Elbow ovality measuring method

Abstract

The invention provides a method for measuring the ovality of a bent pipe, and belongs to the technical field of measurement and detection. The elbow ellipticity measuring device solves the problems that when the ellipticity of an elbow is measured, the measuring precision is not high, and the measuring error is large. The invention discloses a method for measuring the ovality of a bent pipe. The method comprises the following steps: S1, clamping the bent pipe on a clamping device; s2, a motion platform of the industrial camera I shoots the position over the bent section of the bent pipe to determine the bent center of the bent pipe; s3, the center of the rotating platform coincides with the bending center of the bent pipe; s4, the motion platform of the second industrial camera shoots the section of the straight section of the bent pipe and determines the center of the section of the bent pipe; s5, the center of the annular detector coincides with the center of the section of the bent pipe; s6, sampling is conducted on the bent pipe through the annular detector; and S7, resetting the device. The method has the advantages that the bending path of the bent pipe is accurately tracked, the bent section center and the section center of the bent pipe are accurately positioned, the measurement precision is high, and the error is small.

Description

Technical Field

[0001] The invention relates to the field of measurement and detection technology, in particular to a method for measuring the ovality of a bent pipe. Background Art

[0002] In some current high-precision usage scenarios, the accuracy requirements for pipe bending are very high, which is directly related to the overall quality and performance of the product. In response to this demand, it is particularly important to accurately scan the pipe bending to ensure that its accuracy meets the standard.

[0003] The current non-contact measurement and 3D scanning technology do not accurately track the curved path of the curved pipe during the measurement of the curved pipe, resulting in poor measurement accuracy. Secondly, in the process of scanning the curved pipe, the center of the curved section and the center of the cross section of the curved pipe need to be located first, and the current positioning method is not accurate enough. Finally, when measuring the ovality of the curved pipe, the measurement accuracy is not high and the measurement error is large. Summary of the invention

[0004] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides a method for measuring the ovality of a bent pipe, which has the advantages of accurately tracking the curved path of the bent pipe, accurately positioning the center of the curved section and the center of the cross section of the bent pipe, and having high measurement accuracy and small error. This solves the problem that the current non-contact measurement and three-dimensional scanning technology, in the process of measuring the bent pipe, does not accurately track the curved path of the bent pipe, resulting in poor measurement accuracy. Secondly, in the process of scanning the bent pipe, it is first necessary to locate the center of the curved section and the center of the cross section of the bent pipe, and the current positioning method is not accurate enough. Finally, when measuring the ovality of the bent pipe, the measurement accuracy is not high and the measurement error is large.

[0005] (II) Technical solution In order to achieve the above-mentioned purpose of accurately tracking the curved path of the curved pipe, accurately positioning the center of the curved section and the cross-section center of the curved pipe, and having high measurement accuracy and small error, the present invention provides the following technical solutions: A method for measuring the ovality of a curved pipe, comprising the following steps: S1: Clamp and fix the two ends of the elbow on the clamping device; S2: Move the industrial camera-motion platform to the top of the middle part of the bending section of the bent pipe, shoot the bent pipe and generate an image of the bent pipe, and determine the position of the bending center of the bent pipe; S3: The XY motion platform controls the center of the rotating platform to coincide with the bending center of the bent pipe; S4: Move the second motion platform of the industrial camera to a position where one end of the straight section of the curved pipe is directly opposite to the cross section, photograph the cross section of the straight section of the curved pipe and generate an image of the cross section of the straight section of the curved pipe, and determine the center position of the cross section of the straight section of the curved pipe; S5: The XZ motion platform controls the center of the annular detector to coincide with the center of the curved pipe section; S6: The detection inside the annular detector performs reciprocating semicircular motion around the curved pipe section for sampling, and the rotating platform rotates intermittently along the curved path of the curved pipe until the rotating platform rotates 90° and stops sampling; S7: The device is reset.

[0006] Preferably, the XY motion platform includes a linear motion module 1 and a linear motion module 2, the linear motion module 1 and the linear motion module 2 are respectively provided with a motor 1 and a motor 2, the direction of the linear slide rail of the linear motion module 1 is set to the X-axis direction of the device mechanical coordinate system, the direction close to the motor 1 is the positive direction of the X-axis, and the farthest end from the motor 1 within the stroke is the X-axis origin of the device mechanical coordinate system; the direction of the linear slide rail of the linear motion module 2 is set to the Y-axis direction of the device mechanical coordinate system, the direction away from the motor 2 is the positive direction of the Y-axis, and the closest end to the motor 2 within the stroke is the Y-axis origin of the device mechanical coordinate system, the XZ motion platform includes a linear motion module 3, the linear motion module 3 is provided with a motor 3, the direction of the vertical linear slide rail of the linear motion module 3 is set to the Z-axis direction of the device mechanical coordinate system, the direction close to the motor 3 is the positive direction of the Z-axis, and the farthest end from the motor 3 within the stroke is the Z-axis origin of the device mechanical coordinate system; When the device is in the initial position, the rotating platform has a position coordinate in the device mechanical coordinate system, which is the initial position of the center of the rotating platform, and the center of the annular detector has a position coordinate in the device mechanical coordinate system, which is the initial position of the center of the annular detector.

[0007] Preferably, the industrial camera one motion platform comprises a linear motion module four and a linear motion module five, the linear motion module four and the linear motion module five are respectively provided with a motor four and a motor five, the linear motion module four is also provided with an industrial camera one, the linear slide rail direction of the linear motion module four is set to the X-axis direction of the industrial camera one coordinate system, the direction away from the motor four is the positive direction of the X-axis, the closest end to the motor four within the stroke is the X-axis origin of the industrial camera one coordinate system, the linear slide rail direction of the linear motion module five is set to the Y-axis direction of the industrial camera one coordinate system, the direction close to the motor five is the positive direction of the Y-axis, the farthest end from the motor five within the stroke is the Y-axis origin of the industrial camera one coordinate system, the X-axis origin of the industrial camera one coordinate system and the Y-axis origin of the industrial camera one coordinate system are set to the origin of the industrial camera one coordinate system, which is also the initial position of the industrial camera one; The industrial camera 2 motion platform is provided with a motor 6, and the linear slide rail direction of the industrial camera 2 motion platform is set to the Z-axis direction of the industrial camera 2 coordinate system, the direction close to the motor 6 is the positive direction of the Z-axis, and the farthest end from the motor 6 within the stroke is the Z-axis origin of the industrial camera 2 coordinate system. The Z-axis origin of the industrial camera 2 coordinate system is set to the origin of the industrial camera 2 coordinate system, which is also the initial position of the industrial camera 2.

[0008] Preferably, in step S1, the clamping device includes two clamps, which are provided with V-blocks and gas-liquid speed-stabilizing cylinders. The two ends of the bent pipe are manually placed on the V-blocks of the two clamps respectively, and the gas-liquid speed-stabilizing cylinders are manually controlled to clamp and fix the two ends of the bent pipe to keep the overall bent pipe horizontal and fixed. The two gas-liquid speed-stabilizing cylinders can be controlled separately.

[0009] Preferably, in steps S2 and S3, the linear motion module four and the linear motion module five in the industrial camera one motion platform move the industrial camera one to above the bending section of the bent pipe, and the industrial camera one takes a picture of the positioned bent pipe to generate an image of the bent pipe, and the computer calculates the bending center of the bent pipe and determines the coordinates of the bending center in the industrial camera one coordinate system. The absolute position and relative position of the industrial camera one coordinate system and the device mechanical coordinate system are fixed, so the coordinates of the bending center in the device mechanical coordinate system can be calculated, and the computer calculates the displacement required to move the center of the rotating platform to the bending center of the bent pipe, and the XY motion platform controls the center of the rotating platform to move in the XY coordinate plane so that the center of the rotating platform coincides with the bending center of the bent pipe.

[0010] Preferably, in step S4, the industrial camera 2 on the industrial camera 2 motion platform is moved to a position opposite to the cross-section at one end of the straight segment of the curved pipe, and the industrial camera 2 captures the positioned cross-section of the straight segment of the curved pipe to generate an image of the cross-section of the straight segment of the curved pipe, and the computer calculates the center position of the cross-section of the straight segment of the curved pipe, and determines the coordinates of the center of the cross-section of the straight segment of the curved pipe in the coordinate system of the industrial camera 2. The absolute position and relative position of the coordinate system of the industrial camera 2 and the mechanical coordinate system of the device are fixed, so the coordinates of the center of the cross-section of the curved pipe in the mechanical coordinate system of the device can be calculated.

[0011] Preferably, in step S5, the center of the annular detector has a new position coordinate in the mechanical coordinate system of the device after the rotating platform moves. The computer calculates the displacement required to move the center of the annular detector to the center of the curved pipe section, and the XZ motion platform controls the center of the annular detector to move in the XZ coordinate plane so that the center of the annular detector coincides with the center of the curved pipe section.

[0012] Preferably, in step S6, two laser sensors 180° apart are provided on the detection ring inside the annular detector, the detection ring rotates 180°, and then the rotating platform rotates 10°; then the detection ring rotates 180° in the opposite direction, and then the rotating platform rotates 10°; the cycle is repeated until the rotating platform rotates 90° and stops.

[0013] Preferably, the line connecting the two laser sensors passes through the center of the annular detector, and the path of the rotational motion forms a circle with a diameter of D. The two laser sensors detect the distance s from the laser emission source to the surface of the curved pipe, and a sampling is performed every 0.1°. Each laser sensor detects 1800 data, and a total of 3600 data are collected. The 1800 pairs of data are added together to obtain 1800 data, and the largest data p and the smallest data q are taken out. The maximum outer diameter d of the ellipse max =Dq, the minimum outer diameter of the ellipse d min =Dp, ellipticity φ = (d max -d min ) / d0, d0 is the original outer diameter of the pipe.

[0014] (III) Beneficial effects Compared with the prior art, the present invention provides a method for measuring the ovality of a bent pipe, which has the following beneficial effects: The method for measuring the ovality of a bent pipe is to clamp and fix the two ends of the bent pipe on a clamping device, and then move the first motion platform of the industrial camera to the top of the middle part of the bent section of the bent pipe, shoot the bent pipe and generate an image of the bent pipe, and determine the position of the bending center of the bent pipe. The XY motion platform controls the center of the rotating platform to coincide with the bending center of the bent pipe. The second motion platform of the industrial camera is moved to the position of the cross section at one end of the bent pipe, and the cross section of the bent pipe is photographed and an image of the cross section of the bent pipe is generated to determine the center position of the cross section of the bent pipe. The XZ motion platform controls the center of the annular detector to coincide with the center of the cross section of the bent pipe. The detection inside the annular detector performs a reciprocating semicircular motion around the cross section of the bent pipe for sampling, and the rotating platform intermittently rotates along the bending path of the bent pipe until the rotating platform rotates 90° and stops sampling. Finally, the sampled data is calculated to obtain the ovality of the bent pipe, so as to determine whether the bent pipe meets the accuracy requirements. Thereby, the bending path of the bent pipe is accurately tracked, the center of the bending section of the bent pipe and the center of the cross section are accurately positioned, and the measurement accuracy is high and the error is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a measuring device structure of a method for measuring ovality of a bent pipe according to the present invention; Figure 2 A schematic diagram of the internal structure of a measuring device for measuring the ovality of a bent pipe according to the present invention; Figure 3A top view of the internal structure of a measuring device for measuring the ovality of a bent pipe according to the present invention; Figure 4 A schematic diagram of the XY motion platform structure of a method for measuring the ovality of a bent pipe according to the present invention; Figure 5 A schematic diagram of the structure of a rotating platform of a method for measuring the ovality of a bent pipe according to the present invention; Figure 6 A schematic diagram of the XZ motion platform structure of a method for measuring the ovality of a bent pipe according to the present invention; Figure 7 A schematic diagram of the structure of a ring detector for measuring the ovality of a bent pipe according to the present invention; Figure 8 A schematic diagram of the structure of an industrial camera and a motion platform of a method for measuring the ovality of a bent pipe according to the present invention; Fig. 9 A schematic diagram of the structure of the second motion platform of an industrial camera in a method for measuring the ovality of a bent pipe according to the present invention; Fig.10 The present invention is a schematic diagram of the structure of a clamping device for measuring the ovality of a bent pipe.

[0016] In the figure: 1. XY motion platform; 11. Linear motion module 1; 111. Motor 1; 12. Linear motion module 2; 121. Motor 2; 2. Rotating platform; 3. XZ motion platform; 31. Linear motion module three; 311. Motor three; 4. Ring detector; 41. Detection ring; 42. Laser sensor; 5. Industrial camera one motion platform; 51. Linear motion module four; 511. Motor four; 52. Linear motion module five; 521. Motor five; 53. Industrial camera one; 6. Industrial camera 2 motion platform; 61. Motor 6; 62. Industrial camera 2; 7. Clamping device; 71. Clamp; 711. V-block; 712. Gas-liquid speed-stabilizing cylinder. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] See also Figure 1-Figure 10A method for measuring the ovality of a bent pipe. First, a coordinate system needs to be determined before measurement. In this measurement method, three coordinate systems are used to locate the position of the bent pipe, making the measurement result more accurate.

[0019] Device mechanical coordinate system: XY motion platform 1 includes linear motion module 11 and linear motion module 2 12, linear motion module 11 and linear motion module 2 12 are respectively provided with motor 1 111 and motor 2 121, the direction of linear slide rail of linear motion module 11 is set to X-axis direction of device mechanical coordinate system, the direction close to motor 111 is the positive direction of X-axis, and the farthest end from motor 111 within the stroke is the origin of X-axis of device mechanical coordinate system; the direction of linear slide rail of linear motion module 2 12 is set to Y-axis direction of device mechanical coordinate system, the direction away from motor 2 121 is the positive direction of Y-axis, and the closest end to motor 2 121 within the stroke is the origin of Y-axis of device mechanical coordinate system, XZ motion platform 3 includes linear motion module 3 31, linear motion module 3 31 is provided with motor 3 311, the direction of vertical linear slide rail of linear motion module 3 31 is set to Z-axis direction of device mechanical coordinate system, the direction close to motor 3 311 is the positive direction of Z-axis, and the farthest end from motor 3 311 within the stroke is the origin of Z-axis of device mechanical coordinate system; When the device is in the initial position, the rotating platform 2 has a position coordinate in the device mechanical coordinate system, which is the initial position of the center of the rotating platform 2, and the center of the annular detection has a position coordinate in the device mechanical coordinate system, which is the initial position of the center of the annular detector 4.

[0020] Industrial camera 153 coordinate system: The industrial camera 1 motion platform 5 includes a linear motion module 451 and a linear motion module 52. The linear motion module 451 and the linear motion module 52 are respectively provided with a motor 4511 and a motor 521. The linear motion module 451 is also provided with an industrial camera 153. The direction of the linear slide rail of the linear motion module 451 is set to the X-axis direction of the industrial camera 153 coordinate system. The direction away from the motor 4511 is the positive direction of the X-axis. The end closest to the motor 4511 within the stroke is the X-axis origin of the industrial camera 153 coordinate system. The direction of the linear slide rail of the linear motion module 552 is set to the Y-axis direction of the industrial camera 153 coordinate system. The direction close to the motor 521 is the positive direction of the Y-axis. The farthest end from the motor 521 within the stroke is the Y-axis origin of the industrial camera 153 coordinate system. The X-axis origin of the industrial camera 153 coordinate system and the Y-axis origin of the industrial camera 153 coordinate system are set as the origin of the industrial camera 153 coordinate system, which is also the initial position of the industrial camera 153.

[0021] Industrial camera 2 62 coordinate system: The industrial camera 2 motion platform 6 is provided with a motor 61, and the linear slide rail direction of the industrial camera 2 motion platform 6 is set to the Z-axis direction of the industrial camera 2 62 coordinate system. The direction close to the motor 61 is the positive direction of the Z-axis, and the farthest end from the motor 61 within the stroke is the Z-axis origin of the industrial camera 2 62 coordinate system. The Z-axis origin of the industrial camera 2 62 coordinate system is set to the origin of the industrial camera 2 62 coordinate system, which is also the initial position of the industrial camera 2 62.

[0022] The measurement includes the following steps: Step 1: Clamp and fix the two ends of the elbow on the clamping device 7. The clamping device 7 includes two clamps 71, and the clamps 71 are provided with V-blocks 711 and gas-liquid speed-stabilizing cylinders 712. The two ends of the elbow are manually placed on the V-blocks 711 of the two clamps 71, and the gas-liquid speed-stabilizing cylinders 712 are manually controlled to clamp and fix the two ends of the elbow to keep the elbow horizontal and fixed as a whole. The two gas-liquid speed-stabilizing cylinders 712 can be controlled separately.

[0023] Step 2: Move the industrial camera 1 motion platform 5 to the top of the middle part of the bending section of the curved pipe, take a picture of the curved pipe and generate a curved pipe image, and determine the position of the bending center of the curved pipe. The linear motion module 4 51 and the linear motion module 5 52 in the industrial camera 1 motion platform 5 move the industrial camera 1 53 to the top of the curved section of the curved pipe, and the industrial camera 1 53 takes a picture of the positioned curved pipe to generate a curved pipe image. The computer calculates the bending center of the curved pipe and determines the coordinates of the bending center in the industrial camera 1 53 coordinate system. The absolute position and relative position of the industrial camera 1 53 coordinate system and the device mechanical coordinate system are fixed, so the coordinates of the bending center in the device mechanical coordinate system can be calculated. At this time, by determining the bending center of the curved pipe and the initial position of the center of the rotating platform 2 before, the path for moving the center of the rotating platform 2 to the bending center of the curved pipe can be obtained.

[0024] Step 3: The XY motion platform 1 controls the center of the rotating platform 2 to coincide with the bending center of the bent pipe. The computer calculates the displacement required to move the center of the rotating platform 2 to the bending center of the bent pipe, and the XY motion platform 1 controls the center of the rotating platform 2 to move in the XY coordinate plane so that the center of the rotating platform 2 coincides with the bending center of the bent pipe.

[0025] Step 4: Move the industrial camera 2 motion platform 6 to the position where one end of the straight section of the curved pipe is facing the cross section, shoot the cross section of the straight section of the curved pipe and generate the cross section image of the straight section of the curved pipe, and determine the center position of the cross section of the straight section of the curved pipe. Determine the coordinates of the center of the curved section in the industrial camera 2 62 coordinate system. The absolute position and relative position of the industrial camera 2 62 coordinate system and the device mechanical coordinate system are fixed, so the coordinates of the center of the straight section of the curved pipe in the device mechanical coordinate system can be calculated.

[0026] Step 5: The XZ motion platform 3 controls the center of the annular detector 4 to coincide with the center of the curved pipe section. Since the annular detector 4 is mounted on the rotating platform 2, the XY motion platform 1 has moved the rotating platform 2 once in step 3. Therefore, the center of the annular detector 4 has a new position coordinate in the device mechanical coordinate system after the rotating platform 2 moves. The computer calculates the displacement required to move the center of the annular detector 4 to the center of the curved pipe section, and the XZ motion platform 3 controls the center of the annular detector 4 to move in the XZ coordinate plane so that the center of the annular detector 4 coincides with the center of the curved pipe section.

[0027] Step 6: The detection ring 41 inside the annular detector 4 performs reciprocating semicircular motion around the cross section of the curved pipe for sampling, and the rotating platform 2 intermittently rotates along the curved path of the curved pipe until the rotating platform 2 rotates 90° and stops sampling. Two laser sensors 42 are arranged on the detection ring 41 inside the annular detector 4, which are 180° apart. The detection ring 41 rotates 180°, and then the rotating platform 2 rotates 10°; then the detection ring 41 rotates 180° in the opposite direction, and then the rotating platform 2 rotates 10°; the cycle is repeated until the rotating platform 2 rotates 90° and stops. The connecting line of the two laser sensors 42 passes through the center of the annular detector 4, and the path when performing the rotational motion forms a circle with a diameter of D. The two laser sensors 42 detect the distance s from the laser emission source to the surface of the curved pipe, and sampling is performed every 0.1°. Each laser sensor 42 detects 1800 data, and a total of 3600 data are collected. The 1800 pairs of data are added correspondingly to obtain 1800 data, and the largest data p and the smallest data q are taken out, and the maximum outer diameter d of the ellipse is max =Dq, the minimum outer diameter of the ellipse d min =Dp, ellipticity φ = (d max -d min ) / d0, d0 is the original outer diameter of the pipe.

[0028] Step 7: Reset the device.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0030] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for measuring the ovality of a bent pipe, characterized in that The following steps are involved: S1: clamping and fixing the two ends of the bent pipe on the clamping device (7); S2: moving the industrial camera-motion platform (5) to the position directly above the middle part of the bending section of the bent pipe, photographing the bent pipe and generating an image of the bent pipe, and determining the position of the bending center of the bent pipe; S3: The XY motion platform (1) controls the center of the rotating platform (2) to coincide with the bending center of the bent pipe; S4: Move the second motion platform (6) of the industrial camera to a position where one end of the straight section of the curved pipe faces the cross section, photograph the cross section of the straight section of the curved pipe and generate an image of the cross section of the straight section of the curved pipe, and determine the center position of the cross section of the straight section of the curved pipe; S5: The XZ motion platform (3) controls the center of the annular detector (4) to coincide with the center of the cross section of the straight section of the curved pipe; S6: The detection ring (41) inside the annular detector (4) performs a reciprocating semicircular motion around the curved pipe section to perform sampling, and the rotating platform (2) intermittently rotates along the curved path of the curved pipe until the rotating platform (2) stops sampling after rotating 90°; S7: The device is reset.

2. A method for measuring the ovality of a bent pipe according to claim 1, characterized in that: The XY motion platform (1) comprises a linear motion module 1 (11) and a linear motion module 2 (12), wherein the linear motion module 1 (11) and the linear motion module 2 (12) are respectively provided with a motor 1 (111) and a motor 2 (121), wherein the direction of the linear slide rail of the linear motion module 1 (11) is set to the X-axis direction of the device mechanical coordinate system, the direction close to the motor 1 (111) is the positive direction of the X-axis, and the farthest end from the motor 1 (111) within the stroke is the origin of the X-axis of the device mechanical coordinate system; the direction of the linear slide rail of the linear motion module 2 (12) is set to the X-axis direction of the device mechanical coordinate system The Y-axis direction of the mechanical coordinate system is the direction away from the second motor (121) as the positive direction of the Y-axis, and the end closest to the second motor (121) within the stroke is the origin of the Y-axis of the mechanical coordinate system of the device. The XZ motion platform (3) includes a linear motion module (31), and the linear motion module (31) is provided with a third motor (311). The vertical linear slide rail direction of the third linear motion module (31) is set as the Z-axis direction of the mechanical coordinate system of the device, and the direction close to the third motor (311) is the positive direction of the Z-axis. The end farthest from the third motor (311) within the stroke is the origin of the Z-axis of the mechanical coordinate system of the device. When the device is in the initial position, the rotating platform (2) has a position coordinate in the device mechanical coordinate system, which is the initial position of the center of the rotating platform (2), and the center of the annular detector (4) has a position coordinate in the device mechanical coordinate system, which is the initial position of the center of the annular detector (4).

3. A method for measuring the ovality of a bent pipe according to claim 1, characterized in that: The industrial camera one motion platform (5) comprises a linear motion module four (51) and a linear motion module five (52), wherein the linear motion module four (51) and the linear motion module five (52) are respectively provided with a motor four (511) and a motor five (521), and the linear motion module four (51) is also provided with an industrial camera one (53), and the linear slide rail direction of the linear motion module four (51) is set to be the X-axis direction of the coordinate system of the industrial camera one (53), the direction away from the motor four (511) is the positive direction of the X-axis, and the distance within the stroke from the motor four (511) is The closest end is the X-axis origin of the industrial camera 1 (53) coordinate system. The direction of the linear slide rail of the linear motion module 5 (52) is set to the Y-axis direction of the industrial camera 1 (53) coordinate system. The direction close to the motor 5 (521) is the positive direction of the Y-axis. The farthest end from the motor 5 (521) within the stroke is the Y-axis origin of the industrial camera 1 (53) coordinate system. The X-axis origin and the Y-axis origin of the industrial camera 1 (53) coordinate system are set as the origin of the industrial camera 1 (53) coordinate system, which is also the initial position of the industrial camera 1 (53). The industrial camera 2 motion platform (6) is provided with a motor 6 (61), and the direction of the linear slide rail of the industrial camera 2 motion platform (6) is set to the Z-axis direction of the industrial camera 2 (62) coordinate system, the direction close to the motor 6 (61) is the positive direction of the Z-axis, and the farthest end from the motor 6 (61) within the stroke is the Z-axis origin of the industrial camera 2 (62) coordinate system. The Z-axis origin of the industrial camera 2 (62) coordinate system is set to the origin of the industrial camera 2 (62) coordinate system, which is also the initial position of the industrial camera 2 (62).

4. A method for measuring the ovality of a bent pipe according to claim 1, characterized in that: In step S1, the clamping device (7) comprises two clamps (71), the clamps (71) are provided with V-shaped blocks (711) and gas-liquid speed-stabilizing cylinders (712), the two ends of the bent pipe are manually placed on the V-shaped blocks (711) of the two clamps (71), and the gas-liquid speed-stabilizing cylinders (712) are manually controlled to clamp and fix the two ends of the bent pipe, so as to keep the bent pipe as a whole horizontally fixed. The two gas-liquid speed-stabilizing cylinders (712) can be controlled separately.

5. The method for measuring the ovality of a bent pipe according to claim 1, characterized in that: In steps S2 and S3, the linear motion module four (51) and the linear motion module five (52) in the industrial camera one motion platform (5) move the industrial camera one (53) to the top of the bending section of the bent pipe, and the industrial camera one (53) takes a picture of the positioned bent pipe to generate an image of the bent pipe. The bending center of the bent pipe is calculated by a computer, and the coordinates of the bending center in the coordinate system of the industrial camera one (53) are determined. The absolute position and relative position of the coordinate system of the industrial camera one (53) and the mechanical coordinate system of the device are fixed, so the coordinates of the bending center in the mechanical coordinate system of the device can be calculated. The computer calculates the displacement required to move the center of the rotating platform (2) to the bending center of the bent pipe, and the XY motion platform (1) controls the center of the rotating platform (2) to move in the XY coordinate plane so that the center of the rotating platform (2) coincides with the bending center of the bent pipe.

6. A method for measuring the ovality of a bent pipe according to claim 1, characterized in that: In step S4, the industrial camera 2 (62) on the industrial camera 2 motion platform (6) is moved to a position facing the cross section at one end of the straight section of the curved pipe, and the industrial camera 2 (62) takes a picture of the positioned cross section of the curved pipe straight section to generate a cross section image of the curved pipe straight section. The computer calculates the center position of the cross section of the curved pipe straight section, and determines the coordinates of the center of the cross section of the curved pipe straight section in the coordinate system of the industrial camera 2 (62). The absolute position and relative position of the coordinate system of the industrial camera 2 (62) and the mechanical coordinate system of the device are fixed, so the coordinates of the center of the curved pipe cross section in the mechanical coordinate system of the device can be calculated.

7. A method for measuring the ovality of a bent pipe according to claim 1, characterized in that: In step S5, after the rotating platform (2) moves, the center of the annular detector (4) has a new position coordinate in the device mechanical coordinate system. The computer calculates the displacement required to move the center of the annular detector (4) to the center of the curved pipe section, and the XZ motion platform (3) controls the center of the annular detector (4) to move in the XZ coordinate plane so that the center of the annular detector (4) coincides with the center of the curved pipe section.

8. A method for measuring the ovality of a bent pipe according to claim 1, characterized in that: In step S6, two laser sensors (42) are arranged on the detection ring (41) inside the annular detector (4), which are 180 degrees apart. The detection ring (41) rotates 180 degrees, and then the rotating platform (2) rotates 10 degrees. Then the detection ring (41) rotates 180 degrees in the opposite direction, and then the rotating platform (2) rotates 10 degrees. The cycle is repeated until the rotating platform (2) rotates 90 degrees and stops.

9. A method for measuring the ovality of a bent pipe according to claim 8, characterized in that: The line connecting the two laser sensors (42) passes through the center of the annular detector (4), and the path of the rotational motion forms a circle with a diameter D. The two laser sensors (42) detect the distance s from the laser emission source to the surface of the curved pipe, and sampling is performed every 0.1°. Each laser sensor (42) detects 1800 data, and a total of 3600 data are collected. The 1800 pairs of data are added together to obtain 1800 data, and the largest data p and the smallest data q are taken out. The maximum outer diameter d of the ellipse max =Dq, the minimum outer diameter of the ellipse d min =Dp, ellipticity φ = (d max -d min ) / d0, d0 is the original outer diameter of the pipe.

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