A gun barrel inner diameter measuring instrument and a gun barrel inner diameter measuring method

Abstract

The present invention relates to the measurement of the inner diameter of a tubular structure, and is used for accurately measuring the cross-sectional dimensions of the inner diameter of a pipeline (yin-yang line). Specifically, it is a gun barrel inner diameter measuring instrument and a gun barrel inner diameter measuring method. The gun barrel inner diameter measuring instrument mainly consists of two parts, namely a measurement unit and a data processing and display unit. The measurement unit is placed in the gun barrel. By emitting laser light through the probe of the color confocal sensor module built into the measurement unit to irradiate the surface of the object to be measured and forming a reflection method, the size measurement of the inner diameter of the gun barrel is realized. The measurement optical signal is converted into an electrical signal through the optoelectronic conversion module, and after data processing through an algorithm, the measured physical size is analyzed. The display module on the data processing and display unit displays information such as the measurement value and the measurement angle. The product design fully considers the use environmental conditions and installation space requirements, and the overall design adopts an integrated design.

Description

Technical Field

[0001] The present invention relates to the measurement of the inner diameter of a tubular structure, and is used for accurately measuring the cross-sectional dimensions of the inner diameter (yin-yang line) of a pipeline. Specifically, it is a gun barrel inner diameter measuring instrument and a gun barrel inner diameter measuring method. Background Art

[0002] For the measurement of the inner diameter of a gun barrel and other long and narrow pipe-like structures, currently, factories use an extended caliper for measurement. The accuracy of the caliper is 0.02 mm, which cannot meet the requirement of a measurement accuracy of 0.01 mm. In addition, the measurement results are different for different personnel, and there are differences in the measurement process. In the prior art, the inner diameter of a gun barrel can be measured by an imaging device similar to an endoscope, but this device is expensive (in the millions) and very inconvenient to use. Summary of the Invention

[0003] In order to solve the technical problem that there is a lack of a device with a relatively low cost and accurate measurement results when measuring the inner diameter of a gun barrel and long pipe-like structures, the present invention provides a gun barrel inner diameter measuring instrument and a gun barrel inner diameter measuring method.

[0004] A gun barrel inner diameter measuring instrument according to the present invention includes a measurement unit and a data processing and display unit;

[0005] The measurement unit includes a measurement head, a measurement body, a measurement rod connected in sequence, and a gyroscope with wireless transceiver function installed on the measurement unit; the measurement head includes a camera protection cover and a camera installed inside the camera protection cover for collecting the front image; the measurement body includes a deformation ring and a tubular fixed bracket connected in sequence at the end of the camera protection cover. A color confocal sensor module with wireless transceiver function is installed inside the deformation ring and the fixed bracket. A collection hole is opened on the side wall of the deformation ring. A reflection prism is provided at the front end of the color confocal sensor module. The reflection prism can reflect the detection light emitted by the color confocal sensor module through the collection hole and at the same time collect the reflected light through the collection hole;

[0006] The camera is connected with a camera cable, and the camera cable passes through the inside of the measurement body and the measurement rod from front to back and is led out; the color confocal sensor module is connected with an optical cable, and the optical cable passes through the inside of the measurement body and the measurement rod from front to back and is led out;

[0007] The data processing and display unit includes an integrated wireless transceiver module, a power conversion module, a data calculation module, a data processing module, an optoelectronic conversion module, and a display module; the power conversion module is used to connect to an external power supply and supply power to other modules. The wireless transceiver module communicates wirelessly with the color confocal sensor module and the gyroscope, controls the operation of the color confocal sensor module, and at the same time acquires the rotation angle data of the measurement unit collected by the gyroscope and transmits it to the data calculation module; the camera line is connected to the display module, the optical cable is connected to the optoelectronic conversion module, the optoelectronic conversion module is connected to the data calculation module through the data processing module, and the data calculation module is connected to the display module.

[0008] The measuring instrument receives the measurement optical signal through the optical cable. The optoelectronic conversion module converts the measurement optical signal into an electrical signal, and then through algorithm-based data processing, the measured physical dimension is analyzed. The display module on the data processing and display unit displays information such as the measurement value and the measurement angle.

[0009] Further, a handwheel is installed at the end of the measuring rod, and the gyroscope is installed inside the handwheel; the handwheel is provided with a central hole for the optical cable and the camera line to pass through, and angle scale lines are engraved on the outer circumference of the handwheel.

[0010] Further, length scale lines are engraved on the outer surface of the measuring rod along the axial direction.

[0011] Further, a slider is slidably sleeved on the measuring rod. The end of the slider has a radially protruding structure, and a limiting bolt for limiting the slider is provided on the protruding structure.

[0012] Further, a locking nut is fixedly connected to the end of the camera protective cover; the front end of the fixed bracket is a reduced-diameter extension section, and this extension section extends into the deformation ring and is clamped; internal threads are provided on the inner wall of the front end of the extension section, the end of the locking nut protrudes backward, and external threads are provided on the outer wall of the protruding section. The locking nut is screwed onto the front end of the extension section through the protruding section; a hole is provided at the position corresponding to the collection hole on the extension section;

[0013] The end of the fixed bracket is connected to a movable nut. A limiting ring is sleeved on the middle section of the movable nut, and a connecting block is threadedly connected to the outer ring of the end of the movable nut. The end of the connecting block is threadedly connected to the measuring rod.

[0014] Further, the measuring rod is of a multi-section structure, and adjacent sections are connected by connecting screw sleeves.

[0015] A method for measuring the inner diameter of a gun barrel according to the present invention includes the following steps: Insert the measuring head and the measuring body of the measuring unit into the inner part of the gun barrel or narrow tube to be measured, and leave the end of the measuring rod outside the gun barrel or narrow tube to be measured. The deformation ring of the measuring unit is in interference fit with the inner wall of the gun barrel or narrow tube to be measured. After the position of the measuring unit is determined, the data processing and display unit controls the probe of the color confocal sensor module built in the measuring unit to emit laser light to irradiate the inner wall of the gun barrel or narrow tube to be measured through the wireless transceiver module, and at the same time collect the reflected light of the inner wall of the gun barrel or narrow tube to be measured. Rotate the measuring unit one week, and the color confocal sensor module collects the reflected light signals of a certain cross-section circumference inside the gun barrel or narrow tube to be measured, and takes it as the measuring light signal and transmits it to the data processing and display unit through the optical cable;

[0016] The power conversion module converts the external power supply into the power supply required by the measuring instrument to supply power to each module; the wireless transceiver module communicates with the gyroscope to obtain the rotation angle data; the measuring light signal is transmitted to the photoelectric conversion module through the optical cable, and the photoelectric conversion module converts the measuring light signal into an analog voltage signal, and the data processing module converts the analog voltage signal into a data volume signal and sends it to the data calculation module as the measuring light data; the data calculation module synchronously calculates the received rotation angle data and the measuring light data, and finally obtains the inner diameter measurement value of a certain cross-section of the gun barrel or narrow tube to be measured, and displays it through the display module. At the same time, the display module displays the internal image of the gun barrel or narrow tube to be measured collected by the camera in real time.

[0017] Further, the algorithm for the data calculation module to perform the calculation is as follows: Let the distance between the main optical axis of the color confocal sensor module and the central axis of the measuring unit be b, and the distance between the gun barrel or narrow tube to be measured and the main optical axis of the color confocal sensor module measured at a certain angle be a. Then the inner radius of the gun barrel or narrow tube at a certain angle is R(x)=a + b, where 0°≤x≤180°, and the inner diameter of the gun barrel or narrow tube to be measured is obtained as d = R(x) + R(x + 180°); Rotate the measuring unit one week to obtain multiple groups of inner diameter data of the gun barrel or narrow tube to be measured, and take the average to obtain the final inner diameter measurement value of the gun barrel or narrow tube to be measured.

[0018] Advantages of the present invention: The measuring instrument and the measuring method of the present invention have high measurement accuracy, and the portable design is convenient to carry; it meets the requirements of the factory environment: waterproof and dustproof; the temperature measurement range is 15 - 30 degrees Celsius; the measurement accuracy can reach 0.0001 mm; the technical requirements for personnel are not high and no professional training is required. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the measuring unit.

[0020] Figure 2 It is a schematic external structure diagram of the measuring head and the measuring body.

[0021] Figure 3 It is a sectional view of the measuring head and the measuring body.

[0022] Figure 4 It is a schematic diagram of the emission and collection of reflected light by the color confocal sensor module.

[0023] Figure 5 It is a schematic structural diagram of the deformation ring.

[0024] Figure 6 It is a schematic diagram of the deformation of the deformation ring.

[0025] Figure 7 It is a schematic structural diagram of the slider.

[0026] Figure 8 It is a schematic diagram of the length scale on the measuring rod.

[0027] Figure 9 It is a schematic diagram of the external structure of the handwheel.

[0028] Figure 10 It is a schematic diagram of the internal structure of the handwheel.

[0029] Figure 11 It is a cross-linking relationship diagram of the measuring unit and the data processing and display unit.

[0030] Figure 12 It is a schematic diagram of the internal picture of the gun barrel taken by the camera.

[0031] Figure 13 It is a schematic diagram of the algorithm of the data settlement module Figure 1 .

[0032] Figure 14 It is a schematic diagram of the algorithm of the data settlement module Figure 2 .

[0033] Figure 15 It is a schematic diagram of the measurement process displayed by the display module Figure 1 .

[0034] Figure 16 It is a schematic diagram of the measurement process displayed by the display module Figure 2 .

[0035] 1 - Camera, 2 - Camera protection cover, 3 - Locking nut, 4 - Deformation ring, 5 - Color confocal sensor module, 6 - Fixed bracket, 7 - Movable nut, 8 - Limit ring, 9 - Connecting block, 10 - Optical cable, 11 - Camera cable, 12 - Reflecting prism, 13 - Collection hole, 14 - Slider, 15 - Limit bolt, 16 - Measuring rod, 17 - Connecting sleeve, 18 - Handwheel, 19 - Gyroscope, 20 - L-shaped mounting bracket. Detailed implementation method

[0036] The inner diameter measuring instrument of the present invention mainly consists of two parts, namely a measuring unit and a data processing and display unit. The measuring unit is placed in the gun barrel. The color confocal sensor module 5 built into the measuring unit emits laser light to irradiate the surface of the object to be measured, and forms a reflection method to realize the dimensional measurement of the inner diameter of the gun barrel. The data processing and display unit receives the measured optical signal through the optical cable 10, converts the measured optical signal into an electrical signal through the optoelectronic conversion module, and then processes the data through an algorithm to analyze the measured physical dimensions. The display module (display screen) on the data processing and display unit displays information such as the measured value and the measurement angle. The product design fully considers the use environmental conditions and the installation space requirements, and the overall design adopts an integrated design. The following further introduces the specific implementation plan of the present invention in conjunction with the drawings.

[0037] As Figures 1-4 shown, an inner diameter measuring instrument of a gun barrel includes a measuring unit and a data processing and display unit;

[0038] The measuring unit includes a measuring head, a measuring body, a measuring rod 16 connected in sequence, and a gyroscope 19 with wireless transceiver function installed on the measuring unit; the measuring head includes a camera protection cover 2 and a camera 1 installed inside the camera protection cover 2 for collecting the front image; the measuring body includes a deformation ring 4 and a tubular fixed bracket 6 connected in sequence at the end of the camera protection cover 2. A color confocal sensor module 5 with wireless transceiver function is installed inside the deformation ring 4 and the fixed bracket 6. A collection hole 13 is opened on the side wall of the deformation ring 4. A reflection prism 12 is provided at the front end of the color confocal sensor module 5. The reflection prism 12 can reflect the detection light emitted by the color confocal sensor module 5 out through the collection hole 13, and at the same time collect the reflected light through the collection hole 13;

[0039] The camera 1 is connected with a camera line 11, and the camera line 11 passes through the inside of the measuring body and the measuring rod 16 from front to back and is led out; the color confocal sensor module 5 is connected with an optical cable 10, and the optical cable 10 passes through the inside of the measuring body and the measuring rod 16 from front to back and is led out;

[0040] As Figure 11As shown in the figure, the data processing and display unit includes an integrated wireless transceiver module, a power conversion module, a data calculation module, a data processing module, an optoelectronic conversion module, and a display module; the power conversion module is used to connect to an external power supply and supply power to other modules. The wireless transceiver module communicates wirelessly with the color confocal sensor module 5 and the gyroscope 19, controls the operation of the color confocal sensor module 5, and at the same time acquires the rotation angle data of the measurement unit collected by the gyroscope 19 and transmits it to the data calculation module; the camera cable 11 is connected to the display module, the optical cable 10 is connected to the optoelectronic conversion module, the optoelectronic conversion module is connected to the data calculation module through the data processing module, and the data calculation module is connected to the display module. The length of the measuring head and the measuring body is about 300 mm, and the length of the optical cable at the tail is about 5 meters. The camera protection cover 2 is designed to be conical, with a semi-circular front end and a smooth surface; the material is polytetrafluoroethylene, and the camera 1 is installed inside, which can not only protect the camera 1 but also avoid scratching the inner wall of the gun barrel.

[0041] Combined with Figure 9 、 10 As shown in the figure, a handwheel 18 is installed at the end of the measuring rod 16. Inside the handwheel, a gyroscope 19, a wireless module, and a battery are installed; the handwheel 18 is provided with a central hole for the optical cable 10 and the camera cable 11 to pass through. Angle scale lines are engraved on the outer circumference of the handwheel 18 to facilitate observing the rotation angle of the measuring rod 16; the lengths of the external optical cable 10 and the camera cable 11 are at least more than one meter, so when the measuring rod 16 rotates one week, it will not affect the connection between the optical cable 10 and the camera cable 11 and the data processing and display unit. The length of the handwheel 18 with the rod is about 300 mm.

[0042] As Figure 8 shown in the figure, length scale marks are engraved on the outer surface of the measuring rod 16 along the axial direction to facilitate observing and recording the length of the measuring rod 16 extending into the gun barrel.

[0043] As Figure 7 shown in the figure, a slider 14 is slidably sleeved on the measuring rod 16. The end of the slider 14 has a radially protruding structure, and a limit bolt 15 for limiting the slider 14 is equipped on the protruding structure. The protruding structure is convenient for being stuck at the external port of the gun barrel to position the axial direction of the measuring rod 16 and improve the measurement accuracy; the limit bolt 15 is used to position and unlock the slider 14.

[0044] As Figure 3As shown, a locking nut 3 is fixedly connected to the end of the camera protective cover 2; the front end of the fixed bracket 6 is a reduced-diameter extension section, which extends into the deformation ring 4 and is clamped; an internal thread is provided on the inner wall of the front end of the extension section, and the end of the locking nut 3 protrudes backward and an external thread is provided on the outer wall of the protruding section. The locking nut 3 is spirally connected to the front end of the extension section through the protruding section; a hole is provided at a position corresponding to the acquisition hole 13 on the extension section; the end of the fixed bracket 6 is connected to a movable nut 7, a limiting ring 8 is sleeved on the outer ring of the middle section of the movable nut 7, and the outer ring of the end of the movable nut 7 is threadedly connected to a connecting block 9, and the end of the connecting block 9 is threadedly connected to the measuring rod 16.

[0045] As Figure 1 can be seen, the measuring rod 16 is a multi-section structure, and adjacent sections are connected by a connecting sleeve 17. The length of each section is 500 mm. The measuring rod is generally composed of 5 sections and can be lengthened or shortened according to specific situations.

[0046] The deformation ring 4 is used to measure the small changes in the caliber of the measuring instrument. The material is polytetrafluoroethylene to protect the body tube from being scratched. When it extends into the body tube, the contact surface (annular) will have an interference fit with the body tube to eliminate the gap. As Figure 5 shown, there are two radial protrusions on it. As Figure 6 shown, the deformation ring 4 expands to different degrees in different spaces. When the diameter is too small, the protrusions of the deformation ring 4 tend to be flat; when the diameter is too large, the protrusions of the deformation ring 4 tend to be steeper. The maximum expansion diameter of the deformation ring 4 is (40.1 ± 0.05 mm).

[0047] The data processing and display unit is integrated into a body, and its structure conforms to ergonomics, with good human-machine operability; the external dimensions are approximately 480´370´205 mm, and it can be placed in a box for easy carrying; each component of the measuring unit is also equipped with a corresponding toolbox. After use, each component of the measuring unit can be disassembled and placed in the toolbox and carried together with the body.

[0048] The present invention also provides a method for measuring the inner diameter of a body tube, which specifically includes the following steps: inserting the measuring head and the measuring body of the measuring unit into the internal part of the body tube or narrow tube to be measured, leaving the end of the measuring rod 16 outside the body tube or narrow tube to be measured, and making the deformation ring 4 of the measuring unit have an interference fit with the inner wall of the body tube or narrow tube to be measured; after the position of the measuring unit is determined, the data processing and display unit controls the probe of the color confocal sensor module 5 built in the measuring unit to emit laser light to irradiate the inner wall of the body tube or narrow tube to be measured through the wireless transceiver module, and at the same time collects the reflected light of the inner wall of the body tube or narrow tube to be measured; rotating the measuring unit one week, the color confocal sensor module 5 collects the reflected light signals of a certain cross-section circumference inside the body tube or narrow tube to be measured, takes it as the measuring light signal and transmits it to the data processing and display unit through the optical cable 10;

[0049] The power conversion module converts the external power supply into the power supply required by the system to supply power to each module; the wireless transceiver module communicates with the gyroscope 19 to obtain the rotation angle data; the measurement optical signal is transmitted to the photoelectric conversion module through the optical cable 10, and the photoelectric conversion module converts the measurement optical signal into an analog voltage signal. The data processing module converts the analog voltage signal into a data volume signal and sends it to the data calculation module as the measurement optical data; the data calculation module synchronously calculates the received rotation angle data and measurement optical data, and finally obtains the inner diameter measurement value of a certain cross-section of the tube or narrow tube to be measured, and displays it through the display module. At the same time, the display module displays the internal image of the tube or narrow tube to be measured collected by the camera 1 in real time.

[0050] Such as Figure 12 is the internal image of the tube captured by the camera. Such as Figure 13 、 14 As shown, the algorithm for the data calculation module during calculation is as follows: Let the distance between the main optical axis of the color confocal sensor module 5 and the central axis of the measurement unit be b, and the distance between the tube or narrow tube to be measured and the main optical axis of the color confocal sensor module measured by the color confocal sensor module 5 at a certain angle be a. Then the inner radius of a certain angle of the tube or narrow tube to be measured is R(x) = a + b, where 0° ≤ x ≤ 180°. Furthermore, the inner diameter of the tube or narrow tube to be measured is d = R(x) + R(x + 180°); rotate the measurement unit one week to obtain multiple groups of inner diameter data of the tube or narrow tube to be measured, and take the average to obtain the final inner diameter measurement value of the tube or narrow tube to be measured. As an implementation manner, as Figure 13 shown, the reflecting prism 12 can be installed inside the fixed bracket 6 and the deformation ring 4 through an L-shaped mounting bracket 20, and the color confocal sensor module 5 is also installed close to the L-shaped mounting bracket 20, or the two can also be installed together.

[0051] Such as Figure 15 、 16 As shown is the display screen on the display module during the specific measurement of the present invention. The rotation angle and the measurement data corresponding to each angle can be displayed in real time on the screen.

Claims

1. A barrel inner diameter measuring instrument, comprising a measuring unit and a data processing and display unit, characterized in that: The measuring unit comprises a measuring head, a measuring body, a measuring rod (16) connected in sequence, and a gyroscope (19) with a wireless transceiver function installed on the measuring unit; the measuring head comprises a camera protection cover (2) and a camera (1) installed inside the camera protection cover (2) for collecting front images; the measuring body comprises a deformation ring (4) and a tubular fixed bracket (6) connected in sequence to the end of the camera protection cover (2); a color confocal sensor module (5) with a wireless transceiver function is installed inside the deformation ring (4) and the fixed bracket (6); a collection hole (13) is opened on the side wall of the deformation ring (4); a reflection prism (12) is provided at the front end of the color confocal sensor module (5); the reflection prism (12) is capable of reflecting detection light emitted by the color confocal sensor module (5) through the collection hole (13) and collecting reflected light through the collection hole (13); The camera (1) is connected to a camera line (11), which passes through the inside of the measuring body and the measuring rod (16) from front to back and is led out; the color confocal sensor module (5) is connected to an optical cable (10), which passes through the inside of the measuring body and the measuring rod (16) from front to back and is led out; The data processing and display unit comprises a wireless transceiver module, a power conversion module, a data solution module, a data processing module, a photoelectric conversion module and a display module integrated in a box; the power conversion module is used to connect an external power supply and supply power to other modules; the wireless transceiver module wirelessly communicates with the color confocal sensor module (5) and the gyroscope (19) to control the action of the color confocal sensor module (5), and simultaneously obtains the rotation angle data of the measurement unit collected by the gyroscope (19) and transmits it to the data solution module; the camera line (11) is connected to the display module, the optical cable (10) is connected to the photoelectric conversion module, the photoelectric conversion module is connected to the data solution module through the data processing module, and the data solution module is connected to the display module; The end of the camera protection cover (2) is fixedly connected with a locking nut (3); the front end of the fixing bracket (6) is an extension section with a reduced diameter, and the extension section extends into the interior of the deformation ring (4) and is clamped; the inner wall of the front end of the extension section is provided with an internal thread, the end of the locking nut (3) protrudes backwards and the outer wall of the protruding section is provided with an external thread, and the locking nut (3) is spirally connected to the front end of the extension section through the protruding section; a hole is provided at a position corresponding to the collection hole (13) on the extension section; the deformation ring (4) has two radial protrusions, and when the deformation ring (4) is extended into the barrel, the contact surface is interference-fitted with the barrel to eliminate the gap; The end of the fixed bracket (6) is connected with a movable nut (7), the middle outer ring of the movable nut (7) is sleeved with a limit ring (8), the outer ring of the end of the movable nut (7) is threadedly connected with a connecting block (9), and the end of the connecting block (9) is connected to the measuring rod (16) through a thread.

2. A barrel inner diameter measuring instrument as claimed in claim 1, characterized in that: A hand wheel (18) is installed at the end of the measuring rod (16), and the gyroscope (19) is installed inside the hand wheel (18); the hand wheel (18) has a central hole for the optical cable (10) and the camera line (11) to pass through, and the outer circumference of the hand wheel (18) is engraved with angle scale lines.

3. A barrel inner diameter measuring instrument as claimed in claim 2, characterized in that: The outer surface of the measuring rod (16) is engraved with a length scale along the axial direction.

4. A barrel inner diameter measuring instrument as claimed in any one of claims 1 to 3, characterized in that: A slider (14) is slidably sleeved on the measuring rod (16), the end of the slider (14) is a radially protruding structure, and the protruding structure is provided with a limiting bolt (15) for limiting the position of the slider (14).

5. A barrel inner diameter measuring instrument as claimed in any one of claims 1 to 3, characterized in that: The measuring rod (16) is a multi-section structure, and adjacent sections are connected via connecting screw sleeves (17).

6. A method for measuring the inner diameter of a barrel, implemented by using a barrel inner diameter measuring instrument according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: extending a measuring head and a measuring body of a measuring unit into the interior of a barrel or a narrow tube to be measured, leaving the end of a measuring rod (16) outside the barrel or the narrow tube to be measured, and having an interference fit between a deformation ring (4) of the measuring unit and the inner wall of the barrel or the narrow tube to be measured; after the position of the measuring unit is determined, a data processing and display unit controls a probe of a color confocal sensor module (5) built into the measuring unit through a wireless transceiver module to emit laser light to illuminate the inner wall of the barrel or the narrow tube to be measured, and simultaneously collects reflected light from the inner wall of the barrel or the narrow tube to be measured; rotating the measuring unit one circle, the color confocal sensor module (5) collects reflected light signals around a certain cross section inside the barrel or the narrow tube to be measured, and transmits the reflected light signals as measurement light signals to the data processing and display unit through an optical cable (10); The power conversion module converts the external power supply into the power supply required by the measuring instrument to supply power to each module; the wireless transceiver module communicates with the gyroscope (19) to obtain the rotation angle data; the measurement light signal is transmitted to the photoelectric conversion module through the optical cable (10); the photoelectric conversion module converts the measurement light signal into an analog voltage signal; the data processing module converts the analog voltage signal into a data quantity signal and sends it to the data solution module as the measurement light data; the data solution module synchronously solves the received rotation angle data and the measurement light data, and finally obtains the inner diameter measurement value of a certain section of the barrel or narrow tube to be measured, and displays it through the display module, and at the same time, the display module displays the internal image of the barrel or narrow tube to be measured collected by the camera (1) in real time.

7. A method for measuring the inner diameter of a barrel as claimed in claim 6, characterized in that: The algorithm used by the data solving module for solving is as follows: assuming that the distance between the main optical axis of the color confocal sensor module (5) and the central axis of the measuring unit is b, and the distance between the main optical axis of the color confocal sensor module and the tube to be measured measured by the color confocal sensor module (5) at a certain angle is a, then the inner radius of the tube to be measured at a certain angle is R (x) = a + b, where 0° ≤ x ≤ 180°, and the inner diameter of the tube to be measured is d = R (x) + R (x + 180°); the measuring unit is rotated once to obtain multiple sets of inner diameter data of the tube to be measured, and the final inner diameter measurement value of the tube to be measured is obtained by averaging.

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