An accurate detection device and method for complex coal seam structures in a working face

Abstract

The present invention discloses a precise detection device and method for complex coal seam structures in a working face, belonging to the field of detection of complex coal seam structures. It includes a mobile trolley platform, a hydraulic lifting system, a rotating mechanism and a ground penetrating radar system; the mobile trolley platform includes wheels, a U-shaped support plate, a vehicle bottom plate and a triaxial acceleration sensor; the hydraulic lifting system consists of an electric pump, a support rod member and a hydraulic cylinder; the rotating mechanism includes a rotating chassis, a cantilever rod and a spherical hinge structure; the ground penetrating radar system includes a radar antenna integrating transmission and reception and a radar host. By fusing the detection results of radar antennas with multiple frequencies and integrating multiple detection information onto the same coordinate map, both the detection accuracy and the detection distance are ensured. It can achieve precise detection of complex structures such as faults, parting rocks and goafs within 30 m of the coal seam working face.

Description

Technical Field

[0001] The present invention relates to a precise detection device and method for complex coal seam structures in a working face, which is particularly suitable for use in underground coal mines and belongs to the field of detection of complex coal seam structures.

Background Art

[0002] Coal mines are an important part of China's energy resources and play an important role in China's economic development. Intelligent mines and transparent working faces are the development trends of the coal mining industry. The precise detection of complex coal seam structures inside the working face is the prerequisite and guarantee for transparent working faces, and it is also an effective way for the safe and green mining of China's coal mining industry.

[0003] Currently, the main methods for detecting complex coal seam structures in the working face include trough wave detection, Rayleigh wave seismic detection, and transient electromagnetic method detection, etc. However, due to the limited underground space and the existence of interference conditions such as mesh aiming and mechanical noise, it is difficult to deploy an ideal observation system, which affects the detection results. Moreover, the transient electromagnetic method is prone to generating short-distance detection blind areas during the detection process, which is likely to cause missed solutions. Most of the detections of complex coal seam structures are carried out at fixed points and fixed distances, and it is difficult to achieve continuous measurement inside the working face, and small coal seam structures are easily overlooked. How to reduce detection interference and achieve precise detection of complex coal seam structures is an urgent task.

Summary of the Invention

[0004] Aiming at the deficiencies of the above technologies, the purpose of the present invention is to provide a precise detection method and device for complex coal seam structures in a working face. Through this device and method, continuous measurement can be carried out on the complex coal seam structures inside the coal mining working face, and precise detection can be carried out on complex structures such as faults, parting rocks, and goafs within the range of 0 - 15 m inside the working face.

[0005] To achieve this purpose, a precise detection device for complex coal seam structures in a working face of the present invention includes a mobile trolley platform. Above the mobile trolley platform, there is a hydraulic lifting system. On the hydraulic lifting system, there is a rotating mechanism, and at the end of the rotating mechanism, there is a ground penetrating radar system;

[0006] The mobile trolley platform includes a vehicle bottom plate. Below the vehicle bottom plate, four wheels are connected through four U-shaped support frames, and a triaxial acceleration sensor is located at the exact center above the vehicle bottom plate;

[0007] The hydraulic lifting system includes a support bottom frame and an upper bottom plate with a frame structure. Between the support bottom frame and the upper bottom plate, there is a scissor expansion and contraction frame. On the scissor expansion and contraction frame, there is a cross bar. Between the cross bar and the vehicle bottom plate, there is a hydraulic cylinder for controlling the expansion and contraction of the scissor expansion and contraction frame. The oil circuit of the hydraulic cylinder is connected to an electric pump arranged on the top of the vehicle bottom plate;

[0008] The rotating mechanism includes a rotating base frame arranged above the upper base plate. The upper half of the rotating base frame can rotate horizontally relative to the lower half. A cantilever rod that can swing vertically is movably connected to the top of the rotating base frame. The end of the cantilever rod is connected to the ground penetrating radar system through a ball hinge structure, and a counterweight rod is provided at the tail to maintain balance.

[0009] The ground penetrating radar system includes a radar antenna that integrates transmission and reception and a posture sensor. The posture sensor is set at the center of the back of the radar antenna.

[0010] Furthermore, the wheels of the mobile trolley platform are provided with thickened rims to ensure that the four wheels can be fully connected with both sides of the scraper book conveyor; height-adjustable threaded hole structures are provided on both sides of the wheels, and a V-shaped obstacle removal mechanism for clearing small coal fragments on the moving track is connected in front of the wheel through the threaded hole structure; the U-shaped support frame is connected to the vehicle bottom plate through position-adjustable and left-right symmetrical threaded holes, and the wheelbase is adjusted by adjusting the position of the U-shaped support frame in the threaded hole.

[0011] Furthermore, the scissors telescopic frame is composed of multiple cross-arranged support rods. A U-shaped groove is provided at the upper end surface of the support base. The support rods slide in the U-shaped groove on the support base to raise and lower the upper base plate. The actual maximum adjustment height is 3.5m to adapt to the detection of coal seams of different thicknesses.

[0012] Furthermore, the radar antenna includes a transmitting antenna and a receiving antenna, and analyzes the reflected waves of the complex structure of the coal seam received by the receiving antenna, mainly analyzing the changes in the phase axis and amplitude to determine the round-trip travel time t of the electromagnetic wave.

[0013] Furthermore, the height of the U-shaped support is 0.45m.

[0014] A detection method for accurately detecting a complex coal seam structure in a working face, the steps of which are as follows:

[0015] Use the mobile trolley platform to drive to the position to be tested on the coal mining face, and adjust the threaded holes on the bottom plate of the trolley to change the wheelbase so that the wheels are fully connected with both sides of the scraper conveyor, so that the wheels use both sides of the scraper conveyor as moving guide rails;

[0016] The electric pump drives the hydraulic cylinder to extend and retract, and the angle of the radar antenna transmitting electromagnetic waves is adjusted by adjusting the rotation angle of the cantilever rod of the rotating mechanism and the angle of the ball hinge structure, so that the radar antenna is as close to the coal mining face as possible to reduce interference factors in the propagation of electromagnetic waves;

[0017] After the angle and height of the radar antenna are adjusted, the mobile trolley platform carries the radar antenna and moves through the scraper conveyor, and simultaneously uses antennas of different frequencies to detect the coal seam at the same position;

[0018] Detect the coal seam at the same position using radar antennas with different frequencies and collect data. Then, through zero calibration, data filtering, and resampling, fuse the detection response maps of multiple frequency antennas to enhance the obtained detection depth and resolution. By analyzing the in-phase axis and amplitude changes of the fused detection response map, determine whether there is a complex structure in the coal seam at this position. If there is a complex structure in the coal seam, calculate the two-way travel time of the electromagnetic wave. Determine the position of the radar antenna in the plane where the scraper conveyor is located through the position data information of the triaxial acceleration sensor. Combine the propagation speed of the electromagnetic wave, the data of the pose sensor, and the distance calculation formula to determine the position of the complex structure of the coal seam relative to the radar antenna. Through coordinate transformation, obtain the accurate position information of the complex structure of the coal seam in the working face relative to the plane where the scraper conveyor is located.

[0019] Furthermore, the frequencies of the radar antennas include GC100HF, GC270HF, and GC900HF. Continuously detect the same position using radar antennas with different frequencies. Realize the fusion of images by zero calibration and registration processing of detection images with multiple frequencies, which not only improves the detection depth but also increases the resolution of the images.

[0020] Furthermore, taking the ground plane where the mobile platform is located as the reference plane (Z = 0), and the initial starting point of the mobile platform as the reference point, place the triaxial acceleration sensor at the center of the vehicle floor to obtain the acceleration a during the movement of the mobile trolley platform. Take the starting point of the movement of the mobile trolley platform as the origin, and obtain the coordinates (X, Y) of the end point of the movement of the mobile trolley platform by performing double integration on the acceleration:

[0021] X = ∫∫a X dt, Y = ∫∫a Y dt,

[0022] a X is the acceleration of the mobile platform in the X direction; a Y is the acceleration of the mobile platform in the Y direction;

[0023] At this time, obtain the position coordinates of the mobile trolley platform as (X, Y, Z = 0) through integral transformation. Combine the height H0 of the device itself, the length L0 of the cantilever rod, and the rotation angle θ0 to determine the position where the radar antenna is located as:

[0024] (X, Y + L0cosθ0, H0 + sinθ0).

[0025] Furthermore, use the pose sensor to obtain the tilt angle of the radar antenna to determine the emission angle of the electromagnetic wave. Through the two-way travel time, the propagation speed of the electromagnetic wave, and the triaxial acceleration sensor to obtain three-dimensional position information, the position coordinates of the complex structure of the coal seam can be calculated. The calculated position coordinates are:

[0026]

[0027] Where: c is the propagation speed of electromagnetic waves in a vacuum; t is the two-way travel time of electromagnetic waves in the coal seam; ε r is the dielectric constant of the coal seam; θ is the pitch angle of the radar antenna; is the angle between the electromagnetic wave emitted by the radar antenna and the horizontal direction; H0 is the height of the device itself; L0 and θ0 are the length and rotation angle of the cantilever rod.

[0028] Combined with the position of the radar antenna itself, determine the accurate position coordinates of the complex coal seam structure in the plane reference coordinate system of the scraper conveyor.

[0029] Beneficial effects:

[0030] This device can conduct continuous detection inside the coal mining face. Compared with the previous fixed-point and fixed-distance detection, the possibility of ignoring the complex coal seam structure is greatly reduced; through the profile response diagram of the pose and triaxial acceleration sensor combined with radar detection, the coordinate position information of the complex coal seam structure can be accurately determined; by fusing the detection results of radar antennas with multiple frequencies and integrating multiple detection information onto the same coordinate map, both the detection accuracy and the detection distance are increased. By applying this device and method, accurate detection of complex structures such as faults, parting rocks, and goafs within 30 m of the coal seam working face can be achieved.

Description of the Drawings

[0031] Figure 1 is a schematic diagram of the device for accurately detecting complex coal seam structures in the working face of the present invention;

[0032] Figure 2 is a working flow chart of the method for accurately detecting complex coal seam structures in the working face of the present invention;

[0033] In the figure: 1 - Rim, 2 - Wheel, 3 - Threaded hole structure, 4 - U-shaped support plate, 5 - Electric pump, 6 - Vehicle bottom plate, 7 - Support chassis, 8 - Support rod, 9 - Upper bottom plate, 10 - Rotating chassis, 11 - Counterweight rod, 12 - Radar antenna, 13 - Pose sensor, 14 - Ball hinge structure, 15 - Cantilever rod, 16 - U-shaped groove, 17 - Hydraulic cylinder, 18 - Threaded hole, 19 - Triaxial acceleration sensor, 20 - V-shaped obstacle removal mechanism.

Detailed Implementation Modes

[0034] The following further describes the present invention with reference to the drawings.

[0035] As Figure 1As shown in the figure, a precise detection device for complex coal seam structures on the working face of the present invention includes a mobile trolley platform, a hydraulic lifting system, a rotating mechanism, and a ground penetrating radar system; the hydraulic lifting system is arranged above the mobile trolley platform, the rotating mechanism is placed above the hydraulic lifting system, and the ground penetrating radar system is connected to the end of the rotating mechanism.

[0036] The mobile trolley platform includes wheels 2, a U-shaped support frame 4, a vehicle bottom plate 6 placed above the U-shaped support frame 4, and a three-axis acceleration sensor 19 placed at the center of the vehicle bottom plate 6; the hydraulic lifting system includes an electric pump 5, a hydraulic cylinder 17, a support rod member 8 placed above the vehicle bottom plate 6, and an upper bottom plate 9 placed above the support rod member; the rotating mechanism includes a rotating bottom frame 10, a cantilever rod 15, and a counterweight rod member 11 placed above the upper bottom plate 9; the ground penetrating radar system includes a radar host integrating transmission and reception and a detachable radar antenna 12, a spherical hinge structure 14 connected to the back of the radar antenna 12, and a pose sensor placed at the center of the back of the radar antenna 12.

[0037] The wheels 2 of the mobile platform are provided with a rim 1 of a certain thickness to ensure that the four wheels can be fully connected to both sides of the scraper conveyor; both sides of the wheels 2 are provided with a height-adjustable threaded hole structure 3, and a V-shaped obstacle removal mechanism 20 is placed in front of the threaded hole structure 3 to remove small broken coal on the moving track; the vehicle bottom plate 6 is provided with symmetrically arranged threaded holes 18 at a certain interval to adjust the wheelbase of the mobile trolley platform to adapt to different widths of the scraper conveyor; the U-shaped support member 4 with a height of 0.45 m can enable the mobile trolley platform to cross the small coal piles left on the scraper conveyor, realizing the smooth movement of the mobile trolley platform with both sides of the scraper conveyor as the moving guide rails.

[0038] The position of the radar antenna 12 and the angle of the emitted electromagnetic wave are adjusted through the hydraulic lifting system and the rotating mechanism to adapt to measurements under different conditions. The specific operations are as follows: The hydraulic cylinder 17 realizes the telescoping of the cylinder under the control of the electric pump 5, driving the support rod member 8 to slide in the U-shaped groove 16 of the support bottom frame 7, realizing the raising and lowering of the upper bottom plate 9. The actual maximum adjustment height is 3.5 m. A spherical hinge structure 14 is arranged at the end of the cantilever rod 15. By adjusting the angle of the cantilever rod 15, the radar antenna 12 is made to approach the coal mining face as much as possible to reduce the interference with the electromagnetic wave; the electromagnetic wave emission angle of the radar antenna 12 is changed by adjusting the spherical hinge structure 14 to adapt to the detection of coal seams with different thicknesses.

[0039] The radar antenna 12 has frequencies of GC100HF, GC270HF, and GC900HF. Different frequencies can be selected according to the detection depth requirements. Also, the detection images of multiple frequencies can be processed through zero calibration, registration, etc. to achieve image fusion, increasing the resolution of the image while improving the detection depth, and making the detection results more accurate.

[0040] As Figure 2 shown, a precise detection method and device for complex coal seam structures on the working face have the following steps:

[0041] Drive the detection device of the present invention to the position to be measured on the coal mining working face. By adjusting the threaded holes 19 on the vehicle bottom plate 6 to change the wheelbase of the wheels 2, the wheels can be fully connected to both sides of the scraper conveyor. Drive the telescopic movement of the hydraulic cylinder 17 through the electric pump 5, and adjust the rotation angle of the cantilever 15 and the emission angle of the radar antenna 12, so that the radar antenna 12 is as close as possible to the coal mining working face to reduce the interference of electromagnetic waves. After the angle and height of the radar antenna 12 are adjusted, the mobile trolley platform carries the radar antenna 12 to conduct mobile detection on the scraper conveyor. After the detection by a radar antenna of one frequency is completed, replace the radar antenna 12 with different frequencies to carry out coal seam detection at the same position, and fuse the detection response maps of multiple frequency antennas 12; by analyzing the in-phase axis and amplitude changes of the detection response map, determine whether there is a complex coal seam structure at this position, and whether there is a complex coal seam mechanism in the two-way travel time of the electromagnetic wave. Combine the data of the pose sensor 13, and calculate to determine the position coordinates of the complex coal seam structure relative to the radar antenna; determine the position where the radar antenna 12 is located through the data obtained by the triaxial acceleration sensor 19, and determine the precise position of the complex coal seam structure inside the working face through coordinate transformation. Using this method, while increasing the detection depth, the resolution is increased, and the problem of misjudgment and false judgment of complex coal seam structures is better solved, realizing the precise detection of complex coal seam structures.

[0042] The radar antenna 12 includes a transmitting and receiving antenna. By analyzing the reflected wave of the complex coal seam structure received by the receiving antenna, mainly analyze the changes in the in-phase axis and amplitude to determine the two-way travel time t of the electromagnetic wave.

[0043] The triaxial acceleration sensor 19 placed at the center of the vehicle bottom plate 6 obtains the acceleration a during the movement of the mobile trolley platform. By integrating the acceleration twice, the travel distance X of the mobile trolley platform is obtained, that is, X = ∫∫adt, to determine the position where the radar antenna is located.

[0044] Obtain the tilt angle of the radar antenna through the pose sensor 13, that is, determine the emission angle of the electromagnetic wave. The position coordinates of the complex coal seam structure can be calculated through the two-way travel time and the propagation speed of the electromagnetic wave. The calculated position coordinates are: Combined with the position where the radar antenna itself is located, through coordinate transformation, determine the precise position coordinates of the complex coal seam structure in the reference coordinate system.

[0045] In the formula: c is the propagation speed of the electromagnetic wave in vacuum; t is the two-way travel time of the electromagnetic wave in the coal seam; ε r is the dielectric constant of the coal seam; θ is the pitch angle of the radar antenna; It is the angle between the electromagnetic wave emitted by the radar antenna and the horizontal direction.

Claims

1. A precise detection method for complex coal seam structures in the working face, characterized in that: The precise detection device for complex coal seam structures used includes a mobile trolley platform. Above the mobile trolley platform, there is a hydraulic lifting system. On the hydraulic lifting system, there is a rotating mechanism. At the end of the rotating mechanism, there is a ground penetrating radar system; The mobile trolley platform includes a vehicle bottom plate (6). Below the vehicle bottom plate (6), four wheels (2) are connected through four U-shaped support frames (4). At the center above the vehicle bottom plate (6), there is a three-axis acceleration sensor (19); The hydraulic lifting system includes a support bottom frame (7) and an upper bottom plate (9) with a frame structure. Between the support bottom frame (7) and the upper bottom plate (9), there is a scissor telescopic frame. On the scissor telescopic frame, there is a cross bar. Between the cross bar and the vehicle bottom plate (6), there is a hydraulic cylinder (17) for controlling the telescopic movement of the scissor telescopic frame. The oil circuit of the hydraulic cylinder (l7) is connected to an electric pump (5) arranged on the top of the vehicle bottom plate (6); The rotating mechanism includes a rotating bottom frame (10) arranged above the upper bottom plate (9). The upper half of the rotating bottom frame (10) can rotate horizontally relative to the lower half. At the top of the rotating bottom frame (10), there is a cantilever rod (15) that can swing in the vertical direction. The end of the cantilever rod (15) is connected to the ground penetrating radar system through a spherical hinge structure (14), and at the tail, there is a counterweight rod (11) for maintaining balance; The ground penetrating radar system includes a radar antenna (12) that integrates transmission and reception and a pose sensor (13). The pose sensor (13) is arranged at the center of the back of the radar antenna (12); The steps of the detection method are as follows: Use the mobile trolley platform to drive to the position to be measured on the coal mining face. By adjusting the threaded holes (18) on the vehicle bottom plate (6) to change the wheelbase of the wheels (2), make the wheels (2) fully connect with both sides of the scraper conveyor, so that the wheels (2) use both sides of the scraper conveyor as moving guide rails; Drive the hydraulic cylinder (17) to expand and contract through the electric pump (5). By adjusting the rotation angle of the cantilever rod (15) of the rotating mechanism and adjusting the angle of the spherical hinge structure (14), adjust the angle of the electromagnetic wave emitted by the radar antenna (12), so that the radar antenna (12) is as close as possible to the coal mining face to reduce the interference factors during the propagation of the electromagnetic wave; After the angle and height of the radar antenna (12) are adjusted, the mobile trolley platform carries the radar antenna (12) to move through the scraper conveyor and simultaneously detect the coal seam at the same position with antennas of different frequencies; The coal seams at the same location are detected using radar antennas (12) with different frequencies to collect data. Then, through zero calibration, data filtering, and resampling, the detection response maps of multiple-frequency antennas (12) are fused to enhance the detection depth and resolution obtained. By analyzing the in-phase axis and amplitude changes in the fused detection response map, it is determined whether there is a complex structure in the coal seam at this location. If there is a complex coal seam structure, the two-way travel time of the electromagnetic wave is calculated. The position data information of the triaxial acceleration sensor (19) is used to determine the position of the radar antenna (12) in the plane where the scraper conveyor is located. Combining the propagation speed of the electromagnetic wave, the data of the pose sensor (13), and the distance calculation formula, the position of the complex coal seam structure relative to the radar antenna (12) is determined. Through coordinate transformation, the precise position information of the complex coal seam structure in the working face relative to the plane where the scraper conveyor is located is obtained.

2. The accurate detection method for complex coal seam structures on the working face according to claim 1, characterized in that: The wheels (2) of the mobile trolley platform are provided with thickened wheel rims (1) to ensure that the four wheels can be fully connected to both sides of the scraper book conveyor; threaded hole structures (3) with adjustable heights are provided on both sides of the wheels (2), and a V-shaped obstacle removal mechanism (20) for removing small pieces of coal on the moving track is connected in front of the wheels (2) through the threaded hole structures (3); the U-shaped support (4) and the vehicle bottom plate (6) are connected through threaded holes (18) with adjustable positions and symmetry on the left and right. By adjusting the position of the U-shaped support (4) in the threaded holes (18), the wheelbase can be adjusted.

3. The precise detection method for complex coal seam structures on the working face according to claim 1, characterized in that: The scissor telescopic frame is composed of multiple cross-set support rods (8). A U-shaped groove (16) is provided at the upper end face position of the support chassis (7). The support rods (8) slide in the U-shaped groove (16) on the support chassis (7) to realize the elevation and lowering of the upper bottom plate (9). The actual maximum adjustable height is 3.5 m to adapt to the detection of coal seams with different thicknesses.

4. The accurate detection method for complex coal seam structure of the working face according to claim 1, characterized in that: The radar antenna (12) includes a transmitting and receiving antenna. By analyzing the reflected waves of the complex coal seam structure received by the receiving antenna, mainly analyzing the changes in the in-phase axis and amplitude to determine the two-way travel time t of the electromagnetic wave.

5. The precise detection method for complex coal seam structures on the working face according to claim 1, characterized in that: The height of the U-shaped support (4) is 0.45 m.

6. Precision detection method for complex coal seam structure of working face, characterized in that: The frequencies of the radar antenna (12) include GC100HF, GC270HF, and GC900HF. Continuity detection of the same location is carried out using radar antennas with different frequencies. Through zero calibration and registration processing of the detection images of multiple frequencies, image fusion is realized, which not only improves the detection depth but also increases the resolution of the image.

7. Precision detection method for complex coal seam structure of working face, characterized in that: Taking the ground plane where the mobile platform is located as the reference plane (Z = 0), and the initial starting point of the mobile platform as the reference point, the triaxial acceleration sensor (19) placed at the center of the vehicle bottom plate (6) obtains the acceleration a during the movement of the mobile trolley platform. Taking the starting point of the movement of the mobile trolley platform as the origin, the coordinates (X, Y) of the end point of the movement of the mobile trolley platform are obtained by performing a second integral on the acceleration: X = ∫∫a X dt, Y = ∫∫a Y dt, a X is the acceleration of the mobile platform in the X direction; a Y is the acceleration of the mobile platform in the Y direction; At this time, the position coordinates of the mobile trolley platform are obtained through integral transformation as (X, Y, Z = 0). Combining the height H0 of the device itself, the length L0 of the cantilever rod (15), and the rotation angle θ0, the position where the radar antenna is located is determined as: (X, Y + L0cosθ0, H0 + sinθ0). Precise detection method for complex coal seam structure of working face 8, characterized in that: The tilt angle of the radar antenna is obtained by using the pose sensor (13) to determine the emission angle of the electromagnetic wave. The three-dimensional position information is obtained through the two-way travel time, the propagation speed of the electromagnetic wave, and the triaxial acceleration sensor (19). The position coordinates of the complex structure of the coal seam can be calculated, and the calculated position coordinates are: Where: c is the propagation speed of electromagnetic waves in vacuum; t is the two-way travel time of electromagnetic waves in the coal seam; ε r is the dielectric constant of the coal seam; θ is the pitch angle of the radar antenna; is the angle between the electromagnetic wave emitted by the radar antenna and the horizontal direction; H0 is the height of the device itself; L0 and θ0 are the length and rotation angle of the cantilever rod; Combined with the position where the radar antenna itself is located, the accurate position coordinates of the complex structure of the coal seam in the plane reference coordinate system of the scraper conveyor are determined.

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