Method for identifying coal rock trace in extremely thin coal seam and self-adaptive coal rock cutting device and method

Abstract

This invention relates to a method for identifying coal and rock traces in extremely thin coal seams and an adaptive coal and rock cutting device and method, belonging to the field of extremely thin coal seam mining technology. It aims to address the problems of poor accuracy in identifying coal and rock traces in existing methods and the inability of existing coal mining machines to make adaptive adjustments. The method for identifying coal and rock traces in extremely thin coal seams extracts parameters during the cutting process with different coal and rock ratios through experiments. These parameters include the voltage and current of the coal mining machine's cutting motor, the vibration frequency and amplitude of the cutting motor's rocker arm, and the frequency and energy of acoustic emissions from the coal wall. Based on these parameters, the corresponding sensitivity is obtained, and the proportion of each parameter and the functional relationship between their changes and the change in rock depth are derived, thus obtaining the coal and rock traces. The adaptive coal and rock cutting device is equipped with a spring-loaded relaxation device and a hydraulic support device connected to the rocker arm in the horizontal and vertical directions, respectively. The spring-loaded relaxation device and the hydraulic support device have an interlocking function.

Description

Technical Field

[0001] This invention belongs to the field of ultra-thin coal seam mining technology, specifically relating to a trace identification method, and an adaptive coal and rock cutting device and method. Background Technology

[0002] In the early stages of coal mining, the height of the drum needed to be manually controlled. Due to the limitations of the coal mining environment, coal mining machines with memory cutting capabilities are now widely used for coal seam mining. These machines identify coal and rock by remembering the cutting height. While widely used, these machines present certain challenges for mining extremely thin coal seams.

[0003] On the one hand, due to the large coefficient of variation in thin coal seams during deep mining, coal mining machines with memory cutting capabilities often encounter situations where the thinnest coal seam suddenly turns into rock when cutting according to the memory cutting height. Excessive cutting of rock not only leads to severe wear of the cutting teeth but can also cause malfunctions and damage to the mining machinery, increasing mining risks. Furthermore, it results in a higher proportion of rock in the mined coal, reducing coal quality, increasing the workload of subsequent coal preparation, and lowering work efficiency. In addition, the accumulation of gangue impacts the environment. On the other hand, in the mining of thin coal seams, a 97% recovery rate is required at the working face. If the coal-rock traces cannot be accurately identified, it is difficult to achieve this recovery rate requirement.

[0004] Currently, coal and rock identification methods are divided into contact and non-contact methods. Contact methods mainly include monitoring process signals such as vibration, acoustic emission, current, and cutting mechanical parameters. Non-contact methods mainly include infrared thermography, pattern recognition, reflectance spectroscopy, ultrasound, and electromagnetic waves. Due to the complexity of coal and rock and the variability of the mining process, current coal and rock identification methods are ineffective and cannot accurately identify coal and rock traces. This leads to severe wear and tear on the excavating drum of the coal mining machine, even causing direct damage to the drum. It also forces the cutting motor of the coal mining machine to operate under extreme conditions or even be overloaded, resulting in direct damage. More seriously, cutting through rock layers may lead to safety accidents, endangering personnel and property. Summary of the Invention

[0005] This invention aims to solve the problems of poor accuracy in identifying coal and rock traces in existing coal and rock identification methods, and the inability of existing coal mining machines to make adaptive adjustments.

[0006] An adaptive coal and rock cutting device includes a walking servo motor 1, a transmission pulley 2, an integral base 3, a slider 4, a motor base 5, a traveling platform, a rocker arm 6, a digging drum 7, a coal mining machine cutting motor, a linear guide pair 8, a column 9, an elastic relaxation device 10, and a hydraulic support device 11.

[0007] The integral base 3 is set along the coal mining operation direction in the length direction; a linear guide rail pair 8 is set on the integral base 3 along the length direction of the integral base, and multiple sliders 4 are set on the linear guide rail pair. The travel servo motor 1 drives the transmission pulley to rotate, and the transmission pulley drives the sliders 4 to slide along the linear guide rail pair 8; a travel platform is set on the slider 4, and the slider 4 moves along the linear guide rail pair 8 with the travel platform.

[0008] The traveling platform is equipped with a motor base 5 and a column 9; one end of the rocker arm 6 is set on the traveling platform, and the other end of the rocker arm 6 is equipped with a digging roller 7;

[0009] One end of the elastic rigid relaxation device is mounted on the column, and the other end of the elastic rigid relaxation device is rotatably connected to the upper side of the rocker arm 6; a hydraulic support device is also mounted on the traveling platform, and the hydraulic rod end of the hydraulic support device is rotatably connected to the lower side of the rocker arm 6; the axis of the elastic rigid relaxation device, the axis of symmetry of the rocker arm in the length direction, and the axis of the hydraulic support device are located on the same vertical plane.

[0010] The rocker arm 6 can rotate at the end near the traveling platform, thereby realizing the vertical lifting and lowering of the rocker arm 6 to adjust the mining height corresponding to the digging drum 7; the coal mining machine cutting motor is installed on the motor base 5, and the coal mining machine cutting motor is located at the end of the rocker arm 6 near the traveling platform. The coal mining machine cutting motor drives the digging drum 7 to rotate to cut the coal seam through the transmission device set inside the rocker arm.

[0011] The spring-loaded relaxation device includes a first electro-hydraulic servo telescopic rod, a rigid spring, and a first encoder. The telescopic rod section of the first electro-hydraulic servo telescopic rod is connected to the rigid spring, and the rigid spring is hinged to the upper side of the rocker arm. The first electro-hydraulic servo telescopic rod is controlled by a computer to move the telescopic rod. The first encoder is used to measure the moving distance of the telescopic rod, thereby providing the stiffness coefficient of the spring.

[0012] The hydraulic support device includes a second encoder and a second electro-hydraulic servo telescopic rod; the second electro-hydraulic servo telescopic rod is hinged to the lower side of the rocker arm, and its movement is controlled by a computer; the second encoder is used to measure the distance the telescopic rod moves.

[0013] The elastic relaxation device and the hydraulic support device have an interlocking function. That is, when the elastic relaxation device is in a relaxed state, the hydraulic support device provides support, and when the hydraulic support device is in a relaxed state, the elastic relaxation device provides support.

[0014] Furthermore, the first electro-hydraulic servo telescopic rod is controlled by a computer to realize the telescopic rod movement process as follows:

[0015] The computer controls the servo motor to inject hydraulic oil from the oil source into the first electro-hydraulic servo telescopic rod through a high-pressure pipeline, thereby extending the hydraulic servo telescopic rod. When the elastic relaxation device starts working, the oil source pressure relief valve opens, introducing hydraulic oil into the pump-containing oil tank. At this time, the telescopic rod of the first electro-hydraulic servo telescopic rod moves freely, becoming a relaxation device.

[0016] Furthermore, the telescopic rod section and the rigid spring of the first electro-hydraulic servo telescopic rod are provided with protective covers.

[0017] Furthermore, the process of moving the second electro-hydraulic servo telescopic rod under computer control is the same as that of moving the first electro-hydraulic servo telescopic rod under computer control.

[0018] A method for identifying coal rock traces in extremely thin coal seams includes the following steps:

[0019] S1. Set up a similar simulated coal and rock layer in a laboratory environment. The similar simulated coal and rock layer has a cuboid structure. The cut area of ​​the similar simulated coal and rock layer includes the coal seam and the rock layer. The coal seam and the rock layer in the cut area form a cuboid structure with an equilateral triangle structure and an inverse triangle structure, respectively. The coal seam is located below the similar simulated coal and rock layer, and the rock layer is located below and above the similar simulated coal and rock layer. Along the cut direction, the coal seam becomes thinner and the rock layer becomes thicker. There will be different coal and rock ratios at different mining locations, i.e., the cut rock depth.

[0020] Acoustic emission probes were linearly arranged in a similar simulated coal and rock strata;

[0021] S2. Using the adaptive coal and rock cutting device or a proportional model of the adaptive coal and rock cutting device, similar simulated coal and rock strata are mined; multiple sets of test conditions are set to simulate the mining process, including different traction speeds and different excavation drum rotation speeds.

[0022] During the simulation of multiple sets of test conditions, the electrical signals of the coal mining machine cutting motor, including voltage and current signals, were collected. At this time, the hydraulic support device was fixed, and the voltage and current signals under different proportions of coal and rock cutting were obtained.

[0023] While acquiring voltage and current signals, three-dimensional vibration signals on the rocker arm are also acquired to obtain vibration frequency and vibration amplitude in three dimensions.

[0024] While collecting voltage and current signals, the acoustic emission system is used to collect acoustic emission signals from the coal cutting face. The collected acoustic emission signals are then subjected to Fourier transform to analyze the frequency and count of acoustic emission under different coal-rock ratios.

[0025] S3. Extract parameters during the cutting process of different coal-rock ratios. These parameters include the voltage and current of the coal mining machine's cutting motor, the vibration frequency and amplitude of the cutting motor's rocker arm, and the frequency and energy of acoustic emission from the coal wall. The voltage sensitivity of the coal mining machine's cutting motor is then obtained as U. m The current sensitivity of the coal mining machine's cutting motor is A. m The rocker arm amplitude sensitivity is P m The rocker arm frequency sensitivity is F m The acoustic emission energy sensitivity is E m The acoustic emission frequency sensitivity is f m ;

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032] U, A, P, F, E, and f represent the cutting motor voltage, cutting motor current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency of the coal mining machine, respectively. The subscript P of the corresponding parameter indicates the value of the parameter when cutting a certain proportion of coal and rock, and the subscript c of the corresponding parameter represents the value of the parameter of the coal body being cut.

[0033] U corresponding to different rock cutting depths for coal and rock cutting m A m P m F m E m f m The proportion of each parameter was obtained by using a homogenization method, and denoted as U. q A q P q F q E q f q ;

[0034] Simultaneously, during the cutting process, the U values ​​corresponding to the cut coal and rock at different cutting rock depths were obtained. m A m P m F m E m f m The respective changes were determined, and the corresponding functional relationships of the changes in rock depth were obtained:

[0035] ΔL S1 =f U ′(ΔU) (13)

[0036] ΔL S2 =f A ′(ΔA) (14)

[0037] ΔL S3 =f P ′(ΔP) (15)

[0038] ΔL S4 =f F ′(ΔF) (16)

[0039] ΔL S5 =f E ′(ΔE) (17)

[0040] ΔL S6 =f f ′(Δf) (18)

[0041] Among them, f U ′、f A ′、f P ′、f F ′、f E ′、f f '' represents the functional relationship between the horizontal rows of the coal mining machine cutting motor voltage, coal mining machine cutting motor current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency and the change in rock depth, respectively. ΔL S1 -ΔL S6 This represents the corresponding change in rock depth;

[0042] Finally, the rock cutting depth L under multi-parameter fusion was calculated by analyzing the relationship between weights, variables, and distance. S That is, the change in rocker arm L S :

[0043] L S =U q ×ΔL S1 +A q ×ΔL S2 +P q ×ΔL S3 +F q ×ΔL S4 +E q ×ΔL S5 +f q ×ΔL S6 (19)

[0044] Where ΔU represents the voltage change of the coal mining machine's cutting motor, and ΔL represents the corresponding rock cutting depth change. S1 ΔA represents the change in current of the coal mining machine's cutting motor, corresponding to the change in rock cutting depth ΔL. S2 ΔP represents the change in the amplitude of the rocker arm vibration, and the corresponding change in the rock cutting depth ΔL. S3 ΔF represents the change in rock arm vibration frequency, corresponding to the change in rock cutting depth ΔL. S4 ΔE represents the change in acoustic emission energy, and ΔL represents the corresponding change in rock cutting depth. S5 Δf is the change in acoustic emission count, corresponding to the change in rock cutting depth ΔL. S6 ;

[0045] Obtain the change in rocker arm L S In reality, it is the result of coal and rock trajectory identification, and the coal and rock trajectory line is obtained by adding the radius of the rocker arm.

[0046] Furthermore, the proportion of each parameter was obtained using a homogenization method as follows:

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] Furthermore, the coal seam and rock strata have heights that match the drum diameter, respectively, with equilateral and inverse triangular structures.

[0054] Furthermore, when S1 arranged similar simulated coal and rock layers of a triangular coal and rock structure in a laboratory environment, similar simulated coal and rock layers corresponding to coal layers of different hardness were set up for experiments.

[0055] An adaptive coal and rock cutting method utilizes an adaptive coal and rock cutting device for cutting, setting traction speed and digging drum rotation speed for coal and rock cutting; during the coal and rock cutting process, the coal and rock traces are identified using the ultra-thin coal seam coal and rock trace identification method, thus obtaining the rocker arm change amount L. S Based on the obtained rocker arm change L S Adaptive adjustment, the adaptive adjustment process is as follows:

[0056] During the initial cutting of the coal seam, information about the top and bottom plates of the coal seam can be revealed, thereby adjusting the height of the support device to ensure that the drum fully enters the coal body and that the initial cutting takes place within the coal body. Once the drum is fully inside the coal body, the support device automatically depressurizes, becoming a pressure-free telescopic structure. At this point, the rock-coal spring rigidity relaxation device activates, extending and retracting based on the spring stiffness exceeding the coal seam cutting force, ensuring the coal mining machine drum is in a pull-back state. This means that when the coal seam is fully cut, the drum will be stretched upwards and stabilize after reaching the coal-coal trace. When cutting into the rock mass, changes occur in the coal mining machine's cutting motor voltage, current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency. This allows for adjustment of the coal mining machine height using the extremely thin coal seam rock-coal trace identification method. At this point, the spring rigidity relaxation device instantly depressurizes, transforming into a pressure-free telescopic structure, based on L... S The rocker arm is automatically raised to the predetermined height. Once the height is reached, the support device automatically releases pressure, transforming into a pressure-free structure. The elastic relaxation device is then activated to support the coal and rock cutting process.

[0057] Beneficial effects:

[0058] The coal and rock cutting device of the present invention adaptively adjusts according to the cutting state, which can not only reduce the cutting of rock and thus extend the service life of the excavating drum, but also reduce the extreme working conditions of the cutting motor, thereby ensuring the safe and stable operation of the cutting motor and extending its service life. More importantly, this can effectively reduce the cutting of rock layers and reduce safety hazards.

[0059] The method for identifying coal and rock traces in ultra-thin coal seams of the present invention can effectively identify coal and rock traces, provide cutting guidance for rocker arms, and make the coal and rock cutting results more accurate, thereby meeting the requirements for recovery rate. Attached Figure Description

[0060] Figure 1 This is a structural diagram of an adaptive coal and rock cutting device.

[0061] Figure 2 This is a schematic diagram of a triangular coal and rock structure.

[0062] Figure 3 This is a schematic diagram of a rigid relaxation device. Detailed Implementation

[0063] To address the problem of coal and rock trace identification, this invention improves upon existing coal and rock cutting devices, proposing an alternative adaptive coal and rock cutting device. Furthermore, based on this adaptive device, this invention proposes a multi-source identification and fusion method for motor signals, rocker arm vibration signals, and coal wall acoustic emission signals from the coal and rock cutting device. It also presents the correlation between the cutting degree of the coal and rock cutting device and the multi-source signals, thus providing a basis for adjusting the rocker arm height. Utilizing the self-locking properties of the hydraulic support and the elastic relaxation device, the coal and rock trace is further corrected, achieving a coal and rock trace identification device that combines adaptive and fusion analysis. Specific implementation method one:

[0065] This embodiment is an adaptive coal and rock cutting device, including a walking servo motor 1, a transmission pulley 2, an integral base 3, a slider 4, a motor base 5, a traveling platform, a rocker arm 6, a digging drum 7, a coal mining machine cutting motor, a linear guide pair 8, a column 9, a spring-loaded relaxation device 10, and a hydraulic support device 11.

[0066] The integral base 3 is set along the coal mining operation direction in the length direction; a linear guide rail pair 8 is set on the integral base 3 along the length direction of the integral base, and multiple sliders 4 are set on the linear guide rail pair. The travel servo motor 1 drives the transmission pulley to rotate, and the transmission pulley drives the sliders 4 to slide along the linear guide rail pair 8; a travel platform is set on the slider 4, and the slider 4 moves along the linear guide rail pair 8 with the travel platform.

[0067] The traveling platform is equipped with a motor base 5 and a column 9; one end of the rocker arm 6 is set on the traveling platform, and the other end of the rocker arm 6 is equipped with a digging roller 7;

[0068] One end of the elastic rigid relaxation device is mounted on the column, and the other end of the elastic rigid relaxation device is rotatably connected to the upper side of the rocker arm 6; a hydraulic support device is also mounted on the traveling platform, and the hydraulic rod end of the hydraulic support device is rotatably connected to the lower side of the rocker arm 6; the axis of the elastic rigid relaxation device, the axis of symmetry of the rocker arm in the length direction, and the axis of the hydraulic support device are located on the same vertical plane.

[0069] The rocker arm 6 can rotate at the end near the traveling platform, thereby realizing the vertical lifting and lowering of the rocker arm 6, which is used to adjust the mining height corresponding to the digging drum 7; the coal mining machine cutting motor is installed on the motor base 5, and the coal mining machine cutting motor is located at the end of the rocker arm 6 near the traveling platform. The coal mining machine cutting motor drives the digging drum 7 to rotate to cut the coal seam through the transmission device set inside the rocker arm.

[0070] like Figure 3As shown, the elastic stiffness relaxation device 10 includes an electro-hydraulic servo telescopic rod 1001, a rigid spring 1002, an encoder 1003, and a protective cover. The telescopic rod section of the electro-hydraulic servo telescopic rod is connected to the rigid spring, which is hinged to the upper side of the rocker arm. A protective cover is provided outside the telescopic rod section and the rigid spring. The electro-hydraulic servo telescopic rod is controlled by a computer 1010 to move. The encoder is used to measure the moving distance of the telescopic rod, thereby providing the stiffness coefficient of the spring to adapt to the resistance of soft, medium-hard, and hard coal. The process of the electro-hydraulic servo telescopic rod moving under the control of the computer 1010 is as follows: the computer controls the servo motor 1011 to inject hydraulic oil from the oil source into the electro-hydraulic servo telescopic rod 1001 through the high-pressure pipeline 1013, thereby extending the hydraulic servo telescopic rod. When the elastic stiffness relaxation device starts working, the oil source pressure relief valve opens instantaneously, introducing hydraulic oil into the pump-containing oil tank 1012. At this time, the telescopic rod of the electro-hydraulic servo telescopic rod moves freely, becoming a relaxation device.

[0071] The hydraulic support device includes an encoder and an electro-hydraulic servo telescopic rod. The electro-hydraulic servo telescopic rod is hinged to the lower side of the rocker arm. The movement of the telescopic rod is controlled by a computer, and the encoder is used to measure the distance the telescopic rod moves. The hydraulic support device works in the same way as the rigid spring relaxation device, the only difference being that it does not have a rigid spring.

[0072] Because of the interlocking function between the elastic relaxation device and the hydraulic support device, when the elastic relaxation device is in a relaxed state, the hydraulic support device provides support, and when the hydraulic support device is in a relaxed state, the elastic relaxation device provides support. In other words, the two do not work at the same time; when one is working, the other is in a free extension and contraction state. Specific Implementation Method Two:

[0074] This embodiment is a method for identifying coal and rock traces in extremely thin coal seams, which includes the following steps:

[0075] S1. A similar simulated coal and rock strata are arranged in a laboratory environment. The structure of the similar simulated coal and rock strata is as follows: Figure 2 As shown, the simulated coal and rock strata have a cuboid structure. The cut-off region of the simulated coal and rock strata includes the coal seam and the rock layer. The coal seam and the rock layer in the cut-off region form cuboid structures with equilateral and inverse triangular structures, respectively. Figure 2The area shown in the diagram (indicated by the cutting depth) is where the coal seam lies below a similar simulated coal-rock stratum, and the rock stratum lies above and below the similar simulated coal-rock stratum. Along the cutting direction, the coal seam thins while the rock stratum thickens. Therefore, different mining locations will have different coal-rock ratios, i.e., the rock cutting depth. During the cutting process, the mining machine automatically adjusts its height to cut the coal seam, which may involve cutting into the rock; the upper part of the mining machine drum represents the coal-rock trace. Since the cutting primarily targets the coal seam, the mining height is adjusted when encountering rock. Therefore, the mining height corresponding to the rock cutting is the rock depth. Figure 2 The left endpoint represents the cutting of the entire coal seam, and the right endpoint represents the cutting of the entire rock. During the entire process, multiple sets of signals with different coal-rock ratios will be collected.

[0076] Acoustic emission probes are linearly arranged in a similar simulated coal and rock strata, such as... Figure 2 As shown in the horizontal rows of circles.

[0077] To study the characteristics of voltage, current, vibration, and acoustic emission signals at different cutting depths of coal and rock, the cutting process was designed to transition from whole coal to whole rock. Therefore, the coal and rock were designed to be cut in a triangular manner, with the height of the triangle being the same as the diameter of the drum. Initially, the cutting was done with whole coal, and as the cutting depth increased, the proportion of coal gradually decreased until the whole rock was cut. This point marks the boundary of the simulation device.

[0078] When arranging a triangular coal and rock structure in a laboratory environment, similar simulated coal and rock layers corresponding to coal seams of different hardness were set up. The coal seams of different hardness included soft coal, medium-hard coal, and hard coal. According to hardness, hard coal seams were classified as 4.0>f>3.0, medium-hard coal seams as 3.0>f>1.5, and soft coal seams as 1.5>f>0.8.

[0079] S2. Using the adaptive coal and rock cutting device or a proportional model of the adaptive coal and rock cutting device, similar simulated coal and rock layers are mined; multiple sets of test conditions are set to simulate the mining process, and the traction speed is set to 4m / min, 5m / min, and 6m / min, and the excavation drum rotation speed is set to 30r / min, 40r / min, and 50r / min, respectively.

[0080] The experiment sets different traction speeds and excavating drum rotation speeds to study the effects of these variables on motor voltage, current, vibration, and acoustic signals. It can also be used to simulate signal characteristics under different working conditions, providing reference data for adjusting the height of coal and rock in different mining backgrounds.

[0081] During the simulation of multiple test conditions, electrical signals, including voltage and current signals, of the coal cutting motor of the coal mining machine were collected. At this time, the hydraulic support device was fixed, and voltage and current signals were obtained under different proportions of coal and rock cutting.

[0082] While acquiring voltage and current signals, the three-dimensional vibration signal on the rocker arm is also acquired, and the vibration signal is preprocessed, including time-frequency conversion, to obtain the vibration frequency and vibration amplitude in three dimensions.

[0083] While collecting voltage and current signals, an acoustic emission system is used to collect acoustic emission signals from the coal cutting face. The collected acoustic emission signals are then subjected to Fourier transform to analyze the frequency and count of acoustic emission under different coal-rock ratios.

[0084] The prerequisite for fusing S3, electrical signals, rocker arm vibration signals, and coal face acoustic emission signals is the selection of indicators and the determination of weights. During the cutting of coal, coal-rock, and rock mass, the voltage and current of the coal mining machine's cutting motor will have significant feedback, the rocker arm will vibrate to varying degrees, and the fracture signals generated by the coal face will also differ. Based on this, this invention extracts the voltage and current of the coal mining machine's cutting motor, the vibration frequency and amplitude of the coal mining machine's cutting motor rocker arm, and the frequency and energy of the coal face acoustic emission during the cutting of different coal-rock ratios. The extracted parameters are all sensitive indicators of the coal-rock fracture process, which helps in establishing corresponding models and identifying the coal-rock cutting scale.

[0085] Based on the selected indicators, weight information needs to be determined, and variable sensitivity analysis should be adopted. This mainly considers the changes in parameters during coal cutting and different coal-rock ratios. Specifically, the voltage sensitivity of the coal mining machine's cutting motor is U. m The current sensitivity of the coal mining machine's cutting motor is A. m The rocker arm amplitude sensitivity is P m The rocker arm frequency sensitivity is F m The acoustic emission energy sensitivity is E m The acoustic emission frequency sensitivity is f m .

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092] U, A, P, F, E, and f represent the cutting motor voltage, cutting motor current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency of the coal mining machine, respectively. The subscript P of the corresponding parameter indicates the value of the parameter when cutting a certain proportion of coal and rock (at the current cutting time), and the subscript c of the corresponding parameter represents the value of the parameter when cutting the coal body (when the triangular coal and rock begins to be cut).

[0093] It should be noted that the rocker arm amplitude P and rocker arm frequency F are both data in three dimensions. Since the three dimensions are represented in the same way, only P and F are used here.

[0094] Based on the obtained parameter sensitivity, the parameters are weighted and a normalization method is used to obtain the proportion of each parameter:

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] Based on the data obtained from the above experiments, the changes in sensitivity parameters corresponding to different rock cutting depths during the cutting process were obtained. Based on the weights obtained from the theory, the cutting depth of coal and rock under complex conditions was calculated, providing a basis for adjusting the hydraulic support device of the coal mining machine cutting motor.

[0102] ΔL S1 =f U ′(ΔU) (13)

[0103] ΔL S2 =f A ′(ΔA) (14)

[0104] ΔL S3 =f P ′(ΔP) (15)

[0105] ΔL S4 =f F ′(ΔF) (16)

[0106] ΔL S5 =f E ′(ΔE) (17)

[0107] ΔL S6 =ff ′(Δf) (18)

[0108] Among them, f U ′、f A ′、f P ′、f F ′、f E ′、f f ′ represent the functional relationships between the horizontal rows of the coal mining machine cutting motor voltage, coal mining machine cutting motor current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency and the change in rock depth, respectively.

[0109] Finally, the rock cutting depth L under multi-parameter fusion was calculated by analyzing the relationship between weights, variables, and distance. S That is, the change in the rocker arm of the coal mining machine, L S :

[0110] L S =U q ×ΔL S1 +A q ×ΔL S2 +P q ×ΔL S3 +F q ×ΔL S4 +E q ×ΔL S5 +f q ×ΔL S6 (19)

[0111] Where ΔU represents the voltage change of the coal mining machine's cutting motor, and ΔL represents the corresponding rock cutting depth change. S1 ΔA represents the change in current of the coal mining machine's cutting motor, corresponding to the change in rock cutting depth ΔL. S2 ΔP represents the change in the amplitude of the rocker arm vibration, and the corresponding change in the rock cutting depth ΔL. S3 ΔF represents the change in rock arm vibration frequency, corresponding to the change in rock cutting depth ΔL. S4 ΔE represents the change in acoustic emission energy, and ΔL represents the corresponding change in rock cutting depth. S5 Δf is the change in acoustic emission count, corresponding to the change in rock cutting depth ΔL. S6 .

[0112] Obtain the change in rocker arm L S In reality, it is the result of coal and rock trajectory identification, and the coal and rock trajectory line is obtained by adding the radius of the rocker arm. Specific implementation method three:

[0114] This embodiment is an adaptive coal and rock cutting method. It utilizes an adaptive coal and rock cutting device as described in Embodiment 1. The traction speed and cutting speed of the coal and rock cutting device are adjusted by a servo motor and a coal mining machine motor. Simultaneously, according to the corresponding traction and cutting speeds, the coal and rock traces are identified using the ultra-thin coal seam coal and rock trace identification method described in Embodiment 2, thus obtaining the rocker arm change L. S It should be noted here that although the data collected during the cutting operation of the adaptive coal and rock cutting device, including the cutting motor voltage, cutting motor current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency, are at that specific moment, the resulting rocker arm change L... S Theoretically, this is for the current moment. However, after research, this invention has found that although the coal seam structure changes abruptly (abrupt change refers to a large-scale structural change at the macroscopic level), based on the principles of coal mining, the sudden change in the coal seam structure also has corresponding changes within a small range. Therefore, within a small distance, it can be considered to have continuous change characteristics. Furthermore, since cutting is a continuous process, the corresponding rocker arm change L can be considered... S While this method is a "lagging" suggestion in the very short term, it serves as a basis for continued cutting. However, for the reasons mentioned above, this cutting method not only meets the actual environment requirements but also ensures the accuracy of the cutting results (which can be considered as the identification results of coal and rock traces). Furthermore, this calculation method is very fast and has low hardware requirements, thus allowing for an increase in the number of calculation cycles within a certain timeframe. This also guarantees the update speed of the cutting results, thereby ensuring accuracy. Therefore, the change in rocker arm L can be used as a basis for further cutting. S Adjusting the height of the support device, thereby adjusting the height of the rocker arm, is based on the obtained rocker arm change L. S Adaptive adjustment, the adaptive adjustment process is as follows:

[0115] During the initial cutting of the coal seam, the information of the top and bottom plates of the coal seam can be revealed, thereby adjusting the height of the support device to ensure that the drum fully enters the coal body and that the initial cutting takes place within the coal body. Once the drum is fully inside the coal body, the support device automatically depressurizes, becoming a pressure-free telescopic structure. At this time, the coal-rock spring rigid relaxation device is activated, extending and retracting according to the fact that the stiffness force of the internal spring of the device is slightly greater than the coal seam cutting force, ensuring that the coal mining machine drum is in a pull-back state. That is, when the coal seam is fully cut, the stretched drum rises and basically stabilizes after reaching the coal-rock trace. This mainly utilizes the difference in hardness coefficients between coal and rock; the rock cutting force is greater than the stiffness force of the internal spring of the elastic rigid relaxation device, so it will not enter the rock mass. However, when the coal seam is undulating or the coal-rock trace is unclear, adjustments may be delayed or impossible. In such cases, rock cutting is unavoidable. During rock cutting, abnormalities may occur in current, voltage, vibration, and sound. Therefore, the height of the coal mining machine is adjusted using the extremely thin coal seam coal-rock trace identification method. At this time, the elastic rigid relaxation device is instantly depressurized and transformed into a pressure-free telescopic structure. Based on the feedback results from multiple sources, the rocker arm is automatically raised. After reaching the predetermined height, the support device is automatically depressurized and transformed into a pressure-free structure. The elastic rigid relaxation device is then activated to support the coal-rock adaptive cutting. This process is repeated to achieve the identification of the coal-rock limit. By recording the spatial position of the rocker arm, the coal-rock trace is drawn, providing basic data for the next coal cutting.

[0116] This invention may have other embodiments. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. An adaptive coal and rock cutting device, comprising a walking servo motor (1), a transmission pulley (2), an integral base (3), a slider (4), a motor base (5), a traveling platform, a rocker arm (6), a digging drum (7), a coal mining machine cutting motor, a linear guide pair (8), and a column (9), characterized in that, It also includes a rigid relaxation device (10) and a hydraulic support device (11). The integral base (3) is set along the coal mining operation direction in the length direction; along the length direction of the integral base, a linear guide pair (8) is set on the integral base (3), and multiple sliders (4) are set on the linear guide pair. The travel servo motor (1) drives the transmission pulley to rotate, and the transmission pulley drives the slider (4) to slide along the linear guide pair (8); a travel platform is set on the slider (4), and the slider (4) moves along the linear guide pair (8) with the travel platform. The traveling platform is equipped with a motor base (5) and a column (9); one end of the rocker arm (6) is set on the traveling platform, and the other end of the rocker arm (6) is equipped with a digging roller (7). One end of the elastic rigid relaxation device is set on the column, and the other end of the elastic rigid relaxation device is rotatably connected to the upper side of the rocker arm (6); a hydraulic support device is also set on the traveling platform, and the hydraulic rod end of the hydraulic support device is rotatably connected to the lower side of the rocker arm (6); the axis of the elastic rigid relaxation device, the axis of symmetry of the rocker arm in the length direction and the axis of the hydraulic support device are located on the same vertical plane. The rocker arm (6) can rotate at the end near the traveling platform, thereby realizing the vertical lifting and lowering of the rocker arm (6) to adjust the corresponding mining height of the digging drum (7); a coal mining machine cutting motor is installed on the motor base (5), and the coal mining machine cutting motor is located at the end of the rocker arm (6) near the traveling platform. The coal mining machine cutting motor drives the digging drum (7) to rotate through the transmission device set inside the rocker arm to cut the coal seam; The spring-loaded relaxation device includes a first electro-hydraulic servo telescopic rod, a rigid spring, and a first encoder. The telescopic rod section of the first electro-hydraulic servo telescopic rod is connected to the rigid spring, and the rigid spring is hinged to the upper side of the rocker arm. The first electro-hydraulic servo telescopic rod is controlled by a computer to move the telescopic rod. The first encoder is used to measure the moving distance of the telescopic rod, thereby providing the stiffness coefficient of the spring. The hydraulic support device includes a second encoder and a second electro-hydraulic servo telescopic rod; the second electro-hydraulic servo telescopic rod is hinged to the lower side of the rocker arm, and its movement is controlled by a computer; the second encoder is used to measure the distance the telescopic rod moves. The elastic relaxation device and the hydraulic support device have an interlocking function. That is, when the elastic relaxation device is in a relaxed state, the hydraulic support device provides support, and when the hydraulic support device is in a relaxed state, the elastic relaxation device provides support.

2. The adaptive coal and rock cutting device according to claim 1, characterized in that, The first electro-hydraulic servo telescopic rod is controlled by a computer to achieve the following telescopic rod movement process: The computer controls the servo motor to inject hydraulic oil from the oil source into the first electro-hydraulic servo telescopic rod through a high-pressure pipeline, thereby extending the hydraulic servo telescopic rod. When the elastic relaxation device starts working, the oil source pressure relief valve opens, introducing hydraulic oil into the pump-containing oil tank. At this time, the telescopic rod of the first electro-hydraulic servo telescopic rod moves freely, becoming a relaxation device.

3. The adaptive coal and rock cutting device according to claim 2, characterized in that, The telescopic rod section and rigid spring of the first electro-hydraulic servo telescopic rod are equipped with protective covers.

4. An adaptive coal and rock cutting device according to claim 2 or 3, characterized in that, The second electro-hydraulic servo telescopic rod is controlled by a computer to move in the same way as the first electro-hydraulic servo telescopic rod.

5. A method for identifying coal and rock traces in extremely thin coal seams, characterized in that, Includes the following steps: S1. Set up a similar simulated coal and rock layer in a laboratory environment. The similar simulated coal and rock layer has a cuboid structure. The cutting area of ​​the similar simulated coal and rock layer includes the coal seam and the rock layer. The coal seam and the rock layer in the cutting area form a cuboid structure with an equilateral triangle structure and an inverse triangle structure, respectively. The coal seam is located below the similar simulated coal and rock layer, and the rock layer is located below and above the similar simulated coal and rock layer. Along the cutting direction, the coal seam becomes thinner and the rock layer becomes thicker. There will be different coal and rock ratios at different mining locations, that is, the cutting depth of the rock. Acoustic emission probes were linearly arranged in a similar simulated coal and rock strata; S2. Using the adaptive coal and rock cutting device or a proportional model of the adaptive coal and rock cutting device as described in claim 1, a similar simulated coal and rock strata are mined; the mining process is simulated by setting multiple sets of test conditions, including different traction speeds and different excavation drum rotation speeds. During the simulation of multiple sets of test conditions, the electrical signals of the coal mining machine cutting motor, including voltage and current signals, were collected. At this time, the hydraulic support device was fixed, and the voltage and current signals under different proportions of coal and rock cutting were obtained. While acquiring voltage and current signals, three-dimensional vibration signals on the rocker arm are also acquired to obtain vibration frequency and vibration amplitude in three dimensions. While collecting voltage and current signals, the acoustic emission system is used to collect acoustic emission signals from the coal cutting face. The collected acoustic emission signals are then subjected to Fourier transform to analyze the frequency and count of acoustic emission under different coal-rock ratios. S3. Extract parameters during the cutting process of different coal-rock ratios. These parameters include the voltage and current of the coal mining machine's cutting motor, the vibration frequency and amplitude of the cutting motor's rocker arm, and the frequency and energy of acoustic emission from the coal wall. The voltage sensitivity of the coal mining machine's cutting motor is then obtained as U. m The current sensitivity of the coal mining machine's cutting motor is A. m The rocker arm amplitude sensitivity is P m The rocker arm frequency sensitivity is F m The acoustic emission energy sensitivity is E m The acoustic emission frequency sensitivity is f m ; （1） （2） （3） （4） （5） （6） U, A, P, F, E, and f represent the cutting motor voltage, cutting motor current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency of the coal mining machine, respectively. The subscript P of the corresponding parameter indicates the value of the parameter when cutting a certain proportion of coal and rock, and the subscript c of the corresponding parameter represents the value of the parameter of the coal body being cut. U corresponding to different rock cutting depths for coal and rock cutting m A m P m F m E m f m The proportion of each parameter was obtained by using a homogenization method, and denoted as follows: , , , , , ; Simultaneously, during the cutting process, the U values ​​corresponding to the cut coal and rock at different cutting rock depths were obtained. m A m P m F m E m f m The respective changes were determined, and the corresponding functional relationships of the changes in rock depth were obtained: （13） （14） （15） （16） （17） （18） in, , , , , , The horizontal rows represent the functional relationships between the cutting motor voltage, cutting motor current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency of the coal mining machine and the change in rock depth, respectively. - This represents the corresponding change in rock depth; Finally, the rock cutting depth L under multi-parameter fusion was calculated by analyzing the relationship between weights, variables, and distance. S That is, the change in rocker arm L S : （19） in, This represents the change in rock cutting depth corresponding to the change in voltage of the coal mining machine's cutting motor. , This represents the change in rock cutting depth corresponding to the change in current of the coal mining machine's cutting motor. , The change in rock cutting depth corresponds to the change in the amplitude of the rocker arm vibration. , The change in rock cutting depth corresponds to the change in the frequency of the rocker arm vibration. ,for The change in acoustic emission energy corresponds to the change in rock cutting depth. , The change in acoustic emission count corresponds to the change in rock cutting depth. ; Obtain the change in rocker arm L S In reality, it is the result of coal and rock trajectory identification, and the coal and rock trajectory line is obtained by adding the radius of the rocker arm.

6. The method for identifying coal and rock traces in extremely thin coal seams according to claim 5, characterized in that, The proportions of each parameter were obtained using a homogenization method as follows: （7） （8） （9） （10） （11） （12）。 7. The method for identifying coal and rock traces in extremely thin coal seams according to claim 5 or 6, characterized in that, The coal seam and rock strata have heights that match the drum diameter, with the coal seam and rock strata having equilateral and inverse triangular structures, respectively.

8. The method for identifying coal and rock traces in extremely thin coal seams according to claim 7, characterized in that, When S1 arranged similar simulated coal and rock layers of a triangular coal and rock structure in a laboratory environment, experiments were conducted by setting up similar simulated coal and rock layers corresponding to coal layers of different hardness.

9. An adaptive coal and rock cutting method, characterized in that, The adaptive coal and rock cutting device according to any one of claims 1 to 4 is used for cutting, and the traction speed and the rotation speed of the digging drum are set for coal and rock cutting; during the coal and rock cutting process, the coal and rock traces are identified using the ultra-thin coal seam coal and rock trace identification method according to any one of claims 5 to 8, that is, the rocker arm change amount L is obtained. S Based on the obtained rocker arm change L S Adaptive adjustment, the adaptive adjustment process is as follows: During the initial cutting of the coal seam, information about the top and bottom plates of the coal seam can be revealed, thereby adjusting the height of the support device to ensure that the drum fully enters the coal body and that the initial cutting takes place within the coal body. Once the drum is fully inside the coal body, the support device automatically depressurizes, becoming a pressure-free telescopic structure. At this point, the rock-coal spring rigidity relaxation device activates, extending and retracting based on the spring stiffness exceeding the coal seam cutting force, ensuring the coal mining machine drum is in a pull-back state. This means that when the coal seam is fully cut, the drum will be stretched upwards and stabilize after reaching the coal-coal trace. When cutting into the rock mass, changes occur in the coal mining machine's cutting motor voltage, current, rocker arm amplitude, rocker arm frequency, acoustic emission energy, and acoustic emission frequency. This allows for adjustment of the coal mining machine height using the extremely thin coal seam rock-coal trace identification method. At this point, the spring rigidity relaxation device instantly depressurizes, transforming into a pressure-free telescopic structure, based on L... S The rocker arm is automatically raised to the predetermined height. Once the height is reached, the support device automatically releases pressure, transforming into a pressure-free structure. The elastic relaxation device is then activated to support the coal and rock cutting process.

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