Recognition method with automatic target recognition function, recognition camera and measurement device

Abstract

The invention relates to a recognition method with an automatic target recognition function, a recognition camera and a measurement device, and the recognition method comprises the steps: sequentially transmitting a first light beam and a second light beam which is different from the first light beam, an imaging element is used for receiving the first light beam and the second light beam reflected by the reflecting object and capturing a first image matched with the first light beam and a second image matched with the second light beam, and the first light beam and the second light beam are emitted by a target light source; the first image comprises a first light spot formed on the imaging element by a first light beam reflected by the target, and the second image comprises a second light spot formed on the imaging element by a second light beam reflected by the target; acquiring a third image based on the feature difference between the first image and the second image; and acquiring at least part of the first light spot and / or at least part of the second light spot as a target light spot based on the third image. Therefore, the recognition precision and the recognition efficiency of the target light spot can be improved.

Description

[0001] This application is a divisional application of the patent application filed on October 30, 2024, with application number 202411523963X and invention titled "Identification Method and Target Identification Unit for Target Identification Unit". Technical Field

[0002] This disclosure relates to the field of intelligent manufacturing equipment industry, specifically to an identification method, identification camera and measuring device with automatic target identification function. Background Technology

[0003] A laser tracker, also known as a coordinate measuring device, works on the principle of placing a target (also called a "reflector" or "target ball") at the point to be measured. The laser beam emitted by the laser tracking head of the laser tracker is emitted along the measuring optical axis of the laser tracker onto the target. The laser beam is reflected by the target and returns to the laser tracking head. When the target moves, the laser tracking head adjusts the direction of the laser beam to aim at the target.

[0004] When the target deviates from the aiming optical axis of the laser tracker, the laser tracker can re-identify the target through Automatic Target Recognition (ATR). In the prior art, the target recognition unit typically includes a scattering light source and an imaging element. The imaging element captures an image that matches the target based on the scattered beam emitted by the scattering light source, and identifies the target by recognizing the light spot formed by the scattered beam reflected by the target on the image (hereinafter referred to as the target light spot).

[0005] However, in actual measurements, the field of view of an imaging element typically contains multiple reflective objects, including both target and non-target objects. These reflective objects scatter the light source, resulting in multiple light spots (including target and non-target spots) in the image captured by the imaging element, making it difficult to accurately identify the target spot. Furthermore, if multiple emitting objects are present in the field of view of the imaging element, the image captured by the element will include light spots corresponding to the non-scattered beams (also known as non-target spots), further hindering the identification of the target spot. Summary of the Invention

[0006] This disclosure is made in view of the above circumstances, and its purpose is to provide an identification method and a target identification unit for a target identification unit that can improve the identification accuracy and efficiency of target light spots.

[0007] To this end, a first aspect of this disclosure provides an identification method for a target identification unit, which is a method for identifying a target light spot that matches a target. The target identification unit includes a target light source for emitting a first light beam and a second light beam, and an imaging element for receiving the first light beam and the second light beam reflected by a reflective object. The identification method includes: sequentially emitting a first light beam and a second light beam; using the imaging element to capture a first image that matches the first light beam and a second image that matches the second light beam; the first image includes a first light spot formed on the imaging element by the first light beam reflected by the target; the second image includes a second light spot formed on the imaging element by the second light beam reflected by the target; the position or shape of the first light spot on the imaging element is different from the position or shape of the second light spot on the imaging element; acquiring a difference image between the first image and the second image as a third image; and based on the third image, acquiring at least a portion of the first light spot and / or at least a portion of the second light spot as the target light spot, wherein the emission positions of the first light beam and the second light beam are different, or the frequencies of the first light beam and the second light beam are different.

[0008] In the identification method disclosed herein, due to the different emission positions of the first and second beams, or the different frequencies of the first and second beams, the positions or shapes of the first and second light spots differ. Furthermore, these differences will exhibit different effects on targets and other reflective objects. A third image obtained based on differential processing of the first and second images can reflect the imaging situation caused by the target beam reflected from the target. In other words, the imaging situation caused by interfering light sources and / or interfering objects can be removed through differential image processing. This reduces the interference of interfering light sources and / or interfering objects in the imaging situation, thereby improving the signal-to-noise ratio of the imaging signal of the target beam emitted by the target light source, and thus improving the accuracy and efficiency of target spot identification. Furthermore, it can improve the accuracy and speed of target identification.

[0009] In addition, in the identification method according to the first aspect of this disclosure, optionally, the emission positions of the first beam and the second beam are different, and the target light source includes a first light source and a second light source symmetrically arranged around the imaging element. The first light source and the second light source located at different positions are controlled to turn on in sequence to emit the first beam and the second beam in sequence and obtain the first image and the second image.

[0010] Furthermore, in the identification method according to the first aspect of this disclosure, optionally, the frequencies of the first beam and the second beam are different. The target includes an auxiliary marker matching the frequency of the first beam or the second beam. The auxiliary marker is arranged around the retroreflection area of ​​the target, and the light spot formed on the imaging element by the first or second beam reflected by the auxiliary marker serves as an auxiliary light spot. The first or second light spot includes the auxiliary light spot, and the target light spot is identified based on the auxiliary light spot. In this case, the target light spot can be identified by an auxiliary light spot of a specific shape, thereby facilitating the differentiation between the target light spot and interfering light spots. For example, assuming there are interfering objects in the measurement environment with the same or similar shape as the retroreflection area, the target light spot can be identified by the auxiliary light spot in the image captured by the imaging element, while the interfering light spot is not identified by the auxiliary light spot. Thus, it is possible to quickly distinguish between the target light spot and the interfering light spot without establishing an image library storing standard light spots.

[0011] Furthermore, in the recognition method according to the first aspect of this disclosure, optionally, the first image and the second image are differentially divided to obtain the third image including the auxiliary spot; the coordinates of the auxiliary spot on the imaging element are obtained based on the third image as auxiliary coordinates; at least a portion of the first spot is cropped from the first image based on the auxiliary coordinates as the target spot, or at least a portion of the second spot is cropped from the second image based on the auxiliary coordinates as the target spot. In this case, since theoretically only the auxiliary spot has a high grayscale value in the third image, the auxiliary spot can be quickly identified directly based on the grayscale value in the third image, and thus the target spot can be identified by means of the auxiliary spot.

[0012] Furthermore, in the identification method according to the first aspect of this disclosure, optionally, the time interval between emitting the first beam and the second beam is matched with the frame rate of the imaging element. In this case, the matching degree between the first image and the second image can be improved, that is, the consistency between the imaging situation caused by interfering light sources and / or interfering objects in the first image and the imaging situation caused by interfering light sources and / or interfering objects in the second image can be improved. Thus, the presence of interfering light spots formed by interfering light sources and / or interfering objects in the third image can be effectively reduced.

[0013] Furthermore, in the identification method according to the first aspect of this disclosure, optionally, before emitting the first beam and the second beam, the method further includes adjusting the configuration mode of the target identification unit based on ambient brightness. The configuration mode includes the power of the target light source and the exposure time of the imaging element. Adjusting the configuration mode of the target identification unit includes: detecting the grayscale value of an image captured by the imaging element, which characterizes the ambient brightness; and adjusting the configuration mode to a first configuration mode in response to the grayscale value of the image not being greater than a first preset value, and adjusting the configuration mode to a second configuration mode in response to the grayscale value of the image being greater than the first preset value. In the first configuration mode, the power of the target light source and the exposure time of the imaging element are not greater than the power of the target light source and the exposure time of the imaging element in the second configuration mode. Therefore, it is convenient to adjust the configuration mode to match the measurement environment based on the ambient brightness.

[0014] Furthermore, in the identification method according to the first aspect of this disclosure, optionally, it further includes, during the measurement process, reducing the gain of the imaging element in response to the grayscale value of the image captured by the imaging element being not less than a grayscale threshold, and increasing the power of the target light source while reducing the gain of the imaging element. In outdoor sunlight, images are prone to overexposure and low contrast, resulting in a large grayscale value. Therefore, when the grayscale value of the image is greater than the grayscale threshold, the target identification unit can automatically adjust the grayscale value of the image below the grayscale threshold by reducing the gain of the imaging element. This reduces information loss due to overexposure and improves the integrity of the light signal captured by the imaging element. Additionally, since the gain of the imaging element is reduced, the grayscale values ​​of the light spots formed by the target beam and the interference beam in the image captured by the imaging element are both low. Increasing the power of the target light source at this time can further distinguish between the target beam and the interference beam, increasing the grayscale value of the light spot formed by the target beam, that is, increasing the contrast of the light spot formed by the target beam compared to the light spot formed by the interference beam, and reducing the adverse effects of the interference beam during the measurement process.

[0015] Additionally, in the identification method according to the first aspect of this disclosure, optionally, the imaging element is a photosensitive element that matches the wavelength of the target light source, which is approximately 940 nanometers. In this case, since the irradiance of natural light (interference beam) is low in this wavelength band, the interference of the interference beam on the imaging of the target beam can be reduced, that is, the background noise can be reduced and the contrast of the light spot formed by the target beam on the imaging element can be improved.

[0016] A second aspect of this disclosure provides a target recognition unit for recognizing a target light spot that matches a target. The target recognition unit includes a target light source, an imaging element, and a processing element. The target light source is configured to sequentially emit a first light beam and a second light beam. The imaging element is configured to capture a first image that matches the first light beam and a second image that matches the second light beam. The first image includes a first light spot formed on the imaging element by the first light beam reflected by the target, and the second image includes a second light spot formed on the imaging element by the second light beam reflected by the target. The position or shape of the first light spot on the imaging element is different from the position or shape of the second light spot on the imaging element. The processing element is configured to acquire a difference image between the first image and the second image as a third image, and based on the third image, acquire at least a portion of the first light spot and / or at least a portion of the second light spot as the target light spot. The emission positions of the first light beam and the second light beam are different, or the frequencies of the first light beam and the second light beam are different.

[0017] Additionally, in the target recognition unit according to the second aspect of this disclosure, optionally, the target light source includes a first light source and a second light source symmetrically arranged around the imaging element.

[0018] According to this disclosure, a method for identifying a target identification unit and a target identification unit can be provided to improve the accuracy and efficiency of target spot identification. Attached Figure Description

[0019] This disclosure will now be explained in further detail by way of example only with reference to the accompanying drawings.

[0020] Figure 1 This is a diagram illustrating an application scenario of the measuring device involved in the examples of this disclosure.

[0021] Figure 2A This is a schematic diagram illustrating the structure of a first embodiment of the objective involved in this disclosure. Figure 2B It shows Figure 2A A schematic diagram of the target light spot corresponding to the indicated target.

[0022] Figure 3 This is a schematic diagram showing the target recognition unit disposed on the optical body according to the example of this disclosure.

[0023] Figure 4 This is a flowchart illustrating a first embodiment of the identification method involved in the examples of this disclosure.

[0024] Figure 5A This is a schematic diagram illustrating a first image in a first embodiment of the identification method involved in the present disclosure. Figure 5B This is a schematic diagram illustrating a second image in a first embodiment of the identification method involved in the examples of this disclosure. Figure 5C This is a schematic diagram illustrating a third image in a first embodiment of the identification method involved in the examples of this disclosure.

[0025] Figure 6A This is a schematic diagram illustrating the structure of a second embodiment of the objective involved in this disclosure. Figure 6B It shows Figure 6A A schematic diagram of the target light spot corresponding to the indicated target.

[0026] Figure 7 This is a flowchart illustrating a second embodiment of the identification method involved in the examples of this disclosure.

[0027] Figure 8A This is a schematic diagram illustrating a first image in a second embodiment of the identification method involved in the present disclosure. Figure 8B This is a schematic diagram illustrating a second image in a second embodiment of the identification method involved in the examples of this disclosure. Figure 8C This is a schematic diagram illustrating a third image in a second embodiment of the identification method involved in the examples of this disclosure. Figure 8D This is a schematic diagram illustrating a fourth image in a second embodiment of the identification method involved in the examples of this disclosure.

[0028] Figure 9 This is a flowchart illustrating a third embodiment of the identification method involved in the examples of this disclosure.

[0029] Figure 10A This is a schematic diagram illustrating a first image in a third embodiment of the identification method involved in the examples of this disclosure. Figure 10B This is a schematic diagram illustrating a second image in a third embodiment of the identification method involved in the examples of this disclosure. Figure 10C This is a schematic diagram illustrating a third image in a third embodiment of the identification method involved in the examples of this disclosure. Detailed Implementation

[0030] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same components, and repeated descriptions are omitted. Furthermore, the drawings are merely schematic diagrams, and the proportions of the components or the shapes of the components may differ from actual figures.

[0031] Furthermore, the subheadings and similar terms used in the following description of this disclosure are not intended to limit the content or scope of this disclosure; they are merely intended to serve as reading prompts. Such subheadings should not be construed as dividing the content of the article, nor should the content under a subheading be limited to the scope of that subheading.

[0032] This disclosure relates to an identification method for a target recognition unit (hereinafter referred to as the identification method or method), which is a method for identifying target light spots that match a target. The identification method disclosed herein can improve the accuracy of target light spot identification, that is, improve the precision of target light spot identification. Furthermore, the identification method disclosed herein can also improve the efficiency of target light spot identification, that is, improve the efficiency of target identification.

[0033] This disclosure also relates to a target recognition unit, which can improve both the accuracy and efficiency of target recognition. In some examples, the target recognition unit can be used to implement the recognition method disclosed herein.

[0034] This disclosure also relates to a measuring device including a target recognition unit, which is capable of recognizing a target, tracking the target, and measuring the spatial coordinates of the target.

[0035] In some examples, the identification method for the target identification unit disclosed herein may also be referred to as an identification method with automatic target identification function, an ATR identification method, or a method for identifying target light spots, etc. In some examples, the target identification unit disclosed herein may also be referred to as an ATR camera or an identification camera, etc.

[0036] The identification method, target identification unit, and measuring device involved in this disclosure will be described in detail below with reference to the accompanying drawings.

[0037] Figure 1 This is a diagram illustrating an application scenario of the measuring device 1 involved in the example of this disclosure.

[0038] In some examples, measuring device 1 can be used to emit a light beam toward target 2, which can then reflect the received beam back to measuring device 1 (see [reference]). Figure 1 In some examples, measuring device 1 can identify target 2 based on the light beam reflected by target 2. In some examples, measuring device 1 can measure target 2 based on the light beam reflected by target 2. In some examples, measuring device 1 can track target 2 based on the light beam reflected by target 2.

[0039] In some examples, measuring device 1 can measure the spatial coordinates of target 2. In some examples, measuring device 1 can also measure the spatial attitude of target 2. In some examples, measuring device 1 can be a laser measuring instrument such as a laser tracker, lidar, or total station.

[0040] See in some examples Figure 1The measuring device 1 may include a target recognition unit 11 and an optical body 12. In some examples, the target recognition unit 11 may be used to identify a target 2, and the optical body 12 may be used to track the target 2. In some examples, the target recognition unit 11 may be disposed on the optical body 12.

[0041] In some examples, the target recognition unit 11 can emit a scattered light beam. Since the scattered light beam has a large radiation range, the target recognition unit 11 can have a large field of view. Therefore, target 2 can be quickly identified. In some examples, identifying target 2 and roughly aligning the optical body 12 with target 2 can also be referred to as coarsely aiming at target 2. In some examples, the target recognition unit 11 can also measure target 2 based on the scattered light beam.

[0042] In some examples, the optical body 12 can emit a laser beam. The optical body 12 can then measure the target 2 based on the laser beam reflected from it. In some examples, the optical body 12 can achieve precise aiming at the target 2 based on the laser beam. This enables the tracking of the target 2.

[0043] See in some examples Figure 1 The optical body 12 may include a window 121 for emitting a laser beam. In some examples, the target recognition unit 11 may be located near the window 121.

[0044] In some examples, the measuring device 1 can first identify the target 2 based on the scattered beam emitted by the target recognition unit 11, and then track the target 2 based on the laser beam emitted by the optical body 12. In this case, if the tracking of the target 2 is lost, the target recognition unit 11 can quickly re-identify the target 2, and then the optical body 12 can achieve continuous tracking of the target 2.

[0045] Figure 2A This is a schematic diagram illustrating the structure of a first embodiment of objective 2 as described in this disclosure. Figure 2B It shows Figure 2A A schematic diagram of target spot 3 corresponding to target 2. Figure 3 This is a schematic diagram showing the target recognition unit 11 disposed on the optical body 12 according to the example of this disclosure.

[0046] In some examples, target 2 may be a device used in conjunction with measuring device 1. Target 2 may also be referred to as a target or target point. See also [link to relevant documentation] in some examples. Figure 2A Target 2 may include a retroreflection region 21. In some examples, target 2 can reflect a scattered beam or laser beam back to measuring device 1 through the retroreflection region 21. See also [examples omitted for brevity]. Figure 2ATarget 2 may include a housing 22 disposed around the retroreflection area 21. Thus, the retroreflection area 21 can be protected.

[0047] See in some examples Figure 3 The target recognition unit 11 can be positioned on either side of the window 121. In some examples, the target recognition unit 11 can be positioned below, to the left, or to the right of the window 121.

[0048] See in some examples Figure 3 The target recognition unit 11 may include a target light source 111 and an imaging element 112. In some examples, the target light source 111 may be used to emit a scattered light beam. In some examples, the imaging element 112 may be used to receive the scattered light beam reflected by the target 2. In some examples, the scattered light beam emitted by the target light source 111 may also be referred to as the target beam.

[0049] In some examples, the target recognition unit 11 may include an imaging element 112 and a target light source 111 arranged around the imaging element 112. Thus, the target 2 can be identified by recognizing the target light spot 3.

[0050] In some examples, the target recognition unit 11 may include a plurality of imaging elements 112 and a target light source 111 arranged around the plurality of imaging elements 112. For example, see Figure 3 The target recognition unit 11 may include two imaging elements 112 and a target light source 111 arranged around the two imaging elements 112. Thus, it can not only identify the target spot 3, but also obtain the approximate distance of the target 2 based on the target spot 3 on the two imaging elements 112.

[0051] In some examples, the scattered light beam reflected by target 2 can form target spot 3 on imaging element 112. In other words, target spot 3 is the spot formed on imaging element 112 by the scattered light beam reflected by target 2. In some examples, target recognition unit 11 can identify target 2 by recognizing target spot 3. In some examples, Figure 2A The target spot 3 corresponding to target 2 shown can be as follows: Figure 2B As shown.

[0052] In some examples, the light spot formed on the imaging element 112 due to other factors can be referred to as a non-target light spot or an interfering light spot. Specifically, in the actual measurement process, in addition to the light emitted by the target light source 111 itself, there may be other light-emitting objects, such as ambient light and / or natural light (sunlight). For ease of subsequent description, these other light-emitting objects are referred to as interfering light sources, the light beams emitted by these other light-emitting objects are referred to as interfering beams, and the light spot formed on the imaging element 112 by the interfering beams reflected by reflective objects (including target 2 and non-target objects) is referred to as a non-target light spot or an interfering light spot.

[0053] In addition, during actual measurement, besides target 2 reflecting the scattered light beam, there are usually other objects with reflective capabilities (hereinafter referred to as non-targets or interfering objects, such as reflective tags or metal) that reflect the scattered light beam. In some examples, there may be one or more non-targets. For ease of description, target 2 and non-targets are collectively referred to as reflectors, and the light spot formed on the imaging element 112 by the scattered light beam reflected by non-targets is also referred to as a non-target light spot or interfering light spot.

[0054] In some examples, the process of a reflector reflecting a light beam to form a light spot on the imaging element 112 can also be referred to as the process of the imaging element 112 capturing an image. During actual measurement, the image captured by the imaging element 112 may include the target light spot 3 and at least one non-target light spot. The presence of the non-target light spot makes it difficult to accurately identify the target light spot 3, and further, makes it difficult to identify the target 2. Specifically, when there is interfering light beam or interfering object with the same or similar shape as the retroreflection area 21 in the measurement environment, the image captured by the imaging element 112 will also contain interfering light spots with the same or similar shape as the target light spot 3, which will further make it difficult to accurately identify the target light spot 3.

[0055] The identification method disclosed herein can reduce the influence of interfering light beams or objects during the measurement process, improve the contrast between the target spot 3 and the interfering spot in the image captured by the imaging element 112, and thus improve the accuracy of identifying the target spot 3. Furthermore, the identification method can also simultaneously reduce the influence of interfering light beams and objects during the measurement process, thereby further improving the accuracy of identifying the target spot 3.

[0056] In some examples, the imaging element 112 can be a photosensitive element that matches the wavelength of the target light source 111. This improves the sensitivity of the imaging element 112 to the target beam, thereby increasing the contrast of the imaging signal formed by the target beam. In some examples, the wavelength of the target light source 111 can refer to the wavelength of the target beam emitted by the target light source 111.

[0057] In some examples, the target light source 111 can be selected from a band with lower natural light irradiance. In this case, with this band selection, the intensity of the corresponding beam (interference beam) in the natural light is lower, which helps to reduce the interference of the interference beam on the imaging of the target beam, that is, it can reduce background noise and improve the signal-to-noise ratio of the imaging signal of the target beam.

[0058] In some examples, the wavelength of the target light source 111 can be approximately 940 nanometers. In other words, the wavelength of the target beam can be approximately 940 nanometers. In this case, since the irradiance of natural light (interference beam) is low in this wavelength band, the interference of the interference beam on the imaging of the target beam can be reduced, that is, the background noise can be reduced and the contrast of the spot formed by the target beam on the imaging element 112 can be improved.

[0059] In some examples, the wavelength of the target light source 111 being approximately 940 nanometers can mean that the wavelength of the target light source 111 is mainly concentrated around 940 nanometers. For example, the wavelength of the target light source 111 can be 930 nanometers, 940 nanometers, 950 nanometers, or any wavelength between 930 nanometers and 950 nanometers.

[0060] As described above, the imaging element 112 can be a photosensitive element whose wavelength matches that of the target light source 111. In some examples, the imaging element 112 can be a photosensitive element with a 940 nm quantum efficiency optimized. Here, 940 nm quantum efficiency optimization can be understood as the quantum efficiency of the imaging element 112 at 940 nm, meaning that at this specific wavelength, the material has a strong ability to absorb photons and convert them into electrons. This improves the sensitivity to the target light beam and minimizes interference from natural light.

[0061] For ease of explanation, in the first and second embodiments of the identification method disclosed herein, in the image captured by the imaging element 112, the target light spot 3 is represented by blank space, the interference light spot formed by the reflection of the target light beam by the interfering object is represented by grid space, and the interference light spot formed by the interfering light beam is represented by horizontal line space. It should be noted that the above distinction is intended to clearly illustrate this disclosure; in actual measurement, the target light spot 3 and the interference light spot are identical in appearance.

[0062] As described above, the target recognition unit 11 may include a target light source 111 and an imaging element 112. In some examples, the target recognition unit 11 may also include a processing element. The processing element can be used to acquire the target light spot 3. In some examples, the processing element can also identify the target 2 based on the target light spot 3. Hereinafter, the recognition method of this disclosure and the target recognition unit 11 used in the recognition method will be specifically described.

[0063] Figure 4This is a flowchart illustrating a first embodiment of the identification method involved in the examples of this disclosure. Figure 5A This is a schematic diagram illustrating a first image P1 in a first embodiment of the identification method involved in the present disclosure. Figure 5B This is a schematic diagram illustrating a second image P2 in a first embodiment of the identification method involved in the present disclosure. Figure 5C This is a schematic diagram illustrating the third image P3 in a first embodiment of the identification method involved in the example of this disclosure.

[0064] See in some examples Figure 4 The identification method may include acquiring a first image P1 when the target light source 111 is in the off state (step S200), acquiring a second image P2 when the target light source 111 is in the on state (step S220), differentiating the first image P1 and the second image P2 to obtain a third image P3 (step S240), and obtaining the target light spot 3 based on the third image P3 (step S260).

[0065] In some examples, the difference between the first image P1 and the second image P2 in step S240 may refer to calculating the feature differences between the first image P1 and the second image P2. Specifically, the grayscale value of each pixel in the first image P1 can be compared with the grayscale value of the corresponding pixel in the second image P2, and the difference between the two can be calculated. In some examples, the absolute value of the difference can be taken as the difference result.

[0066] Since the target light source 111 is in a turned-off state when the first image P1 is acquired, the first image P1 can reflect the imaging situation caused by interfering light sources other than the target light source 111 (see...). Figure 5A Since the target light source 111 is in the on state when the second image P2 is acquired, the second image P2 can simultaneously reflect the imaging situation caused by the target light source 111 and the interfering light source (see...). Figure 5B In this case, the third image P3 obtained by differential processing of the first image P1 and the second image P2 can reflect the imaging situation caused by the target light source 111. That is, the imaging situation caused by the interfering light source can be removed by the differential image method. In other words, the interference of the imaging situation caused by the interfering light source is reduced. As a result, the signal-to-noise ratio of the imaging signal of the target beam emitted by the target light source 111 can be improved, thereby improving the recognition accuracy and recognition efficiency of the target spot 3.

[0067] In some examples, the third image P3 in step S240 can reflect the feature differences between the first image P1 and the second image P2. See also [other examples]. Figure 5CIn the third image P3, the number of interference spots caused by the interfering light source is significantly reduced. That is, the interference of the imaging caused by the interfering light source on the imaging caused by the target light source 111 is reduced in the third image P3. Therefore, the target spot 3 can be accurately and quickly identified based on the third image P3. In some examples, the order of steps S200 and S220 can be interchanged.

[0068] In some examples, the individual light spots in the third image P3 can be compared with standard light spots pre-stored in a database to identify the target light spot 3. The standard light spots can refer to light spots with the same or similar shape as the target light spot 3 (since the shape of the retroreflection region 21 is determined, the shape of the target light spot 3 can also be determined in advance). Thus, the target light spot 3 can be accurately identified.

[0069] In some examples, the time interval between turning off and turning on the target light source 111 can be matched with the frame rate of the imaging element 112. This allows for the capture of a first image P1 when the target light source 111 is on and a second image P2 when the target light source 111 is off. In some examples, the time interval between turning off and turning on the target light source 111 can be a preset multiple of the frame rate of the imaging element 112. The preset multiple can be determined based on the actual measurement conditions. For example, the preset multiple can be 1, 2, or 3, etc.

[0070] In some examples, the time interval between turning off and turning on the target light source 111 can also refer to the time interval between acquiring the first image P1 and the second image P2. In some examples, the aforementioned matching can mean that the time interval between turning off and turning on the target light source 111 can be the same as the frame rate of the imaging element 112. In other words, the first image P1 and the second image P2 can be two consecutive frames recorded by the imaging element 112. In this case, the matching degree of the first image P1 and the second image P2 can be improved, that is, the consistency between the imaging situation caused by interfering light sources and / or interfering objects in the first image P1 and the imaging situation caused by interfering light sources and / or interfering objects in the second image P2 can be improved. Therefore, the presence of interference spots formed by interfering light sources and / or interfering objects in the third image P3 can be effectively reduced.

[0071] In some examples, the imaging element 112 can be a high-speed camera (high frame rate). This enables rapid identification of target 2.

[0072] Figure 6A This is a schematic diagram illustrating the structure of a second embodiment of objective 2 as described in this disclosure. Figure 6B It shows Figure 6A A schematic diagram of target spot 3 corresponding to target 2.

[0073] See in some examples Figure 6A Target 2 may also include auxiliary marker 23. In some examples, auxiliary marker 23 may reflect the light beam to imaging element 112, and the light beam reflected by auxiliary marker 23 may form a light spot on imaging element 112. In some examples, target light spot 3 may refer to the light spot formed on imaging element 112 by the target light beam reflected by retroreflection region 21. For ease of subsequent description, the light spot formed on imaging element 112 by the target light beam reflected by auxiliary marker 23 can be regarded as auxiliary light spot 4 (see...). Figure 6B ).

[0074] In some examples, auxiliary markers 23 can be used to enhance the salience of target 2. In some examples, auxiliary markers 23 can have a specific shape, such as linear, circular, rectangular, or polygonal shapes. In some examples, auxiliary markers 23 can be arranged around the retroreflection region 21 of target 2. In this case, target spot 3 can be identified by auxiliary spot 4 of a specific shape, thereby facilitating the distinction between target spot 3 and interfering spot. For example, assuming that there are interfering objects in the measurement environment with the same or similar shape as the retroreflection region 21, in the image captured by imaging element 112, target spot 3 can be identified by auxiliary spot 4, while interfering spot is not identified by auxiliary spot 4. Thus, target spot 3 and interfering spot can be quickly distinguished without establishing an image library storing standard spots.

[0075] In some examples, the auxiliary marker 23 may be arranged to partially or completely surround the reflective area 21 of the target 2. In some examples, the shape, position, and orientation of the auxiliary marker 23 can be arbitrarily set according to actual needs.

[0076] In some examples, the first image P1 and the second image P2 can be binarized before being differentiated. In some examples, the third image P3 can also be binarized before identifying the target spot 3. This can further improve the contrast of the target spot 3, thereby improving the recognition effect.

[0077] In some examples, the target 2, which includes auxiliary identifier 23, as described in this disclosure, can also be applied to identification methods in other embodiments.

[0078] Figure 7 This is a flowchart illustrating a second embodiment of the identification method involved in the examples of this disclosure. Figure 8A This is a schematic diagram illustrating the first image P1 in a second embodiment of the identification method involved in the example of this disclosure. Figure 8B This is a schematic diagram illustrating the second image P2 in a second embodiment of the identification method involved in the example of this disclosure. Figure 8C This is a schematic diagram illustrating a third image P3 in a second embodiment of the identification method involved in the example of this disclosure. Figure 8D This is a schematic diagram illustrating the fourth image P4 in a second embodiment of the identification method involved in the example of this disclosure.

[0079] See in some examples Figure 7 The identification method may include sequentially emitting a first light beam and a second light beam (step S400), capturing a first image P1 including a first light spot S1 and a second image P2 including a second light spot S2 using an imaging element 112 (step S420), obtaining the difference image between the first image P1 and the second image P2 as a third image P3 (step S440), and obtaining at least a portion of the light spot of the first light spot S1 or at least a portion of the light spot of the second light spot S2 as a target light spot 3 based on the third image P3 (step S460). The description regarding reducing the influence of interfering light spots after differentiating the first image P1 and the second image P2 can be found in the relevant description in the first embodiment of the identification method, and will not be repeated here.

[0080] In some examples, the first beam and the second beam can be emitted by the target light source 111. In some examples, the first beam and the second beam can be scattered beams emitted by the target light source 111.

[0081] In some examples, in step S400, the time interval between emitting the first beam and the second beam can be matched with the frame rate of the imaging element 112. In this case, the matching degree between the first image P1 and the second image P2 can be improved, that is, the consistency between the imaging situation caused by interfering light sources and / or interfering objects in the first image P1 and the imaging situation caused by interfering light sources and / or interfering objects in the second image P2 can be improved. Thus, the presence of interfering light spots formed by interfering light sources and / or interfering objects in the third image P3 can be effectively reduced. In some examples, "matching with the frame rate of the imaging element 112" can refer to the relevant description in the first embodiment of the recognition method involved in the examples of this disclosure, and will not be repeated here.

[0082] In some examples, in the second embodiment of the identification method, the target light source 111 can be regarded as a light-emitting module. If there are multiple target light sources 111, the multiple target light sources 111 emit the first beam and the second beam as a whole, for example, the first light source 111a and the second light source 111b (see...) Figure 3 The beam emitted simultaneously by the first light source 111a and the second light source 111b can be used as the first beam, or the beam emitted simultaneously by the first light source 111a and the second light source 111b can be used as the second beam.

[0083] In some examples, the frequencies of the first beam and the second beam can be different. In other words, the target light source 111 can emit two beams of different frequencies. As described above, the target 2 can include a reflective region 21 and an auxiliary marker 23. In some examples, the reflective region 21 can be matched with the frequencies of the first beam and the second beam. Thus, the reflective region 21 can reflect both the first and second beams.

[0084] In some examples, the auxiliary identifier 23 may be matched with the frequency of either the first beam or the second beam. In other words, the auxiliary identifier 23 may be matched with only one of the first beam or the second beam. Thus, the auxiliary identifier 23 can reflect either the first beam or the second beam. Hereinafter, in steps S420 to S440, this disclosure will be explained using the example of the auxiliary identifier 23 being matched with the frequency of the second beam (i.e., the auxiliary identifier 23 can only reflect the second beam).

[0085] In some examples, the scattered beams reflected by the retroreflection region 21 and the scattered beams reflected by the auxiliary marker 23 can be received by the imaging element 112 and form a light spot on the imaging element 112. For ease of subsequent description, let the light spot formed on the imaging element 112 by the first beam and the second beam reflected by the retroreflection region 21 be designated as the target light spot 3, and let the light spot formed on the imaging element 112 by the second beam reflected by the auxiliary marker 23 be designated as the auxiliary light spot 4.

[0086] In some examples, in step S420, the imaging element 112 may be used to capture a first image P1 that matches the first beam (see [link]). Figure 8A (See some examples.) Figure 8A The first image P1 may include a first light spot S1. The first light spot S1 may be a light spot formed on the imaging element 112 by a first light beam reflected from the target 2. In some examples, the first image P1 may also include interfering light spots.

[0087] In some examples, in step S420, the imaging element 112 can be used to capture a second image P2 that matches the second beam (see [link]). Figure 8B (See some examples.) Figure 8B The second image P2 may include a second light spot S2. The second light spot S2 may be a light spot formed on the imaging element 112 by a second light beam reflected from the target 2. In some examples, the second image P2 may also include interfering light spots.

[0088] In some examples, the first light spot S1 may be different from the second light spot S2. In some examples, the position of the first light spot S1 on the imaging element 112 may be different from the position of the second light spot S2 on the imaging element 112. In some examples, the difference in position between the first light spot S1 and the second light spot S2 on the imaging element 112 may refer to the fact that the positions of the individual pixels of the first light spot S1 and the second light spot S2 on the imaging element 112 are not exactly the same.

[0089] In some examples, the shape of the first light spot S1 on the imaging element 112 may differ from the shape of the second light spot S2 on the imaging element 112. In some examples, the difference in shape between the first light spot S1 and the second light spot S2 on the imaging element 112 may refer to the difference in geometry between the first light spot S1 and the second light spot S2.

[0090] As described above, if the auxiliary marker 23 matches the frequency of the second beam, then the first beam S1 may include the target beam 3, and the second beam S2 may include the target beam 3 and the auxiliary beam 4 (see...). Figure 8A and Figure 8B In this case, the first light spot S1 can be made different from the second light spot S2, and the feature differences between the first light spot S1 and the second light spot S2, i.e., the auxiliary light spot 4, can be obtained in the subsequent differential image. Furthermore, the target light spot 3 can be identified based on the auxiliary light spot 4.

[0091] It is understood that in the target recognition unit 11, when the target light source 111 emits a first beam and the target 2 reflects the first beam to the imaging element 112, the imaging element 112 can capture a first image P1; when the target light source 111 emits a second beam and the target 2 reflects the second beam to the imaging element 112, the imaging element 112 can capture a second image P2. Therefore, steps S400 and S420 can refer to first activating the target light source 111 to emit the first beam, and the imaging element 112 capturing the first image P1; then activating the target light source 111 to emit the second beam, and the imaging element 112 capturing the second image P2.

[0092] In some examples, in step S440, the first image P1 and the second image P2 can be differentially divided to obtain the third image P3. See also [other examples]. Figure 8CThe third image P3 may include an auxiliary light spot 4. Specifically, the difference between the first image P1 and the second image P2 lies in the difference between the first light spot S1 and the second light spot S2. The difference between the first light spot S1 and the second light spot S2 is the auxiliary light spot 4. Therefore, the third image P3 includes the auxiliary light spot 4. In this case, since theoretically only the auxiliary light spot 4 has a high gray value in the third image P3, the auxiliary light spot 4 can be quickly identified directly based on the gray value in the third image P3, which facilitates the subsequent identification of the target light spot 3 with the help of the auxiliary light spot 4.

[0093] In some examples, if the auxiliary marker 23 matches the frequency of the first beam (i.e., the auxiliary marker 23 can only reflect the first beam), then the first light spot S1 may include the target light spot 3 and the auxiliary light spot 4, and the second light spot S2 may include the target light spot 3. In this case, the technical effect of obtaining a third image P3 including the auxiliary light spot 4 can also be achieved as described above.

[0094] In some examples, in step S460, the target spot 3 can be obtained based on the third image P3. In some examples, in step S460, at least a portion of the first spot S1 can be obtained as the target spot 3 based on the third image P3.

[0095] In some examples, the coordinates of the auxiliary spot 4 on the imaging element 112 can be obtained based on the third image P3. These coordinates are then used as auxiliary coordinates. In some examples, the first spot S1 can be cropped from the first image P1 based on these auxiliary coordinates. This allows for the rapid localization of the target spot 3 within the first image P1.

[0096] In some examples, at least a portion of the first spot S1 can be cropped from the first image P1 based on auxiliary coordinates as the target spot 3. Specifically, if the first spot S1 is the target spot 3, then the entire first spot S1 is cropped as the final identified target spot 3; if the first spot S1 includes an auxiliary spot 4 and the target spot 3, then the target spot 3 in the first spot S1 can be cropped as the final identified target spot 3.

[0097] In some examples, the image obtained by cropping based on auxiliary coordinates can be used as the fourth image P4 (see [link]). Figure 8D In some examples, in the fourth image P4, only the grayscale values ​​of the pixels within the auxiliary spot 4 can be retained. In this case, since the grayscale value of the target spot 3 pixels within the auxiliary spot 4 is significantly higher than the grayscale values ​​of other pixels, the target spot 3 can be quickly identified in the fourth image P4.

[0098] In some examples, the centroid coordinates of the target spot 3 can be calculated based on the fourth image P4. In other examples, the fourth image P4 can be binarized. This allows for the acquisition of a complete and clear target spot 3, thereby improving the accuracy of subsequently obtaining the centroid coordinates of the target spot 3.

[0099] In some examples, the target spot 3 can also be cropped from the second image P2 based on auxiliary coordinates. In some examples, at least a portion of the second spot S2 can be cropped from the second image P2 as the target spot 3 based on auxiliary coordinates. Specifically, if the second spot S2 is the target spot 3, then the entire second spot S2 is cropped as the finally identified target spot 3; if the second spot S2 includes both the auxiliary spot 4 and the target spot 3, then the target spot 3 within the second spot S2 can be cropped as the finally identified target spot 3. The steps for identifying the target spot 3 in the second image P2 are essentially the same as those for identifying the target spot 3 in the first image P1, and will not be repeated here.

[0100] In some examples, the retroreflection region 21 can be matched with the frequency of the first beam or the frequency of the second beam, while the auxiliary marker 23 can be matched with the frequency of the first beam and the frequency of the second beam. In this case, the difference feature between the first image P1 and the second image P2 is the target spot 3. In the third image P3, the spot with the higher gray value is the target spot 3. Therefore, the target spot 3 can be directly identified in the third image P3, thereby improving the efficiency of identifying the target spot 3.

[0101] In some examples, the centroid coordinates of target spot 3 can be calculated after target spot 3 is identified. This allows for the identification of target 2.

[0102] Figure 9 This is a flowchart illustrating a third embodiment of the identification method involved in the examples of this disclosure. Figure 10A This is a schematic diagram illustrating the first image P1 in a third embodiment of the identification method involved in the present disclosure. Figure 10B This is a schematic diagram illustrating the second image P2 in a third embodiment of the identification method involved in the example of this disclosure. Figure 10C This is a schematic diagram illustrating the third image P3 in a third embodiment of the identification method involved in the example of this disclosure.

[0103] As described above, in some examples, there can be multiple target light sources 111. In some examples, the positions of the multiple target light sources 111 can be different. Therefore, the emission positions of the light beams emitted by the multiple target light sources 111 can be different.

[0104] See in some examples Figure 3The target light source 111 may include a first light source 111a and a second light source 111b. The first light source 111a may emit a first light beam, and the second light source 111b may emit a second light beam. The first and second light beams may be scattered light beams as described above.

[0105] In some examples, multiple target light sources 111 may be symmetrically arranged around the imaging element 112. For example, see... Figure 3 The first light source 111a and the second light source 111b can be symmetrically arranged around the imaging element 112. In this case, the first light spot S1 obtained based on the first beam and the second light spot S2 obtained based on the second beam can be spliced ​​together to form a light spot with a regular shape. Therefore, it is convenient to obtain the centroid coordinates of the target light spot 3 and thus facilitate the identification of the target 2.

[0106] See in some examples Figure 9 The identification method may include sequentially emitting a first light beam and a second light beam (step S500), capturing a first image P1 including a first light spot S1 and a second image P2 including a second light spot S2 using an imaging element 112 (step S520), obtaining the difference image between the first image P1 and the second image P2 as a third image P3 (step S540), and obtaining the first light spot S1 and the second light spot S2 as the target light spot 3 based on the third image P3 (step S560). The description regarding reducing the influence of interfering light spots after differentiating the first image P1 and the second image P2 can be found in the relevant description of the first embodiment of the identification method. The description of the first light spot S1, the first image P1, the second light spot S2, and the second image P2 can be found in the relevant description of the second embodiment of the identification method. In some examples, the target 2 in the third embodiment of the identification method may not include the auxiliary identifier 23.

[0107] In some examples, the emission positions of the first beam and the second beam in step S500 can be different. In this case, since the target 2 has a retroreflection region 21, it is more sensitive to the position of the target light source 111. Therefore, the coordinate positions of the first spot S1 in the first image P1 and the second spot S2 in the second image P2 will differ (see...). Figure 10A and Figure 10B ).

[0108] In some examples, a first light source 111a and a second light source 111b located at different positions can be controlled to turn on sequentially to emit a first beam and a second beam in sequence, thereby obtaining a first image P1 and a second image P2. This allows the acquisition of a first light spot S1 and a second light spot S2 with different coordinate positions.

[0109] In some examples, the time interval between emitting the first beam and the second beam can be matched with the frame rate of the imaging element 112. In this case, the matching degree between the first image P1 and the second image P2 can be improved, that is, the consistency between the imaging situation caused by interfering light sources and / or interfering objects in the first image P1 and the imaging situation caused by interfering light sources and / or interfering objects in the second image P2 can be improved. Thus, the presence of interfering light spots formed by interfering light sources and / or interfering objects in the third image P3 can be effectively reduced. In some examples, "matching with the frame rate of the imaging element 112" can refer to the relevant description in the first embodiment of the recognition method involved in the examples of this disclosure, and will not be repeated here.

[0110] It is understood that in the target recognition unit 11, when the first light source 111a emits a first beam and the target 2 reflects the first beam to the imaging element 112, the imaging element 112 can capture a first image P1; when the second light source 111b emits a second beam and the target 2 reflects the second beam to the imaging element 112, the imaging element 112 can capture a second image P2. Therefore, steps S500 and S520 can be understood as first activating the first light source 111a to emit the first beam and obtaining the first image P1 including the first light spot S1; then, activating the second light source 111b to emit the second beam and obtaining the second image P2 including the second light spot S2. In some examples, when the second light source 111b emits the second beam, the first light source 111a is in a turned-off state.

[0111] In some examples, in step S540, the third image P3 may include a first spot S1 and a second spot S2 (see...). Figure 10C Specifically, since the emission positions of the first beam and the second beam are different, the positions of the first spot S1 and the second spot S2 obtained are also different on the imaging element 112. The reflection of the incident beam by the interfering object is usually diffuse reflection; the interfering object is equivalent to a point light source, which can uniformly reflect the incident beam in all directions. This uniform reflection characteristic makes the image of the interfering object on the imaging element 112 relatively fixed and will not change due to changes in the position of the light source. Therefore, whether the interfering spot is caused by the interfering object or by the interfering beam, its position on the imaging element 112 will not change significantly. In this case, the characteristic difference between the first image P1 and the second image P2 is the first spot S1 and the second spot S2. The third image P3 obtained by differential estimation includes the first spot S1 and the second spot S2.

[0112] In some examples, in step S560, the first spot S1 and the second spot S2 can be obtained as the target spot 3 based on the third image P3. Therefore, the target 2 can be identified based on the target spot 3. In some examples, the target spot 3 can be a spot with a regular shape or symmetry. This facilitates the calculation of the centroid coordinates.

[0113] In some examples, the identification method may include emitting more beams at more different locations. In this case, the target spot 3 can be obtained based on more spot data, thereby improving the accuracy of calculating the centroid of the target spot 3, and thus improving the accuracy of identifying the target 2.

[0114] In some examples, steps S500 to S560 can be repeated. In some examples, the average value of the centroids of the target spot 3 obtained multiple times can be calculated as the centroid of the target spot 3. This can further improve the accuracy of calculating the centroid of the target spot 3.

[0115] In some examples, different recognition modules (an imaging element 112 and a target light source 111 surrounding the imaging element 112 can be considered as one recognition module) can be used sequentially to identify the target spot 3. In some examples, the average value of the spot centroids of the target spot 3 obtained by different recognition modules can be calculated as the spot centroid of the target spot 3. This can further improve the accuracy of calculating the spot centroid of the target spot 3. In some examples, the above two methods can be combined to calculate the spot centroid of the target spot 3 to improve the accuracy of the spot centroid. In some examples, the target recognition unit 11, which includes two recognition modules, can also be called a binocular camera. In some examples, the target recognition unit 11 may include a single recognition module.

[0116] In the identification method disclosed herein, due to the different emission positions of the first beam and the second beam, or the different frequencies of the first beam and the second beam, the positions or shapes of the first spot S1 and the second spot S2 differ. Furthermore, this difference will have different effects on the target 2 and other reflective objects. The third image P3, obtained through differential processing of the first image P1 and the second image P2, can reflect the imaging situation caused by the target beam reflected by the target 2. That is, by using differential imaging, the imaging situation caused by interfering light sources and / or interfering objects can be removed. In other words, the interference of interfering light sources and / or interfering objects in the imaging situation is reduced. Therefore, the signal-to-noise ratio of the imaging signal of the target beam emitted by the target light source 111 can be improved, thereby improving the identification accuracy and efficiency of the target spot 3. Furthermore, it can improve the accuracy and speed of identifying the target 2.

[0117] In some examples, the identification method disclosed herein may further include adjusting the configuration mode of the target identification unit 11 (referred to as the adjustment step). In some examples, the adjustment step may be set before steps S200, S400, and S500. In some examples, the configuration mode may be related to the measurement environment. In other words, the configuration mode can be adjusted according to different measurement environments.

[0118] In some examples, the configuration mode may include the power of the target light source 111. This allows the power of the target light source 111 to be adjusted according to different measurement environments, so that the intensity of the beam emitted by the target light source 111 can be adapted to the current measurement environment.

[0119] In some examples, the configuration mode may include the exposure time of the imaging element 112. This allows the exposure time of the imaging element 112 to be adjusted according to different measurement environments, enabling the exposure time of the imaging element 112 to be adapted to the current measurement environment.

[0120] In some examples, during the adjustment step, the configuration mode of the target recognition unit 11 can be adjusted according to environmental parameters of the measurement environment. In some examples, environmental parameters may include ambient brightness. Ambient brightness may refer to the brightness of the environment in which the measuring device 1 is located. In other words, ambient brightness may refer to the brightness caused by the emission of light from other light-emitting objects besides the target light source 111.

[0121] In some examples, the configuration mode can be adjusted based on ambient brightness. Since ambient brightness affects the visibility and reflection of the target beam, adjusting the configuration mode based on ambient brightness can control the contrast of the spot formed by the target beam relative to the spot formed by interfering beams.

[0122] In some examples, adjusting the configuration mode of the target recognition unit 11 may include detecting the grayscale value of the image captured by the imaging element 112, which characterizes the ambient brightness (referred to as the first adjustment step), and adjusting the configuration mode based on the grayscale value of the image captured by the imaging element 112 (referred to as the second adjustment step). In this case, the ambient brightness can be detected based on the imaging element 112, and the configuration mode can be adjusted based on the ambient brightness so that the configuration mode of the target recognition unit 11 can match the ambient brightness, thereby maintaining a high signal-to-noise ratio for the imaging signal of the target beam on the imaging element 112.

[0123] In some examples, ambient brightness can be detected before identifying or measuring target 2. In some examples, target light source 111 can be turned on when detecting ambient brightness. In some examples, target light source 111 can also be turned off.

[0124] As mentioned above, the grayscale value of an image can be used to characterize ambient brightness. In some examples, the grayscale value of an image can be obtained based on the grayscale values ​​of all pixels in the image. In some examples, the average of the grayscale values ​​of all pixels can be used as the grayscale value of the image. In some examples, the median or root mean square of the grayscale values ​​of all pixels can be used as the grayscale value of the image.

[0125] In some examples, the configuration mode may include a first configuration mode and a second configuration mode. In some examples, the power of the target light source 111 in the first configuration mode may not be greater than the power of the target light source 111 in the second configuration mode. In other words, the power of the target light source 111 in the first configuration mode may be lower, and the power of the target light source 111 in the second configuration mode may be higher.

[0126] In some examples, the exposure time of the imaging element 112 in the first configuration mode may not be greater than the exposure time of the imaging element 112 in the second configuration mode. In other words, the exposure time in the first configuration mode can be shorter, and the exposure time in the second configuration mode can be longer.

[0127] In some examples, in measurement environments with low ambient brightness (e.g., indoor environments), the target beam exhibits high contrast relative to interfering beams even when the power of the target light source 111 is adjusted to a lower power configuration mode due to the low ambient brightness. This reduces interference from interfering beams to the target beam during measurement. Furthermore, a lower power target light source 111 reduces unnecessary energy loss and potential thermal interference.

[0128] In some examples, in measurement environments with low ambient light, the lighting is typically relatively stable and uniform. Therefore, adjusting the exposure time of the imaging element 112 to a configuration mode with a lower exposure time allows for the capture of sufficient information. Furthermore, a shorter exposure time reduces background noise introduced by excessively long exposure times and improves image processing speed.

[0129] In some examples, in measurement environments with high ambient brightness (such as outdoor environments), the power of the target light source 111 needs to be adjusted to a higher power configuration mode to ensure that the target beam has higher contrast relative to the interfering beams. This reduces the interference of the interfering beams on the target beam during the measurement process.

[0130] In some examples, in measurement environments with high ambient brightness, the light in the measurement environment often changes dynamically. Therefore, in order for the imaging element 112 to adapt to the aforementioned dynamic changes and capture sufficient information, the exposure time of the imaging element 112 needs to be adjusted to a configuration mode with a higher exposure time.

[0131] In summary, the first configuration mode is suitable for measurement environments with low ambient brightness, such as indoor environments; the second configuration mode is suitable for measurement environments with high ambient brightness, such as outdoor environments.

[0132] In some examples, during the second adjustment step, the configuration mode can be adjusted to the first configuration mode in response to the image's grayscale value not being greater than a first preset value. In some examples, during the second adjustment step, the configuration mode can be adjusted to the second configuration mode in response to the image's grayscale value being greater than the first preset value. This allows for easy adjustment of the configuration mode to match the measurement environment based on the ambient brightness. In some examples, the first preset value can be set according to the parameters of the optics of the measuring device 1.

[0133] In some examples, environmental parameters may also include ambient temperature, ambient humidity, atmospheric pressure, ambient vibration, ambient wind speed, and ambient wind force. In some examples, a configuration mode suitable for the measurement environment can be set based on one or more environmental parameters.

[0134] In some examples, the identification method may also include adjusting the gain of the imaging element 112 during the measurement process. In some examples, adjusting the gain of the imaging element 112 may be performed throughout the entire measurement process.

[0135] In some examples, the grayscale value of the image captured by the imaging element 112 can be monitored in real time to adjust the gain of the imaging element 112. Gain refers to the degree to which the imaging element 112 amplifies the light signal when converting it into an electrical signal. This reduces the likelihood of inaccurate measurements due to a weak light signal in the image captured by the imaging element 112, and also reduces the likelihood of obtaining ineffective data due to excessively high grayscale values ​​in the image captured by the imaging element 112. Excessively high grayscale values ​​in the image captured by the imaging element 112 can be considered as overexposure of the image.

[0136] In some examples, if the grayscale value of the image captured by imaging element 112 is too low when other parameters are set to standard, it can be considered that the light signal captured by imaging element 112 is too weak. In this case, the gain of imaging element 112 can be increased. In this case, the sensitivity of imaging element 112 to light can be improved, and better image quality can be obtained in measurement environments with low ambient brightness.

[0137] In some examples, a grayscale threshold can be set according to the optical parameters of the measuring device 1 and / or the measurement requirements. When the grayscale value of the image captured by the imaging element 112 is not less than the grayscale threshold, it is considered that the image captured by the imaging element 112 has been overexposed.

[0138] Generally, the grayscale value range of an image is usually from 0 to 255. In some examples, the midpoint or a value near the midpoint of the above range can be taken as the grayscale threshold, such as 125, 126, 127, 128, 129 or 130.

[0139] In some examples, during measurement, the gain of imaging element 112 can be reduced in response to the grayscale value of the image captured by imaging element 112 being not less than a grayscale threshold. In this case, under good outdoor sunlight, the image is prone to overexposure and low contrast, resulting in a large grayscale value. Therefore, when the grayscale value of the image is greater than the grayscale threshold, the target recognition unit 11 can adjust the grayscale value of the image below the grayscale threshold by automatically reducing the gain of imaging element 112. This reduces the occurrence of information loss due to overexposure and improves the integrity of the light signal captured by imaging element 112.

[0140] In some examples, the power of the target light source 111 can be increased while reducing the gain of the imaging element 112. In this case, since the gain of the imaging element 112 is reduced, the gray values ​​of the light spots formed by the target beam and the interfering beam in the image captured by the imaging element 112 are both low. Increasing the power of the target light source 111 can further distinguish between the target beam and the interfering beam, increase the gray value of the light spot formed by the target beam, that is, increase the contrast of the light spot formed by the target beam compared with the light spot formed by the interfering beam, and reduce the adverse effects of the interfering beam in the measurement process.

[0141] While the present disclosure has been specifically described above in conjunction with the accompanying drawings and embodiments, it is to be understood that the above description does not limit the present disclosure in any way. Those skilled in the art can make modifications and variations to the present disclosure as needed without departing from its essential spirit and scope, and all such modifications and variations fall within the scope of the present disclosure.

Claims

1. A recognition method with automatic target recognition function, characterized in that, include: A first beam and a second beam different from the first beam are emitted sequentially. An imaging element receives the first beam and the second beam reflected by a reflector and captures a first image matching the first beam and a second image matching the second beam. The first beam and the second beam are emitted by a target light source. The first image includes a first spot formed on the imaging element by the first beam reflected by the target. The second image includes a second spot formed on the imaging element by the second beam reflected by the target. A third image is obtained based on the feature differences between the first image and the second image; Furthermore, based on the third image, at least a portion of the first light spot and / or at least a portion of the second light spot are obtained as the target light spot.

2. The identification method with automatic target identification function according to claim 1, characterized in that, The position or shape of the first light spot on the imaging element is different from the position or shape of the second light spot on the imaging element.

3. The identification method with automatic target identification function according to claim 2, characterized in that, The time interval between emitting the first beam and the second beam is matched to the frame rate of the imaging element.

4. The identification method with automatic target identification function according to claim 1, characterized in that, The emission positions of the first beam and the second beam are different, or the frequencies of the first beam and the second beam are different.

5. The identification method with automatic target identification function according to claim 4, characterized in that, The frequency of the first beam and the frequency of the second beam are different. The target includes an auxiliary marker that matches the frequency of the first beam or the frequency of the second beam. The auxiliary marker is arranged around the retroreflection area of ​​the target. The light spot formed on the imaging element by the first beam or the second beam reflected by the auxiliary marker is used as an auxiliary light spot. The first light spot or the second light spot includes the auxiliary light spot. The target light spot is identified based on the auxiliary light spot.

6. The identification method with automatic target identification function according to claim 5, characterized in that, The auxiliary identifier has a specific shape, which is at least one of a line, a ring, a rectangle, and a polygon.

7. The identification method with automatic target identification function according to claim 1, characterized in that, The difference image between the first image and the second image is obtained as the third image.

8. The identification method with automatic target identification function according to claim 1, characterized in that, Also includes: The target light spot is identified sequentially using different recognition modules; The average value of the centroids of the target light spot obtained by different recognition modules is calculated as the centroid of the target light spot, wherein one recognition module is formed by one imaging element and the target light source surrounding the imaging element, and the number of recognition modules is multiple.

9. A recognition camera, characterized in that, The method is used to implement the automatic target recognition function as described in any one of claims 1 to 8 to identify target light spots that match the target.

10. A measuring device, characterized in that, It includes the identification camera and optical body as described in claim 9, wherein the identification camera is used to identify a target, the optical body is used to track the target, and the identification camera is disposed on the optical body.

Images