Optical measurement system for five-dimensional motion change
By designing an optical measurement system including XY direction, Z direction and angle measurement units, and using a dual telecentric optical system, the problem that the existing optical imaging system cannot meet the five-dimensional motion change detection at the same time is solved, and efficient and accurate Five-dimensional motion parameters measurement.
Patent Information
- Application Number
- CN202411809660.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-02-18
AI Technical Summary
The existing optical imaging system cannot meet the detection requirements of five-dimensional motion changes (XY direction posture, Z direction displacement and XY direction tilt) at the same time, especially when performing quality detection of voice coil motors.
An optical measurement system including an XY direction measuring unit and a Z direction and angle measuring unit is designed. A dual telecentric optical system is used to measure the XY direction posture of the object to be measured through an XY direction laser, an imaging optical component and a photodetector. Change; the Z-direction and angle measurement laser, imaging optical components and photodetector are measured, and the Z-direction displacement and XY-direction tilt of the object to be measured.
Simultaneous measurement of the XY direction posture, Z direction displacement and XY direction inclination during the movement of the object to be measured is achieved, which improves measurement efficiency, accuracy and stability, and reduces the difficulty of system distortion and subsequent calibration.
Smart Images
Figure CN119468918A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of optical imaging, and in particular to an optical measurement system for five-dimensional motion changes. Background Art
[0002] In manufacturing activities, product inspection is an important part of the production process. In the industrial inspection process, the optical inspection system is one of the important inspection equipment.
[0003] However, the current optical imaging system can only realize planar (two-axis direction) product inspection, and there are still deficiencies in the inspection process of some products with higher requirements. For example, when conducting quality inspection on voice coil motors, it is necessary to simultaneously inspect the XY direction posture, Z direction displacement and XY direction tilt of the voice coil motor during its movement. However, the existing imaging equipment cannot meet the inspection requirements of five dimensions at the same time, so it needs to be improved. Summary of the invention
[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is: Provided is an optical measurement system for five-dimensional motion change, comprising: an XY direction measurement unit, a Z direction and angle measurement unit, The XY direction measurement unit includes an XY direction laser, an XY direction imaging optical component, and an XY direction photoelectric detector. The XY direction photoelectric detector is coaxially arranged with the XY direction imaging optical component, and the XY direction photoelectric detector is on the focal plane of the XY direction imaging optical component. The XY direction laser is arranged on one side of the XY direction imaging optical component to measure the posture change of the object in the XY direction during the movement of the object under test; the XY direction imaging optical component includes an XY direction first lens, an XY direction negative crescent second lens, an XY direction dichroic prism, an XY direction aperture, an XY direction negative crescent fourth lens, and an XY direction positive crescent fifth lens, which are sequentially and coaxially arranged; The Z direction and angle measurement unit includes a Z direction and angle measurement laser, a Z direction and angle imaging optical component, a Z direction photoelectric detector and an angle photoelectric detector. The Z direction and angle measurement laser and the Z direction and angle imaging optical component are symmetrically arranged on both sides of the XY direction imaging optical component to measure the Z direction displacement and the XY direction inclination during the movement of the object to be measured. The Z direction and angle imaging optical component includes a Z-direction first double convex lens, a Z-direction beam splitter prism, a Z-direction positive crescent third lens, a Z-direction aperture, a Z-direction negative crescent fourth lens, a Z-direction negative crescent fifth lens, a Z-direction positive crescent sixth lens and an angle negative crescent lens arranged on the side of the second lens in sequence and coaxially.
[0005] In a preferred embodiment of the present invention, the first lens in the XY direction is a biconvex lens or a positive meniscus lens.
[0006] In a preferred embodiment of the present invention, the XY beam splitter prism is an aspherical lens.
[0007] In a preferred embodiment of the present invention, the parameters of the first lens in the XY direction, the second lens with negative crescent in the XY direction, the dichroic prism in the XY direction, the aperture in the XY direction, the fourth lens with negative crescent in the XY direction, and the fifth lens with positive crescent in the XY direction are as follows: .
[0008] In a preferred embodiment of the present invention, the Z-direction first biconvex lens, the Z-direction beam splitter, the Z-direction negative crescent third lens, the Z-direction aperture, the Z-direction positive crescent fourth lens, the Z-direction positive crescent fifth lens and the Z-direction negative crescent sixth lens constitute a Z-direction imaging optical component for measuring changes in Z-direction displacement during the movement of the object being measured, and the Z-direction imaging optical component is coaxially arranged with the Z-direction photoelectric detector.
[0009] In a preferred embodiment of the present invention, the second lens and the angle negative meniscus lens form an angle focusing optical component for measuring the angle change during the movement of the object being measured, wherein the Z-direction imaging optical group and the angle focusing optical component share a second lens.
[0010] In a preferred embodiment of the present invention, the angle photodetector is coaxially arranged with the angle focusing optical component, or a reflector is arranged between the angle photodetector and the angle negative meniscus lens.
[0011] In a preferred embodiment of the present invention, the Z-direction beam splitter prism is an aspherical lens.
[0012] In a preferred embodiment of the present invention, the parameters of the first biconvex lens in the Z direction, the dichroic prism in the Z direction, the angled negative crescent lens, the third positive crescent lens in the Z direction, the aperture in the Z direction, the fourth negative crescent lens in the Z direction, the fifth negative crescent lens in the Z direction, and the sixth positive crescent lens in the Z direction are as follows: .
[0013] In a preferred embodiment of the present invention, the distance between the XY direction imaging optical component and the object to be measured is 110 mm, and the distance between the Z direction and angle imaging optical component and the object to be measured is 127.017 mm.
[0014] The beneficial effects of the present invention are as follows: not only can the five-dimensional parameters of the XY direction posture, Z direction displacement and XY direction tilt angle during the movement of the object being measured be measured simultaneously, thereby improving the measurement efficiency, but also the measurement accuracy and stability are effectively improved, the system distortion is small, and the difficulty of subsequent calibration is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which: Figure 1 It is a structural schematic diagram of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Figure 2 It is a schematic diagram of a measurement process of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Figure 3 It is a structural schematic diagram of an XY direction imaging optical component of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Figure 4 It is a structural schematic diagram of the Z-direction and angle imaging optical components of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Figure 5 It is an XY direction spot diagram of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Figure 6 It is an XY direction MTF curve diagram of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Figure 7 It is a Z-direction spot diagram of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Figure 8 It is a Z-direction MTF curve diagram of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Fig. 9 This is a Kohler illumination result diagram of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention; Fig.10 It is a cross-sectional view of the Kohler illumination result of a preferred embodiment of an optical measurement system for five-dimensional motion change of the present invention. DETAILED DESCRIPTION
[0016] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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.
[0017] See also Figure 1-10 , the embodiment of the present invention includes: An optical measurement system for five-dimensional motion changes, comprising an XY direction measurement unit, a Z direction and angle measurement unit, and a double telecentric optical system to simultaneously detect five-dimensional parameters of XY direction posture, Z direction displacement, and XY direction tilt, thereby improving measurement accuracy and reducing subsequent calibration difficulty.
[0018] Initially, the object to be measured is adjusted to the zero point, and during the movement of the object to be measured, the changes of the above five indicators (position / coordinate information) are measured in real time.
[0019] XY direction measurement unit: It is set vertically above the object to be measured to measure the position change of the object in the XY direction during its movement.
[0020] The XY direction measurement unit includes an XY direction laser 11, an XY direction imaging optical component 12, and an XY direction photodetector 13. The XY direction photodetector and the XY direction imaging optical component are arranged in sequence from top to bottom. The XY direction laser is arranged on one side of the XY direction imaging optical component, and the XY direction photodetector is on the focal plane of the XY direction imaging optical component to simultaneously obtain changes in the XY two dimensions.
[0021] The XY direction imaging optical component 12 includes an XY direction first lens 121 , an XY direction negative crescent second lens 122 , an XY direction beam splitter prism 123 , an XY direction aperture 124 , an XY direction negative crescent fourth lens 125 , and an XY direction positive crescent fifth lens 126 which are arranged sequentially and coaxially.
[0022] Further preferably, the first lens in the XY direction is a biconvex lens or a positive meniscus lens.
[0023] Further preferably, the XY beam splitter prism is an aspherical lens.
[0024] The parameters of the XY-direction imaging optical components are shown in the table below, where the surface of the XY-direction negative crescent first lens facing the object to be measured is the first surface, from right to left.
[0025]
[0026] For example, the thickness of the first lens in the XY direction (i.e., the distance between the S1 surface and the S2 surface) is 5.70 mm, the distance between the first lens in the XY direction, the aperture and the XY negative crescent second lens (i.e., the distance between the S2 surface and the S3 surface) is 1.92 mm, and so on; in addition, the thickness of the XY beam splitter prism is 16.00 mm, the aperture is not set with a thickness or is set at 0.5 mm, therefore, the distance between the XY aperture S7 and the XY beam splitter prism S6 is 11.82 mm, the distance between the XY aperture S7 and the XY negative crescent fourth lens S8 is 14.78 mm, and the thickness of the XY negative crescent fourth lens is 5.99 mm.
[0027] The outgoing light of the XY direction laser is incident from the side of the beam splitter prism, and after passing through the XY direction imaging optical component, it is evenly irradiated to the surface of the object to be measured. The reflected light from the surface of the object to be measured is imaged on the XY direction photoelectric detector through the XY direction imaging optical component. When the object to be measured continues to move within the measurement range, the laser continues to emit light, and the detector collects data every 2us, and 500 tests can be performed in one second.
[0028] Z direction and angle measurement unit: It is arranged on the side of the XY direction imaging optical unit and forms a certain angle with the optical axis of the XY direction imaging optical unit.
[0029] The Z direction and angle measurement unit includes a Z direction and angle measurement laser 21, a Z direction and angle imaging optical component 22, a Z direction photodetector 23 and an angle photodetector 24. The Z direction and angle measurement laser and the Z direction and angle imaging optical component are symmetrically arranged on both sides of the XY direction imaging optical component.
[0030] The Z-direction and angle imaging optical component 22 includes a Z-direction first biconvex lens 221, a Z-direction beam splitter prism 222, a Z-direction positive crescent third lens 223, a Z-direction aperture 224, a Z-direction negative crescent fourth lens 225, a Z-direction negative crescent fifth lens 226, a Z-direction positive crescent sixth lens 227 and an angle negative crescent lens 228 arranged on the side of the second lens.
[0031] Further preferably, the Z-direction first biconvex lens, the Z-direction beam splitter prism, the Z-direction negative crescent third lens, the Z-direction aperture, the Z-direction positive crescent fourth lens, the Z-direction positive crescent fifth lens and the Z-direction negative crescent sixth lens constitute a Z-direction imaging optical component, which is used to measure the change of Z-direction displacement during the movement of the object under test, and the Z-direction imaging optical component is coaxially arranged with the Z-direction photoelectric detector, and the Z-direction photoelectric detector is on the focal plane of the Z-direction imaging optical component.
[0032] Further preferably, the second lens and the angle negative crescent lens form an angle focusing optical assembly for measuring the angle change of the object under test during its movement, and the angle photodetector is on the focal plane of the angle focusing optical assembly. The Z-direction imaging optical group and the angle focusing optical assembly share a second lens.
[0033] Further preferably, the angle photodetector can be directly located on the image plane of the angle focusing optical component, or a reflector can be arranged between the angle photodetector and the angle negative meniscus lens, so as to be arranged according to actual size and installation requirements.
[0034] Further preferably, the Z-direction beam splitter prism is an aspherical lens.
[0035] The parameters of the Z-direction and angle imaging optical components are shown below, where the surface of the first Z-direction biconvex lens facing the object to be measured is the first surface, from right to left.
[0036]
[0037] Among them, the thickness of the Z-axis aperture is not set or is set to 0.5mm.
[0038] The working principle of the Z direction and angle measurement unit is similar to that of the XY direction measurement unit. The Z direction and angle measurement laser emits a collimated small spot laser to illuminate the surface of the object to be measured. The reflected light from the surface of the object to be measured is imaged on the Z direction photodetector and the angle photodetector through the Z direction and angle imaging optical components. However, due to the angle between the side surface and the displacement surface, compensation is required in the later data processing, and the angle measurement is detected by the principle of parallel light focusing.
[0039] The beneficial effects of the optical measurement system for five-dimensional motion change of the present invention are: 1. It can simultaneously measure the five-dimensional parameters of the XY direction posture, Z direction displacement and XY direction tilt angle during the movement of the object, which improves the measurement efficiency; 2. The XY direction laser forms Kohler illumination after passing through the XY imaging optical component to produce a uniform illumination spot on the surface of the object being measured, and the illumination distribution of the spot is not affected by the laser output spot, which solves the problem of changes in the measured value caused by changes in the laser spot energy distribution due to temperature increase, and improves the accuracy and stability of the measurement; 3. The XY imaging optical system and the Z-direction imaging optical system adopt a double telecentric optical path, so that when the object being measured moves in the Z direction, the center of mass position of the image of its light spot on the photodetector remains unchanged, which improves the measurement accuracy, and the system distortion is small, reducing the difficulty of subsequent calibration.
[0040] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. An optical measurement system for five-dimensional motion changes, characterized in that: include: XY direction measurement unit, Z direction and angle measurement unit, The XY direction measurement unit includes an XY direction laser, an XY direction imaging optical component, and an XY direction photoelectric detector. The XY direction photoelectric detector is coaxially arranged with the XY direction imaging optical component, and the XY direction photoelectric detector is on the focal plane of the XY direction imaging optical component. The XY direction laser is arranged on one side of the XY direction imaging optical component to measure the posture change of the object in the XY direction during the movement of the object under test; the XY direction imaging optical component includes an XY direction first lens, an XY direction negative crescent second lens, an XY direction dichroic prism, an XY direction aperture, an XY direction negative crescent fourth lens, and an XY direction positive crescent fifth lens, which are sequentially and coaxially arranged; The Z direction and angle measurement unit includes a Z direction and angle measurement laser, a Z direction and angle imaging optical component, a Z direction photoelectric detector and an angle photoelectric detector. The Z direction and angle measurement laser and the Z direction and angle imaging optical component are symmetrically arranged on both sides of the XY direction imaging optical component to measure the Z direction displacement and the XY direction inclination during the movement of the object to be measured. The Z direction and angle imaging optical component includes a Z-direction first double convex lens, a Z-direction beam splitter prism, a Z-direction positive crescent third lens, a Z-direction aperture, a Z-direction negative crescent fourth lens, a Z-direction negative crescent fifth lens, a Z-direction positive crescent sixth lens and an angle negative crescent lens arranged on the side of the second lens in sequence and coaxially.
2. An optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The first lens in the XY direction is a biconvex lens or a positive meniscus lens.
3. An optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The XY beam splitter prism is an aspherical lens.
4. The optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The parameters of the first lens in XY direction, the second lens with negative crescent in XY direction, the beam splitter in XY direction, the aperture in XY direction, the fourth lens with negative crescent in XY direction, and the fifth lens with positive crescent in XY direction are as follows: 。 5. The optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The Z-direction first biconvex lens, the Z-direction beam splitter, the Z-direction negative crescent third lens, the Z-direction aperture, the Z-direction positive crescent fourth lens, the Z-direction positive crescent fifth lens and the Z-direction negative crescent sixth lens constitute a Z-direction imaging optical component, which is used to measure the change in Z-direction displacement during the movement of the object being measured. The Z-direction imaging optical component is coaxially arranged with the Z-direction photoelectric detector.
6. The optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The second lens and the angle negative meniscus lens form an angle focusing optical component for measuring the angle change of the object under test during movement, wherein the Z-direction imaging optical group and the angle focusing optical component share a second lens.
7. An optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The angle photodetector is coaxially arranged with the angle focusing optical component, or a reflecting mirror is arranged between the angle photodetector and the angle negative crescent lens.
8. An optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The Z-direction beam splitter prism is an aspherical lens.
9. An optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The parameters of the first double convex lens in the Z direction, the beam splitter in the Z direction, the angle negative crescent lens, the third positive crescent lens in the Z direction, the aperture in the Z direction, the fourth negative crescent lens in the Z direction, the fifth negative crescent lens in the Z direction, and the sixth positive crescent lens in the Z direction are as follows: 。 10. An optical measurement system for five-dimensional motion change according to claim 1, characterized in that: The distance between the XY direction imaging optical component and the object to be measured is 110 mm, and the distance between the Z direction and angle imaging optical component and the object to be measured is 127.017 mm.