scholarly journals Design of automatic pressurizing device of hydraulic support initial force

2020 ◽  
Vol 8 (8) ◽  
pp. 2868-2877
Author(s):  
Lianmin Cao ◽  
Guotai Xu ◽  
Guoxiu Su ◽  
Jiulong Cui ◽  
Yong Cai ◽  
...  
Keyword(s):  
Hydraulic Support ◽  
Initial Force

Add-On Function Development of Design and Analysis System for Hydraulic Support Column Standardization

2017 ◽  
Vol 10 (3) ◽  
Author(s):  
Qingliang Zeng ◽  
Kao Jiang ◽  
Kuidong Gao ◽  
Lirong Wan ◽  
Yang Yang ◽  
...  
Keyword(s):  
Hydraulic Support ◽  
Analysis System

scholarly journals Virtual straightening of scraper conveyor based on the position and attitude solution of industrial robot model

2021 ◽  
Author(s):  
Suhua Li ◽  
Jiacheng Xie ◽  
Fang Ren ◽  
Xin Zhang ◽  
Xuewen Wang ◽  
...  
Keyword(s):  
Coal Seam ◽  
Industrial Robot ◽  
Steering Committee ◽  
High Accuracy ◽  
Simulation System ◽  
Direct Proportion ◽  
Hydraulic Support ◽  
Actual Distance ◽  
Scraper Conveyor ◽  
Comparison And Analysis

AbstractThe movement of the floating connecting mechanism between a hydraulic support and scraper conveyor is space movement; thus, when the hydraulic support pushes the scraper conveyor, there is an error between the actual distance of the scraper conveyor and the theoretical moving distance. As a result, the scraper conveyor cannot obtain the straightness requirement. Therefore, the movement law of the floating connecting mechanism between the hydraulic support and scraper conveyor is analyzed and programmed into the Unity3D to realize accurate pushing of the scraper conveyor via hydraulic support. The Coal Seam + Equipment Joint Virtual Straightening System is established, and a straightening method based on the motion law of a floating connection is proposed as the default method of the system. In addition, a straightening simulation of the scraper conveyor was performed on a complex coal seam floor, the results demonstrate that the average straightening error of the scraper conveyor is within 2–8 mm, and is in direct proportion to the fluctuation of the coal seam floor in the strike of the seam with high accuracy, the straightness of scraper conveyor is more affected by the subsidence terrain during straightening than by the bulge terrain. And some conclusions are verified by experiment. Based on the verification of the relevant conclusions, a comparison and analysis of Longwall Automation Steering Committee (LASC) straightening technology and default straightening method in the simulation system shows that the straightness accuracy of LASC straightening technology under complex floor conditions is slightly less than that of the default straightening method in the proposed system.

scholarly journals Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

2020 ◽  
Vol 12 (1) ◽  
pp. 703-717
Author(s):  
Yin Wei ◽  
Wang Jiaqi ◽  
Bai Xiaomin ◽  
Sun Wenjie ◽  
Zhou Zheyuan
Keyword(s):  
Numerical Simulation ◽  
Control Strategy ◽  
Three Dimensional ◽  
Simulation Method ◽  
Mine Pressure ◽  
Hydraulic Support ◽  
Transition Area ◽  
Pressure Concentration ◽  
Strata Behavior ◽  
And Control

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

scholarly journals New Method and Experiment for Detecting Relative Position and Posture of the Hydraulic Support

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 181842-181854 ◽  
Author(s):  
Yi Zhang ◽  
Hongyang Zhang ◽  
Kuidong Gao ◽  
Wenbo Xu ◽  
Qingliang Zeng
Keyword(s):  
Relative Position ◽  
New Method ◽  
Hydraulic Support

Semi-inverse method for predicting stress–strain relationship from cone indentations

2003 ◽  
Vol 18 (9) ◽  
pp. 2068-2078 ◽  
Author(s):  
A. DiCarlo ◽  
H. T. Y. Yang ◽  
S. Chandrasekar
Keyword(s):  
A Priori ◽  
Model Material ◽  
Material Behavior ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Indentation Tests ◽  
Strain Relationship ◽  
Initial Force ◽  
Relationship Of ◽  
Force Displacement

A method for determining the stress–strain relationship of a material from hardness values H obtained from cone indentation tests with various apical angles is presented. The materials studied were assumed to exhibit power-law hardening. As a result, the properties of importance are the Young's modulus E, yield strength Y, and the work-hardening exponent n. Previous work [W.C. Oliver and G.M. Pharr, J. Mater. Res. 7, 1564 (1992)] showed that E can be determined from initial force–displacement data collected while unloading the indenter from the material. Consequently, the properties that need to be determined are Y and n. Dimensional analysis was used to generalize H/E so that it was a function of Y/E and n [Y-T. Cheng and C-M. Cheng, J. Appl. Phys. 84, 1284 (1999); Philos. Mag. Lett. 77, 39 (1998)]. A parametric study of Y/E and n was conducted using the finite element method to model material behavior. Regression analysis was used to correlate the H/E findings from the simulations to Y/E and n. With the a priori knowledge of E, this correlation was used to estimate Y and n.

scholarly journals Fatigue Behavior of a Box-Type Welded Structure of Hydraulic Support Used in Coal Mine

Materials ◽  
2015 ◽  
Vol 8 (10) ◽  
pp. 6609-6622 ◽  
Author(s):  
Xiaohui Zhao ◽  
Fuyong Li ◽  
Yu Liu ◽  
Yanjun Fan
Keyword(s):  
Coal Mine ◽  
Fatigue Behavior ◽  
Hydraulic Support ◽  
Welded Structure

Accuracy of Orthodontic Force and Tooth Movement Measurements

1996 ◽  
Vol 23 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Dan Lundgren ◽  
Py Owman-Moll ◽  
Jüri Kurol ◽  
Birgit Mårtensson
Keyword(s):  
Tooth Movement ◽  
Mean Value ◽  
Measurement Methods ◽  
Calibration Data ◽  
Force Measurements ◽  
Accuracy Of Measurement ◽  
Measuring Machine ◽  
Initial Force ◽  
Level Of Agreement

This study was designed to test the accuracy of measurement methods for assessment of force and tooth movement in orthodontic procedures. Daily in vivo measurements of the force produced by activated archwires showed that the initial force declined substantially (by 20 per cent of mean value) within 3 days. Both the ‘trueness’ (validity) and precision of the force measurements, obtained with a strain gauge, were found to be high (SD values were 1·0 cN and 0·4 cN, respectively). Horizontal tooth movements were measured with three different instruments: a slide calliper, a co-ordinate measuring machine, and laser measuring equipment based on holograms. There was a good level of agreement between these methods. This was also confirmed by calibration data. The precision of the methods was (SD values) 0·06, 0·07, and 0·13 mm, respectively. The benefits of the use of the co-ordinate measuring machine are obvious, since it can measure tooth movements in relation to reference planes in all directions.

Research on Throttle Optimal Control of Flipper Jack for Hydraulic Support

2012 ◽  
Vol 503-504 ◽  
pp. 824-827
Author(s):  
Chun Qiang Jia ◽  
Wei Li ◽  
Ling Yu
Keyword(s):  
Optimal Control ◽  
Simulation Model ◽  
High Efficiency ◽  
Hydraulic Support ◽  
Simulation Results ◽  
Amesim Simulation

To solve the problem of support speed of hydraulic support flipper, the match relations between the flipper throttle control and shearer cutting coal speed are analyzed, the AMESim simulation model of the throttle optimal control for hydraulic support flipper jack is established, the simulation results show that flipper can be supported timely by speed optimal control of flipper jack which improve the reliability of the system and provide certain theory basis to meet the miner safety and high efficiency production.

Coal gangue recognition using multichannel auditory spectrogram of hydraulic support sound in convolutional neural network

2021 ◽  
Author(s):  
xu chen ◽  
Shibo Wang ◽  
Houguang Liu ◽  
Jianhua Yang ◽  
Songyong Liu ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Spectral Characteristics ◽  
Coal Gangue ◽  
Hydraulic Support ◽  
Practical Applications ◽  
Network Training ◽  
Auditory Recognition ◽  
Auditory Signals ◽  
Fully Connected

Abstract Many data-driven coal gangue recognition (CGR) methods based on the vibration or sound of collapsed coal and gangue have been proposed to achieve automatic CGR, which is important for realizing intelligent top-coal caving. However, the strong background noise and complex environment in underground coal mines render this task challenging in practical applications. Inspired by the fact that workers distinguish coal and gangue from underground noise by listening to the hydraulic support sound, we propose an auditory model based CGR method that simulates human auditory recognition by combining an auditory spectrogram with a convolutional neural network (CNN). First, we adjust the characteristic frequency (CF) distribution of the auditory peripheral model (APM) based on the spectral characteristics of collapsed sound signals from coal and gangue and then process the sound signals using the adjusted APM to obtain inferior colliculus auditory signals with multiple CFs. Subsequently, the auditory signals of all CFs are converted into gray images separately and then concatenated into a multichannel auditory spectrum along the channel dimension. Finally, we input the multichannel auditory spectrum as a feature map to the two-dimensional CNN, whose convolutional layers are used to automatically extract features, and the fully connected layer and softmax layer are used to flatten features and predict the recognition result, respectively. The CNN is optimized for the CGR based on a comparison study of four typical types of CNN structures with different network training hyperparameters. The experimental results show that this method affords an accurate CGR with a recognition accuracy of 99.5%. Moreover, this method offers excellent noise immunity compared with typically used CGR methods under various noisy conditions.

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