A collimator light path rapid adjustment device and method based on dual-camera cooperation

Abstract

The application discloses a collimator light path rapid adjustment device and method based on two-camera cooperation, which comprises a two-dimensional translation table, a laser communication terminal, a collimator, a beam splitter, a short-focus lens, a tracking camera, a capturing camera and a computer. The application realizes the deviation closed-loop control of the two-dimensional displacement table by the coarse capturing of the capturing camera with a large field of view, the accurate tracking of the tracking camera with a small field of view, and the calculation of the deviation between the center of the captured and tracked light spot and the calibration center, so as to complete the light path alignment. The application does not need to rely on the professional experience and subjective judgment of the operator, and automatically completes the whole process of scanning, positioning and alignment, and has the characteristics of high alignment efficiency and reliability.

Description

Technical Field

[0001] This invention relates to the field of collimator technology, and specifically to a device and method for rapid adjustment of the optical path of a collimator based on dual-camera collaboration. Background Technology

[0002] A collimator is a precision optical instrument whose core function is to generate a parallel beam of light to illuminate a target simulating an infinitely distant object. It plays a crucial role as a benchmark in optical laboratories and precision manufacturing, and is commonly used in the assembly, testing, and parameter measurement of optical instruments. As the core optical device for generating parallel beams, the collimator's optical path alignment efficiency and accuracy directly determine the reliability of the measurement results. Existing collimator optical path adjustment methods mainly rely on a single camera and manual adjustment, which have obvious technical defects: 1) Low adjustment efficiency: Observing the spot position with only a single camera requires repeated fine-tuning of equipment and components, and a single alignment can take tens of minutes or even longer, which cannot meet the needs of industrial batch testing or rapid assembly and adjustment scenarios; 2) High alignment difficulty: During manual adjustment, the operator's judgment of the offset of the spot calibration point is easily affected by subjective factors, resulting in alignment deviation; a single camera is limited by the field of view, making it difficult to achieve both large-area capture and high-precision positioning, further reducing alignment accuracy; 3) High operating threshold: Relying on the experience and judgment of optical professionals, the optical path alignment is completed through multiple trials and errors, which requires a high level of operational proficiency. The consistency of adjustment results among different operators is poor, affecting the reliability of measurement data. Summary of the Invention

[0003] The present invention addresses the shortcomings of existing collimator adjustment methods, such as low optical path alignment efficiency, poor accuracy, and complex operation, by providing a collimator optical path rapid adjustment device and method based on dual-camera collaboration.

[0004] To solve the above problems, the present invention is achieved through the following technical solution:

[0005] A method for rapid adjustment of the collimator optical path based on dual-camera collaboration includes the following steps:

[0006] Step 1: First, mark the calibration center coordinates on the target optical axis reference of the collimator, i.e., the target surface of the tracking camera;

[0007] Step 2: The laser beam emitted by the laser communication terminal is collimated by a collimator and then enters the beam splitter. The laser beam reflected by the beam splitter is transmitted to the acquisition camera through a short focal length lens, and the laser beam transmitted by the beam splitter is directly transmitted to the tracking camera.

[0008] Step 3: The computer controls the two-dimensional displacement stage to drive the laser communication terminal to perform a traversal scan within the working stroke range of the two-dimensional displacement stage;

[0009] Step 4: The computer continuously acquires the captured images from the capture camera. When a complete light spot appears in the captured image, the computer sends a command to the two-dimensional displacement stage to stop the laser communication terminal from traversing the scan.

[0010] Step 5: The computer controls the two-dimensional displacement stage to move the laser communication terminal, and makes the laser beam emitted by the laser communication terminal fall on the edge of the captured image, so as to establish the mapping relationship between the field of view of the capture camera and the travel of the two-dimensional displacement stage.

[0011] Step 6: The computer controls the two-dimensional displacement stage to drive the laser communication terminal to perform a traversal scan within the stroke range of the two-dimensional displacement stage corresponding to the field of view of the capture camera;

[0012] Step 7: The computer continuously acquires the tracking images collected by the tracking camera. When a complete light spot appears in the tracking image, the computer sends a command to the two-dimensional displacement stage to stop the laser communication terminal from traversing the scan.

[0013] Step 8: The computer calculates the deviation between the center coordinates of the light spot in the tracking image and the coordinates of the calibration center. Based on this deviation, the computer controls the two-dimensional displacement stage to move the laser communication terminal and positions the center of the laser beam emitted by the laser communication terminal to the calibration center, thus completing the optical path alignment of the collimator.

[0014] In step 3 above, the laser communication terminal uses a concentric circle trajectory scan for traversal scanning, while in step 6 above, the laser communication terminal uses a square spiral trajectory scan for traversal scanning.

[0015] A dual-camera collaborative collimator optical path rapid adjustment device for realizing the aforementioned collimator optical path rapid adjustment method includes a two-dimensional translation stage, a laser communication terminal, a collimator, a beam splitter, a short-focal-length lens, a tracking camera, a capture camera, and a computer. The driving end of the two-dimensional translation stage is rigidly connected to the laser communication terminal. The laser output end of the laser communication terminal is connected to the incident end of the collimator, the emitting end of the collimator is connected to the incident end of the beam splitter, the transmission end of the beam splitter is connected to the input end of the tracking camera, and the reflection end of the beam splitter is connected to the input end of the capture camera after passing through the short-focal-length lens. The output ends of the tracking camera and the capture camera are electrically connected to the input end of the computer, and the output end of the computer is electrically connected to the control end of the two-dimensional translation stage.

[0016] In the above scheme, the field of view of the capture camera is larger than that of the tracking camera.

[0017] In the above scheme, both the tracking camera and the capture camera are CCD cameras.

[0018] In the above scheme, the beam splitting ratio between the transparent end and the reflective end of the beam splitter is 7:3.

[0019] Compared with the prior art, the present invention has the following characteristics:

[0020] 1) Significantly improved alignment efficiency: The large field-of-view scanning of the capture camera enables rapid coarse acquisition, while the small field-of-view scanning of the fine tracking camera enables precise tracking and alignment. The entire process is automated and requires no repeated manual adjustments. The overall alignment time is reduced by 4 to 6 times compared to traditional methods, making it suitable for batch testing and rapid assembly and adjustment needs.

[0021] 2) Significantly improved alignment accuracy: The tracking camera tracks the light spot and provides a closed-loop control input signal to the two-dimensional displacement stage to achieve deviation closed-loop control. The optical path alignment accuracy is high (usually the error is less than one pixel), which solves the problem that a single camera cannot simultaneously achieve large-area capture and high-precision positioning.

[0022] 3) The operation threshold is effectively reduced: It does not rely on the professional experience and subjective judgment of the operator. It automates the entire process of scanning, positioning and alignment. It has good consistency in adjustment in different scenarios and improves the reliability of measurement data.

[0023] 4) High adaptability and flexibility: By adjusting the mapping relationship between the field of view and the displacement stage stroke and the control parameters, it can be adapted to collimators of different models and diameters, and is compatible with the alignment requirements of diverse optical measurement systems. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structural composition of a parallel light tube optical path rapid adjustment device based on dual-camera collaboration;

[0025] Figure 2 is a schematic diagram of the laser communication terminal scanning trajectory within the working stroke range of the two-dimensional displacement stage and the principle of the capture camera capturing the light spot.

[0026] Figure 3 is a schematic diagram of the mapping relationship between the field of view of the camera and the travel of the two-dimensional displacement stage.

[0027] Figure 4 is a schematic diagram of the principle of the laser communication terminal scanning traversing the two-dimensional displacement stage within the field of view of the capture camera and tracking the captured light spot. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific examples.

[0029] See Figure 1A rapid optical path adjustment device for a collimator based on dual-camera collaboration includes a two-dimensional translation stage, a laser communication terminal, a collimator, a beam splitter, a short-focal-length lens, a tracking camera, a capture camera, and a computer. In this embodiment, both the tracking camera and the capture camera are CCD cameras. The field of view of the capture camera is larger than that of the tracking camera; the capture camera has a large monitoring field of view (e.g., ≥10mrad), ensuring a large coverage area; the tracking camera has a smaller monitoring field of view (e.g., ≥400μrad), ensuring positioning accuracy. The beam splitting ratio between the transmitting end and the reflecting end of the beam splitter is 7:3, meaning that 70% of the laser light is emitted from the transmitting end of the beam splitter, and 30% of the reflected light is emitted from the reflecting end of the beam splitter.

[0030] The driving end of the two-dimensional translation stage is rigidly connected to the laser communication terminal. The two-dimensional translation stage drives the laser communication terminal to move in two dimensions in the horizontal and vertical directions, and ensures that the attitude is stable during the movement.

[0031] The laser output end of the laser communication terminal is connected to the incident end of the collimator, the emitting end of the collimator is connected to the incident end of the beam splitter, the transmitting end of the beam splitter is connected to the input end of the tracking camera, and the reflecting end of the beam splitter, after passing through a short-focal-length lens, is connected to the input end of the capture camera. The laser beam emitted by the laser communication terminal is collimated by the collimator and then split by the beam splitter. Part of the laser energy is transmitted along the main optical path to the tracking camera for imaging, while the other part is reflected and transmitted to the short-focal-length lens. The short-focal-length lens achieves a large field of view with a small focal length before entering the capture camera for imaging.

[0032] The outputs of the tracking and acquisition cameras are electrically connected to the inputs of the computer. The tracking and acquisition cameras transmit the acquired light spot images to the computer for subsequent analysis of the light spot and to determine its deviation from the calibration point. The computer's output is electrically connected to the control terminal of the 2D translation stage, used to control the stage for scanning, probing, and positioning. The computer achieves rapid coarse acquisition through a large field-of-view scan by the acquisition camera, combined with precise tracking and alignment through a small field-of-view scan by the fine tracking camera. This efficient scanning acquisition and probing tracking enables rapid positioning and precise alignment of the light spot.

[0033] The above-mentioned collimator optical path rapid adjustment device implements a collimator optical path rapid adjustment method based on dual-camera cooperation, which includes the following steps:

[0034] Step 1: First, mark the calibration center coordinates (x0, y0) on the target optical axis reference of the collimator, i.e., the target surface of the tracking camera.

[0035] Step 2: The laser beam emitted by the laser communication terminal is collimated by a collimator and then enters the beam splitter. The laser beam reflected by the beam splitter is transmitted to the acquisition camera through a short focal length lens, and the laser beam transmitted by the beam splitter is directly transmitted to the tracking camera.

[0036] Step 3: The computer controls the two-dimensional displacement stage to drive the laser communication terminal to perform a traversal scan within the working stroke range of the two-dimensional displacement stage.

[0037] In this embodiment, the traversal scanning of the laser communication terminal adopts concentric circle trajectory scanning, that is, the two-dimensional displacement stage drives the laser communication terminal to scan along a series of circular trajectories with increasing radii within the working stroke range of the two-dimensional displacement stage, such as... Figure 2 As shown.

[0038] Step 4: The computer continuously acquires the captured images from the capture camera. When a complete light spot appears in the captured image, it indicates that the capture camera has captured the light spot. At this time, the computer sends a command to the two-dimensional displacement stage to stop the laser communication terminal from traversing the scan. Figure 2 As shown.

[0039] Step 5: The computer controls the two-dimensional displacement stage to move the laser communication terminal, and makes the laser beam emitted by the laser communication terminal fall on the edge of the captured image, so as to establish the mapping relationship between the field of view of the capture camera and the travel of the two-dimensional displacement stage.

[0040] In this embodiment, since the field of view of the capture camera is rectangular, it is only necessary to place the upper, lower, left, and right edges of the light spot onto the upper, lower, left, and right edges of the captured image, respectively, and record the corresponding positions of the two-dimensional translation stage to establish a mapping relationship between the field of view of the capture camera and the travel of the two-dimensional translation stage. Specifically, as follows... Figure 3 As shown, when the left edge of the light spot falls on the left edge of the captured image, the horizontal coordinate of the 2D translation stage is its lower limit of horizontal travel, *a*; when the right edge of the light spot falls on the right edge of the captured image, the horizontal coordinate of the 2D translation stage is its upper limit of horizontal travel, *b*. Therefore, the horizontal travel of the 2D translation stage corresponding to the horizontal direction of the captured camera's field of view is *ab*. When the upper edge of the light spot falls on the upper edge of the captured image, the horizontal coordinate of the 2D translation stage is its lower limit of horizontal travel, *c*; when the lower edge of the light spot falls on the lower edge of the captured image, the horizontal coordinate of the 2D translation stage is its upper limit of horizontal travel, *d*. Therefore, the horizontal travel of the 2D translation stage corresponding to the horizontal direction of the captured camera's field of view is *cd*.

[0041] Step 6: The computer controls the two-dimensional displacement stage to drive the laser communication terminal to perform a traversal scan within the travel range of the two-dimensional displacement stage corresponding to the field of view of the capture camera.

[0042] In this embodiment, the traversal scanning of the laser communication terminal adopts a square spiral trajectory scanning, that is, the two-dimensional displacement stage drives the laser communication terminal to scan in a square spiral trajectory from the center to the edge (from inside to outside) or from the edge to the center (from outside to inside) within the stroke range of the two-dimensional displacement stage corresponding to the field of view of the capture camera. Figure 4 As shown.

[0043] Step 7: The computer continuously acquires tracking images from the tracking camera. When a complete light spot appears in the tracking image, the computer sends a command to the two-dimensional displacement stage to stop the laser communication terminal from traversing the scan. For example... Figure 4 As shown.

[0044] Step 8: The computer calculates the deviation between the center coordinates of the light spot in the tracking image and the coordinates of the calibration center. Based on this deviation, the computer controls the two-dimensional displacement stage to move the laser communication terminal and positions the center of the laser beam emitted by the laser communication terminal to the calibration center, thus completing the optical path alignment of the collimator.

[0045] Since the field of view of the acquisition camera covers that of the tracking camera, only one scan of the path is needed to detect the light spot within the tracking camera's field of view. When the tracking camera detects the light spot, it calculates the deviation between the center coordinates (x1, y1) and the calibration center coordinates (x0, y0), i.e., Δx = x1 - x0, Δy = y1 - y0. This deviation (Δx, Δy) is used as the closed-loop control input signal to drive the two-dimensional displacement stage to move the laser communication terminal, thereby aligning the center of the light spot with the calibration center and achieving optical path alignment of the collimator.

[0046] It should be noted that although the embodiments described above are illustrative, they are not intended to limit the invention. Therefore, the invention is not limited to the specific embodiments described above. Any other embodiments obtained by those skilled in the art under the guidance of this invention without departing from its principles are considered to be within the protection scope of this invention.

Claims

1. A method for rapid adjustment of the optical path of a collimator based on dual-camera collaboration, characterized in that, The steps include the following: Step 1: First, mark the calibration center coordinates on the target optical axis reference of the collimator, i.e., the target surface of the tracking camera; Step 2: The laser beam emitted by the laser communication terminal is collimated by a collimator and then enters the beam splitter. The laser beam reflected by the beam splitter is transmitted to the acquisition camera through a short focal length lens, and the laser beam transmitted by the beam splitter is directly transmitted to the tracking camera. Step 3: The computer controls the two-dimensional displacement stage to drive the laser communication terminal to perform a traversal scan within the working stroke range of the two-dimensional displacement stage; Step 4: The computer continuously acquires the captured images from the capture camera. When a complete light spot appears in the captured image, the computer sends a command to the two-dimensional displacement stage to stop the laser communication terminal from traversing the scan. Step 5: The computer controls the two-dimensional displacement stage to move the laser communication terminal, and makes the laser beam emitted by the laser communication terminal fall on the edge of the captured image, so as to establish the mapping relationship between the field of view of the capture camera and the travel of the two-dimensional displacement stage. Step 6: The computer controls the two-dimensional displacement stage to drive the laser communication terminal to perform a traversal scan within the stroke range of the two-dimensional displacement stage corresponding to the field of view of the capture camera; Step 7: The computer continuously acquires the tracking images collected by the tracking camera. When a complete light spot appears in the tracking image, the computer sends a command to the two-dimensional displacement stage to stop the laser communication terminal from traversing the scan. Step 8: The computer calculates the deviation between the center coordinates of the light spot in the tracking image and the coordinates of the calibration center. Based on this deviation, the computer controls the two-dimensional displacement stage to move the laser communication terminal and positions the center of the laser beam emitted by the laser communication terminal to the calibration center, thus completing the optical path alignment of the collimator.

2. The method for rapid adjustment of the collimator optical path based on dual-camera collaboration according to claim 1, characterized in that, In step 3, the laser communication terminal uses a concentric circle trajectory scan for traversal scanning, while in step 6, the laser communication terminal uses a square spiral trajectory scan for traversal scanning.

3. A device for rapid adjustment of the collimator optical path based on dual-camera cooperation, which implements the rapid adjustment method of the collimator optical path as described in claim 1, is characterized in that... The system includes a two-dimensional translation stage, a laser communication terminal, a collimator, a beam splitter, a short-focal-length lens, a tracking camera, a capture camera, and a computer. The driving end of the two-dimensional translation stage is rigidly connected to the laser communication terminal. The laser output end of the laser communication terminal is connected to the incident end of the collimator, the emitting end of the collimator is connected to the incident end of the beam splitter, the transmitting end of the beam splitter is connected to the input end of the tracking camera, and the reflecting end of the beam splitter, after passing through the short-focal-length lens, is connected to the input end of the capture camera. The output ends of the tracking camera and the capture camera are electrically connected to the input end of the computer, and the output end of the computer is electrically connected to the control end of the two-dimensional translation stage.

4. The device for rapid adjustment of the collimator optical path based on dual-camera collaboration according to claim 3, characterized in that, The field of view of the capture camera is larger than that of the tracking camera.

5. The rapid adjustment device for the optical path of a collimator based on dual-camera collaboration according to claim 3, characterized in that, Both the tracking camera and the capture camera are CCD cameras.

6. The device for rapid adjustment of the collimator optical path based on dual-camera collaboration according to claim 3, characterized in that, The beam splitting ratio between the transmitting end and the reflecting end of the beam splitter is 7:3.

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