A coaxiality measurement method based on light beam detection positioning

Abstract

The application discloses a coaxiality measuring device based on light beam detection positioning, which is structurally characterized in that: a guide rail one is installed on a first multi-dimensional adjusting table, a collimating light source is installed on the guide rail one, a guide rail two is installed on a second multi-dimensional adjusting table, and an imaging CCD is installed on the guide rail two; the first multi-dimensional adjusting table is installed on a first axis to be measured, and the second multi-dimensional adjusting table is installed on a second axis to be measured; the collimating light source is moved to a position one, the first axis to be measured is rotated, and the imaging CCD records a light spot center position one; the collimating light source is moved to a position two, the first axis to be measured is rotated, and the imaging CCD records a light spot center position two; the axis line position of the first axis to be measured is calculated according to the light spot center positions one and two and the distance that the collimating light source moves on the guide rail; the second axis to be measured is rotated by the same method, and the position of the second axis to be measured is calculated; and the coaxiality error of the two axes is calculated by comparing the positions of the first axis and the second axis. The application has the advantages of simple structure, easy realization and no introduction of other measuring errors.

Description

Technical Field

[0001] This invention belongs to the field of mechanical processing and assembly technology, and relates to a coaxiality measuring device and method based on beam detection and positioning for dual separation axes during mechanical processing or assembly. Background Technology

[0002] In recent years, with the continuous advancement of precision machining and precision instrument R&D technologies, the requirements for the coaxiality detection accuracy of separating shafts have been continuously increasing during these processes. Coaxiality detection of separating shafts is widely used in optical instrument assembly, machining, and precision instrument R&D, and its demand is also growing in fields such as defense optical metrology and precision machining. With the development of optical inspection and machining, this invention proposes a detection method for a coaxial scanning mechanism based on spot detection and positioning to accurately detect the coaxiality of separating shaft mechanisms.

[0003] Currently, the coaxiality testing of split shafts mainly uses a fixed fixture and a measuring head. By rotating the two split shafts and selecting a certain point, the value on the measuring head is read, and the coaxiality error of the two shafts is calculated. However, the accuracy of the coaxiality testing can be affected by changes in the fixed fixture, the tension of the micrometer head spring, and the contact stress with the shaft. Lü Jiahui's patent number "CN 212806897 U" is a typical coaxiality measuring device, which mainly uses a fixed fixture and a measuring head to measure the coaxiality of two shafts. Summary of the Invention

[0004] (a) Purpose of the invention

[0005] The purpose of this invention is to provide a coaxiality measuring device and method based on beam detection and positioning. It can measure the displacement and included angle of two axes according to different measurement requirements. The structure is simple, the two axes do not need to contact each other, and it is not affected by the fixed clamp, the tension of the micrometer head spring, or the change of contact stress with the axis.

[0006] (II) Technical Solution

[0007] This invention provides a coaxiality measuring device and method based on beam detection and positioning. The relative position of two axes is calculated by beam detection and positioning. Compared with traditional measurement methods, this invention solves the measurement errors caused by changes in the contact force between the probe and the shaft under test, as well as machining errors at the shaft end, in traditional measurements.

[0008] The coaxiality measurement device based on beam detection and positioning of the present invention includes: a first multidimensional adjustment stage, a first guide rail, a collimating light source, an imaging CCD, a second multidimensional adjustment stage, and a second guide rail; the first guide rail is mounted on the first multidimensional adjustment stage, the collimating light source is mounted on the first guide rail, the second guide rail is mounted on the second multidimensional adjustment stage, and the imaging CCD is mounted on the second guide rail; the first multidimensional adjustment stage is mounted on the axis to be measured (axis 1), and the second multidimensional adjustment stage is mounted on the axis to be measured (axis 2); the laser light source on the guide rail is moved to position 1, and then the axis to be measured (axis 1) is rotated, and the imaging CCD images and records the center position of the light spot at position 1; the laser light source on the guide rail is moved to position 2, and then the axis to be measured (axis 1) is rotated, and the imaging CCD images and records the center position of the light spot at position 2; the axial position of the axis to be measured (axis 1) is calculated using the center positions of the light spot (positions 1 and 2) and the distance the collimating light source moves on the guide rail; the position of the axis to be measured (axis 2) is calculated by rotating the axis in the same way; the coaxiality error of the two axes is calculated by comparing the positions of the two axes.

[0009] The multi-dimensional adjustment platform is equipped with two-dimensional translation and pitch adjustment, which makes adjustments more convenient.

[0010] The collimating light source can be a laser light source, a white light source, or a light source with adjustable brightness.

[0011] An attenuator or brightness adjustment device is installed at the output port of the collimated light source.

[0012] When installing the collimating light source and the imaging CCD, align the center of the collimating light source with the first axis to be measured, and align the center of the imaging CCD with the second axis to be measured.

[0013] The coaxiality measurement method based on beam detection and positioning of the present invention includes:

[0014] Step 1: Press Figure 1 After installing the device of this invention, turn on the collimating light source and check whether the imaging CCD is saturated. If the imaging CCD is saturated with the light source, an attenuation plate can be added at the light source outlet or the brightness of the light source can be reduced by a brightness adjustment device until the imaging CCD can collide with the light source to form a clear spot image.

[0015] Step 2: Move the imaging CCD to position A1, rotate the second axis under test, and simultaneously record the trajectory of the spot center on the imaging CCD as the second axis under test rotates. By calculating the trajectory of the spot center on the imaging CCD, the distance of the spot from the axis under test can be calculated.

[0016] Step 3: Adjust the first multi-dimensional adjustment stage to align the light spot position with the axis of the second axis to be measured. Rotate the second axis to be measured again. At this time, the position of the center of the light spot on the CCD will not change. Record the position of the center of the light spot on the CCD as A1(X,Y).

[0017] Step 4: Move the imaging CCD to position A2. The distance between A1 and A2 is L. Repeat the above steps and record the center position of the light spot A2(x,y). At this time, the rotation axis of the second axis to be measured is uniquely determined by A1(x,y), A2(x,y) and the distance L between the two planes.

[0018] After completing the above steps, move the imaging CCD back to position A1, move the collimating light source to position B1, and then rotate the first axis under test, recording the trajectory of the light spot on the CCD. By calculating the trajectory of the light spot on the imaging CCD, the distance of the light spot from the axis under test can be calculated. Adjust the first multi-dimensional adjustment stage to align the light spot position with the axis under test, and rotate the first axis under test again. At this time, the position of the light spot center on the CCD will not change. After completing the above steps, move the collimating light source to position B2, rotate the first axis under test again, and record the trajectory of the light spot on the imaging CCD. If the position of the light spot center does not change, the center of the collimating light source is aligned with the rotation axis of the first axis under test. If the center of the light spot changes, adjust the first multi-dimensional adjustment stage again until the center of the light spot no longer changes. After completing the above steps, move the collimating light source back to position B1, rotate the first axis under test again, and at this time, the position of the light spot center no longer changes. Record the current position of the light spot center as B1(x,y).

[0019] After completing all the above steps, move the imaging CCD to position A2 and record the center position of the light spot B2(x,y). By calculating the relative relationships between A1(x,y), A2(x,y), B1(x,y), B2(x,y) and the distance L, the coaxiality, tilt angle, displacement and other parameters of the two axes under test can be calculated.

[0020] (III) Beneficial Effects

[0021] The coaxiality measuring device and method based on beam detection and positioning provided by the above technical solution are not limited to measuring the coaxiality of two axes, but can also measure parameters such as the tilt angle and displacement of two axes. The present invention can greatly improve the measurement accuracy of the coaxiality of two separate axes. It has a simple structure and is easy to implement. At the same time, since it does not require an external mounting bracket or contact between the probe and the part under test, it will not introduce other measurement errors. Attached Figure Description

[0022] Figure 1 This is a diagram showing the composition of the coaxiality measurement device based on beam detection and positioning according to the present invention.

[0023] Figure 2 This is a schematic diagram illustrating the measurement principle of the coaxiality measuring device based on beam detection and positioning according to the present invention. Detailed Implementation

[0024] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0025] like Figure 1 As shown, the coaxiality measurement device based on beam detection and positioning in this embodiment includes a first multi-dimensional adjustment stage, a guide rail one, a collimating light source, an imaging CCD, a second multi-dimensional adjustment stage, and a guide rail two. Guide rail one is mounted on the first multi-dimensional adjustment stage, the collimating light source is mounted on guide rail one, guide rail two is mounted on the second multi-dimensional adjustment stage, and the imaging CCD is mounted on guide rail two. The first multi-dimensional adjustment stage is mounted on the axis to be measured (axis one), and the second multi-dimensional adjustment stage is mounted on the axis to be measured (axis two). The laser light source on the guide rail is moved to position one, and then the axis to be measured (axis one) is rotated, and the imaging CCD records the center position of the light spot at position one. The laser light source on the guide rail is moved to position two, and then the axis to be measured (axis one) is rotated, and the imaging CCD records the center position of the light spot at position two. The axial position of the axis to be measured (axis one) is calculated using the center positions of the light spot (position one and position two) and the distance the collimating light source moves on the guide rail. The position of axis two is calculated by rotating axis two in the same way. The coaxiality error between the two axes is calculated by comparing the positions of axis one and axis two.

[0026] The multi-dimensional adjustment platform is equipped with two-dimensional translation and pitch adjustment, which makes adjustments more convenient.

[0027] The collimation light source can be a laser light source or a white light source. The choice of light source can be based on parameters such as the distance between the two axes being measured and the dynamic range of the CCD. Alternatively, a light source with adjustable brightness can be selected. When the distance between the two axes is large, a laser light source should be used as much as possible, as this will result in clearer CCD imaging and more accurate measurement results.

[0028] In addition, to reduce the amount of adjustment, when installing the collimating light source and the imaging CCD, the center of the collimating light source should be aligned with the first axis to be measured, and the center of the imaging CCD should be aligned with the second axis to be measured.

[0029] like Figure 2 As shown, based on the above-mentioned coaxiality measurement device based on beam detection and positioning, the process of the coaxiality measurement method based on beam detection and positioning in this embodiment is as follows:

[0030] Step 1: Press Figure 1 After installing the device of this invention, turn on the collimating light source and check whether the CCD is saturated. If the CCD is saturated for imaging the light source, an attenuation plate can be added to the light source outlet or the brightness of the light source can be reduced by a brightness adjustment device until the imaging CCD can collide with the light source to form a clear spot image.

[0031] Step 2: Move the imaging CCD to position A1, rotate the second axis to be measured, and simultaneously record the trajectory of the spot center on the imaging CCD. By calculating the trajectory of the spot center on the imaging CCD, the coordinates of the second axis can be calculated.

[0032] Step 3: Adjust the multi-dimensional adjustment stage one to adjust the position of the light spot to the coordinates of the second axis to be measured. Rotate the second axis to be measured again. At this time, the position of the center of the light spot on the CCD will not change. Record the position of the center of the light spot on the CCD A1(x,y).

[0033] Step 4: Move the imaging CCD to position A2, the distance between A1 and A2 is L.

[0034] Step 5: Rotate the second axis to be measured, and simultaneously record the trajectory of the light spot center on the imaging CCD. By calculating the trajectory of the light spot center on the imaging CCD, the axis coordinates of the second axis to be measured can be calculated.

[0035] Step 6: Adjust the multi-dimensional adjustment stage one to align the center position of the light spot with the axis coordinate of the second axis to be measured. Rotate the second axis to be measured again. At this time, the position of the center of the light spot on the CCD will not change. Record the center position of the light spot on the CCD at this time as A2(x,y).

[0036] Step 7: Move the imaging CCD back to position A1.

[0037] Step 8: Move the collimating light source to position B1, then rotate the axis to be measured, record the light spot trajectory on the CCD, and calculate the axis coordinates of the axis to be measured by calculating the trajectory of the light spot center on the imaging CCD.

[0038] Step 9: Adjust the multi-dimensional adjustment stage one to align the light spot position with the coordinates of the axis to be measured one, and rotate the axis to be measured one again. At this time, the position of the center of the light spot on the CCD will not change.

[0039] Step 10: After completing the above steps, move the collimating light source to position B2, rotate the first axis to be measured again, and record the trajectory of the light spot on the imaging CCD. If the center of the light spot does not change, record the position of the center of the light spot B2 (x, y). If the center of the light spot changes, the axis coordinates of the first axis to be measured can be obtained by calculating the motion trajectory of the center of the light spot, and then proceed to step 11.

[0040] Step 11: Adjust the angle of the multi-dimensional adjustment stage one to move the center of the light spot to the axis coordinate of the first axis to be measured. Then repeat steps 8, 9, and 10 until the collimated light source no longer changes the center position of the light spot at positions B1 and B2 when rotating the second axis to be measured.

[0041] Step 12: Move the collimated light source to position B1 and record the center position of the light spot at this time, B1(x,y).

[0042] Step 13: The displacement deviation, tilt angle deviation, coaxiality error and other parameters of the two shafts to be measured can be calculated by using A1(x,y), A2(x,y), B1(x,y), B2(x,y) and the distance L between A1 and A2.

[0043] Using the methods described above, users can measure parameters such as the coaxiality, tilt angle, and displacement of the split shaft to achieve the following objectives:

[0044] 1. This invention can measure parameters such as coaxiality, tilt angle, and displacement of the separating shaft. The device is simple and easy to implement.

[0045] 2. This invention improves the accuracy of measuring parameters such as coaxiality, tilt angle, and displacement of the separation shaft.

[0046] 3. The coaxiality accuracy of the two separate axes measured by the CCD super-resolution algorithm is greatly improved compared with the traditional method.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A coaxiality measurement method based on beam detection and positioning, characterized in that, The measurement method employs a coaxiality measuring device based on beam detection and positioning. This device includes: a first multidimensional adjustment stage, a first guide rail, a collimating light source, an imaging CCD, a second multidimensional adjustment stage, and a second guide rail. The first guide rail is mounted on the first multidimensional adjustment stage, the collimating light source is mounted on the first guide rail, the second guide rail is mounted on the second multidimensional adjustment stage, and the imaging CCD is mounted on the second guide rail. The first multidimensional adjustment stage is mounted on the axis to be measured (axis 1), and the second multidimensional adjustment stage is mounted on the axis to be measured (axis 2). The laser light source on the guide rail is moved to position 1, and then the axis to be measured (axis 1) is rotated, and the imaging CCD records the center position of the light spot. The laser light source on the guide rail is then moved to position 2, and then the axis to be measured (axis 2) is rotated. First, the imaging CCD records the center position of the light spot. Second, using the center positions of the light spot (position one and position two) and the distance the collimating light source moves on the guide rail, the axial position of the first axis to be measured is calculated. The position of the second axis is calculated by rotating the second axis in the same way. The coaxiality error of the two axes is calculated by comparing the positions of the first and second axes. The multi-dimensional adjustment stage is a platform with two-dimensional translation and pitch adjustment capabilities. The collimating light source is a laser light source, a white light source, or a brightness-adjustable light source. An attenuator or brightness adjustment device is installed at the light outlet of the collimating light source. When installing the collimating light source and the imaging CCD, the center of the collimating light source is aligned with the first axis to be measured, and the center of the imaging CCD is aligned with the second axis to be measured. The measurement method includes the following process: S1: Move the imaging CCD to the preset position A1, rotate the second axis to be measured, and at the same time record the running trajectory of the spot center on the imaging CCD when the second axis to be measured rotates. Calculate the running trajectory of the spot center on the imaging CCD and calculate the distance of the spot from the axis to be measured. S2: Adjust the first multi-dimensional adjustment stage to position the light spot on the axis of the second axis to be measured. Rotate the second axis to be measured again. At this time, the position of the center of the light spot on the CCD will not change. Record the position of the center of the light spot on the CCD A1(X,Y). S3: Move the imaging CCD to the preset position A2. The distance between A1 and A2 is L. Repeat the above steps and record the center position of the light spot A2(x,y). At this time, the rotation axis of the second axis to be measured is uniquely determined by A1(x,y), A2(x,y) and the distance L between the two planes. After completing the above steps, move the imaging CCD back to position A1, move the collimating light source to the preset position B1, then rotate the first axis to be measured, record the light spot trajectory on the CCD, calculate the trajectory of the light spot on the imaging CCD, and calculate the distance of the light spot from the axis to be measured. Adjust the first multi-dimensional adjustment stage to adjust the position of the light spot to the axis to be measured, and rotate the first axis to be measured again. At this time, the position of the center of the light spot on the CCD will not change. After completing the above steps, move the collimating light source to the preset position B2, rotate the first axis to be measured again, and record the light spot trajectory on the imaging CCD. If the position of the center of the light spot does not change, at this time, the center of the collimating light source is consistent with the rotation axis of the first axis to be measured. If the center of the light spot changes, adjust the first multi-dimensional adjustment stage again until the center of the light spot no longer changes. After completing the above steps, move the collimating light source back to position B1, rotate the first axis to be measured again, and at this time, the position of the center of the light spot no longer changes. Record the position of the center of the light spot B1(x,y). After completing all the above steps, move the imaging CCD to position A2 and record the center position of the light spot B2(x,y); calculate the relative relationship between A1(x,y), A2(x,y), B1(x,y), B2(x,y) and distance L, and calculate the coaxiality between the first and second axes to be measured.

2. The coaxiality measurement method based on beam detection and positioning as described in claim 1, characterized in that, Based on the relative relationships between A1(x,y), A2(x,y), B1(x,y), B2(x,y) and distance L, the tilt angle and displacement parameters can also be calculated.

3. The coaxiality measurement method based on beam detection and positioning as described in claim 2, characterized in that, Before process S1, the process also includes: first turning on the collimating light source and checking whether the imaging CCD is saturated. If the imaging CCD is saturated with the light source, then an attenuator is added at the light source outlet or the brightness of the light source is reduced by a brightness adjustment device until the imaging CCD can collide with the light source to form a clear spot image.

4. An application of a coaxiality measurement method based on beam detection and positioning as described in any one of 1-3 in the field of machining and assembly technology.

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