A method and apparatus for calibrating a light source

Abstract

The application relates to the technical field of optical calibration, and discloses a light source calibration method and device, the calibration method is realized based on a surface array imaging system and an auxiliary calibration device, the auxiliary calibration device comprises at least two calibration plates, the at least two calibration plates are sequentially arranged along the light path direction of a light source, and each calibration plate corresponds to a light source with different angles; the calibration method comprises the following steps: focusing the surface array imaging system on a target calibration plate corresponding to a to-be-calibrated light source; lighting the to-be-calibrated light source, making the surface array imaging system take an image to obtain a detection image; and calibrating the to-be-calibrated light source based on the detection image. By arranging the auxiliary calibration device comprising at least two calibration plates, the to-be-calibrated light source and the surface array imaging system simultaneously act on the calibration plate to obtain the detection image, and the to-be-calibrated light source is calibrated based on the detection image, so that more accurate calibration effect than a calibration tool can be obtained, and the detection effect of the visual imaging system can be greatly improved, so as to adapt to actual requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical calibration technology, and in particular to a light source calibration method and device. BACKGROUND

[0002] With the development of machine vision imaging technology and the increasing demand for large-size high-precision detection applications, multiple light sources are often used in combination in machine vision imaging systems to obtain more detection features.

[0003] In current machine vision imaging systems, coaxial light sources and inclined light sources are usually included, and the coaxial light sources and the inclined light sources need to be calibrated respectively before detection to ensure that the light source parameters meet the requirements, so as to make the detection results more accurate. However, since the divergence angle and the illumination angle of the light source are determined by the lamp beads and the optical components in the light source, and multiple light sources need to be fixed by fixed components, a certain cumulative error is formed. In the prior art, the light source is calibrated based on the naked eye by using a calibration tool, and the calibration accuracy is low, which makes the detection effect poor and difficult to meet the actual needs. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a light source calibration method and device to solve the problem that the calibration accuracy is low in the prior art, which makes the detection effect poor and difficult to meet the actual needs.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] A light source calibration method is realized based on a surface array imaging system and an auxiliary calibration device, and the surface array imaging system and the light source both act on a measured area;

[0007] The auxiliary calibration device includes at least two calibration plates, and the at least two calibration plates are arranged in sequence along the light path direction of the light source, and each calibration plate corresponds to a light source with different angles;

[0008] The calibration method includes:

[0009] The surface array imaging system is focused on the target calibration plate corresponding to the light source to be calibrated;

[0010] The light source to be calibrated is turned on, and the surface array imaging system takes an image to obtain a detection image;

[0011] Based on the detection image, the light source to be calibrated is calibrated.

[0012] Optionally, the calibration of the light source to be calibrated based on the detection image includes:

[0013] comparing the detection image with a preset standard calibration image, and calibrating the to-be-calibrated light source based on a comparison result.

[0014] Optionally, before the focusing of the area array imaging system on the target calibration board corresponding to the to-be-calibrated light source, the method further comprises:

[0015] focusing the area array imaging system on each calibration board in a predetermined sequence;

[0016] turning on the to-be-calibrated light source when the area array imaging system focuses on each calibration board, and making the area array imaging system take an image to obtain a pre-calibration image;

[0017] pre-calibrating the to-be-calibrated light source based on the pre-calibration image.

[0018] Optionally, the pre-calibrating of the to-be-calibrated light source based on the pre-calibration image comprises:

[0019] comparing the detection image with a preset standard pre-calibration image, and calibrating the to-be-calibrated light source based on a comparison result.

[0020] Optionally, the light source comprises a coaxial light source, and the auxiliary calibration device comprises a coaxial calibration board corresponding to the coaxial light source.

[0021] Optionally, the light source comprises an angle light source, and the auxiliary calibration device comprises an angle calibration board corresponding to the angle light source, the angle calibration board being switchable to a calibration state corresponding to a light source of a different angle.

[0022] When the to-be-calibrated light source is an angle light source, before the focusing of the area array imaging system on the target calibration board corresponding to the to-be-calibrated light source, the method further comprises:

[0023] adjusting the target calibration board to a calibration state corresponding to the to-be-calibrated light source.

[0024] The application further provides a light source calibration device for implementing the light source calibration method according to any one of the above, comprising:

[0025] an area array imaging system, the area array imaging system and the light source both acting on a measured region;

[0026] an auxiliary calibration device, the auxiliary calibration device comprising at least two calibration boards, the at least two calibration boards being sequentially arranged along a light path direction of the light source, each calibration board corresponding to a light source of a different angle;

[0027] an imaging execution unit configured to focus the area array imaging system on a target calibration plate corresponding to the light source to be calibrated, and configured to light up the light source to be calibrated, so that the area array imaging system takes an image to obtain a detection image;

[0028] a calibration unit configured to calibrate the light source to be calibrated based on the detection image.

[0029] Optionally, the light source comprises a coaxial light source, and the auxiliary calibration device comprises a coaxial calibration plate corresponding to the coaxial light source.

[0030] Optionally, the light source comprises an angle light source, and the auxiliary calibration device comprises an angle calibration plate corresponding to the angle light source, the angle calibration plate being switchable to a calibration state corresponding to an angle light source of a different angle.

[0031] When the light source to be calibrated is an angle light source, the imaging execution unit is further configured to:

[0032] adjust the target calibration plate to a calibration state corresponding to the light source to be calibrated.

[0033] Optionally, the coaxial calibration plate is provided with at least one slot, and the angle calibration plate is provided with at least three slots.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] The present application provides a calibration method and device for a light source, which comprises an auxiliary calibration device provided with at least two calibration plates, so that the light source to be calibrated and the area array imaging system act on the calibration plates to obtain a detection image, and the light source to be calibrated is calibrated based on the detection image, which can obtain a more accurate calibration effect than a calibration tool, thereby greatly improving the detection effect of the visual imaging system to meet actual needs. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0037] Figure 1 A combination structure schematic diagram of an area array system and an auxiliary calibration device in a calibration method for a light source provided by the present application;

[0038] Figure 2 A method flowchart of a calibration method for a light source provided by the present application;

[0039] Figure 3 Yet another flow chart of a calibration method of a light source provided by the present application;

[0040] Figure 4 Still another flow chart of a calibration method of a light source provided by the present application;

[0041] Figure 5 Structural block diagram of a calibration device of a light source provided by the present application;

[0042] Figure 6 Structural schematic diagram of a coaxial calibration plate in a calibration device of a light source provided by the present application;

[0043] Figure 7 Structural schematic diagram of a first angle calibration plate in a high angle calibration state in a calibration device of a light source provided by the present application;

[0044] Figure 8 Structural schematic diagram of a first angle calibration plate in a sub-high angle calibration state in a calibration device of a light source provided by the present application;

[0045] Figure 9 Structural schematic diagram of a second angle calibration plate in a high angle calibration state in a calibration device of a light source provided by the present application;

[0046] Figure 10 Structural schematic diagram of a second angle calibration plate in a sub-high angle state in a calibration device of a light source provided by the present application;

[0047] Figure 11 Structural schematic diagram of a calibration device of a light source provided by the present application;

[0048] In the above figures: 11, coaxial light source; 12, high angle light source; 13, sub-high angle light source; 20, auxiliary calibration device; 21, coaxial calibration plate; 22, first angle calibration plate; 23, second angle calibration plate; 30, imaging execution unit; 40, calibration unit; 50, area array imaging system. DETAILED DESCRIPTION

[0049] In order to make the objectives, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the embodiments described below are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0050] It is to be understood that the embodiments are only for explaining the present application, but not for limiting the present application. In the description of the present application, the exemplary embodiments are described as processes or methods depicted as flow diagrams; although the processes depicted by the flow diagrams are in a particular order, many of the operations or steps can be performed in parallel, concurrently, or at the same time, and the order of the operations can be re-arranged. The corresponding processes can be terminated when their operations or steps are completed, and can have additional steps not included in the flow diagrams. The aforementioned processes can correspond to methods, functions, routines, subroutines, subprograms, etc. The embodiments and features in the embodiments can be combined with each other, if there is no conflict.

[0051] The term "comprising" and its derivations, as used in the present application, are open-ended, that is, "comprising but not limited to". The term "based on" is "based at least in part on". The technical solutions of the present application are further illustrated below in conjunction with the accompanying drawings and through specific embodiments; it can be understood that, for the convenience of description, only the parts related to the present application are shown in the drawings, not all the structures.

[0052] In the prior art, the light source is calibrated based on the naked eye by using a calibration tool, and the calibration accuracy is low, so that the detection effect is poor and it is difficult to meet the actual needs. The present application aims to provide a light source calibration scheme to solve the aforementioned problems in the prior art.

[0053] Embodiment one

[0054] The present application provides a light source calibration method, which is realized based on a surface array imaging system and an auxiliary calibration device. The surface array imaging system and the light source both act on a measured region. The light source calibration method provided in the present embodiment can be applied to the calibration of a line scanning light source assembly, which contains multiple light sources, specifically coaxial light sources and angle light sources. The coaxial light sources are vertically incident into the measured region, and the angle light sources are incident into the measured region at a certain inclination angle.

[0055] Please refer to Figure 1 The calibration method provided in the present embodiment is realized based on an auxiliary calibration device 20. The auxiliary calibration device 20 includes at least two calibration plates, which are sequentially arranged along the light path direction of the light source. Each calibration plate corresponds to a light source of different angle.

[0056] The auxiliary calibration device 20 includes a coaxial calibration plate 21 corresponding to the coaxial light source 11, and an angle calibration plate corresponding to the angle light source. The angle calibration plate can be driven to switch to a calibration state corresponding to the angle light source of different angle.

[0057] In this embodiment, the angle light source includes two types of light sources, i.e., a high-angle light source 12 and a sub-high-angle light source 13, and the angle calibration plate is provided with two angle calibration plates, i.e., a first angle calibration plate 22 and a second angle calibration plate 23, each of which can be adjusted to a high-angle calibration state and a sub-high-angle calibration state. The high-angle state of the first angle calibration plate 22 is different from that of the second angle calibration plate 23, and the sub-high-angle calibration state is also different, so that secondary calibration of the high-angle light source 12 and the sub-high-angle light source 13 can be formed, which is beneficial to improving the calibration accuracy of the angle light source 12.

[0058] Specifically, the coaxial calibration plate 21 is provided with at least one slot, and the angle calibration plate is provided with at least three slots and / or through holes. The angle calibration plate is provided with a movable plate, and the position of each slot is adjusted by adjusting the position of the movable plate, so as to realize the adjustment of the calibration state.

[0059] Please refer to Figures 1 to 3 Based on this, the calibration method of the light source provided in this embodiment includes:

[0060] S1, focusing the area imaging system 50 on the target calibration plate corresponding to the light source to be calibrated.

[0061] In this step, first, the light source to be calibrated is determined, then the target calibration plate corresponding to the light source to be calibrated is determined from the auxiliary calibration device 20, and finally the area imaging system 50 is controlled to focus on the target calibration plate.

[0062] It can be understood that, in the calibration process, the auxiliary calibration device 20 is located in the measured area.

[0063] Specifically, when the light source to be calibrated is an angle light source, the following steps are further included before step S1:

[0064] S01, adjusting the target calibration plate to a calibration state corresponding to the light source to be calibrated.

[0065] Each angle calibration plate is provided with an adjustment driver, and the position of the movable plate on the angle calibration plate is adjusted by controlling the operation of the adjustment driver, so as to change the position and size of the slot on the angle calibration plate, and then the adjustment of the calibration state on the angle calibration plate is realized.

[0066] In this embodiment, at least two calibration plates are sequentially arranged along the light path direction of the light source, and each calibration plate corresponds to a light source of different angle. Specifically, the coaxial calibration plate 21 and the angle calibration plate are sequentially arranged along the light path direction of the light source, and when calibrated, the light source is focused on the coaxial calibration plate 21 and then continues to be irradiated on the angle calibration plate in a diverging manner.

[0067] S2, turn on the light source to be calibrated, and make the area array imaging system 50 take an image to obtain a detection image.

[0068] At the same time or after the area array imaging system 50 successfully focuses on the target calibration plate, turn on the light source to be calibrated, and make the area array imaging system 50 take an image to obtain a detection image.

[0069] S3, calibrate the light source to be calibrated based on the detection image.

[0070] Specifically, in this step, the detection image is compared with a preset standard calibration image to obtain a comparison result, and the light source to be calibrated is calibrated based on the comparison result.

[0071] In this embodiment, the standard calibration image contains a light spot with a standard size, position and shape. When the detection image is compared with the preset standard calibration image, the light spot in the detection image is compared with the standard light spot in the standard calibration image to obtain a size deviation value, a position deviation value and a shape deviation value, and the light source parameters of the light source to be calibrated are calibrated based on the size deviation value, the position deviation value and the shape deviation value, such as the illumination angle and the divergence angle of the light source to be calibrated.

[0072] Please refer to Figure 4 Further, before the area array imaging system 50 is focused on the target calibration plate corresponding to the light source to be calibrated, the embodiment further includes:

[0073] S02, sequentially focus the area array imaging system 50 on each calibration plate in a predetermined order;

[0074] S03, when the area array imaging system 50 is focused on each calibration plate, turn on the light source to be calibrated, and make the area array imaging system 50 take an image to obtain a pre-calibration image;

[0075] S04, pre-calibrate the light source to be calibrated based on the pre-calibration image.

[0076] The predetermined order in step S02 can be the order of all the calibration plates formed according to the light path direction of the light source, or can be set as other order according to actual needs. The predetermined order is only set to realize the smoothness of program execution.

[0077] In step S04, the light source to be calibrated is pre-calibrated based on the pre-calibration image, including:

[0078] Compare the detection image with a preset standard pre-calibration image, and calibrate the light source to be calibrated based on the comparison result.

[0079] It can be understood that, in steps S02-S04, by making the area array imaging system 50 focus on each calibration plate in a predetermined order in turn, repeated focusing can be performed before calibration of the to-be-calibrated light source to pre-calibrate the remaining light sources except the to-be-calibrated light source, so as to achieve the purpose of controlling variables, so that the calibration effect of the to-be-calibrated light source is more accurate.

[0080] Specifically, the detailed steps of steps S02-S04 are introduced as follows. For the convenience of description, the spot size is taken as the comparison object when comparing the detection image with the preset standard calibration image.

[0081] 1) Adjust the focal length of the area array imaging system 50 to the position of the first calibration surface (the coaxial calibration plate 21);

[0082] 2) Turn on the coaxial light source 11;

[0083] 3) Adjust the position of the coaxial light source 11;

[0084] 4) The area array imaging system 50 images;

[0085] 5) Determine whether the spot size meets the standard through the image. If yes, focus the camera of the area array imaging system 50 on the position of the second calibration surface (the first angle calibration plate 22). If no, return to step 3 and continue to execute until the spot size meets the standard;

[0086] 6) Adjust the position of the coaxial light source 11;

[0087] 7) The area array imaging system 50 images;

[0088] 8) Determine whether the spot size meets the standard through the image. If yes, focus the camera of the area array imaging system 50 on the position of the third calibration surface (the second angle calibration plate 23). If no, return to step 6 and continue to execute until the spot size meets the standard;

[0089] 9) Adjust the position of the coaxial light source 11;

[0090] 10) The area array imaging system 50 images;

[0091] 11) Determine whether the spot size meets the standard through the image. If yes, refocus the camera of the area array imaging system 50 on the position of the first calibration surface (the coaxial calibration plate 21). If no, return to step 9 and continue to execute until the spot size meets the standard.

[0092] Up to now, the calibration of the coaxial light source 11 is completed.

[0093] 12) Turn on the high-angle light source 12;

[0094] 13) Adjust the position of the high-angle light source 12;

[0095] 14) Face array imaging system 50 imaging;

[0096] 15) Determine if spot size is acceptable by image, if yes, focus camera of face array imaging system 50 to position of second calibration plane (first angle calibration plate 22), if no, return to step 13 and continue until spot size is acceptable;

[0097] 16) Adjust position of high angle light source 12;

[0098] 17) Face array imaging system 50 imaging;

[0099] 18) Determine if spot size is acceptable by image, if yes, focus camera of face array imaging system 50 to position of third calibration plane (second angle calibration plate 23), if no, return to step 16 and continue until spot size is acceptable;

[0100] 19) Turn on high angle light source 12;

[0101] 20) Face array imaging system 50 imaging;

[0102] 21) Determine if spot size is acceptable by image, if yes, focus camera of face array imaging system 50 to position of first calibration plane (on-axis calibration plate 21), if no, return to step 19 and continue until spot size is acceptable;

[0103] 22) Turn on second high angle light source 13;

[0104] 23) Adjust position of second high angle light source 13;

[0105] 24) Face array imaging system 50 imaging;

[0106] 25) Determine if spot size is acceptable by image, if yes, focus camera of face array imaging system 50 to position of second calibration plane (first angle calibration plate 22), if no, return to step 23 and continue until spot size is acceptable;

[0107] 26) Adjust position of second high angle light source 13;

[0108] 27) Adjust position of second high angle light source 13;

[0109] 28) Determine if spot size is acceptable by image, if yes, focus camera of face array imaging system 50 to position of third calibration plane (second angle calibration plate 23), if no, return to step 26 and continue until spot size is acceptable;

[0110] 29) Adjust position of second high angle light source 13;

[0111] 30) Area array imaging system 50 imaging;

[0112] 31) Determine whether the spot size meets the standard by examining the image. If it does, the calibration is complete. Then return to step 29 to continue until the spot size meets the standard.

[0113] Before the area array imaging system 50 forms an image, the state of the first angle calibration plate 22 or the second angle calibration plate 23 that it is focused on has been adjusted to correspond to the current light source to be calibrated. For example, when the current light source to be calibrated is a high-angle light source 12, the first angle calibration plate 22 or the second angle calibration plate 23 that it is focused on has been adjusted to a high-angle calibration state before the area array imaging system 50 forms an image.

[0114] Example 2

[0115] Referring to the figures, based on the foregoing embodiments, this embodiment of the invention also provides a light source calibration device for implementing the light source calibration method as described in the above embodiments; the light source calibration device includes:

[0116] The area array imaging system 50 and the light source to be calibrated both act on a measured area.

[0117] Auxiliary calibration device 20; Auxiliary calibration device 20 includes at least two calibration plates, which are arranged sequentially along the optical path of the light source, and each calibration plate corresponds to a light source at a different angle.

[0118] Please refer to this again. Figure 1 The auxiliary calibration device 20 includes a coaxial calibration plate 21 corresponding to the coaxial light source 11 and an angle calibration plate corresponding to the angle light source. The angle calibration plate can be driven to switch to a calibration state corresponding to angle light sources of different angles.

[0119] Specifically, the coaxial calibration plate 21 has at least one slot, and the angle calibration plate has at least three slots. The angle calibration plate includes a movable plate; by adjusting the position of the movable plate, the position of each slot can be adjusted, thereby adjusting the calibration state.

[0120] Each angle calibration plate is equipped with an adjustment driver. By controlling the operation of the adjustment driver, the position of the movable plate on the angle calibration plate can be adjusted, thereby changing the position and size of the slot on the angle calibration plate, and thus adjusting the calibration status on the angle calibration plate.

[0121] In this embodiment, at least two calibration plates are arranged sequentially along the optical path of the light source, with each calibration plate corresponding to a light source at a different angle. Specifically, a coaxial calibration plate 21 and an angle calibration plate are arranged sequentially along the outgoing optical path of the light source. During calibration, the light source is focused on the coaxial calibration plate 21 and then continues to irradiate the angle calibration plate in a divergent manner.

[0122] In this embodiment, the angle light source includes two types: a high-angle light source 12 and a second-highest-angle light source 13. Two angle calibration plates are provided: a first angle calibration plate 22 and a second angle calibration plate 23. Each angle calibration plate can be adjusted to a high-angle calibration state and a second-highest-angle calibration state. The high-angle calibration states of the first angle calibration plate 22 and the second angle calibration plate 23 produce different shapes, and the second-highest-angle calibration states also produce different shapes. This allows for secondary calibration of the high-angle light source 12 and the second-highest-angle light source 13, which helps improve the calibration accuracy of the angle light source 12.

[0123] As one implementation method in this embodiment, please refer to Figures 6 to 10 These are schematic diagrams of the structure of the coaxial calibration plate 21, the first angle calibration plate 22 in the high-angle calibration state, the first angle calibration plate 22 in the second-highest angle calibration state, the second angle calibration plate 23 in the high-angle calibration state, and the second angle calibration plate 23 in the second-highest angle state.

[0124] Specifically, Figure 6 In the middle, the coaxial calibration plate 21 has a slot; Figure 7 In the high-angle calibration state, the first angle calibration plate 22 has a large slot and a rectangular through hole formed by a hollow frame located in the large slot; Figure 8 In the middle, the first angle calibration plate 22 in the second highest angle calibration state has two large slots spaced apart from each other, and two small slots located between the two large slots, the width of the large slots being greater than the width of the small slots. Figure 9 In the middle, the second angle calibration plate 23 in the high angle calibration state has a large slot and a rectangular through hole formed by a hollow frame located in the large slot; Figure 10 In the middle, the second angle calibration plate 23 in the second highest angle state has two large slots spaced apart from each other, and two small slots located between the two large slots, the width of the large slots being greater than the width of the small slots.

[0125] It is understood that in this application, the slots and through holes on the coaxial calibration plate 21, the first angle calibration plate 22 in the high-angle calibration state, the first angle calibration plate 22 in the second-highest angle calibration state, the second angle calibration plate 23 in the high-angle calibration state, and the second angle calibration plate 23 in the second-highest angle state are all rectangular. In other embodiments, slots of other shapes, such as elliptical, waist-shaped, or combined patterns formed by multiple circular holes arranged according to the position of the slots, can also be used.

[0126] In this embodiment, each calibration plate can perform illumination verification at different illumination angles. If the illumination angle of the light source does not meet the requirements, the detected image obtained by imaging will be different from the preset standard calibration image.

[0127] Let the illumination angle of the coaxial light source 11 be a1, and the divergence angle be b1; the illumination angle of the high-angle light source 12 be a2, and the divergence angle be b2; the illumination angle of the second-highest-angle light source 13 be a3, and the divergence angle be b3; the distance between the first angle calibration plate 22 and the coaxial calibration plate 21 be Y1, and the distance between the second angle calibration plate 23 and the coaxial calibration plate 21 be Y2; let the slot width of the coaxial calibration plate 21 be C, the slot width of the first angle calibration plate 22 be A, and the slot width of the second angle calibration plate 23 be B; and let the coaxial calibration plate 21 be located at the focal point of the light source, and the coaxial calibration plate 21, the first angle calibration plate 22, and the second angle calibration plate 23 be centered and aligned. The slot dimensions of each calibration plate are as follows:

[0128] During coaxial light source 11 calibration:

[0129] The slot width of the first angle calibration plate 22 is: 2*tan(b1 / 2)*Y1+C;

[0130] The slot width of the second angle calibration plate 23 is: 2*tan(b1 / 2)*Y2+C.

[0131] High-angle light source 12 calibration:

[0132] The starting position of the slot in the first angle calibration plate 22 is: 2*tan(a2-(b2 / 2))*Y1+C, and the ending position of the slot is: 2*tan(a2+(b2 / 2))*Y1+C;

[0133] The starting position of the slot in the second angle calibration plate 23 is: 2*tan(a2-(b2 / 2))*Y2+C, and the ending position of the slot in the second angle calibration plate 23 during the calibration of the high-angle light source 12 is: 2*tan(a2+(b2 / 2))*Y2+C.

[0134] When calibrating the second-highest angle light source 13:

[0135] The starting position of the slot in the first angle calibration plate 22 is: 2*tan(a3-(b3 / 2))*Y1+C; the ending position of the slot in the first angle calibration plate 22 when calibrating the second highest angle light source 13 is: 2*tan(a3+(b3 / 2))*Y1+C;

[0136] The starting position of the slot in the second angle calibration plate 23 is: 2*tan(a3-(b3 / 2))*Y2+C; the ending position of the slot in the second angle calibration plate 23 during the calibration of the second highest angle light source 13 is:

[0137] =2*tan(a3+(b3 / 2))*Y2+C.

[0138] It is understandable that the slot width on the first angle calibration plate 22 and the second angle calibration plate 23 can be calculated by subtracting the slot opening position from the slot opening position.

[0139] Please refer to Figure 11 The diagram shows the distance Y1 between the first angle calibration plate 22 and the coaxial calibration plate 21, the distance Y2 between the second angle calibration plate 23 and the coaxial calibration plate 21, the slot width C of the coaxial calibration plate 21, the slot width A of the first angle calibration plate 22, the slot width B of the second angle calibration plate 23, the illumination angle a1 of the coaxial light source 11, the illumination angle a2 of the high-angle light source 12, and the illumination angle a3 of the second-highest-angle light source 13, as well as the specific values ​​of each data point, which are used to corroborate the aforementioned slot widths of each calibration plate.

[0140] In this embodiment, the calibration device further includes an imaging execution unit 30, which is used to focus the area array imaging system 50 on the target calibration plate corresponding to the light source to be calibrated; and to illuminate the light source to be calibrated so that the area array imaging system 50 can capture an image and obtain a detection image.

[0141] The imaging execution unit 30 first determines the light source to be calibrated, then determines the target calibration plate corresponding to the light source from the auxiliary calibration device 20, and finally controls the area array imaging system 50 to focus on the target calibration plate.

[0142] Understandably, during the calibration process, the auxiliary calibration device 20 is located in the area being measured.

[0143] Specifically, when the light source to be calibrated is an angular light source, the imaging execution unit 30 is also used to adjust the target calibration plate to the calibration state corresponding to the light source to be calibrated. Each angular calibration plate is equipped with an adjustment driver. By controlling the operation of the adjustment driver, the position of the movable plate on the angular calibration plate is adjusted, thereby changing the position and size of the slot on the angular calibration plate, and thus adjusting the calibration state on the angular calibration plate.

[0144] In this embodiment, at least two calibration plates are arranged sequentially along the optical path of the light source, with each calibration plate corresponding to a light source at a different angle. Specifically, a coaxial calibration plate 21 and an angle calibration plate are arranged sequentially along the outgoing optical path of the light source. During calibration, the light source is focused on the coaxial calibration plate 21 and then continues to irradiate the angle calibration plate in a divergent manner.

[0145] Then, at the same time or after the area array imaging system 50 successfully focuses on the target calibration plate, the imaging execution unit 30 illuminates the light source to be calibrated and causes the area array imaging system 50 to capture an image to obtain the detection image.

[0146] In this embodiment, the calibration device further includes a calibration unit 40, which is used to calibrate the light source to be calibrated based on the detected image.

[0147] The calibration unit 40 obtains the comparison result by comparing the detection image with the preset standard calibration image, and calibrates the light source to be calibrated based on the comparison result.

[0148] In this embodiment, the standard calibration image contains light spots with standard size, position and shape. When comparing the detection image with the preset standard calibration image, the light spots in the detection image are compared with the standard light spots in the standard calibration image to obtain size deviation value, position deviation value and shape deviation value. Based on the size deviation value, position deviation value and shape deviation value, the light source parameters of the light source to be calibrated are calibrated, such as the illumination angle and divergence angle of the light source to be calibrated.

[0149] Furthermore, the calibration unit 40 is also used to perform the following operations before focusing the area array imaging system 50 on the target calibration plate corresponding to the light source to be calibrated:

[0150] The area array imaging system 50 is made to focus on each calibration plate in a predetermined order; when the area array imaging system 50 focuses on each calibration plate, the light source to be calibrated is lit, and the area array imaging system 50 takes an image to obtain a pre-calibrated image; based on the pre-calibrated image, the light source to be calibrated is pre-calibrated.

[0151] The aforementioned predetermined order is that all calibration plates are arranged in the order in which they are formed according to the optical path direction of the light source.

[0152] Among them, when the calibration unit 40 precalibrates the light source to be calibrated based on the precalibrated image, it compares the detection image with the preset standard precalibrated image and calibrates the light source to be calibrated based on the comparison result.

[0153] It is understandable that by having the area array imaging system 50 focus on each calibration in a predetermined order, the calibration unit 40 can repeatedly focus before calibrating the light source to be calibrated, thereby pre-calibrating the light sources other than the light source to be calibrated, thus achieving the purpose of controlling variables and making the calibration effect of the light source to be calibrated more accurate.

[0154] In this embodiment, the angle light source includes two types: a high-angle light source 12 and a second-highest-angle light source 13. Two angle calibration plates are provided: a first angle calibration plate 22 and a second angle calibration plate 23. Each angle calibration plate can be adjusted to both a high-angle calibration state and a second-highest-angle calibration state. The high-angle calibration of the first angle calibration plate 22 and the second angle calibration plate 23 differs, and their second-highest-angle calibration states also differ. This allows for secondary calibration of the high-angle light source 12 and the second-highest-angle light source 13, which helps improve the calibration accuracy of the angle light source 12.

[0155] Based on the foregoing embodiments, the present invention, by setting an auxiliary calibration device 20 containing at least two calibration plates, enables the light source to be calibrated and the area array imaging system 50 to act simultaneously on the calibration plates to obtain a detection image, and calibrates the light source to be calibrated based on the detection image. This can achieve a more accurate calibration effect than calibration tools, thereby significantly improving the detection effect of the visual imaging system and thus meeting practical needs.

[0156] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calibrating a light source, characterized in that, This is achieved using an area array imaging system and an auxiliary calibration device, wherein both the area array imaging system and the light source act on a measured area. The auxiliary calibration device includes at least two calibration plates, which are arranged sequentially along the optical path of the light source, with each calibration plate corresponding to a light source at a different angle. The calibration method includes: The area array imaging system is focused on the target calibration plate corresponding to the light source to be calibrated. The light source to be calibrated is lit, enabling the area array imaging system to capture an image and obtain a detection image; Based on the detected image, the light source to be calibrated is calibrated; The step of calibrating the light source to be calibrated based on the detected image includes: The detected image is compared with a preset standard calibration image, and the light source to be calibrated is calibrated based on the comparison result; Standard calibration images include light spots with standard size, position, and shape; The comparison of the detected image with a preset standard calibration image includes: By comparing the light spot in the detection image with the standard light spot in the standard calibration image, size deviation value, position deviation value, and shape deviation value are obtained, and the light source parameters of the light source to be calibrated are calibrated based on the size deviation value, position deviation value, and shape deviation value. The light source includes a coaxial light source, and the auxiliary calibration device includes a coaxial calibration plate corresponding to the coaxial light source; The light source includes an angle light source, and the auxiliary calibration device includes an angle calibration plate corresponding to the angle light source. The angle calibration plate can be driven to switch to a calibration state corresponding to angle light sources of different angles. When the light source to be calibrated is an angular light source, before focusing the area array imaging system on the target calibration plate corresponding to the light source to be calibrated, the method further includes: Adjust the target calibration plate to the calibration state corresponding to the light source to be calibrated.

2. The calibration method for the light source according to claim 1, characterized in that, Before focusing the area array imaging system on the target calibration plate corresponding to the light source to be calibrated, the method further includes: The area array imaging system is made to focus on each calibration plate in a predetermined order; When the area array imaging system focuses on each of the calibration plates, the light source to be calibrated is lit up, so that the area array imaging system can capture an image and obtain a pre-calibrated image. Based on the pre-calibrated image, the light source to be calibrated is pre-calibrated.

3. The calibration method for the light source according to claim 2, characterized in that, The step of pre-calibrating the light source to be calibrated based on the pre-calibrated image includes: The detected image is compared with the pre-calibrated image, and the light source to be calibrated is calibrated based on the comparison result.

4. A calibration device for a light source, characterized in that, A calibration method for implementing the light source as described in any one of claims 1 to 3, comprising: An area array imaging system, wherein both the area array imaging system and the light source act on a measured area; An auxiliary calibration device, comprising at least two calibration plates arranged sequentially along the optical path of the light source, each calibration plate corresponding to a light source at a different angle; An imaging execution unit is configured to focus the area array imaging system on a target calibration plate corresponding to the light source to be calibrated; and to illuminate the light source to be calibrated, thereby enabling the area array imaging system to capture an image and obtain a detection image. A calibration unit is used to calibrate the light source to be calibrated based on the detected image; The light source includes a coaxial light source, and the auxiliary calibration device includes a coaxial calibration plate corresponding to the coaxial light source; The light source includes an angle light source, and the auxiliary calibration device includes an angle calibration plate corresponding to the angle light source. The angle calibration plate can be driven to switch to a calibration state corresponding to angle light sources of different angles. When the light source to be calibrated is an angular light source, the imaging execution unit is further configured to: Adjust the target calibration plate to the calibration state corresponding to the light source to be calibrated.

5. The calibration device for the light source according to claim 4, characterized in that, The coaxial calibration plate has at least one slot, and the angle calibration plate includes at least three slots.

Images