Coal mine roof multi-point displacement monitoring system based on universal joint

Abstract

The utility model discloses a coal mine roof multi-point displacement monitoring system based on universal joints, which comprises a plurality of sections of measuring rods and a data collector arranged at the tail end of the plurality of sections of measuring rods, and is characterized in that a universal joint is arranged between every two sections of measuring rods in the plurality of sections of measuring rods, and the universal joints are used for realizing that the plurality of sections of measuring rods incline towards any direction; a measuring module and a transmitter are arranged in each section of measuring rod, a first end of the transmitter is electrically connected with the measuring module, and a second end of the transmitter is electrically connected with the data collector through a cable. The connecting part of the rod body adopts a universal joint structure, and is different from a traditional inclinometer with a pulley type structure, so that the rod body can be prevented from being broken when the rod body deflects in a drill hole, the rod body can be prevented from freely rotating, and the deflection in each direction can be ensured to be not less than 45 degrees. And meanwhile, the expansion shell type anchor fluke structure is adopted, so that each section of rod body can be firmly fixed, and the sliding of the rod body caused by the deformation of a drill hole is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of coal mine roof monitoring, and in particular to a coal mine roof multi-point displacement monitoring system based on a universal joint. Background Art

[0002] Safety monitoring of coal mine tunnel roofs and surrounding rocks is an important project for mine disaster prediction. Mine roof falls and surrounding rock collapses are one of the major disasters in all types of mines, which seriously threaten the production safety of mines. In recent years, due to the increase in mining depth and the expansion of mining scope, mine production has developed in depth, and the threats of roof falls and collapses have become increasingly serious. Carrying out roof monitoring and supervision can timely discover hidden dangers and take measures. It is an important means of roof management and prevention of roof accidents.

[0003] Currently, mechanical dual-height indicators, four-point roof separation indicators, and acoustic probe multi-point displacement meters are used to monitor deep displacement in roadways. However, while the mechanical dual-height and four-point roof separation indicators can provide direct readings, they have low precision and limited measurement points, making them routine observation tools and unable to determine the extent of deep displacement in the roadway surrounding rock or the length of the anchor cables. While the acoustic probe multi-point displacement meter accurately reflects the location of surrounding rock separation, failure depth, and deformation, horizontal displacement in the roadway can cause the magnetic anchor head in the borehole to become misaligned, making measurement impossible. Furthermore, the acoustic probe multi-point displacement meter requires manual reading and cannot continuously record the roadway deformation process.

[0004] Therefore, how to achieve accurate monitoring of coal mine roofs is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] In order to solve the above technical problems, this application proposes the following technical solutions:

[0006] In the first aspect, an embodiment of the present application provides a multi-point displacement monitoring system for a coal mine roof based on a universal joint, comprising: a multi-section measuring rod, and a data collector arranged at the end of the multi-section measuring rod, a universal joint is arranged between each section of the measuring rod in the multi-section measuring rod, and the universal joint is used to enable the multi-section measuring rod to tilt in any direction; a measuring module and a transmitter are provided in each section of the measuring rod, the first end of the transmitter is electrically connected to the measuring module, and the second end of the transmitter is electrically connected to the data collector through a cable.

[0007] In a possible implementation, the universal joint includes a yoke, the yoke cooperates with a cross shaft, and a needle bearing is provided between the cross shaft and the yoke.

[0008] In a possible implementation, an anchor claw is provided at the top end of each measuring rod section, and each measuring rod section is fixed in a drilled hole in the top plate through the anchor claw.

[0009] In one possible implementation, the measurement module includes: a sliding rod, a first end of which is connected to the end of the fluke, and a second end of which is provided with a vertical displacement sensor and a horizontal displacement sensor, respectively used to monitor the vertical displacement and horizontal displacement of the top plate.

[0010] In one possible implementation, the horizontal displacement sensor uses an accelerometer chip, the SCL port of the accelerometer chip is connected to the single-chip microcomputer through a first pull-up resistor, the SDA port of the accelerometer chip is connected to the single-chip microcomputer through a second pull-up resistor, the YLOGIC port of the accelerometer chip is electrically connected to a 3.3V power supply, the CPOUT port of the accelerometer chip is electrically connected to the first end of the first capacitor, the VDD port of the accelerometer chip is electrically connected to the first end of the second capacitor and the 3.3V power supply, respectively, the REGOUT port of the accelerometer chip is electrically connected to the first end of the third capacitor, and the CLKIN port, AD0 port, PAD port, GND port, FSYNC port, the second end of the first capacitor, the second end of the second capacitor, and the second end of the third capacitor of the accelerometer chip are grounded.

[0011] In one possible implementation, the transmitter includes an AD chip, the VDD port of the AD chip is electrically connected to a 3.3V power supply, the AIN0 port of the AD chip is a signal input port, and the A0 port, A1 port, AIN3 port and GND port of the AD chip are grounded.

[0012] In a possible implementation, the universal joint-based coal mine roof multi-point displacement monitoring system further includes a handheld reader, which is used to read the inspection data of the data collector through wireless signals.

[0013] In one possible implementation, the universal joint-based coal mine roof multi-point displacement monitoring system also includes a collection substation, a first end of which is wirelessly connected to the data collector, and a second end of which is electrically connected to a ground monitoring room.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] The rod connection of this new model utilizes a universal joint structure, unlike traditional pulley-type inclinometers. This prevents the rod from breaking and rotating freely when deflected within the borehole, and ensures that the deflection in each direction is no less than 45 degrees. Furthermore, the use of an expanding shell-type anchor claw structure securely secures each rod section, preventing slippage caused by borehole deformation.

[0016] The monitoring system of the utility model reduces the number of holes to be drilled for measuring holes and also improves the accuracy of displacement in both axial and radial directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a universal joint-based coal mine roof multi-point displacement monitoring system provided in an embodiment of the present application;

[0018] Figure 2 A schematic structural diagram of a universal joint provided in an embodiment of the present application;

[0019] Figure 3 A schematic diagram of the structure of the measurement module provided in an embodiment of the present application;

[0020] Figure 4 A circuit schematic diagram of the accelerometer chip provided in an embodiment of the present application;

[0021] Figure 5 This is a circuit diagram of the AD chip provided in an embodiment of the present application.

[0022] in, Figure 1-5 The symbols in the figure are: 1-measuring rod, 2-data collector, 3-handheld reader, 4-collection substation, 5-ground monitoring room, 6-anchor claw, 7-measurement module, 8-universal joint, 9-cable, 10-sliding rod, 11-vertical displacement sensor, 12-horizontal displacement sensor. DETAILED DESCRIPTION

[0023] The present invention will be described below with reference to the accompanying drawings and specific implementation methods.

[0024] Figure 1 The schematic diagram of the structure of the multi-point displacement monitoring system of the coal mine roof based on the universal joint provided in the embodiment of the present application is shown in FIG. Figure 1 In this embodiment, a multi-point displacement monitoring system for a coal mine roof based on a universal joint includes: a multi-section measuring rod 1, and a data collector 2 arranged at the end of the multi-section measuring rod 1. A universal joint 8 is arranged between each section of the multi-section measuring rod 1. The universal joint 8 is used to realize the tilting of the multi-section measuring rod 1 in any direction. A measuring module 7 and a transmitter are provided in each section of the measuring rod 1. The first end of the transmitter is electrically connected to the measuring module 7, and the second end of the transmitter is electrically connected to the data collector 2 through a cable 9.

[0025] In this embodiment, each section of the measuring rod 1 is equipped with an anchor claw 6 suitable for installation in drill holes with a diameter of 55-65 mm. The anchor claw secures the measuring rod in the drilled hole in the roof, enabling multi-point horizontal and vertical displacement measurement. In this embodiment, the measuring rod 1 is a hollow structure with a certain degree of rigidity, made of flame-retardant fiberglass tube. The measuring rod 1 is designed to be 600-1000 mm long per section, with the length adjusted to suit the varying rock formations. The measuring rod is installed in the specified orientation within the roadway. The coordinate system's X-axis is parallel to the roadway's direction, and the Y-axis is perpendicular to it. The measurement results reflect the direction of horizontal displacement.

[0026] See also Figure 2 In this embodiment, the universal joint 8 includes a universal joint fork, which cooperates with the cross shaft. A needle roller bearing is provided between the cross shaft and the universal joint fork, and the needle roller bearing is used to ensure smoothness during power transmission.

[0027] See also Figure 3 The schematic diagram of the measurement module provided in this embodiment shows the measurement module 7 comprising a slide rod 10, the first end of which is connected to the end of the fluke 6. A vertical displacement sensor 11 and a horizontal displacement sensor 12 are provided at the second end of the slide rod 10. These sensors are used to monitor the vertical and horizontal displacements of the roof, respectively. In this embodiment, the vertical displacement sensor 11 is a tensile displacement sensor, characterized by its compact size, suitability for installation within a borehole, excellent sealing, waterproofness, and high measurement accuracy, meeting the 1mm measurement accuracy requirement. When the rock formation undergoes vertical displacement, the tensile displacement sensor extends and outputs a vertical displacement data signal.

[0028] The horizontal displacement sensor 12 uses an accelerometer sensor. Its compact size makes it suitable for installation in small spaces. It also offers low cost, low power consumption, and high accuracy, reducing manufacturing costs and allowing for long standby periods while meeting measurement accuracy requirements. When the rock formation undergoes horizontal displacement, the measuring rod tilts, and the horizontal displacement sensor within the measurement module outputs a data signal. The accelerometer chip processes this data and converts it into horizontal displacement.

[0029] See also Figure 4, a circuit schematic diagram of an accelerometer chip provided in an embodiment of the present application, wherein the SCL port of the accelerometer chip is connected to the single-chip microcomputer through a first pull-up resistor R1, the SDA port of the accelerometer chip is connected to the single-chip microcomputer through a second pull-up resistor R2, the YLOGIC port of the accelerometer chip is electrically connected to a 3.3V power supply, the CPOUT port of the accelerometer chip is electrically connected to a first end of a first capacitor C3, the VDD port of the accelerometer chip is electrically connected to a first end of a second capacitor C2 and a 3.3V power supply, respectively, the REGOUT port of the accelerometer chip is electrically connected to a first end of a third capacitor C1, and the CLKIN port, AD0 port, PAD port, GND port, FSYNC port, the second end of the first capacitor C3, the second end of the second capacitor C2, and the second end of the third capacitor C1 of the accelerometer chip are grounded.

[0030] In this embodiment, each measuring rod 1 is equipped with a transmitter, which is responsible for collecting sensor data from the measuring module 7 and calculating and outputting the horizontal and vertical displacement. The transmitter samples the voltage value of the tensile sensor through a high-precision 12-bit AD chip. Figure 5 , the circuit schematic diagram of the AD chip provided in an embodiment of the present application, the VDD port of the AD chip is electrically connected to the 3.3V power supply, the AIN0 port of the AD chip is the signal input port, and the A0 port, A1 port, AIN3 port and GND port of the AD chip are grounded.

[0031] In addition, the universal joint-based coal mine roof multi-point displacement monitoring system in the embodiment of the present application also includes a data acquisition substation 4 and a handheld reader 3. The first signal terminal of the data acquisition substation 4 is wirelessly connected to the data collector 2, and the second signal terminal of the data acquisition substation 4 is electrically connected to the ground monitoring room 5. The collected inspection data is output through the communication port and transmitted to the ground monitoring room via a connection to the coal mine monitoring system. The handheld reader 3 is used to read the inspection data from the data collector 2 via a wireless signal.

[0032] In this embodiment, the data collector 2 is in a power-saving sleep mode during off-hours, connecting the transmitter inside the measuring rod to collect data only during inspections. The data collector 2 uses a reed switch or magnetic sensor as a wake-up element. When the handheld reader 3 begins collecting data, an external magnetic sensor wakes the data collector. The handheld reader 3 and the data collector 2 utilize wireless communication, with data transmission taking place in wireless mode.

[0033] In the embodiment of the present invention, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0035] The above description is merely a specific embodiment of the present invention. Any modifications or substitutions that can be readily conceived by a person skilled in the art within the technical scope disclosed in the present invention are intended to be covered by the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A multi-point displacement monitoring system for coal mine roof based on universal joints, characterized in that: include: A multi-section measuring rod and a data collector arranged at the end of the multi-section measuring rod, a universal joint is arranged between each measuring rod in the multi-section measuring rod, and the universal joint is used to enable the multi-section measuring rod to tilt in any direction; a measuring module and a transmitter are provided in each measuring rod section, the first end of the transmitter is electrically connected to the measuring module, and the second end of the transmitter is electrically connected to the data collector via a cable.

2. The multi-point displacement monitoring system for coal mine roof based on universal joint according to claim 1, characterized in that: The universal joint comprises a universal joint fork, the universal joint fork cooperates with a cross shaft, and a needle bearing is provided between the cross shaft and the universal joint fork.

3. The universal joint-based coal mine roof multi-point displacement monitoring system according to claim 1, characterized in that: An anchor claw is provided at the top end of each measuring rod section, and each measuring rod section is fixed in a drilled hole of the top plate through the anchor claw.

4. The multi-point displacement monitoring system for coal mine roof based on universal joints according to claim 1, characterized in that: The measurement module includes: a sliding rod, a first end of which is connected to the end of the anchor claw, and a second end of which is sequentially provided with a vertical displacement sensor and a horizontal displacement sensor, which are used to monitor the vertical displacement and horizontal displacement of the top plate respectively.

5. The universal joint-based coal mine roof multi-point displacement monitoring system according to claim 4, characterized in that: include: The horizontal displacement sensor uses an accelerometer chip. The SCL port of the accelerometer chip is connected to the single-chip microcomputer through a first pull-up resistor, the SDA port of the accelerometer chip is connected to the single-chip microcomputer through a second pull-up resistor, the YLOGIC port of the accelerometer chip is electrically connected to a 3.3V power supply, the CPOUT port of the accelerometer chip is electrically connected to the first end of the first capacitor, the VDD port of the accelerometer chip is electrically connected to the first end of the second capacitor and the 3.3V power supply respectively, the REGOUT port of the accelerometer chip is electrically connected to the first end of the third capacitor, and the CLKIN port, AD0 port, PAD port, GND port, FSYNC port of the accelerometer chip, the second end of the first capacitor, the second end of the second capacitor, and the second end of the third capacitor are grounded.

6. The multi-point displacement monitoring system for coal mine roof based on universal joints according to claim 1, characterized in that: The transmitter includes an AD chip, a VDD port of the AD chip is electrically connected to a 3.3V power supply, an AIN0 port of the AD chip is a signal input port, and an A0 port, an A1 port, an AIN3 port and a GND port of the AD chip are grounded.

7. The universal joint-based coal mine roof multi-point displacement monitoring system according to claim 1, characterized in that: It also includes a handheld reader, which is used to read the inspection data of the data collector through wireless signals.

8. The universal joint-based coal mine roof multi-point displacement monitoring system according to claim 1, characterized in that: It also includes a collection substation, a first end of which is wirelessly connected to the data collector, and a second end of which is electrically connected to a ground monitoring room.

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