Method for aligning mechanical axis of rotary table with optical axis of test equipment

Abstract

The invention provides a method for aligning a mechanical axis of a rotary table and an optical axis of test equipment, and the method comprises the steps: fixing an imager on a rolling axis of the rotary table, preliminarily adjusting the position and angle of an azimuth axis and a pitch axis of the rotary table or the test equipment, and enabling a round hole target of the test equipment to be imaged near the central region of an image surface of the imager; the initial angle state of the rotary table is recorded, the rolling shaft is rotated, the position change of the image point is observed, and the azimuth shaft and the pitch shaft are adjusted to ensure that the image point is always located in the view field range of the imager in the rolling process; in the adjusted angle state, images of the rolling shaft at the first angle and the second angle are collected, and pixel coordinates of image points are obtained respectively; calculating the circle center position of the image point track according to the pixel coordinates of the image points; the azimuth axis and the pitch axis are adjusted, the image point is moved to the circle center position, and the rolling axis of the rotary table is aligned with the optical axis of the test equipment.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of optoelectronic testing, and particularly relates to a method for aligning a mechanical shaft of a rotary table with an optical axis of a testing device. BACKGROUND

[0002] In the modulation process of an optoelectronic imaging system, the optical path of a testing rotary table needs to be aligned with the optical path of a testing device, i.e., the optical axis needs to be aligned with the mechanical axis. Traditional methods usually adopt the principle of optoelectronic autocollimation, and calibrate the optical path by means of a mirror and an autocollimator, or use a laser for rough aiming alignment. However, these methods not only have a complex operation process, but also have high requirements for the precision of the device and the technical level of the operator, and need to be equipped with special optical alignment instruments, which have high cost and poor adaptability, and are difficult to implement in the case of on-site debugging or limited device conditions. Therefore, there is an urgent need for an optical axis alignment method which is simple to operate, has low dependence on devices, and is suitable for engineering sites. SUMMARY

[0003] In view of the above defects or deficiencies in the prior art, it is desirable to provide a method for aligning a mechanical shaft of a rotary table with an optical axis of a testing device to solve the above problems.

[0004] The present application provides a method for aligning a mechanical shaft of a rotary table with an optical axis of a testing device, comprising: fixing an imager on a rolling shaft of a rotary table, preliminarily adjusting the position and angle of an azimuth axis and a pitch axis of the rotary table or a testing device, so that a circular hole target of the testing device is imaged near the center region of the image plane of the imager; recording the initial angle state of the rotary table, rotating the rolling shaft and observing the position change of the image point, adjusting the azimuth axis and the pitch axis to ensure that the image point is always located within the field of view of the imager during rolling; under the adjusted angle state, collecting images when the rolling shaft is at a first angle and a second angle, respectively acquiring the pixel coordinates of the image point; calculating the center position of the image point trajectory according to the pixel coordinates of the image point; adjusting the azimuth axis and the pitch axis to move the image point to the center position, so as to align the rolling shaft of the rotary table with the optical axis of the testing device.

[0005] According to the technical scheme provided by the embodiments of the present application, the preliminary adjustment comprises fixing the imager on the rolling shaft of the three-axis rotary table by means of a tooling, and the tooling has an adjustable clamping structure.

[0006] According to the technical scheme provided by the embodiments of the present application, the first angle is the initial angle of the rolling shaft , and the second angle is .

[0007] According to the technical scheme provided by the embodiment of the present application, the center position of the image point track is calculated by the following formula: ; ; wherein, , respectively represent the horizontal coordinate and the vertical coordinate of the center of the image point track, represents the image point coordinate under the first angle, represents the image point coordinate under the second angle.

[0008] According to the technical scheme provided by the embodiment of the present application, the process of adjusting the azimuth axis and the pitch axis comprises: If the image point disappears during the rolling process, the azimuth axis and the pitch axis are gradually fine-tuned until the image point is always visible within the rolling axis rotation range.

[0009] According to the technical scheme provided by the embodiment of the present application, the method further comprises verifying whether the image point position remains unchanged during the rolling process after final alignment.

[0010] According to the technical scheme provided by the embodiment of the present application, the verification step comprises: rotating the rolling axis to any initial angle , and rotating any angle based on , respectively collecting two images and extracting the coordinates of the image point, if the deviation of the two coordinates from the center coordinate is less than the preset threshold, determining that the alignment is successful.

[0011] According to the technical scheme provided by the embodiment of the present application, the method further comprises recording the final azimuth angle and the pitch angle after completing the alignment, and storing them as the alignment parameters of the turntable and the test equipment.

[0012] According to the technical scheme provided by the embodiment of the present application, the preset threshold is determined according to the alignment angle accuracy.

[0013] According to the technical scheme provided by the embodiment of the present application, the imager is a face array imaging camera.

[0014] Compared with the prior art, the beneficial effects of the present application are that: by utilizing the change relationship of the imaging point trajectory in the rolling process of the turntable, the angular deviation between the rolling axis of the turntable and the optical axis of the test equipment is accurately determined, and high-precision alignment of the optical axis of the test equipment and the mechanical axis of the turntable can be realized by adjusting only the azimuth axis and the pitch axis of the turntable, without relying on external optical equipment such as autocollimators and lasers, thereby significantly reducing the technical requirements for the test equipment and the operator, and the operation is simple and low in cost, which is suitable for various photoelectric debugging scenes and has good engineering application value. BRIEF DESCRIPTION OF DRAWINGS

[0015] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings: Figure 1 A step flow chart of the alignment method of the mechanical axis of the turntable and the optical axis of the test equipment provided by the present application; Figure 2 An imaging point trajectory diagram for steps S100-S400; Figure 3 An imaging point trajectory diagram for step S500. DETAILED DESCRIPTION

[0016] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related application, and not to limit the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for ease of description.

[0017] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

[0018] Please refer to Figure 1 , the present application provides an alignment method of the mechanical axis of the turntable and the optical axis of the test equipment, comprising: S100: fixing an imager on the rolling axis of the turntable, and preliminarily adjusting the position and angle of the azimuth axis and the pitch axis of the turntable or the test equipment, so that the circular hole target of the test equipment is imaged near the center region of the image plane of the imager.

[0019] Specifically, the turntable is a three-axis turntable, including an azimuth axis, a pitch axis and a rolling axis, the recorded azimuth axis rotation angle is , the recorded pitch axis rotation angle is , and the recorded rolling axis rotation angle is In step S100, the imager is first installed on the rolling axis of the turntable to ensure stable connection without looseness; then the azimuth axis rotation angle of the turntable is preliminarily adjusted by manual or electric method the roll axis rotation angle , or corresponding adjustment of the position and angle of the test equipment, so that the light beam emitted from the light-emitting hole of the test equipment forms a clear image point near the center of the image plane of the imager after passing through the optical system.

[0020] The step S100 is simple to operate and fast to position, significantly reduces the difficulty of initial adjustment of alignment, does not need to rely on high-precision optical auxiliary equipment, and is suitable for rapid deployment on site.

[0021] Further, the preliminary adjustment includes fixing the imager on the roll axis of the three-axis turntable by a tooling, and the tooling has an adjustable clamping structure.

[0022] Specifically, in the step S100, an appropriate tooling clamp is selected according to the size and interface type of the imager, the clamp has an adjustable clamping range and a locking mechanism, the selected tooling is fixed on the mounting surface of the roll axis of the turntable by bolts, the imager is placed in the clamping groove of the tooling clamp, and the position is preliminarily fixed by rotating the adjusting knob or sliding the clamping block; the connection rigidity of the imager and the roll axis of the turntable is checked to ensure that there is no relative displacement or vibration when the turntable rotates at high speed.

[0023] S200: record the initial angle state of the turntable, rotate the roll axis and observe the change of the image point position, and adjust the azimuth axis and the pitch axis to ensure that the image point is always located within the field of view of the imager during the rolling process.

[0024] Specifically, in the step S200, the azimuth axis angle , the pitch axis angle and the roll axis angle of the turntable are first recorded as the initial state; then the roll axis is slowly rotated at a constant speed, and the moving track of the image point in the field of view of the imager is observed in real time through the image display device; if the image point moves to the edge of the field of view or even disappears during the rotation of the roll axis, the azimuth axis rotation angle and / or the pitch axis rotation angle are adjusted in the reverse direction to make the image point always in the visible area within the full rotation range of the roll axis, and the adjusted azimuth axis rotation angle and the pitch axis rotation angle are recorded.

[0025] The step S200 can react to the deviation of the optical axis and the mechanical axis in real time, avoid re-initialization due to loss of the image point, and improve the debugging efficiency and system adaptability.

[0026] Further, the process of adjusting the azimuth axis and the pitch axis includes: If the image point disappears during the rolling process, the azimuth axis and the pitch axis are gradually adjusted until the image point is always in the visible area within the full rotation range of the roll axis. It remains visible within the specified range.

[0027] Specifically, if an image point moves out of the field of view or disappears during the rotation of the scroll axis, immediately stop the rotation, adjust the scroll axis angle, and return to the starting position. The center direction is determined based on the image point trajectory, which in turn determines the adjustment direction of the azimuth and pitch axes; manual fine-tuning knobs or electronic fine-tuning modes are used to... Adjust the azimuth axis angle sequentially for each step unit. and pitch axis angle After each adjustment step, the rolling shaft is driven to rotate again. Observe whether the image point remains visible throughout the entire stroke; if the image point still has a vanishing range, increase the adjustment step of the corresponding axis according to the vanishing direction. The image point is continuously adjusted using an iterative approximation method until it rotates on the scroll axis. The image is complete within its range and its trajectory is smooth and continuous; the azimuth angle at which the image point is finally visible throughout its entire range is recorded. and pitch axis angle This serves as the reference attitude for subsequent circle center calculations.

[0028] S300: Under the adjusted angle state, acquire images of the scroll axis at the first angle and the second angle, and obtain the pixel coordinates of the image points respectively.

[0029] Specifically, in step S300, the rotation angle of the azimuth axis is... and pitch axis angle With the rotation angle fixed, first rotate the roller. Return to initial angle , This is the first angle, the angle of rotation around the azimuth axis. and pitch axis angle The first image P1 is acquired under the condition of [condition], and the center pixel coordinates of the image points in P1 are extracted and denoted as [value]. Location such as Figure 2 As shown at point A; then rotate the rolling shaft. to , This is the second angle, the angle of rotation around the azimuth axis. and pitch axis angle In the same state, acquire the second image P2, and similarly extract the center pixel coordinates of the image points in P2, denoted as... Location such as Figure 2 Point B is shown in the middle.

[0030] Step S300 provides a reliable data foundation for subsequent circle center calculation, improving the repeatability and accuracy of the measurement.

[0031] S400: calculating the center position of the image point trajectory according to the pixel coordinates of the image point.

[0032] Specifically, in step S400, based on the coordinate data of the image point at the first angle and the second angle, according to the physical characteristics that the image point generates a circular trajectory when rotating around the optical axis, the pixel position of the trajectory center on the image plane is calculated, and the center coordinates are marked as , which is the ideal position of the intersection of the optical axis of the test equipment and the image plane, and the center position is as shown by point C in Figure 2 .

[0033] Step S400 directly solves the optical axis deviation by using geometric relationships, without the need for complex algorithms or external sensors, thereby reducing the calculation complexity and equipment cost.

[0034] Further, the center position of the image point trajectory is calculated by the following formula: ; ; wherein, , respectively represent the horizontal coordinate and the vertical coordinate of the center of the image point trajectory, represents the image point coordinate at the first angle, represents the image point coordinate at the second angle.

[0035] Specifically, by substituting the image point coordinates collected in P1 and the image point coordinates collected in P2 into the above formula, the coordinates of the center of the image point trajectory can be obtained. To verify the effectiveness of the calculation, the image point coordinates of the rolling axis rotation and positions can be additionally collected, and the center coordinates are calculated by the four-point fitting circle method, and compared with the calculation results of the two points. If the deviation is less than 1 pixel, it is confirmed that the two-point calculation method is effective.

[0036] S500: adjusting the azimuth axis and the pitch axis to move the image point to the center position, and realizing the alignment of the rolling axis of the turntable and the optical axis of the test equipment.

[0037] Specifically, in step S500, by fine-tuning the azimuth axis and the pitch axis, the image point is gradually moved to the coordinates , and after the image point is stable at the center position, the azimuth axis rotation angle and the pitch axis rotation angle of the turntable at this time are recorded, and the precise alignment of the rolling axis of the turntable and the optical axis of the test equipment is completed.

[0038] Further, after step S500, it further includes: S600: verifying whether the image point position remains unchanged during rolling after final alignment.

[0039] Specifically, the iterative optimization of the alignment process is achieved by verification until a preset accuracy index is reached, ensuring the stability of the alignment quality.

[0040] Further, the verification step comprises: rotating the rolling axis to an arbitrary initial angle , and rotating the rolling axis by an arbitrary angle based on , respectively collecting two images and extracting the coordinates of the image points, and if the deviations of the two coordinates from the center coordinates are both less than a preset threshold, determining that the alignment is successful.

[0041] Specifically, after completing the preliminary alignment of the optical axis, the azimuth axis angle and the pitch axis angle are kept unchanged, the rolling axis is rotated to an arbitrary initial angle by the turntable control system, and after stabilization, image P4 is collected, the image point coordinates are extracted and recorded as , as shown in Figure 3 ; then the rolling axis is rotated by an arbitrary angle to position based on the angle , and after stabilization, image P5 is collected and the image point coordinates are recorded as , as shown in Figure 3 ; the Euclidean distance deviation between the two sets of coordinates and the center reference coordinates is calculated, and if the deviation is greater than a preset threshold, the center calculation and axis system adjustment process of S400-S500 is repeated until the verification is qualified.

[0042] Further, the preset threshold is determined according to the alignment angle accuracy.

[0043] Specifically, the threshold is dynamically set according to the alignment angle accuracy to ensure that the determination standard matches the actual alignment accuracy and avoid the problem of insufficient adaptability caused by a fixed threshold.

[0044] Further, the method further comprises recording the final azimuth angle and pitch angle after completing the alignment and storing them as the alignment parameters of the turntable and the test equipment.

[0045] Specifically, by digitizing and storing the alignment parameters, repeated alignment operations are avoided, and the efficiency of equipment debugging is significantly improved, which is particularly suitable for batch testing and periodic detection scenarios.

[0046] Further, the imager is a face array camera.

[0047] Specifically, for the imaging system of visible light, the imager can adopt a CCD camera or a CMOS camera; for the imaging system of infrared light, the imager can adopt other imaging cameras. The camera type is selected according to the spectral characteristics, and the universality and measurement accuracy of the method are improved.

[0048] The above description is merely preferred embodiments of the present application and a description of the principles of the technology used. It should be understood by those skilled in the art that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combinations of the above technical features, and also covers other technical solutions formed by any combination of the above technical features or equivalent features without departing from the inventive concept. For example, the above features are replaced with each other to form a technical solution with similar functions disclosed in the present application (but not limited to).

Claims

1. A method for aligning the mechanical axis of a turntable with the optical axis of a testing device, characterized in that, include: The imager is fixed on the rolling axis of the turntable, and the position and angle of the azimuth axis and pitch axis of the turntable or the test equipment are initially adjusted so that the circular target of the test equipment is imaged near the center area of ​​the image plane of the imager. Record the initial angle state of the turntable, rotate the rolling axis and observe the change in the image point position, and adjust the azimuth axis and the pitch axis to ensure that the image point is always within the field of view of the imager during the rolling process; Under the adjusted angle state, images are acquired when the scroll axis is at the first angle and the second angle, and the pixel coordinates of the image points are obtained respectively; The center position of the image point trajectory is calculated based on the pixel coordinates of the image point; Adjust the azimuth axis and the pitch axis to move the image point to the center position, thereby aligning the rolling axis of the turntable with the optical axis of the testing equipment.

2. The alignment method between the turntable mechanical axis and the optical axis of the testing equipment according to claim 1, characterized in that, The initial adjustment includes fixing the imager to the rolling axis of a three-axis turntable using a fixture with an adjustable clamping structure.

3. The alignment method between the turntable mechanical axis and the optical axis of the testing equipment according to claim 2, characterized in that, The first angle is the initial angle of the rolling axis. The second angle is .

4. The alignment method between the turntable mechanical axis and the optical axis of the testing equipment according to claim 3, characterized in that, The center position of the image point trajectory is calculated using the following formula: ； ； in, , These represent the x-coordinate and y-coordinate of the center of the circle of the image point trajectory, respectively. This represents the coordinates of the image point at the first angle. This represents the coordinates of the image point at the second angle.

5. The alignment method between the turntable mechanical axis and the optical axis of the testing equipment according to claim 4, characterized in that, The process of adjusting the azimuth and pitch axes includes: If the image point disappears during the rolling process, the azimuth axis and the pitch axis are gradually fine-tuned until the image point rotates on the rolling axis. It is always visible within the range.

6. The alignment method between the turntable mechanical axis and the optical axis of the testing equipment according to claim 5, characterized in that, The method also includes verifying, after final alignment, whether the image point position remains unchanged during the rolling process.

7. The alignment method between the mechanical axis of the turntable and the optical axis of the testing equipment according to claim 6, characterized in that, The verification steps include: Rotate the rolling shaft to any initial angle and in Rotate at any angle on top of that. Two images are acquired and the coordinates of the image points are extracted. If the deviations of the two coordinates from the center coordinates are both less than a preset threshold, the alignment is considered successful.

8. The method for aligning the mechanical axis of the turntable with the optical axis of the testing equipment according to claim 7, characterized in that, The method further includes recording the final azimuth and pitch angles after alignment is completed, and storing them as alignment parameters between the turntable and the test equipment.

9. The method for aligning the mechanical axis of the turntable with the optical axis of the testing equipment according to claim 8, characterized in that, The preset threshold is determined based on the alignment angle accuracy.

10. The method for aligning the mechanical axis of the turntable with the optical axis of the testing equipment according to claim 9, characterized in that, The imager is an area array imaging camera.

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