2013 Vol. 39, No. 9

Display Method:
Causes of false data of coal mine monitoring and control system and its countermeasures
ZOU Zhe-qiang, ZHANG Li-bin, JIANG Ze, QU Shi-jia, WANG Qi-feng
2013, 39(9): 1-4. doi: 10.7526/j.issn.1671-251X.2013.09.001
Abstract:
In view of problem of false data existed in coal mine monitoring and control system, the paper summed up main causes of false data of coal mine monitoring and control system through field investigation, testing and analyzing, pointed out surge interference of power cable in roadway is the most main cause. It put forward main technical measures to remove the false data, concrete measures of anti-interference measures for power cable surge, and proposed method of using substation software to filter false data by identifying change rate of data.
Design of structure health monitoring system for coal mine roadway roof separatio
ZHAO Bai-ting, ZHU Long-ji, WEI Lan-lan
2013, 39(9): 5-7. doi: 10.7526/j.issn.1671-251X.2013.09.002
Abstract:
In view of problems of inconvenient observations, bigger error and poor data real-time performance existed in monitoring for coal mine roadway roof separation with mechanical device, the paper designed a structure health monitoring system for coal mine roadway roof separation. The system uses optical fiber displacement sensor to measure displacement condition of roadway roof separation automatically, adopts computer control program to monitor strain and displacement of coal mine roadway roof separation, and evaluates security of structure, thus safeguards the health of the structure. The practical application shows that the system has advantages such as real-time observation, small error and high efficiency.
Design of active anti-noise earmuffs in heavy noise environment
SUN Ke-wei, LI Jian-hai, YANG Hai-dong, SONG Bo
2013, 39(9): 8-12. doi: 10.7526/j.issn.1671-251X.2013.09.003
Abstract:
In view of problems of expensive and inconvenient to wear of existing active anti-noise earmuffs, an active anti-noise earmuff in heavy noise environment was designed. The earmuff takes TMS320VC5509 as processor, and adopts adaptive noise cancellation method and the normalized least mean square algorithm to enhance adaptive noise cancellation performance. Combined with passive noise reduction technology, the earmuff realizes purpose of noise cancellation in heavy noise environment. The experimental results show that anti-noise performance of the earmuffs is up to 30 dB.
Design of face recognition access control system based on ARM
LIU Xin-peng, LANG Li-ying
2013, 39(9): 12-15. doi: 10.7526/j.issn.1671-251X.2013.09.004
Abstract:
In view of problems that existing access control system with IC card or RF card can only recognize card but cannot recognize people, and the system with finger prints iris recognition technology that fingerprint is easy to be damaged, the paper designed a face recognition access control system based on ARM. The system takes S3C2440B as processor, USB camera as device of capturing video, which can search face and take photo automatically. The system adopts face recognition algorithm based on PCA to recognize the image. If the face is not in library, the system will alarm and send message to notice administrator by GPRS. The test result proves the system can recognize face accurately and efficiently under the strict test environment,and the average recognition rate is above 95%.
Design of dynamic load identification device for cutting mechanism of rock roadheader
WANG Wei-qin, LI Xiao-ming, TIAN Mu-qin, SONG Jian-cheng, WANG Wei, YAN Li
2013, 39(9): 16-20. doi: 10.7526/j.issn.1671-251X.2013.09.005
Abstract:
In view of problems of poor ability of automation cutting, bad stability and difficult real-time identification of dynamic load of cutting of extra-heavy type rock roadheader, a kind of dynamic load identification device for cutting mechanism of rock roadheader based on RBF neural network was designed according to characteristics of mining roadway, and designs of hardware and software of the identification device were introduced in details. To take industrial computer as analysis center, the device can real-timely monitor signals of cutting motor current and cutting head vibration, and uses multi-sensor fusion technology and RBF neural network to realize signal processing and intelligent analysis, so as to realize feature extraction and recognition of dynamic load of cutting rock and achieve effective distinction of rocks with different hardness.
Design and application of mine-used dust concentration sensor
TAO De-bao, YAO Jun, FENG Yu-dong
2013, 39(9): 20-22. doi: 10.7526/j.issn.1671-251X.2013.09.006
Abstract:
For problem that existing dust measurement methods can not real-timely reflect dust concentration of on-site air, the paper designed a mine-used dust concentration sensor, described composition, working principle of the sensor and its application in automatic spraying device for dust falling in coal mine. The sensor uses principle of laser light scattering to measure concentration of dust particles suspended in air, adopts precision mechanical structure and laser lens brush mirror institutions designed by dust sedimentation principle to ensure measurements reliability and accuracy of the sensor.
Design of ultrasonic liquid level sensor for sealed container
LU Gui-rong, NI Peng-hao, CHEN Shu-yue
2013, 39(9): 23-27. doi: 10.7526/j.issn.1671-251X.2013.09.007
Abstract:
In view of problem that existing ultrasonic liquid level detection methods need to open door of container in process of installing, so as to damage the container structure and affect sound wave because of volatile medium, a non-contact ultrasonic liquid level sensor was designed. Selection of ultrasonic frequency of the sensor was analyzed, and hardware circuit implementation scheme of the sensor was also given. According to principle of ultrasonic liquid level detection, the sensor takes AT89S52 as core control chip , uses ultrasonic transducer with transceiver and selects nRF2401 as wireless transceiver module to realize level measurement and data transmission of sealed container. The test results show that the sensor has high precision and relative error is within 3%, which meets needs of real-time measurement of local level.
Research of water quality detection system based on FPGA
ZHOU Meng-ran, LIU Fan, NIE Meng-ya
2013, 39(9): 27-30. doi: 10.7526/j.issn.1671-251X.2013.09.008
Abstract:
In view of problems that present discriminated methods of water burst source ca't realize prediction of water burst and has long processing time and high complexity, the paper designed a water quality detection system which adopts laser induce fluorescence technology and uses FPGA as core processor. Through on-line detection of fluorescence spectrum, the system can real-timely monitor changes of chemical components of underground water and rapidly monitor movement precursor of the water burst source, so as to achieve forewarning of water burst. The test results show that the system has high detection precision and fast response speed.
Research of insulation condition monitoring and fault diagnosing method of motor of mine main ventilator
BI Xiao-yu, TIAN Mu-qin, SONG Jian-cheng, LIN Ling-yan, ZHENG Li-jun, LI Chuan-yang
2013, 39(9): 31-36. doi: 10.7526/j.issn.1671-251X.2013.09.009
Abstract:
The paper analyzed causes of insulation aging status and insulation failure and its evolution process of motor of mine main ventilator, introduced an online insulation condition monitoring and fault diagnosing system of motor of mine main ventilator. In order to solve problems which will lead to signal ambiguity in insulation status failure diagnosing process, it proposed insulation fault diagnosing method of motor based on fuzzy theory and D-S evidence theory combining with existing database of fault diagnostic information. The method uses fuzzy theory to calculate membership function values of fault information, and uses combination rules of the D-S evidence theory to realize information fusion and processing to determine types of insulation fault of the system according to corresponding diagnostic criteria. The instance analysis of the system verifies feasibility and validity of the method.
2013, 39(9): 36-39. doi: 10.7526/j.issn.1671-251X.2013.09.010
Abstract:
Current situation of through-the-earth communication system and analysis of its mainstream technology
HUO Zhen-long
2013, 39(9): 40-42. doi: 10.7526/j.issn.1671-251X.2013.09.011
Abstract:
The paper briefly reviewed development history of through-the-earth communication system, introduced research status and application effect of through-the-earth communication system of domestic and foreign, analyzed current mainstream technology of the through-the-earth communication, and prospected application and development direction of the through-the-earth communication technology in coal mine.
Comparison research of control mode of frequency-conversion speed-regulation of electrical traction shearer
LI Chun-yang
2013, 39(9): 43-45.
Abstract:
On basis of analysis of principle of control mode of frequency converter, experiment platform of control mode was established by use of Drivewizard to monitor output current and frequency of the frequency converter, torque and speed of motor, so as to compare speed-regulation performance of V/f mode and VC mode, and to get specific function index of the two control modes. The test results show that frequency-conversion speed-regulation system based on VC mode can significantly improve load capacity of the shearer in low frequency range.
Research of coal mine water burst forecasting method based on PCA-ELM
LI Pei, CHEN Ying, MA Xiao-ping, YU De-xiang
2013, 39(9): 46-50. doi: 10.7526/j.issn.1671-251X.2013.09.013
Abstract:
In view of problems of slow training speed, poor generalization performance and low test precision existed in coal mine water burst forecasting model with traditional algorithm, the paper proposed a coal mine water burst forecasting method based on PCA-ELM , and established coal mine water burst forecasting model with the method. The method takes mine water burst historical data as sample, uses PCA to obtain mine water burst controlling factors, and divides the sample data containing the main controlling factors into train set, validation set and test set; then, takes the train set as input of ELM to train the model; finally, uses validation set to validate the model. The experimental results show that input variables of the method are less than the traditional methods, time of modeling and computing is shorter, operating speed and prediction accuracy of the model are higher.
Application of perception technology of Internet of Things in early warning system of dangerous sources
WU Yan-chang, WANG Hong
2013, 39(9): 50-53. doi: 10.7526/j.issn.1671-251X.2013.09.014
Abstract:
For problems of single data source, reliance on manual experience to judge danger existed in current early warning system, perception technology of Internet of Things was applied to the early warning system of dangerous sources to establish a cluster-tree wireless sensor network and hardware structures of sensor nodes and sink node were designed. Algorithm of information fusion and processing based on Relief algorithm and BP neural network was studied and simulated. The experiment results show that the application of the perception technology of Internet of Things in early warning system of dangerous sources can improve efficiency of data acquisition and coverage of environmental monitoring, and reduce false alarm rate and undetected rate.
Application of Kalman filter in underground personnel tracking and positioning
LUO Yu-feng, LIU Yong, LI Fang
2013, 39(9): 54-58. doi: 10.7526/j.issn.1671-251X.2013.09.015
Abstract:
In view of problem that RSSI location algorithm does not have continuity in positioning process, the paper proposed an underground personnel positioning method with continuity based on Kalman filter. The method adopts Kalman filter to filter processing position coordinates of underground personnel estimated by RSSI location algorithm, and established a Kalman filter model on the basis of this coordinate in order to real-timely track underground personnel. The experimental results show that the positioning method based on Kalman filter has accurate tracking effect, and can improve real-time performance and tracking accuracy of underground personnel tracking and positioning system.
Experiment and analysis of coal sample destruction precursor based on load-unload response ratio
SUN Zhen-yu, GAO Yun
2013, 39(9): 58-62. doi: 10.7526/j.issn.1671-251X.2013.09.016
Abstract:
The paper researched and analyzed response ratio characteristics of acoustic emission and electromagnetic radiation of coal sample in load-unload by experiment based on load-unload response ratio theory , and got conclusions: ① Load-unload response ratio of acoustic emission and electromagnetic radiation can well reflect stable state of coal samples in process of homotaxial load-unload, and load-unload response ratio is lower when coal sample status is stable , otherwise is higher. ② The coal samples will begin to follow itself evolution rule after the load-unload response ratio increased to peak, and the load-unload response ratio has process 'sharp growth-quickly dow' before the coal samples break, which can be used to predict macroscopic damage of the coal sample. ③ Peak time and macroscopic damage time of the load-unload response ratio is inconsistent because of inhomogeneity of the coal sample, so when method of load-unload response ratio is used to predict disaster, uneven degree of coal and rock should be considered to determine characteristic time. The experiment results show that predicting coal or rock dynamic disasters has certain feasibility by load-unload response ratio of acoustic emission and electromagnetic radiation.
Algorithm research of ore body 3D model with integration of surface-volume elements and its implementatio
LIU Ya-jing, LI Mei
2013, 39(9): 63-67. doi: 10.7526/j.issn.1671-251X.2013.09.017
Abstract:
In view of problem that current surface-volume hybrid modeling method for ore body divided a number of subblocks at boundary of surface model and interior volume element model, while calculation amount of subblocks will increase rapidly along with accuracy, the paper proposed an ore body modeling algorithm based on vector-grid integration method. It studied implementation of algorithm of intersection inspection of surface model and volume element model, algorithm of sectioning intersection volume element with ARTP volume element. The algorithm adopts divisional volume elements instead of subblocks and improves calculation accuracy and reduces data redundancy.
Research of efficiency optimization scheme of mine frequency-conversion vector control system
WANG Dun-sheng, LIANG Yu, YAO Suo-gui
2013, 39(9): 67-70. doi: 10.7526/j.issn.1671-251X.2013.09.018
Abstract:
In view of problems of serious loss and low efficiency of operation existed in induction motor of frequency-conversion speed-regulation system controlled by constant flux, the paper put forward a kind of efficiency optimization control scheme of mine frequency-conversion vector control system. Under two-phase d-q rotating coordinate system, the scheme established loss model of the system including set and rotor copper loss and iron loss, derived corresponding relationship between motor loss and rotor flux under different operating conditions. In order to solve problem of slow dynamic response of the system caused by weak magnetic operation, it optimized proportion of torque current and flux current to get fast response of electromagnetic torque and speed tracking of the motor. It established experimental platform of speed regulation system of 22 kW three-level induction motor based on DSP+FPGA control system, and the experimental results show that the optimized scheme can reduce loss of vector control system of induction motor, improve operation efficiency of the system, and ensure steady-state performance and dynamic response performance of the system.
Simulation research of vector control system for coal mine trackless rubber-tyred electric vehicle
ZHANG Chuan-wei, WAN Ying-ying, XI Zong-hu, ZHANG Rui-fang
2013, 39(9): 71-74. doi: 10.7526/j.issn.1671-251X.2013.09.019
Abstract:
Taking AC three-phase asynchronous motor as research object, the paper analyzed vector control theory of asynchronous motor, and established simulation model of vector control system of asynchronous motor for trackless rubber-tyred electric vehicle and did simulation. The simulation results show that the vector control system has good steady and dynamic performance.
A kind of speed identification method of model reference adaptive system based on improved back-EMF
CHEN Yi-heng, ZHANG Ai-ling, ZHANG Yi-hai
2013, 39(9): 75-79. doi: 10.7526/j.issn.1671-251X.2013.09.020
Abstract:
A mathematical model of induction motor was constructed. A new speed identification method of model reference adaptive system based on improved back-EMF was proposed on basis of analysis of stability of the model reference adaptive system based on reactive power. Error signal of speed identification of model reference adaptive system was re-constructed by the method. The error signal was composed of cross and dot product of the back-EMF error vector and the rotor flux vector. The rotor speed of the motor was identified by the error signal. The experimental results show that the new method is effective to solve problem of instability of the model referencing adaptive system under status of motor parking brake and power generation.
Improved Newton algorithm for power flow calculation of distribution grid considering load type
TIAN Shu, WANG Li
2013, 39(9): 79-83. doi: 10.7526/j.issn.1671-251X.2013.09.021
Abstract:
The traditional Newton algorithm has heavy calculation burden and low efficiency, its iterations and time will significantly increase when load type is no longer a constant power. In view of these problems, an improved Newton algorithm for power flow was proposed. The algorithm considers load type to constitute ZIP model with constant power load, constant current load and constant impedance load, and uses matrix splitting and relaxation method of matrix inversion to make the algorithm not only has simple and fast computed process, but also can improve algorithm efficiency and weaken influence of load type on iterations and time. The effectiveness of the algorithm was verified by using 33 nodes system to test and compare the iterations and times. Influence of load types on system voltage was analyzed though power flow calculation results, it shows that increase of constant impedance load proportion can improve system node voltage.
One-step-ahead predictive rotating speed control of wind power system based on data-drive
ZHANG Yu, LI Ming, XU De-zhi
2013, 39(9): 83-86. doi: 10.7526/j.issn.1671-251X.2013.09.022
Abstract:
In view of characteristics of rotor speed control system of wind power system, the paper presented an one-step ahead predictive control method based on data-driven. Firstly, the method uses dynamic linearization technique and adopts pseudo-projection algorithm to estimate online partial derivative, and then uses the minimizing weighted performance indicators of one-step ahead to get generalized minimum variance predictive control algorithm. In order to achieve better tracking results, an adaptive item was induced to enhance output tracking capability, so make the system have stronger output response tracking. The simulation results show that the method is effective.
Application research of modeling method based on neural networks with parallel chaotic search
FU Bo-na, CHENG Yong
2013, 39(9): 87-91. doi: 10.7526/j.issn.1671-251X.2013.09.023
Abstract:
In view of nonlinear characteristic of switched reluctance motor and existing modeling method has shortcomings of random initial weights of network parameters and is easy to fall into local minimum point, the paper put forward a modeling method using parallel optimization chaotic and BP neural network. Firstly, the method uses chaotic system to optimize neural network weight vector and initial threshold vector, and then uses Levenberg-Marquardt algorithm of BP neural network to train convergence. If it drops into the local minimum point, then it needs to use parallel chaotic search to optimize model again, so as to make the model have characteristics of high precision and fast speed. The dynamic simulation results of training model and speed-regulation system of switched reluctance motor show that the model established by the method has stable operation, good dynamic performance, and fast response speed.
Line selection method with transient state based on intrinsic mode energy
WANG Qing-liang, DU Hui, ZHAO Yi-jie, LI Lu, ZHONG Ming-sheng
2013, 39(9): 92-95. doi: 10.7526/j.issn.1671-251X.2013.09.024
Abstract:
In view of problem that fault line selection method based on wavelet analysis of coal mine power grid ca't guarantee the optimal decomposition effect due to the decomposition effect depends on choice of primary function, the paper presented a fault line selection method with transient state based on intrinsic mode energy. The method uses adaptivity of empirical mode decomposition to signal local feature to analyze transient characteristics of zero sequence current for single-phase grounding fault, and defines intrinsic mode energy and energy weight factor as parameters of fault characteristics, so as to realize data mining of fault information of transient state. It obtained intrinsic mode energy of zero sequence transient current of each line after fault and calculated energy weight factor, then determined fault line by comparing the energy weight factors, namely, the line with the biggest energy weight factor is fault line. The theoretical analysis and simulation results show that the method is not affected by transition resistance, fault time and other fault conditions, and can accurately achieve fault line selection of coal mine high-voltage power grid.
Direct torque control based on space vector modulatio
JING Xiao-dong, GAO Yun, LI Yan-tao, WANG Kun
2013, 39(9): 96-99. doi: 10.7526/j.issn.1671-251X.2013.09.025
Abstract:
In view of problems of big ripple of torque and flux linkage of traditional direct torque control, the paper proposed a control strategy of direct torque control based on space vector modulation. The control strategy uses flux and torque PI controller to instead of hysteresis comparator of traditional direct torque control system, and adopts space vector pulse width modulation to instead of voltage vector switch to synthetic voltage vector which can compensate for flux error and torque error to avoid hysteresis ripple. The Matlab/Simulink simulation result shows that the flux truck of control system of motor based on space vector pulse width modulation is more closed to round, and its torque and flux and current ripple is smaller compared with the traditional direct torque control system.
Research of current control method of model predictive for three-level active power filter
LIU Tao-tao, HUANG Luo-cheng, ZHANG Xiao
2013, 39(9): 100-103. doi: 10.7526/j.issn.1671-251X.2013.09.026
Abstract:
In view of problem of inherent delay of digital system caused by digital controller used in active power filter, the paper proposed a current control method of model predictive and applied it to control system of three-level active power filter. The method designs quality function based on the actual active power filter model, evaluates twenty-seven voltage vectors of frequency converter at each sampling interval, and selects a voltage vector which makes the quality function smallest to control switch conduction in the next sampling period, so as to make the compensation current of active power filter track the reference value rapidly. The simulation results show that the method of model predictive not only can make active power filter realize high performance compensation, but also reduce inherent delay of digital system.
Research of fault diagnosis and prediction for diesel engine based on probabilistic neural network
ZHENG Xiao-qian, HU Shi-qiang, WU Jian
2013, 39(9): 104-108. doi: 10.7526/j.issn.1671-251X.2013.09.027
Abstract:
In view of problem of difficult fault diagnosis and prediction for diesel engine, the paper analyzed common faults and influencing factors of diesel engine, introduced method of extraction, analysis and processing of the failure data, and built a model of fault diagnosis and prediction based on probabilistic neural network. The simulation results show that the model can diagnose and forecast fault of complex mechanical system such as diesel engine and give diagnosis results accurately, and its accuracy rate of fault diagnosis and prediction is up to 94.84 percent.
Design of control system of hydraulic pump station of reclaimer rake in coal preparation plant
WANG Xin-huan, ZHOU Fei, ZHANG Hong-wei
2013, 39(9): 108-112. doi: 10.7526/j.issn.1671-251X.2013.09.028
Abstract:
Most oil pump motors of hydraulic pump station of reclaimer rake in coal preparation plant uses direct starting mode to start, and adopts analog instrument to detect hydraulic oil temperature at present, which exist some problems such as big starting shock, low detection accuracy of oil temperature and poor reliability. In view of above problems, the paper proposed a design scheme of control system of hydraulic pump station based on soft starter and PLC. The system uses PLC to collect the oil temperature and equipment operation condition of hydraulic pump station, controls the hydraulic pump station according to set operation mode, and displays running status, fault diagnosis and alarm information on-line. The control system has protection functions of oil temperature overheat, oil filter plug and motor overcurrent.
Non-destructive measurement method of anchor stock length based on electricity standing wave
XU Zhao, FANG Mi-mi, ZHOU Hong-wei, CUI Can, FANG Ming
2013, 39(9): 112-1153. doi: 10.7526/j.issn.1671-251X.2013.09.029
Abstract:
For common non-destructive measurement methods of anchor stock have problem that vibration wave ca't couple well with the anchor stock, the paper proposed a new non-destructive measurement method of anchor stock legth based on electricity standing wave. The method is based on equivalent principle between transmission line and antenna, and uses standing wave theory of transmission line to measure length of metal anchor stock, that is, scan input signal frequency, when the first minimum voltage of the anchor stock appears, the corresponding signal wavelength is 4 times of anchor stock length, and the anchor stock length can be calculated. The measured result shows that the method has convenient coupling and good measurement result.
Design of pre-warning system of coal mine water disaster
DUAN Li-hong
2013, 39(9): 116-118. doi: 10.7526/j.issn.1671-251X.2013.09.030
Abstract:
The paper designed a pre-warning system of coal mine water disaster according to characteristics of complexity and sudden of coal mine water disaster, introduced design objectives and principles of the system, analyzed main influence factors on coal mine water disaster, described design of function modules of the system. The actual application shows that the system can fully consider influence of multiple factors, and the obtained results can effectively reflect the actual situation.