A method for monitoring the mining height of a coal mining machine

Abstract

The present invention discloses a method for monitoring the mining height of a coal mining machine, comprising the following steps: 1. calibrating a tilt sensor at four positions to obtain a calibration matrix for each tilt sensor; 2. installing the calibrated tilt sensor on the coal mining machine; 3. performing two calibration compensations on the output values of the first tilt sensor, the second tilt sensor, and the third tilt sensor; and 4. calculating the mining height of the coal mining machine. The present invention performs four-position calibration on the tilt sensor before installation, and uses the obtained calibration matrix to perform two calibration compensations on the output of the installed tilt sensor. The second calibration compensation uses a method of constructing virtual Z-axis data to perform calibration compensation, thereby making the output result of the tilt sensor more accurate. Using a high-precision tilt sensor can achieve accurate monitoring of the mining height of the coal mining machine, thereby reducing damage to the coal mining machine caused by inappropriate mining height and avoiding downtime.

Description

Technical Field

[0001] The invention belongs to the technical field of coal shearer mining height monitoring, and particularly relates to a coal shearer mining height monitoring method. Background Art

[0002] During coal mining operation, real-time monitoring and simultaneous display of top and bottom shearer data are required. This allows remote control systems to issue adjustment data for mining height, or for on-site personnel to adjust the shearer's mining height accordingly. This ensures mining progress and improves efficiency while significantly reducing downtime and damage to the shearer caused by improper mining height and bottom shearer positioning. Currently, shearer mining height monitoring often uses inclinometers. However, conventional inclinometers require biaxial error calibration, requiring two-axis installation to compensate for errors in the installation angle. This poor installation environment of shearers hinders calibration and thus compromises the accuracy of the inclinometers. Furthermore, in actual coal mining operations, the bottom surface of the working face is uneven, requiring real-time calculation of the shearer drum's height. However, most methods for calculating mining height are computationally intensive, resulting in delayed monitoring results. Therefore, reducing the difficulty of inclinometer calibration, improving detection accuracy, and reducing computational complexity are pressing challenges. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and provide a method for monitoring the mining height of a coal mining machine. The inclination sensor is calibrated at four positions before installation, and the output of the installed inclination sensor is calibrated and compensated twice using the obtained calibration matrix. The second calibration compensation adopts the method of constructing virtual Z-axis data to make the output result of the inclination sensor more accurate. The use of a high-precision inclination sensor can realize accurate monitoring of the mining height of the coal mining machine, thereby reducing the damage to the coal mining machine caused by inappropriate mining height and avoiding shutdown.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for monitoring the mining height of a coal mining machine, characterized in that the method comprises the following steps:

[0005] Step 1: calibrate the i inclination sensors at four positions to obtain the calibration matrix Q of each i inclination sensor. i ; i is the number of the tilt sensor, i = 1, 2, 3;

[0006] Step 2: Install i calibrated inclination sensors on the coal mining machine:

[0007] A first inclination sensor is installed on the left rocker arm of the coal shearer, a second inclination sensor is installed on the right rocker arm of the coal shearer, and a third inclination sensor is installed on the body of the coal shearer. An initial coordinate system OXYZ is established, with the center of the body as the coordinate origin O, the positive direction of the X axis perpendicular to the coal mining face and pointing to the goaf, the positive direction of the Y axis perpendicular to the X axis and pointing to the right, and the positive direction of the Z axis perpendicular to the upward direction.

[0008] Step 3: Perform two calibration compensations on the output values of the first inclination sensor, the second inclination sensor, and the third inclination sensor at the current moment. The process of the two calibration compensations is as follows:

[0009] Step 301: collecting the X-axis output value Exi0(t) and the Y-axis output value Eyi0(t) of the first, second, and third inclination sensors at the current moment, where t is the current moment;

[0010] Step 302: Use the calibration matrix Q i Perform initial calibration compensation on the X-axis output value and the Y-axis output value according to the formula Calculate the X-axis output value Exi1(t) and Y-axis output value Eyi1(t) of the i-th inclination sensor after initial calibration and compensation;

[0011] Step 303: According to the formula Calculate the roll angle of the i-th inclination sensor after initial calibration compensation and pitch angle θ i1 (t);

[0012] Step 304: According to the formula Calculate the output value Ezi(t) of the virtual Z axis of the i-th inclination sensor;

[0013] Step 305: Perform secondary calibration compensation on the X-axis output value and the Y-axis output value according to the formula Calculate the X-axis output value Exi2(t) and Y-axis output value Eyi2(t) of the i-th inclination sensor after secondary calibration compensation;

[0014] Step 306: According to the formula Calculate the roll angles of the first, second, and third inclination sensors after secondary calibration compensation and pitch angle θ i2 (t), -90°<θ i2 (t)<90°;

[0015] Step 4: The roll angle of the i-th inclination sensor after two calibrations and compensations in step 3 Calculate the mining height of the left and right drums of the shearer at the current moment:

[0016] When the left drum cuts the bottom coal and the right drum cuts the top coal,

[0017] According to the formula Calculate the distance H1(t) between the lowest point of the left drum and the bottom of the working surface at the current moment; where H0 is the distance from the center point of the connection between the left rocker arm and the fuselage to the bottom of the working surface, or the distance from the center point of the connection between the right rocker arm and the fuselage to the bottom of the working surface, L is the length of the left rocker arm or the right rocker arm, and r is the radius of the left drum or the right drum;

[0018] According to the formula Calculate the distance H2(t) between the highest point of the right roller and the bottom of the working surface at the current moment;

[0019] When the left drum cuts the top coal and the right drum cuts the bottom coal,

[0020] According to the formula Calculate the distance H3(t) between the highest point of the left roller and the bottom of the working surface at the current moment;

[0021] According to the formula Calculate the distance H4(t) between the lowest point of the right drum and the bottom of the working surface at the current moment.

[0022] The advantages of the present invention compared with the prior art are: the inclination sensor is calibrated at four positions before installation, and the output of the installed inclination sensor is calibrated and compensated twice using the obtained calibration matrix. The second calibration compensation adopts the method of constructing virtual Z-axis data to make the output result of the inclination sensor more accurate. The use of high-precision inclination sensors can realize accurate monitoring of the mining height of the coal mining machine, thereby reducing the damage to the coal mining machine caused by inappropriate mining height and avoiding shutdown.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flowchart of the method of the present invention.

[0025] Figure 2 This is a schematic diagram of the installation position of the tilt sensor of the present invention.

[0026] Description of the accompanying drawings:

[0027] 1—first inclination sensor; 2—second inclination sensor; 3—third inclination sensor;

[0028] 4—left rocker arm; 5—right rocker arm; 6—fuselage;

[0029] 7—left roller; 8—right roller; 9—bottom of working surface. DETAILED DESCRIPTION

[0030] like Figure 1 and Figure 2 As shown, a method for monitoring the mining height of a coal mining machine of the present invention comprises the following steps:

[0031] Step 1: calibrate the i inclination sensors at four positions to obtain the calibration matrix Q of each i inclination sensor. i ; i is the number of the tilt sensor, i = 1, 2, 3;

[0032] Step 2: Install i calibrated inclination sensors on the coal mining machine:

[0033] A first inclination sensor 1 is installed on the left rocker arm 4 of the coal mining machine, a second inclination sensor 2 is installed on the right rocker arm 5 of the coal mining machine, and a third inclination sensor 3 is installed on the body 6 of the coal mining machine. An initial coordinate system OXYZ is established, with the center position of the body 6 as the coordinate origin O, the positive direction of its X axis is perpendicular to the coal mining working face and points to the goaf, the positive direction of the Y axis is perpendicular to the X axis and points to the right, and the positive direction of the Z axis is perpendicular to the upward direction.

[0034] Step 3: Perform two calibration compensations on the output values of the first inclination sensor, the second inclination sensor, and the third inclination sensor at the current moment. The process of the two calibration compensations is as follows:

[0035] Step 301: collecting the X-axis output value Exi0(t) and the Y-axis output value Eyi0(t) of the first tilt sensor 1, the second tilt sensor 2, and the third tilt sensor 3 at the current moment, where t is the current moment;

[0036] Step 302: Use the calibration matrix Q i Perform initial calibration compensation on the X-axis output value and the Y-axis output value according to the formula Calculate the X-axis output value Exi1(t) and Y-axis output value Eyi1(t) of the i-th inclination sensor after initial calibration and compensation;

[0037] Step 303: According to the formula Calculate the roll angle of the i-th inclination sensor after initial calibration compensation and pitch angle θ i1 (t);

[0038] Step 304: According to the formula Calculate the output value Ezi(t0) of the virtual Z axis of the i-th inclination sensor

[0039] Step 305: Perform secondary calibration compensation on the X-axis output value and the Y-axis output value according to the formula Calculate the X-axis output value Exi2(t) and Y-axis output value Eyi2(t) of the i-th inclination sensor after secondary calibration compensation;

[0040] Step 306: According to the formula Calculate the roll angles of the first inclination sensor 1, the second inclination sensor 2, and the third inclination sensor 3 after secondary calibration compensation and pitch angle θ i2 (t0, -90°<θ i2 (t0<90°;

[0041] Step 4: The roll angle of the i-th inclination sensor after two calibrations and compensations in step 3 Calculate the mining height of the left and right drums of the shearer at the current moment:

[0042] When the left drum 7 cuts the bottom coal and the right drum 8 cuts the top coal,

[0043] According to the formula Calculate the current distance H1(t) between the lowest point of the left roller 7 and the bottom of the working surface. Here, H0 is the distance from the center point of the connection between the left rocker arm 4 and the body 6 to the bottom of the working surface 9, or the distance from the center point of the connection between the right rocker arm 5 and the body 6 to the bottom of the working surface 9. L is the length of the left rocker arm 4 or the right rocker arm 5. r is the radius of the left roller 7 or the radius of the right roller 8.

[0044] According to the formula Calculate the distance H2(t) between the highest point of the right roller 8 and the bottom surface of the working surface 9 at the current moment;

[0045] When the left drum 7 cuts the top coal and the right drum 8 cuts the bottom coal,

[0046] According to the formula Calculate the distance H3(t) between the highest point of the left roller 7 and the bottom surface 9 of the working surface at the current moment;

[0047] According to the formula Calculate the distance H4(t) between the lowest point of the right drum 8 and the bottom surface 9 of the working surface at the current moment.

[0048] In this embodiment, the specific steps of step one are:

[0049] Step 101: define the X-axis of the tilt sensor as the roll axis and the Y-axis as the pitch axis, and install the tilt sensor on a horizontally leveled dual-axis turntable;

[0050] Step 102: Rotate the dual-axis turntable so that the X-axis and Y-axis of the inclination sensor are in four positions, where the Y-axis is defined as position 1 and rotate the X-axis and Y-axis 90° around the origin O in the XOY plane from position 1 to positions 2, 3, and 4, respectively. Collect inclination sensor data at each position and take the average value of the data to obtain the average value Xin of the X-axis data at position n and the average value Yin of the Y-axis data at position n.

[0051] Step 103: Calculate the X-axis data zero position Xi0 according to the formula Xi0=(Xi2+Xi4) / 2, and calculate the Y-axis data zero position Yi0 according to the formula Yi0=(Yi1+Yi3) / 2;

[0052] Step 104: Calculate the data after zero compensation of the X-axis and Y-axis according to the formulas Axin=Xin-Xi0 and Ayin=Yin-Y0;

[0053] Step 105: According to Q i =((X'*X) -1 *X'*Y)' calculate the calibration matrix Q i ,in X' is the transposed matrix of X, X -1 is the inverse matrix of X.

[0054] In this embodiment, since the bottom surface 9 of the working face is not flat during actual mining, a third inclination sensor 3 is installed on the body 6 of the coal mining machine to detect and reflect the undulation of the bottom surface 9 of the working face. Combined with the detection results of the first inclination sensor 1 and the second inclination sensor 2, the true swing arm angles of the left rocker arm 4 and the right rocker arm 5 relative to the bottom surface 9 of the working face can be obtained, thereby calculating the true heights of the left roller 7 and the right roller 8 relative to the bottom surface 9 of the working face, so as to control the high mining amount and the low mining amount of the coal mining machine.

[0055] In this embodiment, the tilt sensor is a dual-axis tilt sensor.

[0056] It should be noted that the inclination sensor is calibrated at four positions before installation, and the obtained calibration matrix is used to perform two calibration compensations on the output of the installed inclination sensor. The second calibration compensation adopts the method of constructing virtual Z-axis data to make the output result of the inclination sensor more accurate. The use of high-precision inclination sensors can realize accurate monitoring of the mining height of the coal mining machine, thereby reducing the damage to the coal mining machine caused by inappropriate mining height and avoiding shutdown.

[0057] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for monitoring the mining height of a coal mining machine, characterized in that: The method comprises the following steps: Step 1: calibrate the i inclination sensors at four positions to obtain the calibration matrix Q of each i inclination sensor. i ; i is the number of the tilt sensor, i = 1, 2, 3; Step 2: Install i calibrated inclination sensors on the coal mining machine: A first inclination sensor (1) is installed on the left rocker arm (4) of the coal mining machine, a second inclination sensor (2) is installed on the right rocker arm (5) of the coal mining machine, and a third inclination sensor (3) is installed on the body (6) of the coal mining machine; and an initial coordinate system OXYZ is established, with the center position of the body (6) as the coordinate origin O, the positive direction of its X axis is perpendicular to the coal mining working face and points to the goaf, the positive direction of the Y axis is perpendicular to the X axis and points to the right, and the positive direction of the Z axis is vertically upward; Step 3: Perform two calibration compensations on the output values of the first inclination sensor, the second inclination sensor, and the third inclination sensor at the current moment. The process of the two calibration compensations is as follows: Step 301, collecting the X-axis output value Exi0(t) and the Y-axis output value Eyi0(t) of the first tilt sensor (1), the second tilt sensor (2), and the third tilt sensor (3) at the current moment, wherein t is the current moment; Step 302: Use the calibration matrix Q i Perform initial calibration compensation on the X-axis output value and the Y-axis output value according to the formula Calculate the X-axis output value Exi1(t) and Y-axis output value Eyi1(t) of the i-th inclination sensor after initial calibration and compensation; Step 303: According to the formula Calculate the roll angle of the i-th inclination sensor after initial calibration compensation and pitch angle θ i1 (t); Step 304: According to the formula Calculate the output value Ezi(t) of the virtual Z axis of the i-th inclination sensor; Step 305: Perform secondary calibration compensation on the X-axis output value and the Y-axis output value according to the formula Calculate the X-axis output value Exi2(t) and Y-axis output value Eyi2(t) of the i-th inclination sensor after secondary calibration compensation; Step 306: According to the formula Calculating the roll angles of the first inclination sensor (1), the second inclination sensor (2), and the third inclination sensor (3) after secondary calibration compensation and pitch angle θ i2 (t), -90°<θ i2 (t)<90°; Step 4: The roll angle of the i-th inclination sensor after two calibrations and compensations in step 3 Calculate the mining height of the left and right drums of the shearer at the current moment: When the left drum (7) cuts the bottom coal and the right drum (8) cuts the top coal, According to the formula Calculate the distance H1(t) between the lowest point of the left roller (7) and the bottom surface of the working surface at the current moment; wherein H0 is the distance from the center point of the connection between the left rocker arm (4) and the fuselage (6) to the bottom surface of the working surface (9) or the distance from the center point of the connection between the right rocker arm (5) and the fuselage (6) to the bottom surface of the working surface (9), L is the length of the left rocker arm (4) or the right rocker arm (5), and r is the radius of the left roller (7) or the radius of the right roller (8); According to the formula Calculate the distance H2(t) between the highest point of the right roller (8) and the bottom surface of the working surface (9) at the current moment; When the left drum (7) cuts the top coal and the right drum (8) cuts the bottom coal, According to the formula Calculate the distance H3(t) between the highest point of the left roller (7) and the bottom surface of the working surface (9) at the current moment; According to the formula Calculate the distance H4(t) between the lowest point of the right roller (8) and the bottom surface of the working surface (9) at the current moment.

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