Positioning method of hydraulic support guard plate in coal mining face

Abstract

The present invention discloses a method for positioning the side guard of a hydraulic support on a coal mining face, including installing and calibrating a camera; establishing a relative position model between the camera and the side guard, and setting a number for the side guard in the model; controlling the rotation of the camera, and obtaining the rotation angle of the camera and the image taken; theoretically calculating the theoretical imaging interval corresponding to each side guard number under the rotation angle; using a computer to identify the actual imaging interval of the side guard in the image; comparing and judging the actual imaging interval of the side guard with the theoretical imaging interval one by one to determine the position of the side guard. The present invention has the advantage of using a monocular camera, and does not require setting a marker or machine learning training on the side guard to be detected, so as to accurately determine the position of the side guard, eradicate the dependence of the object to be detected on the marker or machine learning, and is not restricted by the movement of the coal mining machine and the underground working environment, and effectively prevents the coal mining machine drum from damaging the side guard.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, in particular to a method for positioning a side guard plate of a hydraulic support on a coal mining working face. Background Art

[0002] In coal mining, the positional relationship between the drum and the guard plate of the coal mining machine is one of the key issues in intelligent and safe coal mining. According to the normal coal mining process, the guard plates within 3 frames in front of the coal mining machine must be retracted to prevent the drum from damaging the guard plates. In actual projects, the guard plates are often unable to be fully retracted due to jamming, improper remote operation, etc., and computer vision is required to determine which guard plate has not been fully retracted, thereby triggering an alarm, protection or rescue mechanism. Since the appearance characteristics of hydraulic supports are basically the same, it is impossible to directly obtain target features through images. Therefore, the commonly used method is to spray numbers on the guard plates, post reflective strips with specific visual meanings, etc., and then use computer vision to identify and judge. After actual application, it was found that this method can better achieve target recognition and positioning in scenarios with good operating environment and single conditions. The environment underground in coal mines is harsh, especially in coal mining working faces. The drum of the coal mining machine cuts the coal wall to produce a large amount of coal ash and coal dust, which greatly hinders the correct identification of markers. At the same time, under the action of the spray system, the combination of water mist and coal dust will quickly stain the markers, and it is very difficult to clean; during the coal cutting process, the markers are easily damaged by large pieces of coal and rocks that roll down. Therefore, the method of using markers to calibrate the position of the guard plate is not applicable to the field of coal mining. It is necessary to propose a new non-calibrated method to locate the hydraulic support guard plate of the coal mining face. Summary of the invention

[0003] The invention aims to provide a method for positioning a hydraulic support guard plate of a coal mining working face.

[0004] To achieve the above purpose, the present invention can adopt the following technical solutions:

[0005] The method for positioning the side guard plate of a hydraulic support of a coal mining working face of the present invention comprises the following steps:

[0006] S1, install and calibrate the camera;

[0007] S2, establishing a relative position model between the camera and the guard plate, and setting a number for the guard plate in the model;

[0008] S3, controlling the rotation of the camera and obtaining the rotation angle of the camera and the captured image;

[0009] S4, theoretically calculating the number interval of the guard plates within the shooting range at the rotation angle;

[0010] S5, theoretically calculating the theoretical imaging interval of the guard plate corresponding to each number under the rotation angle;

[0011] S6, using a computer to identify the actual imaging interval of the support plate in the image;

[0012] S7, comparing the actual imaging interval of the side guard plate with the theoretical imaging interval one by one to determine the number of the side guard plate;

[0013] S8, determine the position of the guard plate according to the model established in step S2.

[0014] Furthermore, in step S1, the camera is installed below the top beam of the hydraulic support, and the horizontal viewing angle of the camera is parallel to the base of the hydraulic support, and can be rotated left and right under remote control.

[0015] Furthermore, in step S1, when calibrating the camera, the state where the center line of the horizontal viewing angle of the camera and the center of the guard plate of the hydraulic support where the camera is located intersect vertically is determined as the calibration position, and the object distance of the camera, the actual width of the guard plate and the imaging width of the guard plate in the calibration position are recorded.

[0016] In step S2, when the camera is set to rotate left in the model, the rotation angle , when the camera rotates right, the rotation angle , the camera rotates at the calibration position ; and set the number of the guard plate of the hydraulic support where the camera is located to 0, and record it as negative integers from guard plate No. 0 to the right; and record it as positive integers from guard plate No. 0 to the left.

[0017] Furthermore, in step S4, based on the model established in step S2, the number of the guard plate where the center line of the horizontal viewing angle of the camera is located under the rotation angle is derived through the relationship between the rotation angle, the distance moved by the center line of the horizontal viewing angle relative to the calibrated position, the actual width of the guard plate and the number of the guard plate, and the number range of the guard plates within the shooting range is determined.

[0018] Furthermore, in step S5, the theoretical imaging interval is represented by a vertical distance from the left end point of the guard plate to the center line of the horizontal viewing angle and a vertical distance from the right end point to the center line of the horizontal viewing angle.

[0019] Furthermore, in step S6, the actual imaging interval is represented by the starting point of the left end point of the guard plate in the image and the width of the guard plate in the image.

[0020] The advantages of the present invention are that it uses a monocular camera, does not need to set a marker on the guard plate to be detected, and does not need machine learning training, and can accurately determine the position of the guard plate, eliminating the dependence of the object to be detected on the marker or machine learning. At the same time, the present invention is applied to the field of coal mining, is not limited by the movement of the coal mining machine and the underground working environment during the coal mining process, and effectively prevents the coal mining machine drum from damaging the guard plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flowchart of the method for positioning the side guard plate.

[0022] Figure 2 The present invention is a schematic diagram of camera installation in the method for positioning the side guard plate.

[0023] Figure 3 The present invention is a schematic diagram of camera calibration for the side guard plate positioning method.

[0024] Figure 4 It is a schematic diagram of a model of the side guard plate positioning method of the present invention.

[0025] Figure 5 It is a schematic diagram of the center line of the horizontal viewing angle after the camera is rotated in the side guard plate positioning method described in the present invention.

[0026] Figure 6 It is a relationship diagram between the guard plate and the center line of the horizontal viewing angle of the camera after the camera rotates in the guard plate positioning method of the present invention.

[0027] Figure 7 It is a theoretical imaging relationship diagram after the camera rotates in the side guard plate positioning method of the present invention.

[0028] Figure 8 It is a schematic diagram of the theoretical imaging interval and the actual imaging interval of the side guard plate positioning method described in the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] like Figure 1 As shown, the method for positioning the side guard plate of a hydraulic support of a coal mining working face of the present invention comprises the following steps:

[0031] S1, install and calibrate the camera;

[0032] like Figure 2 , Figure 3As shown, the camera 1 is installed below the top beam 3 of the hydraulic support 2, and the horizontal viewing angle of the camera 1 is parallel to the base 4 of the hydraulic support 2, and can rotate left and right under remote control.

[0033] When calibrating the camera 1, make the horizontal viewing angle center line 6 of the camera 1 intersect vertically with the center of the guard plate 5 of the hydraulic support 2 where the camera 1 is located, and record the object distance of the camera 1 at this position. , Width of guard plate 5 And the imaging width of the guard plate 5 ;

[0034] S2, establishing a relative position model between the camera 1 and the side guard plate 5, and setting a number for the side guard plate 5 in the model;

[0035] like Figure 4 As shown, the relative position model of the camera 1 and the guard plate 5 is set in the computer. When the camera 1 is set to rotate left, the rotation angle , when camera 1 rotates right, the rotation angle , when camera 1 is at the calibration position, the rotation angle ; For example, if camera 1 rotates 10° to the left, then , and camera 1 rotates right 10°, recorded as .

[0036] The guard plate 5 corresponding to the hydraulic support 2 where the camera 1 is located is numbered as 0, and negative integers are recorded from the guard plate 5 No. 0 to the right; positive integers are recorded from the guard plate 5 No. 0 to the left;

[0037] S3, controlling the rotation of the camera 1, and obtaining the rotation angle of the camera 1 and the captured image;

[0038] S4, theoretically calculating the number interval of the guard plate 5 within the shooting range at the rotation angle;

[0039] The calculation derivation process is as follows:

[0040] First, if Figure 5 As shown, the distance that the horizontal viewing angle center line 6 of the camera 1 moves relative to the calibrated position under the rotation angle is calculated; the calculation formula is as follows:

[0041] (1)

[0042] in, Represents the rotation angle of camera 1; represents the object distance of camera 1 at the calibration position;

[0043] Secondly, according to the relative position model of the camera 1 and the guard plate 5 established in step S2, the distance moved by the horizontal viewing angle center line 6 relative to the calibrated position and the width of the guard plate 5 satisfy the following relationship:

[0044] (2)

[0045] in, represents the width of the guard plate 5; i represents the number of the guard plate 5;

[0046] Substituting formula (1) into formula (2), we get the following formula:

[0047] (3)

[0048] The following formula is derived from formula (3):

[0049] (4)

[0050] In the range determined by formula (4), the integer value of i is the number of the guard plate 5 where the center line 6 of the horizontal viewing angle of the camera is located at the rotation angle;

[0051] Based on the number of the guard plate 5 where the center line 6 of the camera's horizontal viewing angle is located, the number interval of the guard plate 5 within the shooting range of the camera 1 at the rotation angle can be determined;

[0052] For example, when camera 1 rotates 30° to the left, the width of the guard plate 5 is 0.9 m, and the object distance of camera 1 at the calibration position is 3 m. The interval of i is determined by formula (4) as That is, when the camera 1 is rotated 30° to the left, the center line 6 of the horizontal viewing angle of the camera 1 is located on the guard plate 5 numbered 2. It can be further determined that when the rotation angle of the camera 1 is 30°, the number of guard plates 5 photographed corresponds to the number of guard plates 5 in the model of step S2.

[0053] For example, when the camera 1 rotates at an angle of 30° and captures 3 side guards 5, the corresponding numbers are 1, 2, and 3; when the camera captures 5, the corresponding numbers are 4, 3, 2, 1, and 0; when the number of side guards 5 captured is an even number, the numbering interval of the side guards 5 at the rotation angle can be determined by comparing the actual recognition results of the computer with the model.

[0054] S5, theoretically calculating the theoretical imaging interval 7 of each numbered guard plate 5 corresponding to the rotation angle; Figure 8 As shown, the theoretical imaging interval 7 is expressed by the vertical distance from the left end point of the guard plate 5 to the horizontal viewing angle center line 6 and the vertical distance from the right end point of the guard plate 5 to the horizontal viewing angle center line 6;

[0055] The calculation derivation process is as follows:

[0056] S5.1, such as Figure 6 As shown, according to the geometric relationship, the angle formed by the right end point of the guard plate 5 and the line connecting the camera 1 is obtained. ;

[0057] S5.2, according to the relative position model, calculate the distance between the right end point of the guard plate 5 and the center line 6 of the horizontal viewing angle of the camera 1 in the same horizontal plane ;

[0058] Similarly, the distance between the right end point of the guard plate 5 and the center line 6 of the horizontal viewing angle of the camera 1 in the same horizontal plane is obtained. ;

[0059] S5.3, according to the law of sine, we get the following formula:

[0060]

[0061] Obtain the vertical distance between the left end point of the guard plate 5 and the center line 6 of the horizontal viewing angle of the camera 1:

[0062]

[0063] Similarly, the vertical distance between the right end point of the guard plate 5 and the center line 6 of the horizontal viewing angle of the camera 1 is obtained:

[0064]

[0065] like Figure 7 As shown, S5.4 calculates the object distance of camera 1 at this rotation angle. :

[0066]

[0067] S5.5, based on the geometric relationship, calculate the theoretical imaging width at this rotation angle The actual width ;

[0068]

[0069] therefore,

[0070]

[0071] S5.6, according to the geometric relationship,

[0072]

[0073] but,

[0074]

[0075] Similarly,

[0076]

[0077] S6, using a computer to identify the actual imaging interval 8 of the guard plate 5 in the image, comparing the actual imaging interval 8 of the guard plate 5 with the theoretical imaging interval 7 one by one, and determining the number of the guard plate 5; the actual imaging interval 8 is represented by the starting point of the left end point of the guard plate 5 in the image and the width of the guard plate 5 in the image; the judgment standard is as follows:

[0078] when When both are established at the same time, the guard plate 5 is numbered i;

[0079] when When both are established at the same time, the guard plate 5 is numbered i;

[0080] when At the same time

[0081] When it is immediately, the guard plate 5 is numbered as i-1;

[0082] in, Represents the starting point of the left end point of the guard plate 5 in the image; Represents the width of the guard plate 5 in the image; represents the vertical distance from the left end point of the guard plate 5 to the horizontal viewing angle center line 6 in the theoretical imaging interval 7; represents the vertical distance from the right end point of the guard plate 5 to the horizontal viewing angle center line 6 in the theoretical imaging interval 7; wherein i represents i represents the number of the guard plate 5;

[0083] S7, determine the position of the guard plate 5 according to the model established in step S2.

[0084] like Figure 8 As shown, through the comparison in step S7, it is determined that the guard plate 5 is numbered 2. According to the relative position relationship model between the camera 1 and the guard plate 5, the guard plate 5 of the hydraulic support 2 where the camera 1 is located is numbered 0, and the second guard plate 5 from the guard plate 5 No. 0 to the left is the position of the guard plate 5 numbered 2. The on-site personnel find the camera 1 according to the frame number of the hydraulic support 2 where the camera 1 is located, such as the frame number of the hydraulic support 2 where the camera 1 is installed is 120; and then find the second guard plate 5 from the left to find the located guard plate 5.

Claims

1. A method for positioning a hydraulic support guard plate of a coal mining face, characterized in that: The following steps are involved: S1, install and calibrate the camera; S2, establishing a relative position model between the camera and the guard plate, and setting a number for the guard plate in the model; S3, controlling the rotation of the camera and obtaining the rotation angle of the camera and the captured image; S4, theoretically calculating the number interval of the guard plates within the shooting range at the rotation angle; deriving the number of the guard plate where the center line of the horizontal viewing angle of the camera is located at the rotation angle according to the relationship between the rotation angle, the distance moved by the center line of the horizontal viewing angle of the camera relative to the calibrated position, the actual width of the guard plate and the guard plate number, and determining the number interval of the guard plates within the shooting range; S5, theoretically calculating the theoretical imaging interval of the guard plate corresponding to each number under the rotation angle; the theoretical imaging interval is represented by the vertical distance from the left end point of the guard plate to the center line of the horizontal viewing angle and the vertical distance from the right end point to the center line of the horizontal viewing angle; S6, using a computer to identify the actual imaging interval of the guard plate in the image; the actual imaging interval is represented by the starting point of the left end point of the guard plate in the image and the width of the guard plate in the image; S7, comparing the actual imaging interval of the side guard plate with the theoretical imaging interval one by one to determine the number of the side guard plate; S8, determine the position of the guard plate according to the model established in step S2.

2. The method for positioning the side guard plate of a hydraulic support of a coal mining face according to claim 1 is characterized in that: In step S1, the camera is installed below the top beam of the hydraulic support, and the horizontal viewing angle of the camera is parallel to the base of the hydraulic support, and can be rotated left and right under remote control.

3. The method for positioning the side guard plate of a hydraulic support of a coal mining face according to claim 1 is characterized in that: In step S1, when calibrating the camera, the state where the center line of the horizontal viewing angle of the camera and the center of the guard plate of the hydraulic support where the camera is located intersect vertically is determined as the calibration position, and the object distance of the camera, the actual width of the guard plate and the imaging width of the guard plate in the calibration position are recorded; In step S2, when the camera is set to rotate left in the model, the rotation angle , when the camera rotates right, the rotation angle , the camera rotates at the calibration position ; and set the number of the guard plate of the hydraulic support where the camera is located to 0, and record it as negative integers from guard plate No. 0 to the right; and record it as positive integers from guard plate No. 0 to the left.

Images