vibrating screen was in four kinds of states of stopping, normality and suspected fault and fault.
Design of risk prediction and early warning system of coal mine enterprises based on GIS
PENG Yujing, LIU Jian, GAO Tong, LIAO Lingsong, GAO Xiaofeng
2018, 44(6): 96-100. doi: 10.13272/j.issn.1671-251x.2017110031
Abstract:
In order to master risk information of coal mine timely and predict and warn risks effectively, a risk prediction and early warning system of coal mine enterprises based on GIS was designed. The system uses GIS information collection platform to collect and process hazard information effectively; uses risk early warning model to do comprehensive prediction analysis, including data mining analysis and algorithm operation analysis for collected information, and draws conclusion of the risk early warning; and uses GIS analysis and presentation platform to comprehensively visualize early warning results, so as to provide aid decision support for mine safety production and scheduling. The system can realize accurate control for risk management of coal mine enterprises.
Density control method for dense-medium suspension based on fuzzy control
KONG Fanmiao, XU Kang, CHEN Zherui, CUI Qidong
2018, 44(6): 101-104. doi: 10.13272/j.issn.1671-251x.2018010087
Abstract:
In view of problems of poor accuracy and universality of existing density fuzzy control methods for dense-medium suspension, a density control method for dense-medium suspension based on fuzzy control was proposed. The method takes suspension density deviation, variation rate of the suspension density deviation and liquid level of qualified medium bucket as input variables of density fuzzy controller, and takes liquid level deviation of qualified medium bucket and variation rate of the liquid level deviation of qualified medium bucket as input variables of liquid level fuzzy controller. Water supply valve and flow-spitting box are effectively controlled by use of the density fuzzy controller and liquid level fuzzy controller, so as to achieve accurate and stable control of dense-medium suspension density. The application results show that suspension density fluctuation range can be controlled at ±0.007 g/cm3 with fast response speed.