WO2022095202A1

WO2022095202A1 - Fiber grating intelligent coal-rock identification device for shearer drum

Info

Publication number: WO2022095202A1
Application number: PCT/CN2020/135157
Authority: WO
Inventors: 魏世明; 张泽升
Original assignee: 河南理工大学
Priority date: 2020-11-05
Filing date: 2020-12-10
Publication date: 2022-05-12
Also published as: CN112253106B; CN112253106A

Abstract

Disclosed is a fiber grating intelligent coal-rock identification device for a shearer drum. The fiber grating intelligent coal-rock identification device comprises the shearer drum; a fiber grating acceleration sensor is fixedly provided on the shearer drum, the fiber grating acceleration sensor is electrically connected to a fiber grating demodulator, the fiber grating demodulator is electrically connected to a computer, the computer is electrically connected to a signal receiver, and the signal receiver is connected to an oil pump motor for controlling the drum to move. According to the present invention, vibration signals can be effectively transmitted to a computer data processing system in time, and a curve graph is generated; real-time monitoring is achieved, the precision is high, interference of the severe environment of a coal face is avoided, stable real-time data is provided for a shearer lifting control system, deployment and maintenance are easy, and cost is low.

Description

A device for intelligent identification of coal and rock with fiber grating for shearer drum

technical field

The invention relates to the technical field of coal mine equipment, in particular to a device for intelligently recognizing coal and rock with fiber gratings for drums of coal shearers.

Background technique

With the coal mining process entering the intelligent stage, the coal-rock interface recognition is the basis for the automatic control of the shearer, and it is also a prerequisite for the realization of intelligent mining. Due to the harsh working environment in coal mines, it is very easy for the staff to misjudge the cutting state of the shearer, resulting in the inability to adjust the height of the shearer drum in time. When the height of the shearer drum is adjusted too high and the drum cuts the rock, it will lead to accelerated wear of the picks of the drum, shorten the life of the shearer, cause the coal gangue to fall into the coal, increase the cost of coal preparation in the later stage, and cause high dust, The high-noise working environment will cause harm to the life safety of the staff; when the height adjustment of the shearer drum is too low, the remaining top and bottom coal is too thick, the recovery rate of the coal mining face is too low, and the economic efficiency is reduced. At present, more than 20 methods have been studied, including artificial γ-ray method, natural γ-ray method, mechanical vibration method, radar detection method, infrared reflection and memory cutting method. According to whether the shearer needs to cut the rock, the automatic identification technology of coal-rock interface is divided into non-contact technology and contact technology. Non-contact technology, such as machine vision technology, electromagnetic detection technology, etc.; contact technology, such as vibration detection technology, torque detection technology, etc. At present, the most commonly used coal and rock identification technologies are: machine vision technology, electromagnetic detection technology, gamma ray detection technology, and vibration detection technology.

Machine vision technology is to manually create light sources, use industrial cameras to obtain images in front of the shearer drum, and then use various feature extraction methods and recognition algorithms to identify the coal-rock interface. Machine vision technology is consistent with the process of human eye recognition of coal-rock interface, which can be judged intuitively, has high reliability and versatility, and is easy to implement in terms of technology. However, the image quality of machine vision technology is easily affected by the environment, such as high dust concentration, unstable light intensity, and the need for water spray treatment on the working surface, which will affect the image acquisition quality of the camera.

Electromagnetic detection technology includes radar detection technology and electron spin resonance technology. Electromagnetic detection technology uses a pulse generator to generate electromagnetic pulses, uses an antenna transmitter to transmit electromagnetic waves, and the reflected electromagnetic waves are received by a receiving device. Through this process, materials with different reflection properties of electromagnetic waves will be identified. This technology has a wide range of applications and is not limited by ambient light, work surface dust and water mist. However, the electromagnetic detection technology also has limitations, such as: it is easy to be interfered by the overflow of the antenna amplifier, the response of the antenna loop, etc., resulting in the recognition accuracy not meeting the requirements. Electron spin resonance technology is to place a coil under the top coal. When the coil forms a magnetic field and resonates with the electromagnetic wave emitted by the antenna, the electromagnetic wave will be absorbed by the top coal. According to the received electromagnetic wave intensity, the thickness of the coal seam can be calculated. The thicker the coal seam, the currently measured coal thickness can reach 13-152mm. This technology has no requirements on the physical properties of coal and rock, but the wavelength is related to the thickness of the penetrating medium. And this technique has a smaller range of detection.

Gamma ray detection technology uses ray sensor to extract ray intensity signal theory to infer coal seam thickness. This technology is suitable for high gas mines, which increases the scope of application, and at the same time does not require the provision of radioactive sources, reducing the technical cost. The detection range of rays is large, and the thickness of top coal caving can be controlled within 500mm. But this technique requires radioactive elements in the roof and floor of the well, otherwise the ray sensor will not be able to receive the signal. The accuracy of ray detection is easily affected by gangue. If there is too much gangue in the coal seam, the recognition accuracy will be greatly reduced.

When the Platts coefficient of the coal rock is large, the vibration detection technology can be used to identify the coal rock interface. The vibration detection technology is to place the vibration sensor in the appropriate position of the shearer, and obtain the vibration curve through the later signal amplification and data processing, and then judge the coal-rock interface. However, the existing vibration sensor is easily disturbed by the environment, which reduces the recognition accuracy, and the response of the shearer is delayed due to insufficient parameter processing.

Today's coal and rock identification technologies are all affected by the working face environment, especially some non-contact identification technologies. When the dust concentration is high, water spray and dust fall will greatly affect the identification accuracy. Contact coal and rock identification technology needs to develop sensors with strong anti-interference ability and stable parameters, so as to improve the coal and rock identification accuracy as much as possible. Therefore, it is particularly important to develop a sensor that is not disturbed by the working environment for coal-rock interface identification and a complete set of shearer drum automatic lifting system.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a device for intelligently identifying coal and rock with fiber grating for a shearer drum, so as to solve the above-mentioned problems in the prior art.

In order to achieve the above purpose, the present invention provides the following solutions: The present invention provides a coal and rock device for intelligently identifying coal and rock with fiber grating for a shearer drum, including a shearer drum, on which the fiber grating acceleration is fixedly arranged sensor, the fiber grating acceleration sensor is electrically connected with a fiber grating demodulator, the fiber grating demodulator is electrically connected with a computer, the computer is electrically connected with a signal receiver, and the signal receiver is connected with a control The oil pump motor of the roller movement.

Preferably, the fiber grating acceleration sensor includes a housing, a circular vibrator is arranged inside the housing, and six fiber Bragg gratings are fixedly connected in the circumferential direction of the circular vibrator, and the six fiber Bragg gratings are respectively connected to the housing. The six end faces of the fiber Bragg grating are fixedly connected, and all the ends of the fiber Bragg grating are assembled into a bundle and then electrically connected with the fiber grating demodulator.

Preferably, an optical fiber fixing bracket runs through a side of the optical fiber Bragg grating close to the circular vibrator, a preloading column is arranged inside the optical fiber fixing bracket, and the optical fiber Bragg grating penetrates through the preloading column and is connected with the preloading column. Fixed connection; a protective sleeve is sleeved on the outer side of the optical fiber fixing bracket, the protective sleeve is fixedly connected with the housing, a partition is arranged in the protective sleeve, and a damping spring is arranged between the partition and the optical fiber fixing bracket and dampers.

Preferably, the preloading column has an "L"-shaped structure, the damping spring is sleeved on the outer side of the preloading column, and the side wall of the optical fiber fixing bracket is provided with a groove for accommodating the damper. A gap is set between the damping spring and the damper.

Preferably, the optical fiber Bragg grating and the preloading column are fixedly connected by fixing screws, and the fixing screws are arranged between the partition plate and the protective cover.

Preferably, the casing is a cube, the circular vibrator is arranged at the center of the casing, and the fiber Bragg grating is perpendicular to the six end faces of the casing.

Preferably, a fiber grating temperature sensor is fixed inside the casing, and the fiber grating temperature sensor is electrically connected to the fiber grating demodulator.

Preferably, the fiber grating demodulator is a mine intrinsically safe fiber grating demodulator, which demodulates the signal in time and transmits it to an external computer when the fiber grating is subjected to axial strain.

The present invention discloses the following technical effects:

(1) Real-time monitoring with high precision. The invention designs and uses a fiber grating acceleration sensor, the light wave reflection of the fiber grating changes rapidly, and the vibration signal can be transmitted to the computer data processing system in time and effectively to generate a graph, which provides a good environment for the automatic lifting and lowering of the coal shearer.

(2) It will not be disturbed by the harsh environment of the coal mining face. Underground coal mining face has high dust concentration, high ambient humidity and underground electromagnetic wave interference. It is difficult for the existing acceleration sensor to eliminate the influence of the above factors, and the present invention can overcome the above problems and provide stable real-time data for the lift control system of the shearer.

(3) It is easy to deploy and maintain, and the cost is low. The fiber grating technology is mature, the production cost is low, it is more convenient to deploy than other types of acceleration sensors, and the service life can reach 5 years or more.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

Fig. 1 is the position schematic diagram of the optical fiber Bragg grating, circular vibrator and housing of the present invention;

2 is a schematic structural diagram of a fiber grating acceleration sensor of the present invention;

Figure 3 is a schematic diagram of the mechanical model of the fiber grating acceleration sensor;

4 is a schematic structural diagram of the present invention;

Fig. 5 is a linear relationship diagram between the vibration acceleration measured by the fiber grating acceleration sensor and the working time when the drum is cutting coal;

Figure 6 is a linear relationship diagram between the vibration acceleration measured by the fiber grating acceleration sensor and the working time when the roller is in the state of rock cutting;

Figure 7 shows the linear relationship between the vibration acceleration measured by the fiber grating acceleration sensor and the working time when the drum is idling.

Among them, 1 is the fiber Bragg grating, 2 is the circular vibrator, 3 is the housing, 4 is the fixing screw, 5 is the protective sleeve, 6 is the preload column, 7 is the damping spring, 8 is the fiber fixing bracket, and 9 is the damper , 10 is the fiber grating demodulator, 11 is the center point of the shell, 12 is the fiber grating temperature sensor, 13 is the signal receiver, 14 is the computer, 15 is the drum, 16 is the oil pump motor, and 17 is the fiber grating acceleration sensor.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

1-7 , the present invention provides a device for intelligently identifying coal and rock with fiber grating for a shearer drum, including a shearer drum 15 , a fiber grating acceleration sensor 17 is fixed on the shearer drum 15 , and the fiber grating acceleration sensor 17 The sensor 17 is electrically connected with the fiber grating demodulator 10, the fiber grating demodulator 10 is electrically connected with a computer 14, the computer 14 is electrically connected with a signal receiver 13, and the signal receiver 13 is connected with an oil pump motor that controls the movement of the drum 15 16. When the shearer is working, the fiber grating acceleration sensor 17 will transmit the collected vibration signal to the fiber grating demodulator 10 in the form of a waveform. After data processing by the computer 14, the signal will be transmitted to the signal receiver 13 to determine the The cutting state of the machine drum 15, the oil pump motor 16 responds accordingly.

The fiber Bragg grating accelerometer 17 includes a housing 3 , a circular vibrator 2 is arranged inside the housing 3 , and six fiber Bragg gratings 1 are fixedly connected in the circumferential direction of the circular vibrator 2 . The end faces are fixedly connected, the casing 3 is a cube, the circular vibrator 2 is arranged at the center of the casing 3 , and the fiber Bragg grating 1 is perpendicular to the six end faces of the casing 3 . The motion state of the drum 15 can be accurately obtained. The ends of all fiber Bragg gratings 1 are assembled into a bundle and then electrically connected to the fiber grating demodulator 10 .

The fiber Bragg grating 1 has an optical fiber fixing bracket 8 running through the side close to the circular vibrator 2 , and the side of the optical fiber fixing bracket 8 close to the circular vibrator 2 is an arc structure. There is a certain distance, and the optical fiber fixing bracket 8 forms a motion cavity, and the circular vibrator 2 can move in the motion cavity. The interior of the optical fiber fixing bracket 8 is provided with a pre-tightening column 6, the optical fiber Bragg grating 1 penetrates the pre-tightening column 6 and is fixedly connected with the pre-tightening column 6, and the optical fiber Bragg grating 1 and the pre-tightening column 6 are fixedly connected by fixing screws 4, and the fixing screws 4 It is arranged between the separator and the protective cover 5 . The outer side of the optical fiber fixing bracket 8 is sleeved with a protective sleeve 5, the protective sleeve 5 is fixedly connected with the housing 3, a partition is arranged in the protective sleeve 5, and a damping spring 7 and a damper 9 are arranged between the partition and the optical fiber fixing bracket 8 . The preloading column 6 is an "L"-shaped structure, the damping spring 7 is sleeved on the outside of the preloading column 6, the side wall of the optical fiber fixing bracket 8 is provided with a groove for accommodating the damper 9, and the damping spring 7 and the damper 9 are connected. There is a gap between them. The optical fiber fixing bracket 8 will limit the movement range of the circular vibrator 2 . When the circular vibrator 2 hits the optical fiber fixing bracket 8 , the damping spring 7 and the damper 9 will buffer the circular vibrator 2 to prevent it from being fixed with the circular vibrator 2 . The connected fiber Bragg grating 1 is damaged.

Fig. 3 The mechanical model of the fiber grating accelerometer, the damping spring 7 and the fiber grating 1 are simplified into two springs with different elastic moduli, and the end of the fiber grating 1 is connected to the circular vibrator 2 with a certain mass m. According to the analysis, it can be Obtain the natural frequency and frequency response range of the accelerometer. When the external vibration occurs, the circular oscillator 2 responds and generates displacement, and the axial strain of the fiber grating is converted into a change in wavelength.

A fiber grating temperature sensor 12 is fixed inside the housing 3 , and the fiber grating temperature sensor 12 is electrically connected to the fiber grating demodulator 10 . During the vibration monitoring process, the fiber grating temperature sensor 12 under the same temperature condition is used for temperature compensation to prevent the temperature change from interfering with the monitoring results, so as to eliminate the interference caused by temperature and make the monitored data more reliable.

The fiber grating demodulator 10 is a mine intrinsically safe fiber grating demodulator 10 , which demodulates the signal in time and transmits it to the external computer 14 when the fiber grating is subjected to axial strain. The data processing module formed by the fiber grating demodulator 10 and the computer 14 is in the prior art, wherein the fiber grating demodulator 10 includes a photoelectric conversion module, a data acquisition module, a wavelength calculation module and a data analysis module.

Working process: drum 15 vibrates (signal output) → fiber grating acceleration sensor 17 responds (signal response) → fiber grating demodulator 10 and computer 14 (signal processing) → signal receiver 13 (signal reception) → controller (signal output) )→oil pump motor 16 (signal response)→drum 15 adjust height (signal response).

The fiber grating acceleration sensor 17 is installed on the measuring point of the shearer drum 15. When the shearer is working, the fiber grating acceleration sensor 17 will transmit the collected vibration signal to the fiber grating demodulator 10 through the computer 14. After the data is processed, the signal is transmitted to the signal receiver 13, and the cutting state of the shearer drum 15 is judged, which is divided into the following categories:

If it is judged that the shearer drum 15 is in the coal cutting state, the signal receiver 13 transmits the signal to the controller. After the controller judges, it transmits the signal to the oil pump motor 16 that controls the movement of the drum 15. The oil pump motor 16 adjusts the shearer drum 15 according to the setting. The fixed trajectory continues to run, and the linear relationship between the vibration acceleration measured by the fiber grating acceleration sensor and the working time is shown in Figure 5.

If it is judged that the shearer drum 15 is in the state of cutting rock, the signal receiver 13 transmits the signal to the controller, and the controller judges and transmits the signal to the oil pump motor 16 that controls the movement of the drum 15, and the oil pump motor 16 will automatically adjust the height of the shearer drum 15 , the fiber grating accelerometer will detect the latest vibration state and make judgments, and this cycle will continue until the shearer drum 15 maintains the coal cutting state. In Fig. 6, the signal monitored by the fiber grating vibration sensor 17 is processed by the fiber grating demodulator 10 and the computer 14 to obtain a vibration curve image. It can be seen that the shearer drum 15 is in the state of cutting rock at 5s, and the shearer automatically After 10s of the lifting system, the shearer drum 15 is in the coal cutting state.

If it is judged that the shearer drum 15 is in an idling state, the signal receiver 13 transmits the signal to the controller, and the controller judges and transmits the signal to the oil pump motor 16 that controls the movement of the drum 15, and the oil pump motor 16 will automatically adjust the height of the shearer drum 15 , the fiber grating accelerometer will detect the latest vibration state and make judgments, and this cycle will continue until the shearer drum 15 maintains the coal cutting state. Fig. 7 is the vibration curve image obtained after the signal monitored by the fiber grating vibration sensor 17 is processed by the fiber grating demodulator 10 and the computer 14. It can be seen that the shearer drum 15 is idling at 7.5s, and the shearer automatically lifts and lowers. After 13s, the shearer drum 15 is in the coal cutting state.

In the description of the present invention, it should be understood that the terms "portrait", "horizontal", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientation or positional relationship indicated by "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or It is implied that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

The above-mentioned embodiments are only to describe the preferred modes of the present invention, but not to limit the scope of the present invention. Without departing from the design spirit of the present invention, those of ordinary skill in the art can make various modifications to the technical solutions of the present invention. Variations and improvements should fall within the protection scope determined by the claims of the present invention.

Claims

A device for intelligently identifying coal and rock with a fiber grating for a shearer drum, characterized in that it comprises a shearer drum (15), and a fiber grating acceleration sensor (17) is fixedly arranged on the shearer drum (15), The fiber grating acceleration sensor (17) is electrically connected with a fiber grating demodulator (10), the fiber grating demodulator (10) is electrically connected with a computer (14), and the computer (14) is electrically connected with There is a signal receiver (13), and the signal receiver (13) is connected with an oil pump motor (16) that controls the movement of the drum (15).
A device for intelligently identifying coal and rock with fiber grating for a shearer drum according to claim 1, characterized in that: the fiber grating acceleration sensor (17) comprises a casing (3), and the casing (3) A circular vibrator (2) is provided inside, and six optical fiber Bragg gratings (1) are fixedly connected in the circumferential direction of the circular vibrator (2). The end faces are fixedly connected, and the ends of all the fiber Bragg gratings (1) are assembled into a bundle and then electrically connected to the fiber grating demodulator (10).
A device for intelligently identifying coal and rock with fiber grating for a shearer drum according to claim 2, characterized in that an optical fiber runs through the side of the fiber Bragg grating (1) close to the circular vibrator (2). A fixing bracket (8), a pre-tightening column (6) is arranged inside the optical fiber fixing bracket (8), and the optical fiber Bragg grating (1) penetrates through the pre-tightening column (6) and is fixedly connected with the pre-tightening column (6) The outer side of the optical fiber fixing bracket (8) is sleeved with a protective sleeve (5), the protective sleeve (5) is fixedly connected with the housing (3), and a partition plate is arranged in the protective sleeve (5), so A damping spring (7) and a damper (9) are arranged between the partition plate and the optical fiber fixing bracket (8).
A device for intelligently identifying coal and rock with fiber grating for a shearer drum according to claim 3, characterized in that: the preloading column (6) is an "L"-shaped structure, and the damping spring (7) is sleeved Connected to the outer side of the pre-tightening column (6), the side wall of the optical fiber fixing bracket (8) is provided with a groove for accommodating the damper (9), the damping spring (7) and the damper (9) There is a gap between them.
A device for intelligently identifying coal and rock with fiber grating for a shearer drum according to claim 3, characterized in that: the fiber Bragg grating (1) and the preloading column (6) are fixedly connected by fixing screws (4) , the fixing screw (4) is arranged between the partition plate and the protective cover (5).
A device for intelligently identifying coal and rock with fiber grating for a shearer drum according to claim 2, characterized in that: the casing (3) is a cube, and the circular vibrator (2) is arranged on the casing (3). 3), the fiber Bragg grating (1) is perpendicular to the six end faces of the housing (3).
A device for intelligently identifying coal and rock with fiber grating for a shearer drum according to claim 2, characterized in that: a fiber grating temperature sensor (12) is fixedly arranged inside the casing (3), and the fiber grating The temperature sensor (12) is electrically connected with the fiber grating demodulator (10).
A device for intelligently identifying coal and rock with fiber grating for a shearer drum according to claim 1, characterized in that: the fiber grating demodulator (10) is a mine intrinsically safe fiber grating demodulator (10). ), when the fiber grating is subjected to axial strain, the signal is demodulated in time and transmitted to an external computer (14).