Irregular gap measuring device

Abstract

The invention belongs to the technical field of gap measurement, and provides an irregular gap measuring device, which comprises a fixing assembly, a measuring assembly and a measuring assembly, one side wall of the fixing plate is fixedly connected with a limiting plate; the measuring assembly comprises a telescopic assembly, a mounting seat, a laser distance measuring sensor, a gradienter and a control box; the telescopic end of the telescopic assembly is fixedly connected with the mounting base, the side face of the mounting base is of a square structure, the laser ranging sensor is arranged in the center of the mounting base, the gradienter is installed on one surface of the mounting base, and the control box is installed on the telescopic assembly. According to the invention, the fixing assembly and the measuring assembly are arranged, the fixing assembly constructs a stable reference frame, the stability of the measuring reference is ensured, the consistency and comparability of the measured data are realized, and through accurate repeated positioning, it is ensured that multiple times of measurement aims at the same point, and the change trend of the gap is clearly reflected.

Description

Technical Field

[0001] The invention belongs to the technical field of gap measurement, in particular to a device for measuring irregular gaps. Background Art

[0002] The need to measure irregular gaps is widespread in industries such as large concrete bridges, high-rise buildings, and precision machinery manufacturing. For example, during the construction and maintenance of large concrete bridges, various factors, including concrete material properties, temperature stress, and foundation settlement, can cause various irregular gaps in the bridge structure, including structural joints and cracks. Changes in the state of these gaps (such as changes in width and depth) are often key indicators for assessing the health of the bridge structure.

[0003] Traditional gap measurement methods and devices have numerous limitations when dealing with irregular gaps. For example, a wedge-shaped vernier caliper can only measure a single point on the gap at a time. Furthermore, due to the irregularity of the gap, it is extremely difficult to precisely locate the same point the next time you measure. This results in a lack of consistency and comparability in the measured data, making it difficult to accurately reflect the actual changes in the gap. Furthermore, frequently inserting a wedge-shaped vernier caliper into concrete cracks can easily cause physical damage, enlarging the gap and further interfering with subsequent data analysis.

[0004] Therefore, those skilled in the art have proposed a device for measuring irregular gaps to solve the problems raised in the background art. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a device for measuring irregular gaps to solve the problems that the devices in the prior art usually use wedge-shaped vernier calipers, which can only measure a single point when measuring irregular gaps and are difficult to repeatedly and accurately locate the same point, resulting in a lack of consistency and comparability in the data.

[0006] A device for measuring irregular gaps, comprising: a fixing assembly comprising a fixing plate and a baffle; a side wall of the fixing plate being fixedly connected to a limiting plate;

[0007] The measuring assembly includes a telescopic assembly, a mounting base, a laser distance sensor, a level, and a control box; the telescopic end of the telescopic assembly is fixedly connected to the mounting base, the side of the mounting base is a square structure, and the laser distance sensor is arranged at the center of the mounting base. The level is mounted on a surface of the mounting base, and the control box is installed on the telescopic assembly;

[0008] A plurality of positioning pins are fixed on the upper surface of the fixing plate, and a plurality of positioning holes are opened on the bottom surface and both side surfaces of the mounting seat, and the positioning pins are engaged with the positioning holes.

[0009] Preferably, the telescopic assembly includes a holding rod, a telescopic rod, a turntable and a screw rod. A telescopic groove is provided on the inner wall of the holding rod. A screw rod is rotated and connected in the telescopic groove. The screw rod is threadedly engaged with the telescopic rod. One end of the screw rod passes through the holding rod, and one end of the screw rod can be connected to the turntable. The control box is installed on the peripheral side of the holding rod.

[0010] Preferably, a display screen is installed on the surface of the control box, and buttons are also provided on the periphery of the gripping rod. The level, laser ranging sensor and buttons are all electrically connected to the display screen.

[0011] Preferably, a plurality of limiting grooves are provided on the inner wall of the telescopic groove, and a plurality of limiting blocks are fixedly connected to the circumference of the telescopic rod, and the limiting blocks are slidably engaged with the limiting grooves.

[0012] Preferably, a fixing portion is provided at the side wall of the baffle, and screw holes are provided in both the fixing plate and the fixing portion, and screws are installed in the screw holes.

[0013] Preferably, a wire groove is provided between the telescopic rod and the mounting seat, and a data cable is connected between the laser ranging sensor, the level and the control box, and the data cable is located in the wire groove.

[0014] Preferably, the control box has a built-in benchmark management module for executing:

[0015] When first installed, the initial reference value L0 measured by the laser ranging sensor is stored;

[0016] Establishing a unique ID for the measurement point and binding it to the initial reference value L0;

[0017] Automatically calculate the gap change in subsequent measurements: ΔL=L n -L0;

[0018] Among them L n is the nth measurement value.

[0019] Preferably, the control box has a built-in attitude compensation module, and the attitude compensation module dynamically updates the inclination compensation reference plane:

[0020]

[0021] where θ i Installing a dip for history;

[0022] The attitude compensation module uses relative inclination to perform compensation:

[0023]

[0024] Among them L raw is the original output value of the laser ranging sensor; θ currentThe real-time comprehensive inclination angle detected by the level during the current measurement; θ ref It is the historical installation inclination reference value; L corrected is the actual gap width after compensation.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention sets up a fixed component and a measuring component. The fixed component constructs a stable reference frame to ensure the stability of the measurement reference, achieves the consistency and comparability of the measurement data, and ensures that multiple measurements are made at the same point through precise repeated positioning, clearly reflecting the trend of gap changes; the telescopic component realizes smooth telescoping of the measuring component, which is convenient for measurement of special positions; the laser ranging sensor does not need to contact the gap, avoiding physical damage to the gap and ensuring that subsequent data analysis is not interfered with.

[0027] 2. The present invention sets up a built-in reference management module, attitude compensation module and safety mechanism in the control box, which can store the initial reference value of the laser ranging sensor and establish a unique ID, automatically calculate the gap change in subsequent measurements, and accurately track the long-term changes in the gap; the attitude compensation module can dynamically correct according to the historical installation angle, eliminate the measurement deviation caused by the tilt of the device, and ensure data accuracy; when the installation angle deviation is too large, the safety mechanism will lock the system and alarm to prevent erroneous data from affecting the analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention.

[0030] In the picture:

[0031] 1. Fixing plate; 2. Limiting plate; 3. Baffle; 301. Fixing part; 4. Screw; 5. Positioning pin; 6. Mounting seat; 7. Positioning hole; 9. Laser ranging sensor; 10. Level; 11. Holding rod; 1101. Telescopic slot; 12. Control box; 1201. Display screen; 13. Button; 14. Telescopic rod; 15. Turntable; 16. Screw; 17. Limiting slot; 18. Limiting block; 19. Wire duct; 20. Data cable. DETAILED DESCRIPTION

[0032] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0033] Example 1: As shown in the attached Figure 1 To the attached Figure 2As shown: The present invention provides a device for measuring irregular gaps, comprising a fixing component and a measuring component;

[0034] The fixing assembly includes a fixing plate 1 and a baffle 3; one side wall of the fixing plate 1 is fixedly connected to a limiting plate 2; a fixing portion 301 is provided on the side wall of the baffle 3, and both the fixing plate 1 and the fixing portion 301 are provided with screw holes, and screws 4 are installed in the screw holes; the fixing plate 1 and the baffle 3 are fixed to the structures on both sides of the gap through their respective screw holes and screws 4, and the limiting plate 2 assists in limiting the installation position of the fixing plate 1;

[0035] The measuring assembly includes a telescopic assembly, a mounting base 6, a laser distance sensor 9, a level 10 and a control box 12; the telescopic end of the telescopic assembly is fixedly connected to the mounting base 6, the side of the mounting base 6 is a square structure, and the laser distance sensor 9 is arranged at the center of the mounting base 6, the level 10 is mounted on the surface of the mounting base 6, and the control box 12 is installed at the telescopic assembly;

[0036] Several positioning pins 5 are fixed on the upper surface of the fixed plate 1, and several positioning holes 7 are opened on the bottom surface and both side surfaces of the mounting seat 6, and the positioning pins 5 are engaged with the positioning holes 7; the mounting seat 6 is engaged with the positioning pins 5 on the fixed plate 1 through the positioning holes 7 on the bottom surface and both side surfaces, thereby realizing precise positioning of the measuring component and the fixed component, ensuring the position consistency of the laser ranging sensor 9 during each measurement.

[0037] The telescopic assembly includes a holding rod 11, a telescopic rod 14, a turntable 15 and a screw rod 16. A telescopic groove 1101 is provided on the inner wall of the holding rod 11. The screw rod 16 is rotated and connected in the telescopic groove 1101. The screw rod 16 is threadedly engaged with the telescopic rod 14. One end of the screw rod 16 passes through the holding rod 11, and one end of the screw rod 16 can be connected to the turntable 15. The control box 12 is installed on the side of the holding rod 11; rotating the turntable 15 drives the screw rod 16 to rotate in the telescopic groove 1101 of the holding rod 11. Since the screw rod 16 is threadedly engaged with the telescopic rod 14, and the limit block 18 on the side of the telescopic rod 14 slides with the limit groove 17 on the inner wall of the telescopic groove 1101, the telescopic rod 14 will smoothly extend and retract along the telescopic groove 1101, thereby driving the mounting seat 6 to move; in this way, the telescopic length of the telescopic rod 14 can be adjusted, which facilitates the elevation detection of the bottom of the concrete base surface such as bridges.

[0038] A display screen 1201 is installed on the surface of the control box 12, and a button 13 is also provided on the side of the gripping rod 11. The level 10, the laser ranging sensor 9, and the button 13 are all electrically connected to the display screen 1201; a wire groove 19 is provided between the telescopic rod 14 and the mounting seat 6, and a data cable 20 is connected between the laser ranging sensor 9, the level 10 and the control box 12, and the data cable 20 is located in the wire groove 19.

[0039] A plurality of limiting grooves 17 are formed on the inner wall of the telescopic groove 1101 , and a plurality of limiting blocks 18 are fixedly connected to the periphery of the telescopic rod 14 , and the limiting blocks 18 are slidably engaged with the limiting grooves 17 .

[0040] As can be seen from the above, the operator first fits the fixing plate 1 to the edge of the crack, inserts the limit plate 2 vertically into the end of the crack to lock the reference direction, then fits the baffle 3 to the other edge of the crack, and locks the fixing plate 1 and baffle 3 with screws 4 to complete the construction of the L-shaped reference frame; for ground cracks, the device is placed directly horizontally, for top cracks, it is installed upside down as a whole, and for vertical wall cracks, it needs to be installed sideways.

[0041] Then hold the cube mounting base 6 and select the positioning surface: the bottom surface faces downwards or upwards when working on the ground or top surface, and align the bottom surface positioning hole 7 with the positioning pin 5 of the fixing plate 1 to engage;

[0042] For vertical wall working condition, rotate the mounting base 6 90 degrees or 270 degrees to align the side positioning hole 7 with the positioning pin 5, press down and lock it in the same way, and the laser ranging sensor 9 is installed on the limit plate 2. At this time, the optical axis of the laser ranging sensor 9 is automatically vertical to the crack plane.

[0043] Then rotate the turntable 15 to drive the screw 16, pushing the telescopic rod 14 to move forward in a straight line along the telescopic slot 1101 of the holding rod 11, and the limit block 18 of the telescopic rod 14 slides in the limit slot 17 to prevent deviation until the mounting seat 6 reaches the working position; the laser ranging sensor 9 emits a laser to the baffle 3, and the installation position of the laser ranging sensor 9 is aligned with the side wall of the limit plate 2. The reflected signal is transmitted to the control box 12 through the wire groove 19 via the data cable 20, and the original distance value L raw The inclination data of the level 10 is displayed in real time on the display screen 1201; when there is a difference between the laser ranging sensor 9 and the edge of the limit plate 2, the measurement value is obtained by deducting the difference;

[0044] After the operator observes that the data is stable, he / she saves the measured value by pressing button 13 , and the control box 12 automatically associates the spatial coordinates of the current positioning hole 7 .

[0045] After completing the measurement, rotate the turntable 15 in the opposite direction to retract the telescopic rod 14, press the mounting base 6 to release the lock of the positioning pin 5 and the device can be disassembled. The whole set of actions ensures that the spatial position of the optical axis of the sensor 9 is completely consistent when measuring the ground, ceiling and wall through the positioning holes 7 on the three sides of the mounting base 6.

[0046] By setting up a combined structure of a fixing component (fixing plate 1, baffle 3, limit plate 2, screw 4) and a measuring component (telescopic component, mounting seat 6, laser ranging sensor 9, level 10), precise positioning and stable operation of irregular gap measurement are achieved.

[0047] The fixing plate 1 and the baffle 3 are fixed on both sides of the gap by screws 4, and with the auxiliary limit of the limit plate 2, a stable reference frame is constructed to ensure that the measurement reference does not deviate. The positioning holes 7 on the bottom and both sides of the mounting base 6 engage with the positioning pins 5 on the fixing plate 1, ensuring that the spatial position of the laser ranging sensor 9 is consistent during each measurement, solving the problem of traditional tools that make it difficult to repeatedly locate the same point, making the data consistent and comparable.

[0048] The coordination of the holding rod 11, telescopic rod 14, screw 16 and turntable 15 in the telescopic assembly, combined with the guidance of the limit block 18 and the limit groove 17, realizes the smooth extension and retraction of the measuring assembly, which is convenient for measuring special locations such as the bottom of the bridge; the laser ranging sensor 9 can measure without contacting the gap, avoiding the physical damage to the gap caused by traditional wedge rulers, and ensuring the accuracy of subsequent data analysis.

[0049] Example 2: As shown in the attached Figure 1 To the attached Figure 2 As shown: This embodiment is basically the same as the previous embodiment, except that the control box 12 has a built-in reference management module and a posture compensation module;

[0050] The Baseline Management module is used to perform:

[0051] When first installed, the initial reference value L0 measured by the laser ranging sensor 9 is stored;

[0052] Establish a unique ID for the measurement point and bind it to the initial reference value L0;

[0053] Automatically calculate the gap change in subsequent measurements: ΔL=L n -L0;

[0054] Among them L n is the nth measurement value.

[0055] The attitude compensation module is used to perform:

[0056] Dynamic update of the inclination compensation reference surface:

[0057]

[0058] where θ i Installing tilt for history;

[0059] Compensation using relative inclination:

[0060]

[0061] Among them L raw is the original output value of the laser distance sensor 9 (unit: mm), which represents the straight-line distance measured in the direction of the sensor optical axis; θ currentis the real-time integrated inclination angle (unit: radian) detected by the level 10 during the current measurement, which is obtained by the pitch angle α and the yaw angle β according to Synthesis; θ ref is the historical installation inclination reference value (unit: radian), and the arithmetic mean of the inclination of the last k valid measurements (k ≥ 5) is taken. The calculation formula is: When measuring for the first time, the current inclination angle is temporarily stored, and the average value calculation is enabled after k≥5;

[0062] L corrected The actual gap width after compensation (unit: mm), after eliminating the cosine error introduced by the tilt of the mounting reference surface; where Δθ = θ current -θ ref When the mounting base 6 is tilted, there is an angle Δθ between the laser optical axis and the crack normal, resulting in the measured value L raw Greater than the actual width (L raw =L corrected ·cos(Δθ)), this formula corrects the geometric error.

[0063] The safety mechanism is as follows: when |Δθ|>2° (about 0.035rad), the measurement system is locked and an alarm is issued.

[0064] When |θ is detected current -θ ref When |>2°: "Installation reference plane offset" will be displayed on the display 1201; measurement data output will be rejected until recalibration. 2° is the engineering experience threshold. When exceeded, the cosine error exceeds 0.06%, affecting monitoring accuracy.

[0065] From the above, it can be seen that after the operator installs the fixed plate 1, the baffle 3 and the limit plate 2 to build the reference frame according to the method of Example 1, the positioning hole 7 at the corresponding position of the mounting seat 6 is locked with the positioning pin 5 of the fixed plate 1. At this time, the control box 12 automatically detects the direction of the mounting seat 6 and activates the corresponding working mode.

[0066] When measuring for the first time, press button 13, and the laser ranging sensor 9 emits laser to the baffle 3 to measure the initial reference value L0. At the same time, the level 10 collects the pitch angle α and the yaw angle β to synthesize the comprehensive inclination angle θ1. The control box 12 generates a unique ID to bind L0 and the coordinates of the positioning hole 7, and the display screen 1201 displays "Reference setting completed".

[0067] In subsequent measurements, the rotating turntable 15 pushes the telescopic rod 14 to the working position, and the laser distance sensor 9 outputs the original value L in real time. raw , the level 10 synchronously updates the current inclination angle θ current ; The attitude compensation module automatically retrieves the average value of the last five historical inclination angles θ ref , through the formula Dynamically correct the data and highlight the compensated gap width L on the display screen 1201 c orrected and the change relative to the initial value ΔL=L corrected -L0.

[0068] If the level 10 detects |θ current -θ ref |>2°, the control box 12 immediately locks the system, the display 1201 flashes the "installation reference plane deviation" alarm and interrupts the data output, and the reference needs to be recalibrated after disassembly; after the data is stable, click button 13 to save, the compensation value L corrected Automatically associate the ID with the historical database.

[0069] During disassembly, the turntable 15 is rotated in the opposite direction to retract the telescopic rod 14 and the mounting seat 6 is pulled out, thereby completing the closed-loop operation from physical positioning, dynamic compensation to data tracing.

[0070] By setting up the built-in reference management module, attitude compensation module and safety mechanism of the control box 12, intelligent processing of measurement data and improved accuracy are achieved. The reference management module stores the initial reference value L0 of the laser ranging sensor 9, establishes a unique ID for the measurement point and automatically calculates the gap change ΔL. It can accurately track the long-term change of the gap without manual recording, thereby improving data management efficiency; the attitude compensation module calculates the reference value θ based on the historical installation inclination angle ref , and then correct the original measured value to eliminate the error caused by the change of installation inclination angle, ensuring that the true gap width can still be obtained in the tilted state;

[0071] When the tilt angle deflects by more than 2°, the system locks and issues an alarm, preventing erroneous data output and ensuring the reliability of the measurement results. Furthermore, the data cable 20 is hidden within the wire duct 19, minimizing external interference and further enhancing the stability of the device.

[0072] Example 3: Irregular longitudinal cracks (3.2m long, 1.5mm wide) were found in the bottom slab of a highway concrete box girder. Monthly monitoring of the crack width was required to assess structural safety. The crack was located at the bottom of the beam (top surface condition) and had a local inclination of 5°.

[0073] First time installation:

[0074] Benchmark construction: Fixing plate 1 is inverted and pressed against the bottom of the beam. Limiting plate 2 is inserted into the west end point of the crack. Baffle plate 3 is inserted into the south wall of the crack. Tighten screw 4 (torque 2.5 N·m).

[0075] Sensor positioning: The bottom of the mounting base 6 faces upward (0° direction), and the positioning hole 7 is locked with the positioning pin 5;

[0076] Initial calibration: Laser ranging sensor 9 outputs L raw=1.503mm, the level 10 detects the inclination angle α=-2.1°, β=0.8°→the result is θ1=2.24°;

[0077] The system generates ID: F07 and stores L0 = 1.503 mm, θ ref =2.24°(k=1), the screen displays “Benchmark Ready”.

[0078] Second measurement:

[0079] Quick positioning: The positioning hole 7 on the bottom surface of the mounting base 6 and the positioning pin 5 are locked twice (taking less than 20 seconds);

[0080] Dynamic compensation measurement: Laser distance sensor 9 output L raw =1.618mm (widened due to temperature expansion); level 10 detects θ current =2.17°;

[0081] Automatic compensation calculation:

[0082] Δθ=2.17°-2.24°=-0.07°≈-0.0012rad;

[0083] (cosine error < 0.0001%);

[0084] Display: Width 1.618mm | Change +0.115mm (ΔL = 1.618-1.503);

[0085] Click button 13 to save and upload the data to the bridge management platform.

[0086] Sixth measurement:

[0087] Abnormal working condition: baffle 3 is not completely tight during installation, causing the device to tilt;

[0088] Safety mechanism triggered: Level 10 detects θ current =4.31°, historical θ ref =2.20° (average of the previous 5 times); Δθ=4.31°-2.20°=2.11°>2° threshold; the control box 12 is immediately locked, and a red alarm "Installation reference surface offset! Recalibrate" is displayed on the screen;

[0089] Corrective action: disassemble and reinstall, and remeasure the inclination angle θ current =2.18°(qualified); after compensation L corrected =1.842mm, change ΔL=+0.339mm (winter shrinkage).

[0090] The comparison of compensation effects is shown in the following table:

[0091]

[0092] Through 12 months of cumulative monitoring, the standard deviation of data at the same crack point was reduced from ±0.15mm to ±0.03mm; the inclination alarm mechanism avoided uploading 3 erroneous data; and the change ΔL continuously exceeding 0.2mm triggered bridge maintenance.

[0093] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A device for measuring irregular gaps, characterized in that: include: A fixing assembly comprises a fixing plate (1) and a baffle (3); a side wall of the fixing plate (1) is fixedly connected to a limiting plate (2); A measuring assembly comprises a telescopic assembly, a mounting seat (6), a laser distance sensor (9), a level (10) and a control box (12); the telescopic end of the telescopic assembly is fixedly connected to the mounting seat (6), the side of the mounting seat (6) is a square structure, and the laser distance sensor (9) is arranged at the center of the mounting seat (6); the level (10) is mounted on a surface of the mounting seat (6), and the control box (12) is installed at the telescopic assembly; A plurality of positioning pins (5) are fixed on the upper surface of the fixing plate (1), and a plurality of positioning holes (7) are provided on the bottom surface and both side surfaces of the mounting seat (6), and the positioning pins (5) are engaged with the positioning holes (7).

2. The irregular gap measuring device according to claim 1, characterized in that: The telescopic assembly comprises a holding rod (11), a telescopic rod (14), a turntable (15) and a screw rod (16). A telescopic groove (1101) is provided on the inner wall of the holding rod (11). The screw rod (16) is rotatably connected in the telescopic groove (1101). The screw rod (16) is threadedly engaged with the telescopic rod (14). One end of the screw rod (16) passes through the holding rod (11), and one end of the screw rod (16) can be connected to the turntable (15). The control box (12) is installed on the peripheral side of the holding rod (11).

3. The irregular gap measuring device according to claim 2, characterized in that: A display screen (1201) is installed on the surface of the control box (12), and a button (13) is also provided on the peripheral side of the gripping rod (11). The level (10), the laser distance sensor (9), and the button (13) are all electrically connected to the display screen (1201).

4. The irregular gap measuring device according to claim 2, wherein: The inner wall of the telescopic slot (1101) is provided with a plurality of limiting slots (17), and the peripheral side of the telescopic rod (14) is fixedly connected with a plurality of limiting blocks (18), and the limiting blocks (18) are slidably matched with the limiting slots (17).

5. The irregular gap measuring device according to claim 1, wherein: A fixing portion (301) is provided on the side wall of the baffle (3), and screw holes are provided on both the fixing plate (1) and the fixing portion (301), and screws (4) are installed in the screw holes.

6. The irregular gap measuring device according to claim 3, characterized in that: A wire groove (19) is provided between the telescopic rod (14) and the mounting seat (6); a data cable (20) is connected between the laser distance sensor (9), the level (10) and the control box (12); and the data cable (20) is located in the wire groove (19).

7. The irregular gap measuring device according to claim 1, characterized in that: The control box (12) has a built-in benchmark management module for executing: When first installed, an initial reference value L0 measured by the laser distance sensor (9) is stored; Establishing a unique ID for the measurement point and binding it to the initial reference value L0; Automatically calculate the gap change in subsequent measurements: ΔL=L n -L0; Among them, L n is the nth measurement value.

8. The irregular gap measuring device according to claim 7, characterized in that: The control box (12) has a built-in attitude compensation module, which dynamically updates the inclination compensation reference plane: Among them, θ i Installing tilt for history; The attitude compensation module uses relative inclination to perform compensation: Among them, L raw is the original output value of the laser ranging sensor (9); θ current is the real-time integrated inclination angle detected by the level (10) during the current measurement; θ ref It is the historical installation inclination reference value; L corrected is the actual gap width after compensation.

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