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Research on denoising of partial discharge signal of mining high voltage cable based on improved variational modal decomposition
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<Abstract>(314)
Abstract:
Aiming at the problems of large amount of white noise and periodic narrow-band interference in partial discharge (PD) signal of mining high voltage XLPE cable, A denoising method based on improved Variational Modal Decomposition (VMD) is proposed for partial discharge signals of mining high-voltage cable. Firstly, the K in VMD algorithm is optimized by Spearman correlation coefficient, and then the noisy signal is decomposed into a series of intrinsic mode functions (IMF); IMF is divided into noised-dominated IMF and the PD-dominated IMF by kurtosis criterion; The noised-dominated IMF is denoised by improved wavelet threshold, and the rough penalty method is used to smooth the PD-dominated IMF; The processed IMF is reconstructed and the denoised signal is finally obtained. The simulation and measured signal results show that this method can effectively remove the noise in PD signal. Compared with the complete ensemble empirical mode decomposition (CEEMD) algorithm, the signal-to-noise ratio is improved by 46.29% and the mean square error is reduced by 32.61%.
Simulation of spark discharge characteristics of CL composite circuit
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<Abstract>(146)
Abstract:
Based on the current research on the discharge characteristics of CL composite circuit is not particularly comprehensive, so the discharge principle of CL composite circuit is studied, and two different states are obtained, respectively for oscillation and non-oscillation two states. Non oscillatory state because of the previous studies, therefore, the main study of oscillation state, analyzes the principles of the Ann circuit, deduces CL compound circuit sparks current, power, and the mathematical model of spark energy, using MATLAB to the power supply voltage, filter capacitance and inductance parameters of the simulation, get the 3 d and 2 d figure, The influence of power supply voltage, filter capacitance and inductance on discharge characteristics of CL composite circuit is analyzed. The results show that the spark current, power and energy all increase with the increase of filter capacitance. With the increase of inductance, the greater the hindrance to current, the spark power and spark energy will decrease. As the supply voltage increases, spark current, power and energy all increase.
Study on the method of personnel accurate detection in shearer operating space
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<Abstract>(203)
Abstract:
Shearer is one of the key equipment in fully mechanized working face, and its intelligence is the necessary condition to realize less-human and unmanned mining. Unfortunately, although shearer has functions including three-dimensional positioning, memory cutting, remote monitoring and etc., the detection and pre-warning function for errant personnel who straying into the shearer operating space has not yet been realized. The lack of this function may lead to serious safety accidents once underground personnel straying into the shearer operating space. Hence, it is necessary to research the key technologies of personnel detection in shearer operating space to realize the safety production when shearer operating and achieve safe and efficient production of coal mine. In view of the characteristics of low illumination and complex operating environment of fully mechanized working face, an accurate personnel detection system in shearer operating space based on infrared thermal imaging technology is proposed. By analyzing the characteristics of infrared image noise in fully mechanized working face, a multi-level guided filtering model based on Gaussian mask is proposed; Based on Lucas-Kanade optical flow and fuzzy segmentation theory, the motion information extraction for moving foreground target in dynamic background and the segmentation for infrared scene information are realized, respectively; Combined with the moving-target motion information and infrared-scene segmentation results, a weight voting method based on morphology theory is constructed to realize the accurate detection of personnel in shearer operating space. Finally, the underground industrial test was carried out in the 21208 fully mechanized working face of Gengcun Coal Mine of Henan Dayou Energy Co., Ltd. the test results show that the tracking deviation of the proposed personnel detection system in the shearer operating space in the actual fully mechanized working face is as low as 0.1065 pixel width, and the coincidence ratio is 96.10%. As accurate personnel detection in shearer operating space is the premise of effective personnel safety protection, the establishment of the personnel accurate detection system provides technical support for the safety production of intelligent fully mechanized working face.
Study on Mechanism of rock burst behavior induced by coal pillar in multi-coal seam mining with hard- thick roof strata
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<Abstract>(159)
Abstract:
In this paper, order to comprehensively study the mechanism of rock burst induced by coal pillar under the condition of hard-thick roof strata, using numerical simulation and on-site data monitoring, the characteristics of overlying rock movement in the process of fully mechanized top coal caving mining under the condition of hard-thick roof strata was studied, the mechanism of rock burst behavior in the working face was analyzed, and the potential risk of rock burst in the subsequent mining process was analyzed. The results show as follows: Influenced by the coal pillar, hard-thick roof strata and the ahead supporter pressure, the stress of surrounding rock and supporter pressure in the middle and lower part of the working face and near the coal pillar in the section are obviously greater than that of the upper roadway area, which is easy to produce the ruck burst induced by coal pillar and hard-thick roof strata; when the workface is close to the boundary of "knife-shape-like" gob, the boundary stress of the I010405 gob can be transferred down to I010203 workface and stacked with lateral and advanced supporter stress. Finally, the three supporter stress formed, which would cause rock burst hazard of I010203 workface to increase. At this stage, more efforts should be made to prevent the impact of the I010203 workface to pass through the dangerous area smoothly. The rock burst of the field monitoring is consistent with the theoretical analysis results. The research results can provide reference for the prevention and control of rock burst in similar conditions.
Development and Research on the Active Disturbance Control for the Underground Crawler Detection Robot
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<Abstract>(177)
Abstract:
Aiming at the current disaster detection and rescue problems in underground mines, this paper proposed a six-swing arm crawler detection robot for complex ground environments. Firstly, the overall structure of the robot's structure was designed, especially for the mobile chassis, and the working condition parameters of the robot's typical operations were analyzed subsequently. Secondly, aiming at the problem of efficient motion control of the robot on complex ground, the driving scheme of the robot control system was designed creatively. Thirdly, the permanent magnet synchronous motor (PMSM) driven by the crawler on both sides has been mathematically modeled and the field oriented control (FOC) was researched in the robot motion drive system. Moreover, aiming at the shortcomings of traditional direct torque control system such as weak anti-interference performance and large flux pulsation, the speed loop control based on active-disturbance rejection control (ADRC) and the current loop control algorithm based on Proportional integral control (PI) controller were designed to improve the ability of motor disturbance suppression, fast speed and the sports performance. Finally, it was verified by a comparative test with the algorithm of the double PI loop. The test results shown that the motion response of the PMSM system of the robot by using the ADRC algorithm is more fast, without overshoot, and has stronger anti-interference ability, which can effectively improve both of the ability of the climbing obstacles, and the stable operational stability for the robot.
Running State Prediction of Belt Conveyor Based on Audio Feature Fusion Res-CNN-LSTM Network
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<Abstract>(233)
Abstract:
Abstract: In order to solve the problems of inconvenient installation, poor stability, and lack of prediction of the operating status of the belt conveyor using contact sensors and machine vision to monitor the operating status of the mining belt conveyor, Res-CNN-LSTM based on audio feature fusion is proposed. Network-based belt conveyor operation state prediction method. Firstly, the audio signal is filtered and denoised, and then the one-dimensional Mel cepstrum coefficient MFCC0 of the signal is extracted by the Mel cepstrum method (MFCC) as the input of the network model; considering that the deepening of the network model will lead to over-fitting and performance degradation,The residual block is introduced to optimize the network model. Experiments are carried out on the laboratory belt conveyor platform. During the experiment, the network model parameters are continuously optimized. The results show that the audio signal can obtain more information about the operation status of the belt conveyor; compared with other models, the designed network model predicts the accuracy is the highest, and the training time is short; at the same time, it is verified that the model has high robustness under different working conditions.
Information Model based on OPC UA for Intelligent Fully Mechanized Mining face
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<Abstract>(90)
Abstract:
The basis of coal mine intellectualization is to realize information integration and interconnection. Unified communication protocol and information model is the key to solve the problem of coal mine information isolated island. In this paper, this paper studied the information model based on OPC UA and its application to solve the problems of equipment monitoring and rapid functional information integration management for intelligent fully mechanized Mining face. It aims to solve the problems of working face equipment monitoring and function information integration management. Based on the study of the OPC UA information interaction network architecture for fully mechanized Mining face, functional model and information flow satisfied for fully mechanized Mining face was analyzed; furthermore, the comprehensive information model architecture which was consist of static attribute set, monitoring attribute set and functional attribute set was put forward and the information model of various elements was analyzed and modelled; finally achieved the Information model instantiation and practical application for fully mechanized mining face. The result shows that the Information model could realize the rapid data mapping between data acquisition, data transfer, and software development, which proved the practicability of intelligent information model of fully mechanized working face and would lay the data foundation for the information integration and the intelligent functions development of Intelligent Fully Mechanized Mining face.

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