Calibration device and calibration method for hinged rod type displacement sensor

Abstract

The invention provides a calibration device and a calibration method for a hinged rod type displacement sensor. The calibration device comprises two fixing devices, a limiting column, a wood plate, a clamp and a circular level, and the two fixing devices are used for fixing the rod type displacement sensor; the bottoms of the fixing device and the limiting column are fixed to the wood plate, and the circular level is fixed to the end of the wood plate. The clamp is arranged on the limiting column and used for supporting the rod type displacement sensor. The calibration method is realized based on the calibration device, the measurement result of the hinged rod type displacement sensor is compared with the known standard, the error or uncertainty in the measurement process is quantified, and the performance is ensured to reach an acceptable level or be within a tolerance range. According to the calibration device and method provided by the invention, the accuracy of the hinged rod type displacement sensor can be ensured, and the overall performance of the hinged rod type displacement sensor can be improved by adjusting and optimizing the arrangement of the hinged rod type displacement sensor, so that the hinged rod type displacement sensor can provide reliable data under various environmental conditions.

Description

Technical Field

[0001] The invention relates to the field of displacement sensor calibration. Background Art

[0002] There are many existing engineering monitoring methods, but the monitoring frequency is low and the labor input is large. Among them, the projects that have been put into use can only be monitored and measured at specific times. Taking the subway shield tunnel as an example, the relative settlement of the pipe segment is an important monitoring indicator and plays an important role in evaluating the risk of the tunnel. However, in actual measurement, the relative settlement of the pipe segment needs to be measured by a level meter and a level ruler set up on the surface. This process requires a lot of manpower, especially after the subway shield tunnel is put into use, it can only be measured during the shutdown period, and high-frequency monitoring data cannot be obtained.

[0003] Wireless sensor network sensors are widely used in monitoring the tilt state of civil engineering structures because of their advantages such as easy installation, automatic monitoring, and wireless transmission of monitoring data. The articulated rod displacement sensor has a built-in three-axis accelerometer, which can sense its own posture changes through the changes in the component of gravity acceleration in the accelerometer coordinate system. This type of sensor can increase the monitoring frequency by transmitting data through a wireless sensing network. Among them, the series-connected articulated rod displacement sensor can collect data up to once per minute. When installed in a shield tunnel, Figure 1 However, in the assembly process of the articulated rod displacement sensor based on the wireless sensor network, it is inevitable that the three-axis accelerometer cannot be installed strictly in the direction of the sensor shell axis, resulting in errors in the measurement process. This error will be accumulated in the process of connecting the sensors in series, and the performance of the monitoring instrument may degrade over time and with the increase in the frequency of use. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a calibration device and a calibration method for an articulated rod displacement sensor.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a calibration device for an articulated rod displacement sensor, wherein the articulated rod displacement sensor comprises two or more rod displacement sensors connected in series in an articulated manner, and the calibration device comprises a fixing device 1, a limit column 2, a wooden board 3, a clamp 4 and a circular level 5, wherein:

[0007] There are two fixing devices 1, namely a first fixing device 11 and a second fixing device 12, which are used to fix the rod-type displacement sensor;

[0008] The first fixing device 11, the second fixing device 12 and the bottom of the limiting column 2 are fixed on the wooden board 3, and their center lines are located on the same straight line, and the circular level 5 is fixed to the end of the wooden board 3;

[0009] The clamp 4 is disposed on the limiting column 2 and is used to support the rod-type displacement sensor. The angle between two adjacent rod-type displacement sensors of the articulated rod-type displacement sensor is adjusted by changing the height of the clamp 4 on the limiting column 2 .

[0010] Furthermore, the fixing device adopts a symmetrical structure as a whole, and is composed of two identical fixing components 1-1 spliced ​​together. Two first screw holes 1-2 are set at the bottom of the fixing component for connecting with the wooden board 3, and two through holes 1-3 are set on the front and rear walls of the fixing component for connecting the two fixing components into a whole; an arc-shaped groove is set on the rear wall of the fixing component, and when the two fixing components are connected, the two arc-shaped grooves are connected to form a through circular hole 1-4, and a rubber pad 1-5 is set in the circular hole 1-4.

[0011] Furthermore, the limit column 2 includes a base plate 2-1 and two rectangular bodies 2-2 fixed on the base plate. The base plate is provided with four second screw holes 2-3 for connecting the limit column 2 with the wooden board 3. The distance between the two rectangular bodies 2-2 is slightly larger than the outer diameter of the rod-type displacement sensor.

[0012] Furthermore, when the articulated rod-type displacement sensor includes more than two rod-type displacement sensors, the number of the limiting columns 2 is increased accordingly.

[0013] In a second aspect, the present invention provides a calibration method for an articulated rod displacement sensor. The method is based on the calibration device for an articulated rod displacement sensor described above and comprises the following steps:

[0014] S1: Place the calibration device on a horizontal ground, with the center lines of the first fixture 11, the second fixture 12 and the limit column 2 collinear, and make the bubble in the circular level 5 in the center;

[0015] S2: Install the articulated rod displacement sensor into the calibration device, wherein the articulated rod displacement sensor comprises two rod displacement sensors and a hinge connection 6-3 for connecting the two rod displacement sensors in series, wherein the two rod displacement sensors serve as a first measurement unit 6-1 and a second measurement unit 6-2, respectively. Specifically:

[0016] Fix the two ends of the second measuring unit 6-2 in the rubber pads 1-5 of the first fixing device 11 and the second fixing device 12, place the first measuring unit 6-1 between the two rectangular bodies 2-2 of the limiting column 2, and set the clamp 4 on the limiting column 2 and at the lower side of the first measuring unit 6-1 to support the first measuring unit 6-1;

[0017] S3: Fix the first micrometer 71, the second micrometer 72, the third micrometer 73 and the fourth micrometer 74;

[0018] S4: Adjust the measuring rods of the four micrometers so that the measuring rods are in contact with the surface of the articulated rod displacement sensor. The contact point is the measuring point, specifically:

[0019] The measuring rod of the first micrometer 71 is placed on the upper surface of the right end of the first measuring unit 6-1, the measuring rod of the second micrometer 72 is placed on the upper surface of the left end of the first measuring unit 6-1, the measuring rod of the third micrometer 73 is placed on the upper surface of the right end of the second measuring unit 6-2, and the measuring rod of the fourth micrometer 74 is placed on the upper surface of the left end of the second measuring unit 6-2;

[0020] S5: Adjust the fixture 4 so that the first measuring unit 6-1 and the second measuring unit 6-2 are located on the same horizontal plane;

[0021] S6: Measure the distance between the measuring points of the first micrometer 71 and the second micrometer 72, recorded as L1; measure the distance between the measuring point of the second micrometer 72 and the hinge point of the hinge connection 6-3, recorded as L2; ​​measure the distance between the hinge point of the hinge connection 6-3 and the measuring point of the third micrometer 73, recorded as L3; measure the distance between the measuring points of the third micrometer 73 and the fourth micrometer 74, recorded as L4;

[0022] S7: Reset the first micrometer 71, the second micrometer 72, the third micrometer 73 and the fourth micrometer 74, and the initial values ​​of the four micrometers are all 0;

[0023] S8: Record the initial inclination value of the articulated rod displacement sensor, and record the initial inclination value of the first measurement unit 6-1 as θ 1,0 , the initial inclination value of the second measurement unit 6-2 is θ 2,0 ;

[0024] S9: Adjust the height of the fixture 4 so that the first measuring unit 6-1 rotates around the hinge point of the hinge connection 6-3 in the vertical plane, and the angle between the first measuring unit 6-1 and the second measuring unit 6-2 is α i As the height difference between the two ends of the first measuring unit 6-1 changes, the reading of the dial gauge also changes accordingly, and the readings of the four dial gauges are recorded. The difference between each dial gauge reading and the initial value of the dial gauge is taken as the height difference. The height difference of the first dial gauge 71 is Δh 1,i , the height difference of the second micrometer 72 is Δh 2,i , the height difference of the third micrometer 73 is Δh 3,i , the height difference of the fourth micrometer 74 is Δh 4,i The X-axis inclination data returned by the articulated rod displacement sensor is used as the inclination value of the articulated rod displacement sensor, and the inclination value of the first measurement unit 6-1 is recorded as θ1,i , the inclination value of the second measuring unit 6-2 is θ 2,i The difference between the inclination value of each measurement unit and the initial inclination value is recorded as the inclination change value, and the inclination change value of the first measurement unit 6-1 is recorded as Δθ 1,i , the inclination value of the second measurement unit 6-2 is Δθ 2,i , where i is the number of trials;

[0025] S10: The height difference Δh of the first micrometer 71 is 1,i As a known quantity, calculate the height difference Δh at the position of the fourth micrometer 74 measuring point 4,i ′, the calculation formula is: Δh 4,i ′=Δh 1,i -(L1+L2)sinθ 1,i -(L3+L4)sinθ 2,i ;

[0026] S11: Calculate the height difference Δh at the measuring point 74 of the fourth micrometer 4,i ' and the height difference Δh measured by the fourth micrometer 74 4,i By comparison, the error err of the articulated rod displacement sensor is obtained. i =Δh 4,i -Δh 4,i ′;

[0027] S12: Set the number of test groups n according to the test manpower and time cost, and repeat S9-S11 multiple times;

[0028] S13: Take the average value of all articulated rod displacement sensor errors obtained from n groups of tests as the sensor accuracy

[0029] S14: If the sensor accuracy meets the monitoring accuracy requirement required on site, the calibration is completed; otherwise, the sensor accuracy is compensated by a fitting formula according to the angle between the two measuring units.

[0030] Furthermore, the step S14, compensating the sensor accuracy by a fitting formula according to the angle between the two measurement units, specifically includes:

[0031] S141 Based on the data obtained from the above n groups of tests, the angle α between the first measuring unit 6-1 and the second measuring unit 6-2 is i As an independent variable, the height difference Δh between the second micrometer 72 and the third micrometer 73 23,i =Δh 2,i -Δh 3,i As the dependent variable, we get the fitting formula Δh 23,i =f(α i );

[0032] S142 For each test group, obtain the height difference calculation value Δh at the position of the fourth micrometer 74 measuring point 4,i ″=Δh 1,i -L1sinθ 1,i -L4sinθ 2,i -f(α i ), calculate the height difference Δh at the measuring point 74 of the fourth micrometer 4,i ″ and the height difference Δh measured by the fourth micrometer 74 4,i By comparison, the error err of the articulated rod displacement sensor is obtained. i ′=Δh 4,i -Δh 4,i ″;

[0033] S143 takes the average value of all articulated rod displacement sensor errors as the sensor accuracy according to the number of test groups n

[0034] Preferably, in step S8, the data acquisition frequency of the articulated rod displacement sensor is set to 1 minute, and the X-axis inclination data of three acquisition periods transmitted back by the articulated rod displacement sensor are recorded within 3 minutes, and the average value is taken as the initial inclination value.

[0035] Preferably, in step S9, the height of the fixture is adjusted every three acquisition periods, and the average value of the X-axis inclination data of the three acquisition periods transmitted back by the articulated rod displacement sensor is taken as the inclination value of the articulated rod displacement sensor.

[0036] Advantages and beneficial effects of the present invention:

[0037] The calibration device and calibration method provided by the present invention can realize the calibration of the articulated rod displacement sensor. By obtaining the monitoring accuracy of the articulated rod displacement sensor and combining the on-site monitoring accuracy requirements to determine whether to compensate the articulation error of the articulated rod displacement sensor through a fitting formula, the on-site measurement accuracy of the articulated rod displacement sensor can be improved.

[0038] Calibration of an articulated rod displacement sensor can ensure that it maintains its initial specifications and accuracy during long-term use, thereby improving the reliability of monitoring results. The calibration method of the present invention quantifies the error or uncertainty in the measurement process by comparing the measurement results of the articulated rod displacement sensor with a known standard, and ensures that the performance reaches an acceptable level or is within the tolerance range. The calibration device and method proposed in the present invention can not only ensure the accuracy of the articulated rod displacement sensor, but also improve its overall performance by adjusting and optimizing the settings of the articulated rod displacement sensor, so that it can provide reliable data under various environmental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1This is a schematic diagram of the application of articulated rod displacement sensor in shield tunnel settlement monitoring;

[0040] Figure 2 It is a schematic diagram of the coordinate axis of the articulated rod displacement sensor;

[0041] Figure 3 A schematic diagram of a calibration device for an articulated rod type displacement sensor according to an embodiment of the present invention;

[0042] Figure 4 It is a schematic diagram of a fixing device in a calibration device of an articulated rod type displacement sensor of the present invention;

[0043] Figure 5 It is a schematic diagram of a limit column in a calibration device of an articulated rod type displacement sensor of the present invention;

[0044] Figure 6 The present invention is a flow chart of a calibration method of an articulated rod displacement sensor.

[0045] Reference numerals:

[0046] Fixing device 1, first fixing device 11, second fixing device 12;

[0047] Fixing component 1-1, first screw hole 1-2, through hole 1-3, round hole 1-4, rubber pad 1-5;

[0048] Limiting column 2, bottom plate 2-1, cuboid body 2-2, second screw hole 2-3;

[0049] Wooden board 3, clamp 4, round level 5;

[0050] A first measuring unit 6-1, a second measuring unit 6-2, and a hinge connection 6-3;

[0051] A first micrometer 71 , a second micrometer 72 , a third micrometer 73 and a fourth micrometer 74 . DETAILED DESCRIPTION

[0052] The technical solution provided by the present application will be further described below in conjunction with specific embodiments and accompanying drawings. The advantages and features of the present application will become more apparent with the following description.

[0053] Example 1

[0054] like Figure 3As shown, a calibration device for an articulated rod displacement sensor is used to calibrate the articulated rod displacement sensors in series. As an embodiment, the articulated rod displacement sensor includes two rod displacement sensors and a hinge connection 6-3 for connecting the two rod displacement sensors in series, and the two rod displacement sensors serve as a first measurement unit 6-1 and a second measurement unit 6-2 respectively; the calibration device includes a fixing device 1, a limit column 2, a wooden board 3, a clamp 4 and a circular level 5, wherein:

[0055] There are two fixing devices 1, namely a first fixing device 11 and a second fixing device 12, which are used to fix the second measuring unit 6-2;

[0056] The first fixing device 11, the second fixing device 12 and the bottom of the limiting column 2 are fixed on the wooden board 3, and their center lines are located on the same straight line, and the circular level 5 is fixed to the end of the wooden board 3;

[0057] The clamp 4 is disposed on the limiting column 2 for supporting the rod-type displacement sensor, and the angle between the first measuring unit 6 - 1 and the second measuring unit 6 - 2 can be adjusted by changing the height of the clamp 4 on the limiting column 2 .

[0058] Specifically, Figure 4 As shown, the fixing device adopts a symmetrical structure as a whole, and is spliced ​​by two identical fixing components 1-1. Two first screw holes 1-2 are set at the bottom of the fixing component for connecting with the wooden board 3, and two through holes 1-3 are set on the front and rear walls of the fixing component for connecting the two fixing components into a whole; an arc-shaped groove is set on the rear wall of the fixing component. When the two fixing components are connected, the two arc-shaped grooves are connected to form a through circular hole 1-4. A rubber pad 1-5 is set in the circular hole 1-4. When calibrating, the rod-type displacement sensor is sleeved in the rubber pad 1-5, so that the rod-type displacement sensor is more tightly fixed on the fixing device.

[0059] Specifically, Figure 5 As shown, the limit column 2 includes a bottom plate 2-1 and two rectangular bodies 2-2 fixed to the bottom plate, and the bottom plate is provided with four second screw holes 2-3 for connecting the limit column 2 with the wooden board 3. The distance between the two rectangular bodies 2-2 is slightly larger than the outer diameter of the rod-type displacement sensor.

[0060] Furthermore, when the articulated rod displacement sensor includes more than two rod displacement sensors, the number of the limit columns 2 can be increased accordingly to achieve calibration of the articulated rod displacement sensor in which more than two rod displacement sensors are connected in series.

[0061] Example 2

[0062] like Figure 6As shown, a calibration method of an articulated rod displacement sensor is implemented based on a calibration device of an articulated rod displacement sensor in Example 1, and includes the following steps:

[0063] S1: Place the calibration device on a horizontal ground, with the center lines of the first fixture 11, the second fixture 12 and the limit column 2 collinear, and make the bubble in the circular level 5 in the center;

[0064] S2: Install the articulated rod displacement sensor into the calibration device, specifically: fix the two ends of the second measuring unit 6-2 in the rubber pads 1-5 of the first fixing device 11 and the second fixing device 12 to prevent the second measuring unit 6-2 from rotating and displacing, place the first measuring unit 6-1 between the two rectangular bodies 2-2 of the limiting column 2, and set the clamp 4 on the limiting column 2 and at the lower side of the first measuring unit 6-1 to support the first measuring unit 6-1;

[0065] S3: Fix the first micrometer 71, the second micrometer 72, the third micrometer 73 and the fourth micrometer 74 through an external micrometer support (not shown in the figure);

[0066] S4: Adjust the measuring rods of the four micrometers so that the measuring rods are in contact with the surface of the articulated rod displacement sensor, and the contact point is the measuring point, specifically: the measuring rod of the first micrometer 71 is placed on the upper surface of the right end of the first measuring unit 6-1, the measuring rod of the second micrometer 72 is placed on the upper surface of the left end of the first measuring unit 6-1, the measuring rod of the third micrometer 73 is placed on the upper surface of the right end of the second measuring unit 6-2, and the measuring rod of the fourth micrometer 74 is placed on the upper surface of the left end of the second measuring unit 6-2;

[0067] S5: Adjust the fixture 4 so that the first measuring unit 6-1 and the second measuring unit 6-2 are located on the same horizontal plane;

[0068] S6: Measure the distance between the measuring points of the first micrometer 71 and the second micrometer 72, recorded as L1; measure the distance between the measuring point of the second micrometer 72 and the hinge point of the hinge connection 6-3, recorded as L2; ​​measure the distance between the hinge point of the hinge connection 6-3 and the measuring point of the third micrometer 73, recorded as L3; measure the distance between the measuring points of the third micrometer 73 and the fourth micrometer 74, recorded as L4;

[0069] S7: Reset the first micrometer 71, the second micrometer 72, the third micrometer 73 and the fourth micrometer 74, and the initial values ​​of the four micrometers are all 0;

[0070] S8: Record the initial inclination value of the articulated rod displacement sensor, and record the initial inclination value of the first measurement unit 6-1 as θ 1,0 , the initial inclination value of the second measurement unit 6-2 is θ 2,0 ;

[0071] S9: Adjust the height of the fixture 4 so that the first measuring unit 6-1 rotates around the hinge point of the hinge connection 6-3 in the vertical plane, and the angle between the first measuring unit 6-1 and the second measuring unit 6-2 is α i As the height difference between the two ends of the first measuring unit 6-1 changes, the reading of the dial gauge also changes accordingly, and the readings of the four dial gauges are recorded. The difference between each dial gauge reading and the initial value of the dial gauge is taken as the height difference. The height difference of the first dial gauge 71 is Δh 1,i , the height difference of the second micrometer 72 is Δh 2,i , the height difference of the third micrometer 73 is Δh 3,i , the height difference of the fourth micrometer 74 is Δh 4,i The X-axis inclination data returned by the articulated rod displacement sensor is used as the inclination value of the articulated rod displacement sensor, and the inclination value of the first measurement unit 6-1 is recorded as θ 1,i , the inclination value of the second measuring unit 6-2 is θ 2,i The difference between the inclination value of each measurement unit and the initial inclination value is recorded as the inclination change value, and the inclination change value of the first measurement unit 6-1 is recorded as Δθ 1,i , the inclination value of the second measurement unit 6-2 is Δθ 2,i , where i is the number of trials;

[0072] S10: The height difference Δh of the first micrometer 71 is 1,i As a known quantity, calculate the height difference Δh at the position of the fourth micrometer 74 measuring point 4,i ′, the calculation formula is: Δh 4,i ′=Δh 1,i -(L1+L2)sinθ 1,i -(L3+L4)sinθ 2,i ;

[0073] S11: Calculate the height difference Δh at the measuring point 74 of the fourth micrometer 4,i ' and the height difference Δh measured by the fourth micrometer 74 4,i By comparison, the error err of the articulated rod displacement sensor is obtained. i =Δh 4,i -Δh 4,i ′;

[0074] S12: Set the number of test groups n according to the test manpower and time cost, and repeat S9-S11 multiple times (at least 60 times);

[0075] S13: Take the average value of all articulated rod displacement sensor errors obtained from n groups of tests as the sensor accuracy

[0076] S14: If the sensor accuracy meets the monitoring accuracy requirements required on site, the calibration is completed; otherwise, the sensor accuracy is compensated by a fitting formula according to the angle between the two measurement units. The specific operations are as follows:

[0077] S141 Based on the data obtained from the above n groups of tests, the angle α between the first measuring unit 6-1 and the second measuring unit 6-2 is i As an independent variable, the height difference Δh between the second micrometer 72 and the third micrometer 73 23,i =Δh 2,i -Δh 3,i As the dependent variable, we get the fitting formula Δh 23,i =f(α i );

[0078] S142 For each test group, obtain the height difference calculation value Δh at the position of the fourth micrometer 74 measuring point 4,i ″=Δh 1,i -L1sinθ 1,i -L4sinθ 2,i -f(α i ), calculate the height difference Δh at the measuring point 74 of the fourth micrometer 4,i '' and the height difference Δh measured by the fourth micrometer 74 4,i By comparison, the error err of the articulated rod displacement sensor is obtained. i ′=Δh 4,i -Δh 4,i ″;

[0079] S143 takes the average value of all articulated rod displacement sensor errors as the sensor accuracy according to the number of test groups n

[0080] In a preferred embodiment of the present invention, S8: the data acquisition frequency of the articulated rod displacement sensor is set to 1 minute, and the X-axis inclination data of three acquisition periods transmitted back by the articulated rod displacement sensor are recorded within 3 minutes, and the average value is taken as the initial inclination value.

[0081] In a preferred embodiment of the present invention, S9: the height of the clamp is adjusted every three acquisition periods, and the average value of the X-axis inclination data of the three acquisition periods transmitted back by the articulated rod displacement sensor is taken as the inclination value of the articulated rod displacement sensor.

[0082] Matters not covered by the present invention are known technologies, such as input equipment after observing the scale indication, data transmission, data computing equipment, calculated data output, etc.

[0083] The above description is only a description of the preferred embodiments of the present application, and is not intended to limit the scope of the present application. Any changes or modifications made by any person skilled in the art based on the above disclosed technical contents shall be deemed as equivalent effective embodiments and shall fall within the scope of protection of the technical solution of the present application.

Claims

1. A calibration device for an articulated rod displacement sensor, wherein the articulated rod displacement sensor comprises two or more rod displacement sensors connected in series by articulation, characterized in that: The calibration device comprises a fixing device (1), a limiting column (2), a wooden board (3), a clamp (4) and a circular level (5), wherein: The fixing devices (1) have two, namely a first fixing device (11) and a second fixing device (12), which are used to fix the rod-type displacement sensor; The first fixing device (11), the second fixing device (12) and the bottom of the limiting column (2) are fixed on the wooden board (3), and their center lines are located on the same straight line, and the circular level (5) is fixed to the end of the wooden board (3); The clamp (4) is arranged on the limiting column (2) and is used to support the rod-type displacement sensor. The angle between two adjacent rod-type displacement sensors of the articulated rod-type displacement sensor is adjusted by changing the height of the clamp (4) on the limiting column (2).

2. A calibration device for an articulated rod displacement sensor as claimed in claim 1, characterized in that: The fixing device has an overall symmetrical structure and is formed by splicing two identical fixing components (1-1). Two first screw holes (1-2) are arranged at the bottom of the fixing component for connection with a wooden board (3). Two through holes (1-3) are arranged on the front and rear walls of the fixing component for connecting the two fixing components into a whole. An arc-shaped groove is arranged on the rear wall of the fixing component. When the two fixing components are connected, the two arc-shaped grooves are butted to form a through circular hole (1-4). A rubber pad (1-5) is arranged in the circular hole (1-4).

3. The calibration device of the articulated rod displacement sensor according to claim 1, characterized in that: The limiting column (2) comprises a bottom plate (2-1) and two rectangular main bodies (2-2) fixed to the bottom plate, the bottom plate being provided with four second screw holes (2-3) for connecting the limiting column (2) and the wooden board (3); the spacing between the two rectangular main bodies (2-2) is slightly larger than the outer diameter of the rod-type displacement sensor.

4. The calibration device of the articulated rod displacement sensor according to claim 1, characterized in that: When the articulated rod-type displacement sensor comprises more than two rod-type displacement sensors, the number of the limiting columns (2) is increased accordingly.

5. A method for calibrating an articulated rod displacement sensor based on the calibration device for an articulated rod displacement sensor according to claim 1, characterized in that: The following steps are involved: S1: Place the calibration device on a horizontal ground, with the center lines of the first fixing device (11), the second fixing device (12) and the limit column (2) collinear, and the bubble in the circular level (5) in the center; S2: Installing the articulated rod displacement sensor into the calibration device, the articulated rod displacement sensor comprising two rod displacement sensors and a hinge connection (6-3) for connecting the two rod displacement sensors in series, the two rod displacement sensors serving as a first measurement unit (6-1) and a second measurement unit (6-2), respectively, specifically: The two ends of the second measuring unit (6-2) are fixed in the rubber pads (1-5) of the first fixing device (11) and the second fixing device (12), the first measuring unit (6-1) is placed between the two rectangular parallelepiped bodies (2-2) of the limiting column (2), and the clamp (4) is arranged on the limiting column (2) and located at the lower side of the first measuring unit (6-1) to support the first measuring unit (6-1); S3: fixing the first micrometer (71), the second micrometer (72), the third micrometer (73) and the fourth micrometer (74); S4: Adjust the measuring rods of the four micrometers so that the measuring rods are in contact with the surface of the articulated rod displacement sensor. The contact point is the measuring point, specifically: The measuring rod of the first micrometer (71) is placed on the upper surface of the right end of the first measuring unit (6-1), the measuring rod of the second micrometer (72) is placed on the upper surface of the left end of the first measuring unit (6-1), the measuring rod of the third micrometer (73) is placed on the upper surface of the right end of the second measuring unit (6-2), and the measuring rod of the fourth micrometer (74) is placed on the upper surface of the left end of the second measuring unit (6-2); S5: adjusting the fixture (4) so ​​that the first measuring unit (6-1) and the second measuring unit (6-2) are located on the same horizontal plane; S6: measuring the distance between the measuring points of the first micrometer (71) and the second micrometer (72), recorded as L1; measuring the distance between the measuring point of the second micrometer (72) and the hinge point of the hinge connection (6-3), recorded as L2; ​​measuring the distance between the hinge point of the hinge connection (6-3) and the measuring point of the third micrometer (73), recorded as L3; measuring the distance between the measuring points of the third micrometer (73) and the fourth micrometer (74), recorded as L4; S7: Reset the first micrometer (71), the second micrometer (72), the third micrometer (73) and the fourth micrometer (74), and the initial values ​​of the four micrometers are all 0; S8: Record the initial inclination value of the articulated rod displacement sensor, and record the initial inclination value of the first measurement unit (6-1) as θ 1,0 , the initial inclination value of the second measurement unit (6-2) is θ 2,0 ; S9: Adjust the height of the fixture (4) so ​​that the first measuring unit (6-1) rotates around the hinge point of the hinge connection (6-3) in the vertical plane, and the angle between the first measuring unit (6-1) and the second measuring unit (6-2) is α i As the height difference between the two ends of the first measuring unit (6-1) changes, the reading of the dial gauge also changes accordingly, and the readings of the four dial gauges are recorded. The difference between each dial gauge reading and the initial value of the dial gauge is taken as the height difference. The height difference of the first dial gauge (71) is Δh 1,i , the height difference of the second micrometer (72) is Δh 2,i , the height difference of the third micrometer (73) is Δh 3,i , the height difference of the fourth micrometer (74) is Δh 4,i The X-axis inclination data transmitted by the articulated rod displacement sensor is used as the inclination value of the articulated rod displacement sensor, and the inclination value of the first measurement unit (6-1) is recorded as θ 1,i , the inclination value of the second measurement unit (6-2) is θ 2,i The difference between the inclination value of each measurement unit and the initial inclination value is recorded as the inclination change value, and the inclination change value of the first measurement unit (6-1) is recorded as Δθ 1,i , the inclination value of the second measurement unit (6-2) is Δθ 2,i , where i is the number of trials; S10: The height difference Δh of the first micrometer (71) 1,i As a known quantity, calculate the height difference Δh at the measuring point of the fourth micrometer (74) 4,i ′, the calculation formula is: Δh 4,i ′=Δh 1,i -(L1+L2)sinθ 1,i -(L3+L4)sinθ 2,i ; S11: Calculate the height difference Δh at the measuring point of the fourth micrometer (74) 4,i ' and the height difference Δh measured by the fourth micrometer (74) 4,i By comparison, the error err of the articulated rod displacement sensor is obtained. i =Δh 4,i -Δh 4,i ′; S12: Set the number of test groups n according to the test manpower and time cost, and repeat S9-S11 multiple times; S13: Take the average value of all articulated rod displacement sensor errors obtained from n groups of tests as the sensor accuracy S14: If the sensor accuracy meets the monitoring accuracy requirement required on site, the calibration is completed; otherwise, the sensor accuracy is compensated by a fitting formula according to the angle between the two measuring units.

6. The calibration method of the articulated rod displacement sensor according to claim 5, characterized in that: The step S14, compensating the sensor accuracy by a fitting formula according to the angle between the two measurement units, specifically includes: S141 Based on the data obtained from the above n groups of tests, the angle α between the first measuring unit (6-1) and the second measuring unit (6-2) is i As an independent variable, the height difference Δh between the second micrometer (72) and the third micrometer (73) 23,i =Δh 2,i -Δh 3,i As the dependent variable, we get the fitting formula Δh 23,i =f(α i ); S142 For each group of tests, the height difference calculation value Δh at the measuring point of the fourth micrometer (74) is obtained. 4,i ″=Δh 1,i -L1sinθ 1,i -L4sinθ 2,i -f(α i ), calculate the height difference Δh at the measuring point of the fourth micrometer (74) 4,i ″ and the height difference Δh measured by the fourth micrometer (74) 4,i By comparison, the error err′ of the articulated rod displacement sensor is obtained i =Δh 4,i -Δh 4,i ″; S143 takes the average value of all articulated rod displacement sensor errors as the sensor accuracy according to the number of test groups n 7. The calibration method of the articulated rod displacement sensor according to claim 5, characterized in that: In step S8, the data acquisition frequency of the articulated rod displacement sensor is set to 1 minute, and the X-axis inclination data of three acquisition periods transmitted back by the articulated rod displacement sensor are recorded within 3 minutes, and the average value is taken as the initial inclination value.

8. The calibration method of the articulated rod displacement sensor according to claim 7, characterized in that: In step S9, the height of the fixture is adjusted every three acquisition periods, and the average value of the X-axis inclination data of the three acquisition periods transmitted back by the articulated rod displacement sensor is taken as the inclination value of the articulated rod displacement sensor.

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