阅读说明：本技术 一种煤矿工作面带式输送机高效安全运行监控方法 (Efficient and safe operation monitoring method for coal mine working surface belt conveyor ) 是由 毛清华 毛金根 王宇飞 张旭辉 薛旭升 王川伟 张勇强 李晶 赵健博 鲁毛毛 于 2019-11-12 设计创作，主要内容包括：本发明公开了一种煤矿工作面带式输送机高效安全运行监控方法,包括步骤：一、布置用于监控的硬件设备；二、数据采集及传输；三、数据处理及带式输送机高效安全运行控制。本发明方法步骤简单,通过激光雷达检测煤流外轮廓的特征点数据、利用旋转编码器检测传送带的实时带速,再通过计算机上对数据进行分析处理与计算就可以高效、准确检测到煤流量；采用视觉传感器高效、准确检测输送带上煤的轮廓,从而实现工作面大块煤准确自动识别；煤流检测效率高、精度高,大块煤识别方法简单可靠,误差较小,对煤矿井下带式输送机高效、安全运行有着重要的意义,便于推广使用。(The invention discloses a high-efficiency safe operation monitoring method for a coal mine working surface belt conveyor, which comprises the following steps: firstly, arranging hardware equipment for monitoring; secondly, data acquisition and transmission; and thirdly, data processing and high-efficiency safe operation control of the belt conveyor. The method has simple steps, the characteristic point data of the outline of the coal flow is detected through the laser radar, the real-time belt speed of the conveyor belt is detected through the rotary encoder, and the coal flow can be efficiently and accurately detected through analyzing, processing and calculating the data on the computer; the visual sensor is adopted to efficiently and accurately detect the profile of the coal on the conveying belt, so that the large coal blocks on the working face are accurately and automatically identified; the coal flow detection efficiency is high, the precision is high, the method for identifying the large coal blocks is simple and reliable, the error is small, and the method has important significance for the efficient and safe operation of the belt conveyor in the coal mine and is convenient to popularize and use.)

1. A high-efficiency safe operation monitoring method for a coal mine working surface belt conveyor is characterized by comprising the following steps:

step one, arranging hardware equipment for monitoring, and the specific process is as follows:

101, arranging a visual sensor and a crusher on a coal mine working face reversed loader, and enabling the crusher to be positioned between the visual sensor and a belt conveyor in a coal block measured area on the visual sensor straight face reversed loader; placing a calibration plate printed with square black and white lattices right in front of a visual sensor, and enabling the calibration plate to be parallel to the plane of the detected area of the coal briquette;

102, mounting a laser radar (5) at a position with a height H above the middle position of a belt conveyor belt (3), and enabling a scanning plane of the laser radar (5) to be vertical to the advancing direction of the belt conveyor belt (3);

103, mounting a roller on a rotary encoder, mounting the rotary encoder below the conveyor belt (3) of the belt conveyor, and enabling the roller to be in contact with the conveyor belt (3) of the belt conveyor, so that the roller can rotate along with the movement of the conveyor belt (3) of the belt conveyor;

step two, data acquisition and transmission: the visual sensor periodically collects coal block images on a coal mine working face reversed loader, and shoots a calibration plate in the same image to obtain a plurality of coal block images containing the calibration plate and transmits the coal block images to an upper computer; the laser radar (5) scans the coal flow outer contour to obtain the distance between each characteristic point of the coal flow outer contour and the laser radar (5) and transmits the distance to the upper computer, and the upper computer records the serial number of each characteristic point and the distance between each characteristic point and the laser radar (5); wherein the distance between the ith characteristic point and the laser radar (5) is recorded as l_ik(ii) a The rotary encoder detects the belt speed of a conveyor belt (3) of the belt conveyor and transmits the detected belt speed to an upper computer;

step three, data processing and high-efficiency safe operation control of the belt conveyor, the specific process is as follows:

301, acquiring characteristic point cloud data of the coal flow outer contour by the upper computer;

302, the upper computer performs abnormal point elimination and unmeasured point filling processing on the feature point cloud data;

step 303, calculating the area of the coal flow cross section of each frame of the outer contour of the coal flow scanned by the laser radar (5) by the upper computer;

step 304, the upper computer according to the formula

305, the upper computer according to the formula

step 306, the upper computer judges whether the accumulated flow P of the coal exceeds a maximum preset value M, and when the accumulated flow P exceeds the maximum preset value M, a frequency converter is adopted and a PID motor rotating speed adjusting mode is adopted to control a motor driving the belt conveyor 3 to run to accelerate, so that the speed of driving the belt conveyor 3 is increased, and the coal blocks are conveyed smoothly; and when the maximum preset value M is not exceeded, the frequency converter is adopted to adjust the rotating speed of the motor driving the belt conveyor 3 to operate, so that the belt conveyor 3 operates at a normal operating speed.

2. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 1, wherein the method comprises the following steps: in the working process from the first step to the third step, the upper computer processes the coal briquette image which is collected by the visual sensor and comprises the calibration plate, the size of the coal briquette is obtained, whether the coal briquette is crushed by the crusher is judged according to the size of the coal briquette, and the specific process is as follows:

step A, the upper computer respectively enhances each coal block image which is acquired in the step two and contains the calibration plate, wherein the specific process of enhancing one coal block image which contains the calibration plate is as follows:

step A1, converting the coal block image containing the calibration plate acquired in the step two into a gray image by the upper computer;

step A2, converting the gray level image processed in the step A1 into a double-precision image by the upper computer;

step A3, the upper computer according to the formula s ═ c · log₁₀(v '+ 1) carrying out logarithmic transformation on the double-precision image v' to obtain an image s; wherein c is a conversion multiple of logarithmic conversion;

step A4, comparing the energy K of the image s obtained in the step A3 with the energy J of the coal block image containing the calibration plate, which is acquired in the step II, by the upper computer, and executing the step B when K-J is greater than 0; otherwise, changing the value of c, and re-executing the step A3 and the step A4 until K-J > 0;

and step B, calculating the actual size of the coal briquette by the upper computer, wherein the specific process is as follows:

step B1, the upper computer performs edge detection on the coal briquette image containing the calibration plate obtained by processing in the step A by using Canny operators with different threshold values to obtain coal briquette information;

step B2, the upper computer according to the formula

c, judging the actual length B of the coal briquette by the upper computer₁And the actual width B of the coal₂Whether it is larger than 300mm, when the actual length B of the coal briquette₁Or the actual width B of the coal₂When the size is larger than 300mm, the coal blocks are identified to be large coal blocks, the upper computer sends a signal to the crusher, and the crusher is started and stops after crushing the large coal blocks.

3. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 1 or 2, characterized in that: the specific process of acquiring the feature point cloud data of the coal flow outer contour by the host computer in the step 301 is as follows:

3011, the upper computer calculates the formula θ_ik＝θ_1kThe angle theta of the ith characteristic point offset from the horizontal plane of the laser radar (5) is obtained by calculating + lambda i_ik(ii) a Wherein, theta_1kAs an initial feature point M_1kThe angle of the horizontal plane of the laser radar (5) is deviated, and lambda is the angular resolution of the laser radar (5);

step 3012, the upper computer calculates the formula y_ik＝l_ik·cosθ_ikCalculating to obtain a Y-axis coordinate Y of the YOZ plane of the three-dimensional rectangular coordinate system projected by the ith characteristic point_ikAnd according to the formula z_ik＝H-l_ik·sinθ_ikCalculating to obtain a Z-axis coordinate Z of the i-th characteristic point projected to the YOZ plane of the three-dimensional rectangular coordinate system_ik。

4. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 3, wherein the method comprises the following steps: the specific process of calculating the area of the coal flow cross section of each frame of the coal flow outer contour scanned by the laser radar (5) by the upper computer in the step 303 is as follows:

3031, in a coal flow cross-sectional view of each frame of the outer contour of the coal flow scanned by the laser radar (5), connecting the laser radar (5) with the center of the belt by using a vertical line to form a straight line P; from the initial feature point M_1kMaking a vertical line to the straight line P, wherein the vertical point is B to form a horizontal line M_1kB; from the last feature point M_mkMaking a vertical line to the straight line P, wherein the vertical point is A to form a horizontal line M_mkA; will be horizontal line M_1kB. The coal flow cross section area enclosed by the straight line P and the coal flow outline characteristic point connecting line is marked as an area S₁A horizontal line M_mkA. The coal flow cross section area enclosed by the straight line P and the coal flow outline characteristic point connecting line is marked as an area S₂A horizontal line M_1kB. The cross section area of the coal flow enclosed by the straight line P and the edge of the belt conveyor (3) is marked as an area S₃A horizontal line M_mkA. The cross section area of the coal flow enclosed by the straight line P and the edge of the belt conveyor (3) is marked as an area S₄；

3032, the upper computer calculates the formula

3033, the upper computer calculates the formula

3034, the upper computer calculates the formula

3035, the upper computer calculates the formula

3036, the upper computer calculates the formula

5. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 1 or 2, characterized in that: in step 302, the method for the host computer to remove the outliers from the feature point cloud data includes: firstly, filtering acquired data points by adopting a Kalman filtering algorithm, then removing filtered abnormal points by 2 times of standard deviation according to a Lauda criterion, and finally replacing the abnormal points by inserted numerical values by using a mean value interpolation method;

the specific process of performing unmeasured point filling processing on the feature point cloud data by the host computer in step 302 is as follows: and the upper computer judges whether the data output by the laser radar (5) appears at equal intervals, and when the data output by the laser radar (5) does not appear at equal intervals, the included angle between the plane of the detection point and the laser beam is close to 0 degree or 180 degrees, and the upper computer calculates the characteristic point by using a mean value interpolation method.

6. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 1 or 2, characterized in that: and in the step 306, the normal working speed of the belt conveyor (3) is 2-4.4 m/s.

7. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 1 or 2, characterized in that: the angular resolution of the lidar (5) is greater than 0.36 DEG, and the angular range of the scanning of the lidar (5) is 42 deg.

8. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 1, wherein the method comprises the following steps: the belt width of the belt conveyor (3) is 80 cm.

9. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 2, wherein: in the step A3, the value of c ranges from 5 to 40.

10. The method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face according to claim 2, wherein: and B1, wherein the threshold value range of the Canny operator is 0.01-0.3.

Technical Field

The invention belongs to the technical field of monitoring of coal mine production processes, and particularly relates to a method for monitoring efficient and safe operation of a belt conveyor for coal mine working surfaces.

Background

Coal is one of main energy sources in China, and the occupied position of the coal cannot be changed for a long time. Although various countries increasingly intend to develop and utilize energy for one time with the continuous reduction of coal storage in China and even the whole world, underground coal gasification or other technologies are relatively weak in China at present, and certain industries still depend on coal. Coal mining continues to progress for some time in the future.

At present, in the process that coal is transferred to a belt main conveying system through a scraper conveyor and a reversed loader on a fully mechanized mining working face or a tunneling working face of a coal mine, the automation degree is low in the aspect of bulk coal detection, and people stare beside the reversed loader to see whether bulk coal exists or not; at present, most of coal flow detection usually neglects a gap between a belt and a carrier roller, and the belt is considered to be completely contacted with the carrier roller, namely, the belt is treated as a straight line in the coal flow sectional area calculation, and the actual belt is arc-shaped and cannot be completely contacted with the carrier roller, so that the instantaneous sectional area calculation precision in the prior art is low, and the coal flow detection precision is influenced. In the prior art, a belt conveyor efficient operation method based on coal flow monitoring is explored for the aspect of efficient operation of a belt conveyor, an image detection method is mainly adopted for coal flow detection, and the method is complex in extracting the outline of coal on a belt and often ignores the outline fluctuation of the coal, so that the detection precision is not high. Various methods in the prior art cannot efficiently and effectively realize the efficient and safe operation of the belt conveyor on the working face of the coal mine.

Disclosure of Invention

The invention aims to solve the technical problem that the defects in the prior art are overcome, and the method for monitoring the high-efficiency safe operation of the belt conveyor on the working face of the coal mine is provided, has simple steps, detects the characteristic point data of the outline of the coal flow through a laser radar, detects the real-time belt speed of the conveyor belt through a rotary encoder, and can efficiently and accurately detect the coal flow by analyzing, processing and calculating the data on a computer; the visual sensor is adopted to efficiently and accurately detect the profile of the coal on the conveying belt, so that the large coal blocks on the working face are accurately and automatically identified; the coal flow detection efficiency is high, the precision is high, the method for identifying the large coal blocks is simple and reliable, the error is small, and the method has important significance for the efficient and safe operation of the belt conveyor in the coal mine and is convenient to popularize and use.

In order to solve the technical problems, the invention adopts the technical scheme that: a high-efficiency safe operation monitoring method for a coal mine working surface belt conveyor comprises the following steps:

step one, arranging hardware equipment for monitoring, and the specific process is as follows:

101, arranging a visual sensor and a crusher on a coal mine working face reversed loader, and enabling the crusher to be positioned between the visual sensor and a belt conveyor in a coal block measured area on the visual sensor straight face reversed loader; placing a calibration plate printed with square black and white lattices right in front of a visual sensor, and enabling the calibration plate to be parallel to the plane of the detected area of the coal briquette;

102, mounting a laser radar at a position with a height H above the middle position of a conveyor belt of a belt conveyor, and enabling a scanning plane of the laser radar to be vertical to the advancing direction of the conveyor belt of the belt conveyor;

103, mounting a roller on the rotary encoder, mounting the rotary encoder below the conveyor belt of the belt conveyor, and enabling the roller to be in contact with the conveyor belt of the belt conveyor, so that the roller can rotate along with the movement of the conveyor belt of the belt conveyor;

step two, data acquisition and transmission: the visual sensor periodically collects coal block images on a coal mine working face reversed loader, and shoots a calibration plate in the same image to obtain a plurality of coal block images containing the calibration plate and transmits the coal block images to an upper computer; scanning the coal flow outline by the laser radar to obtain the distance between each characteristic point of the coal flow outline and the laser radar and transmitting the distance to the upper computer, and recording the serial number of each characteristic point and the distance between each characteristic point and the laser radar by the upper computer; wherein, the distance between the ith characteristic point and the laser radar is recorded as l_ik(ii) a The rotary encoder detects the belt speed of a conveyor belt of the belt conveyor and transmits the detected belt speed to the upper computer;

step three, data processing and high-efficiency safe operation control of the belt conveyor, the specific process is as follows:

301, acquiring characteristic point cloud data of the coal flow outer contour by the upper computer;

302, the upper computer performs abnormal point elimination and unmeasured point filling processing on the feature point cloud data;

step 303, calculating the area of the coal flow cross section of each frame of the outer contour of the coal flow scanned by the laser radar by the upper computer;

step 304, the upper computer according to the formula

Calculating to obtain t_wInstantaneous flow rate p (t) of coal flow at time_w) (ii) a Wherein f is the frequency of the laser radar scanning coal flow outer contour, rho_bIs the bulk density of the coal stream, v (t)_w) Is t_wThe belt speed of the conveyor belt of the belt conveyor is kept,

is t_wInstantaneous cross-sectional area of the coal flow at the moment;

305, the upper computer according to the formulaCalculating to obtain the accumulated flow P of the coal flow; wherein u is the total number of coal flow cross sections obtained by scanning the coal flow outer contour by the laser radar;

step 306, the upper computer judges whether the accumulated flow P of the coal exceeds a maximum preset value M, and when the accumulated flow P exceeds the maximum preset value M, a frequency converter is adopted and a PID motor rotating speed adjusting mode is adopted to control a motor driving the belt conveyor 3 to run to accelerate, so that the speed of driving the belt conveyor 3 is increased, and the coal blocks are conveyed smoothly; and when the maximum preset value M is not exceeded, the frequency converter is adopted to adjust the rotating speed of the motor driving the belt conveyor 3 to operate, so that the belt conveyor 3 operates at a normal operating speed.

In the working process from the first step to the third step, the upper computer processes the coal briquette image which is acquired by the visual sensor and contains the calibration plate, obtains the size of the coal briquette and judges whether the coal briquette is crushed by the crusher according to the size of the coal briquette, and the specific process is as follows:

step A, the upper computer respectively enhances each coal block image which is acquired in the step two and contains the calibration plate, wherein the specific process of enhancing one coal block image which contains the calibration plate is as follows:

step A1, converting the coal block image containing the calibration plate acquired in the step two into a gray image by the upper computer;

step A2, converting the gray level image processed in the step A1 into a double-precision image by the upper computer;

step A3, the upper computer according to the formula s ═ c · log₁₀(v '+ 1) carrying out logarithmic transformation on the double-precision image v' to obtain an image s; wherein c is a conversion multiple of logarithmic conversion;

step A4, comparing the energy K of the image s obtained in the step A3 with the energy J of the coal block image containing the calibration plate, which is acquired in the step II, by the upper computer, and executing the step B when K-J is greater than 0; otherwise, changing the value of c, and re-executing the step A3 and the step A4 until K-J > 0;

and step B, calculating the actual size of the coal briquette by the upper computer, wherein the specific process is as follows:

step B1, the upper computer performs edge detection on the coal briquette image containing the calibration plate obtained by processing in the step A by using Canny operators with different threshold values to obtain coal briquette information;

step B2, the upper computer according to the formula

Calculating to obtain the actual length B of the coal briquette₁According to the formulaCalculating to obtain the actual width B of the coal briquette₂(ii) a Wherein A is the actual side length of each square black and white lattice on the calibration plate, a is the side length of each square black and white lattice on the calibration plate in the image obtained by the processing in the step A, and b₁For the length of the coal in the image obtained by the processing in step A, b₂B, the width of the coal block in the image obtained by processing in the step A is determined, x is the distance from the calibration plate to the visual sensor, and y is the distance from the coal block on the transfer conveyor of the coal mine working face to the visual sensor;

c, judging the actual length B of the coal briquette by the upper computer₁And the actual width B of the coal₂Whether it is larger than 300mm, when the actual length B of the coal briquette₁Or the actual width B of the coal₂When the size is larger than 300mm, the coal blocks are identified to be large coal blocks, the upper computer sends a signal to the crusher, and the crusher is started and stops after crushing the large coal blocks.

In the above method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working surface, the specific process of the upper computer acquiring the feature point cloud data of the coal flow outer contour in step 301 is as follows:

3011, the upper computer calculates the formula θ_ik＝θ_1kCalculating to obtain the angle theta of the ith characteristic point deviating from the horizontal plane of the laser radar_ik(ii) a Wherein, theta_1kAs an initial feature point M_1kOffsetting the angle of the horizontal plane of the laser radar, wherein lambda is the angular resolution of the laser radar;

step 3012, the upper computer calculates the formula y_ik＝l_ik·cosθ_ikCalculating to obtain a Y-axis coordinate Y of the YOZ plane of the three-dimensional rectangular coordinate system projected by the ith characteristic point_ikAnd according to the formula z_ik＝H-l_ik·sinθ_ikCalculating to obtain a Z-axis coordinate Z of the i-th characteristic point projected to the YOZ plane of the three-dimensional rectangular coordinate system_ik。

In the above method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working surface, the specific process of calculating the area of the coal flow cross section of each frame of the outer contour of the coal flow scanned by the laser radar in step 303 is as follows:

3031, in a coal flow sectional view of each frame of the outline of the coal flow scanned by the laser radar, connecting the laser radar with the center of the belt by using a vertical line to form a straight line P; from the initial feature point M_1kMaking a vertical line to the straight line P, wherein the vertical point is B to form a horizontal line M_1kB; from the last feature point M_mkMaking a vertical line to the straight line P, wherein the vertical point is A to form a horizontal line M_mkA; will be horizontal line M_1kB. The coal flow cross section area enclosed by the straight line P and the coal flow outline characteristic point connecting line is marked as an area S₁A horizontal line M_mkA. The coal flow cross section area enclosed by the straight line P and the coal flow outline characteristic point connecting line is marked as an area S₂A horizontal line M_1kB. The cross-sectional area of the coal flow enclosed by the straight line P and the edge of the belt conveyer is marked as an area S₃A horizontal line M_mkA. The cross-sectional area of the coal flow enclosed by the straight line P and the edge of the belt conveyer is marked as an area S₄；

3032, the upper computer calculates the formula

Calculating to obtain t_wTime zone S₃Area of (2)

Wherein, theta₁As an initial feature point M_1kAngle between line to lidar and line P, y_1kAs an initial feature point M_1kY-axis coordinate and Y of YOZ plane projected to three-dimensional rectangular coordinate system_1k＝l_1k·cosθ_1k，l_1kAs an initial feature point M_1kDistance from the laser radar, z_1kAs an initial feature point M_1kZ-axis coordinate and Z of YOZ plane projected to three-dimensional rectangular coordinate system_1k＝H-l_1k·sinθ_1kW is a natural number of 1-u;

3033, the upper computer calculates the formula

Calculating to obtain t_wTime zone S₄Area of (2)Wherein, theta_mIs the angle between the line connecting the last characteristic point to the laser radar and the straight line P, y_mkAs last feature point M_mkY-axis coordinate and Y of YOZ plane projected to three-dimensional rectangular coordinate system_mk＝l_mk·cosθ_mk，l_mkAs last feature point M_mkDistance from the laser radar, theta_mkAs last feature point M_mkAngle of offset lidar horizontal plane and theta_mk＝θ_1k+λm，z_mkAs last feature point M_mkZ-axis coordinate and Z of YOZ plane projected to three-dimensional rectangular coordinate system_mk＝H-l_mk·sinθ_mk；

3034, the upper computer calculates the formula

Calculating to obtain t_wTime zone S₁Area of (2)

Wherein the content of the first and second substances,z_(i+1)kprojecting the i +1 th characteristic point to the Z-axis coordinate of the YOZ plane of the three-dimensional rectangular coordinate system and obtaining the Z-axis coordinate_(i+1)k＝H-l_(i+1)ksinθ_(i+1)k，l_(i+1)kIs the distance between the ith feature point and the lidar_(i+1)kThe (i +1) th characteristic point is deviated from the horizontal plane of the laser radar by an angle theta_(i+1)k＝θ_1k+λ(i+1)，y_(i+1)kProjecting the (i +1) th characteristic point to the Y-axis coordinate of the YOZ plane of the three-dimensional rectangular coordinate system and Y_(i+1)k＝l_(i+1)k·cosθ_(i+1)kη is from the initial feature point M_1kThe total number of the characteristic points of the laser radar direct projection characteristic points;

3035, the upper computer calculates the formulaCalculating to obtain t_wTime zone S₂Area of (2)

3036, the upper computer calculates the formula

Calculating to obtain t_wArea of the whole coal flow region at any moment

In the above method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working surface, the method for removing the abnormal points from the characteristic point cloud data by the upper computer in step 302 is as follows: firstly, filtering acquired data points by adopting a Kalman filtering algorithm, then removing filtered abnormal points by 2 times of standard deviation according to a Lauda criterion, and finally replacing the abnormal points by inserted numerical values by using a mean value interpolation method;

the specific process of performing unmeasured point filling processing on the feature point cloud data by the host computer in step 302 is as follows: and the upper computer judges whether the data output by the laser radar appears at equal intervals, and when the data output by the laser radar does not appear at equal intervals, the included angle between the plane of the detection point and the laser beam is close to 0 degree or 180 degrees, and the upper computer calculates the characteristic point by using a mean value interpolation method.

In the method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working surface, the normal working speed of the conveyor belt of the belt conveyor in the step 306 is 2-4.4 m/s.

According to the method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face, the angular resolution of the laser radar is greater than 0.36 degrees, and the scanning angle range of the laser radar is 42 degrees.

According to the method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working surface, the belt width of the conveyor belt of the belt conveyor is 80 cm.

In the method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face, the value of c in the step A3 is 5-40.

According to the method for monitoring the efficient and safe operation of the belt conveyor for the coal mine working face, the threshold value range of the Canny operator in the step B1 is 0.01-0.3.

Compared with the prior art, the invention has the following advantages:

1. the method has simple steps, two original data values are obtained through data detection of the laser radar and rotating speed monitoring of the rotary encoder, the flow of the coal flow can be obtained through data processing and calculation of a computer, the coal flow detection efficiency is high, the accuracy is high, the rotating speed of a motor for driving the belt conveyor to operate is controlled through the flow of the coal flow, and the high-efficiency operation of the belt conveyor on the coal mine working face can be realized; and then, the size of the coal blocks on the reversed loader is automatically detected by adopting an image processing method, large coal blocks are identified, the coal blocks are crushed by adopting a crusher, and the safe operation of the belt conveyor on the working face of the coal mine can be realized.

2. The invention adopts the laser radar to measure distance, has the advantages of less scattering, high brightness, concentrated energy, high detection precision, good real-time property, strong working capability in severe environment and the like, can realize the non-contact measurement of the distance between a measured object and the measured object, is different from the point-to-point single-point distance detection mode in the traditional laser distance measurement technology, and provides a brand new technical means for the acquisition of the spatial information of the measured object by the development of the laser radar, so that the traditional manual single-point data acquisition is changed into the acquisition of 'surface' data, and the measurement precision and efficiency are improved.

3. According to the method for identifying the large coal blocks, the vision sensor is used for acquiring the images, the image processor is used for processing the images, the task of detecting the large coal blocks can be completed, manual work is not needed to enter the site, and the method is convenient to implement, high in efficiency and low in cost.

4. According to the method for identifying the large coal blocks, the images are subjected to enhanced denoising by using a logarithmic transformation processing algorithm, then Canny operators with different thresholds are used for edge detection, a calibration plate is adopted, a simple projection principle is adopted for auxiliary calculation, the actual sizes of the coal blocks can be measured in the images, and the method for identifying the large coal blocks is simple and reliable and has small errors.

5. The invention has strong operability, can realize the accurate and automatic identification of the large coal blocks on the working face and the high-efficiency detection of the coal flow, and provides guarantee for the safe and high-efficiency operation of the belt on the working face of the coal mine.

In conclusion, the method has simple steps, the characteristic point data of the outline of the coal flow is detected through the laser radar, the real-time belt speed of the conveyor belt is detected through the rotary encoder, and the coal flow can be efficiently and accurately detected through analyzing, processing and calculating the data on the computer; the visual sensor is adopted to efficiently and accurately detect the profile of the coal on the conveying belt, so that the large coal blocks on the working face are accurately and automatically identified; the coal flow detection efficiency is high, the precision is high, the method for identifying the large coal blocks is simple and reliable, the error is small, and the method has important significance for the efficient and safe operation of the belt conveyor in the coal mine and is convenient to popularize and use.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

FIG. 1 is a block flow diagram of the method of the present invention;

FIG. 2 is a schematic diagram of the coal flow cross section calculation of the present invention.

Fig. 3 is a schematic diagram of coordinate point conversion in the present invention.

Fig. 4 is a schematic view of the scan range setting of the lidar of the present invention.

FIG. 5A is a Gray image obtained by processing according to step A1 of the present invention;

FIG. 5B is the image resulting from the processing of step A4 according to the present invention;

FIG. 6A is a photograph of a single coal block taken in the first experiment of step four of the present invention;

FIG. 6B is a graph of the edge detection effect obtained by performing the edge detection on the graph of FIG. 6A in the first experiment of step four according to the present invention;

FIG. 7A is a photograph of a plurality of coal blocks taken in experiment two, step four of the present invention;

FIG. 7B is a graph of the edge detection effect obtained by performing edge detection on the graph of FIG. 7A in the second experiment in step four according to the present invention;

FIG. 8A shows the measurement of the size of a single large coal block in experiment three of step four according to the present invention;

FIG. 8B is a graph of the calculated results and relative error obtained from the dimensional measurements performed on FIG. 8A in step three of the experiment of step four of the present invention;

FIG. 9A is a graph of multiple bulk coal size measurements in step four of the experiment of the present invention;

fig. 9B shows the calculated results and relative error obtained from the dimensional measurements of fig. 9A in step four experiments of the present invention.

Detailed Description

As shown in fig. 1, 2 and 4, the method for monitoring the efficient and safe operation of the belt conveyor for coal mine work comprises the following steps:

step one, arranging hardware equipment for monitoring, and the specific process is as follows:

101, arranging a visual sensor and a crusher on a coal mine working face reversed loader, and enabling the crusher to be positioned between the visual sensor and a belt conveyor in a coal block measured area on the visual sensor straight face reversed loader; placing a calibration plate printed with square black and white lattices right in front of a visual sensor, and enabling the calibration plate to be parallel to the plane of the detected area of the coal briquette;

102, mounting a laser radar 5 at a position with a height H above the middle position of the belt conveyor 3, and enabling a scanning plane of the laser radar 5 to be vertical to the advancing direction of the belt conveyor 3;

103, mounting a roller on the rotary encoder, mounting the rotary encoder below the belt conveyor 3, and enabling the roller to be in contact with the belt conveyor 3 so that the roller can rotate along with the movement of the belt conveyor 3;