2019 Vol. 45, No. 9

Display Method:
Design of mine drilling rescue and detection robot
MA Hongwei, YAO Yang, ZHAO Hao, LIANG Lin, MA Kun, TIAN Haibo
2019, 45(9): 1-6.. doi: 10.13272/j.issn.1671-251x.17443
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Abstract:
Based on requirements of mine drilling rescue and detection, a mine drilling rescue and detection robot was designed to solve the problems of narrow information detection range, short detection distance, single function and no obstacle crossing ability of existing detection robots. The robot can reach underground coal mine through 225 mm rescue boreholes, and use sensors and cameras to obtain environmental information and trapped people information in disaster areas, and transmit the information to ground in real time. Taking NI myRIO as the control core, the control system is constructed by using LabVIEW graphical programming, the robot can realize data remote control in the disaster area by means of wired communication. The test results show that the robot has good motion performance, small volume, light weight, strong obstacle capability,can smoothly pass the relief hole, and can carry on the real-time detection and transmission of mine environment information, which provides the first-hand information for decision in the ground rescue command center.
Research status and development trend of coal mine rescue robot
ZHENG Xuezhao, ZHAO Ju, ZHANG Duo, GUO Jun
2019, 45(9): 7-12. doi: 10.13272/j.issn.1671-251x.17426
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The research status and application of power system, explosion-proof design, multi-parameter monitoring and communication system of coal mine rescue robots at home and abroad were introduced, and the existing problems of coal mine rescue robots, such as limited cruising ability, short walking control distance, heavy weight of explosion-proof materials, poor reliability of information processing and transmission were pointed out. The development trend of coal mine rescue robots was prospected, that is, research and development of new energy batteries suitable for coal mine is one of the development trends of power supply of coal mine rescue robot, research and development of intelligent robots with autonomous walking, positioning and path planning is the development trend of coal mine rescue robots in the future, lightweight explosion-proof materials, intelligent integration of multi-source information, wireless and wired communication mode will also be the direction of intelligent development of coal mine rescue robots.
Research on explosion-proof technology for coal mine rescue robot
ZHENG Xuezhao, YAN Xing, GUO Jun, ZHANG Duo
2019, 45(9): 13-17. doi: 10.13272/j.issn.1671-251x.2018120017
Abstract:
The paper introduced general situation of explosion-proof technology of coal mine rescue robot, and summarized the research status and application of explosion-proof technology of coal mine rescue robot at home and abroad, and pointed out some progress of explosion-proof technology for coal mine rescue robot, especially in explosion-proof motor, explosion-proof shell and power supply. However, there are still problems in explosion-proof material application technology, energy power technology, intrinsic safety control technology, fault diagnosis and fault-tolerant control technology, it needs to be constantly improved in the aspects of processing materials lightweight, power supply efficiency, intrinsic safety of explosion protection technology, intelligent control system, so as to ensure the explosion-proof technology of each component of coal mine rescue robot is more mature.
Research on method of simultaneous localization and mapping of coal mine inspection robot
YANG Lin, MA Hongwei, WANG Yan, WANG Chuanwei, ZHANG Zhenzhen
2019, 45(9): 18-24. doi: 10.13272/j.issn.1671-251x.17444
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Abstract:
In view of problem of autonomous location of inspection robot without GPS in underground coal mine, a method of simultaneous localization and mapping based on lidar was studied. Firstly, the observation model of lidar and prediction model of odometer are established, and the actual problems of robot localization and mapping are transformed into the logical reasoning problems of probabilistic mathematical model. At the same time, the adaptive Monte Carlo localization algorithm is used to estimate the real-time pose of the robot,the resampling method based on particle weight(maps matching degree) is proposed to remove particles with small weight, accurate representation of posterior probability distribution of robot posture with fewer and better particles is realized, requirement of using sensors to realize the real-time positioning of robots on raster maps is met. Fast-SLAM algorithm is optimized to reduce the number of particles, and mitigate particle dissipation,so as to improve accuracy of mapping. The experimental results show that the method effectively solves the problem of real-time pose estimation and environment mapping of inspection robot, and improves the self-adaptability of robot localization and accuracy of mapping combining with adaptive Monte Carlo localization algorithm and optimized Fast-SLAM algorithm.
Real-time pose estimation of underground unmanned aerial vehicle based on ICP method
WANG Yan, MA Hongwei, WANG Xing, YANG Lin
2019, 45(9): 25-29. doi: 10.13272/j.issn.1671-251x.17441
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In view of characteristics of no GPS signal, low illumination and structured environment in coal mine, a real-time pose estimation method for underground unmanned aerial vehicle (UAV) based on iterative closest point (ICP) was proposed. By establishing quadrotor UAV motion model and airborne laser radar observation model, the problem of position estimation of underground quadrotor UAV is converted into scanning matching problem of airborne laser point cloud data. 3D laser radar is used as airborne environment measurement sensor of quadrotor UAV, and observation point cloud data in current position of the UAV is obtained. Taking the first frame position as initial position,relative transformation matrix between two consecutive points of point cloud data is obtained by ICP method, and the continuous key frame point cloud data is solved iteratively to obtain the real-time pose estimation result of quadrotor UAV in underground coal mine.Filtering and downsampling methods are used to optimize point cloud data, and the solution of transformation matrix is accelerated to meet the real-time requirements of position estimation of quadrotor UAV. The experimental results show that the ICP-based real-time pose estimation method for underground UAV can quickly and effectively solve the pose of quadrotor UAV, and compared with normal distribution transform method, the ICP method is more suitable for real-time pose estimation of quadrotor UAV in underground coal mine.
Research on key technologies of unmanned aerial vehicle monitoring of coalfield fire
JIA Yongxiao, ZHENG Xuezhao, CUI Jiaming, GUO Jun, FEI Jinbiao
2019, 45(9): 30-33. doi: 10.13272/j.issn.1671-251x.17473
Abstract:
In view of problems of short endurance time, long period of data collection, low accuracy of infrared thermal image and slow data transmission and processing of existing technologies of unmanned aerial vehicle(UAV) monitoring of coalfield fire, UAV monitoring technologies based on single/cluster flight, infrared and visible light dual vision monitoring technology, data transmission and processing technology based on 4G network were studied. Multi-station multi-machine cluster flight mode of UAV is designed, and rapid monitoring of large-area coalfield area is realized through route planning and independent control. Data acquisition is carried out by infrared dual-view thermal imager, the UAV triggers infrared dual-view thermal imager to capture infrared thermal images and visible light images when hovering at an equally spaced waypoint.4G network is used as signal transmission channel, and data acquisition front end and data processing software are synergistically used to realize synchronization of data collection, transmission and processing. Field application results show that two UAVs collect 254 infrared thermal images and 254 visible light images, the data acquisition and image pre-processing takes 150 minutes, and the image synthesis takes 10 hours, monitoring time is greatly shortened compared with existing technology; Coincidence degree of temperature displayed by infrared thermal image and the field temperature test result is above 90%, indicating that using UAV for coalfield fire monitoring is effective and feasible.
Design of mine rescue robot group
WEN Hu, LIU Yang, ZHENG Xuezhao, GUO Jun
2019, 45(9): 34-39. doi: 10.13272/j.issn.1671-251x.17476
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Abstract:
In view of problems of poor adaptability, communication ability and maneuverability of current mine robots, a mine rescue robot group was designed. The robot group mainly includes a communication robot, a search and rescue robot, an auxiliary rescue robot, and a data processing center. The communication robot uses UWB radar for life detection to find out specific location of trapped person, and at the same time guarantees information transmission during rescue process through built-in relay device. The search and rescue robot walks according to the real-time path and feedback audio, video, and underground environment information, and acts as a communication device after finding the trapped person, thus constructs a communication channel between the rescuer and the trapped person. The auxiliary rescue robot includes a wrecking robot which is responsible for getting through the rescue route and a material transport robot which is responsible for delivering rescue items to the trapped people. The data processing center plans search and rescue route of rescue robot through GIS according to position information of the trapped person, and correct the path according to underground real-time information. All kinds of robots in the robot group cooperate with each other, complement each other's functions, and unify the information, which can effectively reduce secondary damage caused by unclear environment after the disaster and improve rescue efficiency.
Research on intelligent cutting control system for roadway forming of boom-type tunneling robot
YANG Wenjuan, ZHANG Xuhui, ZHANG Chao, ZHAO Jianxun, MA Hongwei
2019, 45(9): 40-46. doi: 10.13272/j.issn.1671-251x.17445
Abstract:
In view of problems such as low automation degree, low tunneling efficiency and poor roadway forming quality in the tunneling process of underground coal mining, an intelligent cutting control system for roadway forming of boom-type tunneling robot was proposed.According to the size of roadway and the cutting process requirement, based on the joint space trajectory planning method of boom-type tunneling robot based on cubic polynomial smooth function, the system determines the smooth function parameters of trajectory planning by establishing the boom-type tunneling robot coordinate system and solving forward and inverse kinematics problems of boom-type tunneling robot. After planning cutting trajectory, taking the pose data of cutting head of boom-type tunneling robot obtained by visual positioning method as feedback quantity, the cutting trajectory control quantity was calculated in real time by cutting trajectory control algorithm based on feedback linearized integral sliding mode controller. A feedback control system based on the planning track points and visual measurement position point was built to realize dynamic control of cutting process of roadway forming of boom-type tunneling robot. The experimental results show that the system can realize intelligent control of cutting process of roadway forming of boom-type tunneling robot, and has high positioning accuracy and good stability, and trajectory tracking error is less than 25.61 mm, can meet the demand of roadway forming quality.
Research on multi-manipulator coal and gangue sorting robot system based on machine visio
WANG Peng, CAO Xiangang, XIA Jing, WU Xudong, MA Hongwei
2019, 45(9): 47-53. doi: 10.13272/j.issn.1671-251x.17442
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Abstract:
Existing coal and gangue sorting methods mainly use image processing and pattern recognition technology to identify and sort coal and gangue according to texture characteristic values of coal and rock. The grain size of coal and gangue is 25-150 mm, while the coal and gangue above 150 mm still relies on manual sorting. In order to sort coal and gangue with large grain size, a multi-manipulator coal and gangue sorting robot system based on machine vision was proposed.The system uses machine vision to collect coal and gangue information and applies deep learning method to realize coal and gangue identification and grab feature extraction. After obtaining the sequence information of coal and gangue, the sorting work is carried out according to the position of coal and gangue, and the grasping task is assigned to the corresponding manipulator controller by multi-objective task assignment strategy. After the manipulator obtains the task, the target is dynamically monitored according to the acquired task. When the target enters the working space of the manipulator, the visual servo system drives the manipulator to complete the coal and gangue sorting. The test results show that the system can efficiently and quickly sort coal and gangue with grain size of 50-260 mm, and the adopted coal and gangue identification method and sorting strategy have good stability and accuracy under different belt speeds, and the comprehensive accuracy of coal and gangue identification and positioning can reach 93%, which verifies the feasibility of the system.
Structure optimization design of mine crawler robot with two rocker arms
HU Kun, ZHANG Zhiyuan, LI Deyong, WANG Shuang
2019, 45(9): 54-60. doi: 10.13272/j.issn.1671-251x.2019010069
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In view of multi-objective optimization problem in structure design of mine crawler robot with two rocker arms, a structure optimization design scheme of mine crawler robot with two rocker arms based on GA-PSO algorithm was proposed. Influence factors of maximum obstacle crossing height of robot and centroid position change are obtained through geometry and kinematics analysis of obstacle crossing process of the robot. According to work requirements of mine robot, constraint conditions are established to get multi-objective optimization function, and the multi-objective optimization problem is transformed into a single-objective optimization problem by introducing weight coefficient. GA-PSO algorithm is used to solve the single-objective optimization problem, and the optimal structural parameters of the robot are obtained: the quality of the car body is 10 kg, the quality of the rocker arm is 5 kg, the distance between front and rear wheels is 600 mm, the radius of drive wheel is 115 mm. The simulation results show that the energy consumption of the robot adopting above parameters is lower than other design schemes, and the target motion is easier to achieve.
Basic connotation, core problems and key technologies of wisdom mine
LUO Xiangyu, LI Jianan, LANG Ding
2019, 45(9): 61-64. doi: 10.13272/j.issn.1671-251x.2019020046
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Basic connotations of wisdom mine were summarized, which were having active perception ability, automatic analysis ability and quick processing ability, digital mine was the foundation and support of wisdom mine, while unmanned mine was the advanced stage and ultimate goal of wisdom mine. Three core problems to be solved in wisdom mine were pointed out, which were deep perception of mine state, deep mining of mine data and decision support for mine safety production and management. Three key technologies that wisdom mine relied on were analyzed, namely coal mine Internet of things technology, coal mine big data technology and coal mine intelligent decision support technology.
Evolution of smart mine construction and its development tendency
LI Xiaosi, MA Jianmin, WANG Yingying
2019, 45(9): 65-69.. doi: 10.13272/j.issn.1671-251x.2019040032
Abstract:
Combining with construction experiences and lessons of integrated automation to smart mine in each coal mine, smart mine construction was summarized, and it was emphasized that smart mine construction was an evolution process step by step. The evolution process of smart mine construction and its development tendency were discussed from the aspects of network platform, data platform, collaborative work platform of multi-speciality and connection with new technologies and services. Following viewpoints are pointed out: Heterogeneous network structure of backbone network plus access network, flattening, intelligence and resource abstraction are important development tendencies of network platform of smart mine. Unified data platform is basic development tendency of smart mine, and big data and cloud computing are development tendencies of unified data platform application. A definite tendency caused by collaborative work platform of multi-speciality is change of service mode, namely mine purchase service. Above viewpoints verify that the smart mine equals mine Internet of things plus carried services actually. As smart services join into network continuously, the mine would be smarter, safer and more efficient.
Research on precursory signals of microseism of rock burst based on wavelet analysis
WANG Xinxin, YU Shijia
2019, 45(9): 70-74. doi: 10.13272/j.issn.1671-251x.2018110067
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The microseism signals before and after rock burst on 1300 working face of a coal mine were collected, and sequential characteristics were analyzed. The db5 is used as wavelet basis function to decompose microseism signals into five layers, and the spectral characteristics and energy percentage of each sub-frequency band are obtained. The analysis results show that before rock burst, the number and energy of microseism increase first and then decrease and then increase; precursor signal appeared one hour before rock burst occurred, the energy is mainly distributed in the middle and high frequency region of 62.5-250 Hz, and the energy percentage reaches 55%; when the rock burst occurs, the amplitude increases significantly, with obvious vibration fluctuations, low frequency signals are the main component, and the energy is mainly concentrated in the low frequency range of 0-62.5 Hz, and accounts for about 70% of the total energy. Precursory of rock burst is obtained: the amplitude increases, the frequency of the microseism is significantly reduced, the frequency band develops from high frequency to low frequency, and low frequency signal increases as the time of foreshock occurs closer to the main shock, the percentage of energy occupied by the low frequency signal also increases. Therefore, sharp reduction of main frequency of the microseismic, obvious increase of amplitude and increase of energy percentage of low-frequency signals can be used as the main feature of precursory of rock burst, combined with daily microseismic times and energy trends, rock burst can be predicted.
Automatic construction of coal mine accident ontology
GUI Dongdong, WANG Xiangqian, LI Huizong
2019, 45(9): 75-79. doi: 10.13272/j.issn.1671-251x.2019030021
Abstract:
Aiming at problems of time-consuming, labor-consuming and limitation in constructing coal mine accident ontology by manual means, an automatic construction method of coal mine accident ontology was proposed. Firstly, taking text of coal mine accident case as data source, BP neural network is used to automatically extract ontology concept. Then, hierarchical relationship and non-hierarchical relationship between ontology concepts are automatically extracted by adopting hierarchical clustering method and association rules method. Finally, ontology concepts, relationship between concepts and examples of coal mine accident are visualized by use of Protégé ontology editor, so as to obtain coal mine accident ontology. The coal mine accident ontology by automatic construction is more comprehensive and can provide strong support for coal mine safety production work.
Research on the minimum ignition temperature variation law of coal dust cloud with different coal quality
LIU Tianqi
2019, 45(9): 80-85. doi: 10.13272/j.issn.1671-251x.2018120078
Abstract:
In order to research the minimum ignition temperature variation law of coal dust cloud with different coal quality, eight coal samples including lignite, long-flame coal, non-caking coal, gas coal, charred coal, lean coal, meagre coal and anthracite were selected to analyze the minimum ignition temperature variation laws of coal dust cloud with metamorphism degree, particle size and mixing inert rock powder proportion by use of the minimum ignition temperature testing device of coal dust cloud. The research results show that: ① The lower the metamorphism degree is, the more easily the coal dust cloud in a restricted high temperature space catches fire, and the greater the potential explosion danger is. The coal dust cloud ignition process is dominated by flammable gas phase environment. ② With the particle size decreasing from 75 μm to 25 μm, the minimum ignition temperature of coal dust cloud of eight coal quality decreases continuously, and the largest drop of the minimum ignition temperature of lignite dust cloud is the largest of 18.6%, which indicates that lignite dust cloud is the most affected by particle size. The larger the air dried basis is and the smaller the particle size of coal dust is, the more easily the coal dust cloud catches fire. In "sensitive particle size range", the minimum ignition temperature of lignite dust cloud decreased the most by 8.47%. ③ Mixing inert CaCO3 rock powder with different proportions into eight coal dust has a significant inhibitory effect on coal dust cloud ignition.
Starting control method of pipe belt conveyor driven by three motors
SHAN Huiya, XIAO Dongming
2019, 45(9): 86-91. doi: 10.13272/j.issn.1671-251x.2018120069
Abstract:
For working status of pipe belt conveyor driven by two motors at head and one motor at tail, considering viscoelastic mechanics characteristics of conveyor belt, a discrete model for belt and driving drum of pipe belt conveyor was built in AMESim software based on Kelvin-Voigt model. Power balance control principle of three-motor driving system was researched on basis of direct torque control for three-phase asynchronous motor, and a starting control method of pipe belt conveyor was proposed which was based on speed given of master motor and torque given of two slave motors. Starting process of pipe belt conveyor based on the method was researched through Matlab/Simulink simulation and comprehensive test bed of pipe belt conveyor. The research results show that the method can realize stable starting of pipe belt conveyor, output torques of master motor at head and slave motors at head and tail are basically equal during staring process, and load differences are almost zero after starting for 4 s.
Current control of Z-source inverter for hybrid energy storage system of mine-used electric vehicle
WU Zhen, CHEN Jing, DANG Jiao
2019, 45(9): 92-98.. doi: 10.13272/j.issn.1671-251x.2019040091
Abstract:
Aiming at problems of low voltage gain, low power density and low conversion efficiency of traditional Z-source inverter or single-switch inductor Z-source inverter used in hybrid energy storage system of mine-used electric vehicle, a novel Z-source inverter was proposed. Modular switch coupled inductance units based on array magnetic integration technology is used to replace inductance of traditional Z-source inverter, so as to improve power density and voltage gain. By introducing auxiliary soft switch branch to realize zero-voltage switch of power devices, conversion efficiency is improved. Hybrid energy storage system based on the novel Z-source inverter was modeled. Through pole analysis, one pair of conjugated poles causing the system to oscillate and frequency of system oscillation were found, current controller parameters are designed with the model, and design criteria of proportional and integral parameters of current controller were derived. The simulation and experimental results verify correctness of the design criteria of the current controller.
Design of coal mine multi-system fusion linkage platform based on "one map"
WANG Yong
2019, 45(9): 99-102. doi: 10.13272/j.issn.1671-251x.17452
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In order to solve problems of graphical interfaces of existing coal mine safety monitoring and control systems such as inconsistent standards, different representation effect, inability to realize system linkage and so on, a design scheme of coal mine multi-system fusion linkage platform based on "one map" was proposed according to requirements of Technology Schemes of Upgrading of Coal Mine Safety Monitoring and Control System. Structure of the platform and design of fusion linkage communication interface and GIS platform based on "one map" mode were introduced. The platform adopts data dissemination technology of WebGIS and data interchange technologies of WebService and OPC to intensively display data of different coal mine safety monitoring and control systems on the unified GIS platform, and realizes multi-system fusion linkage through relating to logical relationship among each system device. The platform can improve monitoring and control level and supervision efficiency of coal mine safety production.
Design of coal mine gas drainage concentration control system
ZHAO Yong, ZHAO Guoyong, MENG Fanrui, ZHAO Yugang, HOU Qijin
2019, 45(9): 103-108. doi: 10.13272/j.issn.1671-251x.2019050057
Abstract:
In view of the problem of lack of gas drainage concentration control and the high energy consumption of the water ring vacuum pump in the extensive control method of existing coal mine gas drainage control, a coal mine gas drainage concentration control system was designed. The system is based on the hierarchical adjustment idea, and under the centralized control of the control program, the gas concentration in the extraction pipeline is detected by the gas concentration sensor, the gas concentration change rate is calculated by the PLC logic operation function, and then the opening degree of electric gas control valve and the variable frequency motor speed of water ring vacuum pump are adjusted by grade according to the change of gas concentration to increase the concentration of gas extracted, so as to improve utilization rate of the extraction gas. The test results show that the control system can effectively increase the gas concentration of the extraction, and the gas concentration can be increased by 3.6%-4.2%, which greatly improves the gas utilization rate of the extraction. And the energy saving effect is obvious, the energy saving effect is improved by 24% after the gas drainage concentration control.