A method for measuring the optical axis consistency of a laser rangefinder receiver.

Abstract

This invention discloses a method for measuring the optical axis consistency of a laser rangefinder receiver, belonging to the field of computation. It includes using a short-wave infrared camera group to image an object within the laser receiving window via a beam splitter, turning off the laser source, and using the short-wave infrared camera group to image the visual aiming optical axis. The method calculates the pixel difference between the center of the laser receiving optical axis and the center of the visual aiming optical axis, and calculates the optical axis deviation based on parameters such as lens focal length and pixel size. This invention solves the technical problem of measuring optical axis deviation. Through image measurement and optical axis deviation calculation, this invention provides high-precision optical axis consistency measurement without disassembling the laser rangefinder, avoiding errors and recalibration issues caused by disassembly. The measurement process is simple and intuitive, reducing cumbersome steps and enabling rapid optical axis consistency measurement. This significantly improves measurement and calibration speed, enhancing the performance and stability of the laser rangefinder.

Description

Technical Field

[0001] This invention belongs to the field of computing, and in particular relates to a method for measuring the optical axis consistency of a laser rangefinder receiver. Background Technology

[0002] Modern complex optoelectronic devices integrate multiple optoelectronic sensors, such as television, infrared imaging, and laser rangefinders. Because these devices typically contain multiple optical systems, the alignment of their optical axes becomes a crucial and complex issue, especially for laser rangefinder systems. The optical axis alignment of a laser rangefinder directly affects its performance, particularly its maximum range.

[0003] Traditional methods for measuring optical axis consistency have significant drawbacks:

[0004] 1. It is impossible to directly measure the deviation of the laser receiving optical axis, especially without disassembling the equipment.

[0005] 2. The calibration process is cumbersome and inaccurate. For example, removing devices such as avalanche tubes and narrow-band filters may introduce new installation errors, affecting the consistency of the optical axis.

[0006] 3. Insufficient calibration accuracy and lack of effective and quantitative measurement methods lead to unstable or unreliable test results. Summary of the Invention

[0007] The purpose of this invention is to provide a method for measuring the optical axis consistency of a laser rangefinder receiver, which solves the technical problem of measuring optical axis deviation.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A method for measuring the optical axis consistency of a laser rangefinder receiver includes the following steps:

[0010] Step 1: Place the laser rangefinder to be inspected on the stage assembly, and adjust the stage to align the laser receiving window with the light output / input port of the measuring equipment;

[0011] Step 2: Select the preset laser power for the laser rangefinder under test and emit the laser. The laser light is uniformly illuminated by the beam splitter prism group.

[0012] Step 3: Using a short-wave infrared camera group, the object within the laser receiving window is imaged through a beam splitter prism group. The orientation of the short-wave infrared camera group, the laser rangefinder under test, and the beam splitter prism group are adjusted to obtain a clear image of the laser receiving aperture of the laser rangefinder under test.

[0013] Step 4: The shortwave infrared camera group transmits the image of the laser receiving aperture to the image processing module. The image processing module saves the image, and the center of the laser receiving aperture in the image represents the laser receiving optical axis.

[0014] Step 5: Turn off the laser source and use the short-wave infrared camera group to image the visual aiming reticle within the laser receiving window to obtain the reticle image; the reticle center of the reticle image represents the visual aiming optical axis; if there is no visual aiming reticle, introduce the image of the collimator into the optical hinge group, and then transfer the image onto the short-wave infrared camera group; the short-wave infrared camera group sends the visual aiming optical axis image to the image processing module.

[0015] Step 6: The image processing module calculates the pixel difference between the center of the laser receiving optical axis and the center of the visual aiming optical axis, calculates the optical axis deviation based on the lens focal length and pixel size, and outputs the optical axis deviation calculation result;

[0016] Step 7: Replace the corresponding optical components according to different laser bands to adapt to different models of laser rangefinders under test.

[0017] Preferably, the beam splitter assembly includes a beam splitter, a beam splitter base, and a light shield. The beam splitter is mounted on the beam splitter base and equipped with a light shield to prevent stray light. The beam splitter base is used to fine-tune the orientation of the beam splitter.

[0018] Preferably, the laser rangefinder under test includes a laser head, a laser collimating lens, a laser adjustable power supply, and a laser head holder. The laser adjustable power supply is used to adjust the laser output power; the laser collimating lens is used to ensure that the light output by the laser head is parallel; the laser head holder is used to fine-tune the laser head attitude, that is, to fine-tune the output laser direction; and the laser head is used to emit laser light.

[0019] Preferably, the shortwave infrared camera assembly includes a shortwave infrared camera, a shortwave infrared lens, a camera base, a narrowband color filter, and a camera power supply; the shortwave infrared camera is mounted on the camera base; the shortwave infrared lens is used for focusing; the narrowband color filter is used for filtering the image; and the camera base is used for fine-tuning the attitude of the shortwave infrared camera.

[0020] Preferably, the image processing module is a host computer or a tablet computer.

[0021] Preferably, when performing step 6, the formula for calculating the optical axis deviation based on the lens focal length and pixel size is as follows:

[0022]

[0023] Where lP is the deviation amount, n is the number of pixels that deviate from the center of the laser receiving optical axis and the center of the visual aiming optical axis, d is the pixel size, and fa is the focal length of the short-wave infrared lens.

[0024] The present invention provides a method for measuring the optical axis consistency of a laser rangefinder receiver, which solves the technical problem of measuring optical axis deviation. This invention provides high-precision optical axis consistency measurement through image measurement and optical axis deviation calculation. It eliminates the need to disassemble the laser rangefinder, avoiding errors and recalibration issues caused by disassembly. The measurement process is simple and intuitive, reducing cumbersome steps and enabling rapid optical axis consistency measurement. This significantly improves measurement and calibration speed, enhancing the performance and stability of the laser rangefinder. Attached Figure Description

[0025] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0026] like Figure 1 The method for measuring the optical axis consistency of a laser rangefinder receiver includes the following steps:

[0027] Step 1: Place the laser rangefinder to be inspected on the stage assembly, and adjust the stage to align the laser receiving window with the light output / input port of the measuring equipment;

[0028] The laser rangefinder under test includes a laser head, a laser collimating lens, a laser adjustable power supply, and a laser head holder. The laser adjustable power supply is used to adjust the laser output power; the laser collimating lens is used to ensure that the light output by the laser head is parallel; the laser head holder is used to fine-tune the laser head attitude, that is, to fine-tune the output laser direction; and the laser head is used to emit laser light.

[0029] Step 2: Select the preset laser power for the laser rangefinder under test and emit the laser. The laser light is uniformly illuminated by the beam splitter prism group.

[0030] The beam splitter assembly includes a beam splitter, a beam splitter base, and a light shield. The beam splitter is mounted on the beam splitter base and equipped with a light shield to prevent stray light. The beam splitter base is used to fine-tune the orientation of the beam splitter.

[0031] Step 3: Using a short-wave infrared camera group, the object within the laser receiving window is imaged through a beam splitter prism group. The orientation of the short-wave infrared camera group, the laser rangefinder under test, and the beam splitter prism group are adjusted to obtain a clear image of the laser receiving aperture of the laser rangefinder under test.

[0032] The shortwave infrared camera assembly includes a shortwave infrared camera, a shortwave infrared lens, a camera base, a narrowband color filter, and a camera power supply; the shortwave infrared camera is mounted on the camera base; the shortwave infrared lens is used for focusing; the narrowband color filter is used for filtering the image; and the camera base is used for fine-tuning the attitude of the shortwave infrared camera.

[0033] Step 4: The shortwave infrared camera group transmits the image of the laser receiving aperture to the image processing module. The image processing module saves the image, and the center of the laser receiving aperture in the image represents the laser receiving optical axis.

[0034] The image processing module is a host computer or a tablet computer.

[0035] Step 5: Turn off the laser source and use the short-wave infrared camera group to image the visual aiming reticle within the laser receiving window to obtain the reticle image; the reticle center of the reticle image represents the visual aiming optical axis; if there is no visual aiming reticle, introduce the image of the collimator into the optical hinge group, and then transfer the image onto the short-wave infrared camera group; the short-wave infrared camera group sends the visual aiming optical axis image to the image processing module.

[0036] In this embodiment, the optical hinge assembly is positioned in front of the beam splitter prism assembly. When needed, the image from the collimator or other optical reticles can be introduced into the optical hinge assembly and transferred onto the short-wave infrared camera assembly with almost no deviation. For systems with only a laser emission optical axis and no visual aiming optical axis, a visual aiming scope can be added. First, the laser emission optical axis and the visual aiming optical axis can be aligned using other devices based on the laser's image spot on the photographic paper before the image is transferred.

[0037] Step 6: The image processing module calculates the pixel difference between the center of the laser receiving optical axis and the center of the visual aiming optical axis, calculates the optical axis deviation based on the lens focal length and pixel size, and outputs the optical axis deviation calculation result;

[0038] When performing step 6, the formula for calculating the optical axis deviation based on the lens focal length and pixel size is as follows:

[0039]

[0040] Where lP is the deviation amount, n is the number of pixels that deviate from the center of the laser receiving optical axis and the center of the visual aiming optical axis, d is the pixel size, and fa is the focal length of the short-wave infrared lens.

[0041] Step 7: Replace the corresponding optical components according to different laser bands to adapt to different models of laser rangefinders under test.

[0042] For laser rangefinders with different laser bands, such as 1.06m and 1.54m laser rangefinders, the beam splitter, laser, collimating lens, narrowband filter and other individual components of different bands can be replaced to adapt them.

[0043] In this embodiment, the beam splitter prism group, laser light source group, short-wave infrared camera group, and optical hinge group are all mounted on the same flat plate, and their optical paths need to be basically adjusted and aligned. In use, it needs to be used in conjunction with a stage group, collimator group, etc.

[0044] This invention provides a simple, intuitive, and accurate measurement device and method without damaging the laser rangefinder itself, enabling rapid measurement and high-precision interpretation of the optical axis consistency of the laser rangefinder's receiving optical axis.

[0045] The following is a specific application scenario example of this embodiment:

[0046] Step S1: Laser Rangefinder Installation and Positioning: Place the laser rangefinder under test on the stage assembly, and adjust the position and orientation of the stage to ensure that the laser receiving window of the rangefinder is basically aligned with the light output / input port of the device. This alignment ensures precise alignment of the laser irradiation direction with the laser receiving window, avoiding measurement errors.

[0047] The precise adjustment of the stage assembly ensures that the laser beam accurately illuminates the laser receiving window. This precise alignment guarantees the accuracy of subsequent measurements, ensuring no deviation between the laser beam and the laser receiving window.

[0048] Step S2: Laser Emission and Optical Path Adjustment: Select an appropriate laser power and emit the laser through the laser source group. The laser beam is uniformly illuminated inside the laser receiving window by the beam splitter, ensuring that the laser spot size is uniform and covers the entire receiving area. The laser head holder, beam splitter base, and stage can be adjusted to further optimize the beam illumination angle and range.

[0049] The laser beam is evenly distributed through a beam-splitting prism to ensure uniform light intensity distribution across the irradiated area, thereby obtaining a clear and stable spot image during subsequent imaging. The angles and positions of each component are adjusted to ensure precise laser illumination of the receiving window.

[0050] Step S3: Short-wave infrared camera imaging: Using a short-wave infrared camera assembly, an image is formed of the laser receiving aperture within the laser receiving window using a beam splitter prism. The short-wave infrared camera base, beam splitter prism base, and laser head holder are adjustable to ensure that the laser receiving aperture is centered in the camera image.

[0051] The image from the laser receiving window is transmitted to a short-wave infrared camera via a beam splitter, ensuring that the laser receiving aperture is clearly centered in the camera image. The quality and sharpness of the image directly affect the accuracy of subsequent optical axis deviation measurements.

[0052] Step S4: Camera Focusing and Image Optimization: Adjust the short-wave infrared camera lens for precise focusing to ensure the image of the laser receiver aperture is clearly visible. The center of the aperture in the image will represent the receiving optical axis of the laser rangefinder.

[0053] Focusing is used to improve image sharpness and ensure accurate positioning of the center of the laser receiver aperture in the image. A clear image is crucial for subsequent accurate calculations of optical axis deviation.

[0054] Step S5: Save the laser receiving optical axis image: Save the focused image. The center of the laser receiving aperture in the image is the position of the laser receiving optical axis.

[0055] Step S6: Turn off the laser power and image the visual optical reticle: Turn off the laser power, remove the narrowband color filter, and use a short-wave infrared camera group to image the visual optical reticle within the laser receiving window. If necessary, a visible light source (such as a flashlight) can be used for auxiliary illumination to ensure image sharpness.

[0056] Imaging with a visual optical reticle helps us determine the position of the optical axis when aiming. Combining visible light illumination with infrared camera imaging ensures a clear and accurate image of the optical axis.

[0057] Step S7: Introduce the visual aiming optical axis image: If there is no readily available visual optical reticle within the laser receiving window, a visual aiming reticle from another location can be introduced via an optical hinge and the image transferred to the shortwave infrared camera group. If the laser emission optical axis is inconsistent with the visual aiming optical axis, the visual aiming scope can be adjusted to align them before introducing the visual aiming reticle for measurement.

[0058] The step of introducing and converting the visual aiming optical axis image ensures accurate alignment of the optical axis. This step yields a clear visual aiming optical axis image, facilitating comparison and calculation with the laser receiving optical axis image.

[0059] Step S8: Save the visual aiming optical axis image: Save the image containing the visual aiming optical axis. The center of the aiming reticle in the image is the position of the visual aiming optical axis.

[0060] Step S9: Calculate the pixel difference between the two optical axis centers using measurement software, and calculate the optical axis deviation based on lens focal length parameters, pixel size, etc. The calculation formula is as follows:

[0061]

[0062] Where lP is the deviation amount, n is the number of pixels that deviate from the center of the laser receiving optical axis and the center of the visual aiming optical axis, d is the pixel size, and fa is the focal length of the short-wave infrared lens.

[0063] By using a precise pixel difference calculation formula, the deviation between the laser receiving optical axis and the visual aiming optical axis can be quantified, ensuring the accuracy of optical axis consistency measurement.

[0064] Step S10: Output optical axis deviation.

[0065] The present invention provides a method for measuring the optical axis consistency of a laser rangefinder receiver, which solves the technical problem of measuring optical axis deviation. This invention provides high-precision optical axis consistency measurement through image measurement and optical axis deviation calculation. It eliminates the need to disassemble the laser rangefinder, avoiding errors and recalibration issues caused by disassembly. The measurement process is simple and intuitive, reducing cumbersome steps and enabling rapid optical axis consistency measurement. This significantly improves measurement and calibration speed, enhancing the performance and stability of the laser rangefinder.

Claims

1. A method for measuring the optical axis consistency of a laser rangefinder receiver, characterized in that: Includes the following steps: Step 1: Place the laser rangefinder to be inspected on the stage assembly, and adjust the stage to align the laser receiving window with the light output / input port of the measuring equipment; Step 2: Select the preset laser power for the laser rangefinder under test and emit the laser. The laser light is uniformly illuminated by the beam splitter prism group. Step 3: Using a short-wave infrared camera group, the object within the laser receiving window is imaged through a beam splitter prism group. The orientation of the short-wave infrared camera group, the laser rangefinder under test, and the beam splitter prism group are adjusted to obtain a clear image of the laser receiving aperture of the laser rangefinder under test. Step 4: The shortwave infrared camera group transmits the image of the laser receiving aperture to the image processing module. The image processing module saves the image, and the center of the laser receiving aperture in the image represents the laser receiving optical axis. Step 5: Turn off the laser source and use the short-wave infrared camera group to image the visual aiming reticle within the laser receiving window to obtain the reticle image; the reticle center of the reticle image represents the visual aiming optical axis; if there is no visual aiming reticle, introduce the image of the collimator into the optical hinge group, and then transfer the image onto the short-wave infrared camera group; the short-wave infrared camera group sends the visual aiming optical axis image to the image processing module. The optical hinge assembly is positioned in front of the beam splitter assembly. It introduces the image from the collimator or other optical reticle into the optical hinge assembly and transfers the image onto the shortwave infrared camera assembly. Step 6: The image processing module calculates the pixel difference between the center of the laser receiving optical axis and the center of the visual aiming optical axis, calculates the optical axis deviation based on the lens focal length and pixel size, and outputs the optical axis deviation calculation result; Step 7: Replace the corresponding optical components according to different laser bands to adapt to different models of laser rangefinders under test.

2. The method for measuring the optical axis consistency of a laser rangefinder receiver as described in claim 1, characterized in that: The beam splitter assembly includes a beam splitter, a beam splitter base, and a light shield. The beam splitter is mounted on the beam splitter base and equipped with a light shield to prevent stray light. The beam splitter base is used to fine-tune the orientation of the beam splitter to ensure precise guidance of the optical path.

3. The method for measuring the optical axis consistency of a laser rangefinder receiver as described in claim 1, characterized in that: The laser rangefinder under test includes a laser head, a laser collimating lens, a laser adjustable power supply, and a laser head holder. The laser adjustable power supply is used to adjust the laser output power; the laser collimating lens is used to ensure that the light output by the laser head is parallel; the laser head holder is used to fine-tune the laser head attitude, that is, to fine-tune the output laser direction; and the laser head is used to emit laser light.

4. The method for measuring the optical axis consistency of a laser rangefinder receiver as described in claim 1, characterized in that: The shortwave infrared camera assembly includes a shortwave infrared camera, a shortwave infrared lens, a camera base, a narrowband color filter, and a camera power supply; the shortwave infrared camera is mounted on the camera base; the shortwave infrared lens is used for focusing; the narrowband color filter is used for filtering the image; and the camera base is used for fine-tuning the attitude of the shortwave infrared camera.

5. The method for measuring the optical axis consistency of a laser rangefinder receiver as described in claim 1, characterized in that: The image processing module is a host computer or a tablet computer.

6. The method for measuring the optical axis consistency of a laser rangefinder receiver as described in claim 1, characterized in that: When performing step 6, the formula for calculating the optical axis deviation based on the lens focal length and pixel size is as follows: Where lP is the deviation amount, n is the number of pixels that deviate from the center of the laser receiving optical axis and the center of the visual aiming optical axis, d is the pixel size, and fa is the focal length of the short-wave infrared lens.

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