CN110231289B - A multi-light source automatic lighting device and image synthesis method thereof - Google Patents

Abstract

The invention discloses a multi-light source automatic lighting device and an image synthesis method thereof. The lighting device comprises: a lighting bracket, and the lighting bracket comprises a first annular bracket, a second annular bracket and a third annular bracket; It also includes at least a first controllable light source, a second controllable light source and a third controllable light source; an object stage, which is an area to be measured formed at the bottom of the lighting bracket; an array camera assembly, including a A bright field camera and a dark field camera on the top of the lighting bracket; a light source controller for controlling the lighting angle and lighting range of the first controllable light source, the second controllable light source and the third controllable light source; machine vision The detection module is configured to generate a composite image according to the images of the workpiece to be tested obtained by the bright field camera and the dark field camera in different lighting environments. The image synthesis method is applied to the above-mentioned lighting device. The invention has higher detection efficiency and reliability.

Description

A multi-light source automatic lighting device and image synthesis method thereof

technical field

The invention relates to the field of automatic detection devices, in particular to a multi-light source automatic lighting device and an image synthesis method thereof.

Background technique

The existing surface defect detection of parts is usually done manually, which has slow detection speed, great influence of subjective factors, low reliability, and affects the processing quality of products. Therefore, a defect detection method based on image recognition technology has emerged, and the above detection method is largely dependent on the lighting device and the corresponding imaging system. How to provide a reliable lighting device and a reasonable image synthesis method has become an urgent problem to be solved in the industry. question.

SUMMARY OF THE INVENTION

In order to overcome the problems of slow detection speed and low reliability of existing parts surface defects, an embodiment of the present invention provides, on the one hand, a multi-light source automatic lighting device, including:

A lighting bracket, the lighting bracket includes at least a first annular bracket, a second annular bracket and a third annular bracket located at different heights, and at least a first controllable light source arranged on the first annular bracket, a second controllable light source arranged on the second annular support and a third controllable light source arranged on the third annular support;

an object table, the object table is the area to be measured formed at the bottom of the lighting bracket;

an array camera assembly, including a bright field camera and a dark field camera arranged on the top of the lighting bracket;

a light source controller for controlling the illumination angle and illumination range of the first controllable light source, the second controllable light source and the third controllable light source;

The machine vision detection module is used for generating a composite image according to the images of the workpiece to be tested obtained by the bright field camera and the dark field camera under different lighting environments.

Further, the number of the above-mentioned bright-field cameras and dark-field cameras is two each, the bright-field cameras and the dark-field cameras are arranged above the area to be measured, and the bright-field cameras and the dark-field cameras are in the circumferential direction. upper interval distribution.

Further, the above-mentioned lighting bracket includes an outer bracket and an inner bracket, and the first annular bracket, the second annular bracket and the third annular bracket are formed on the inner bracket; the outer bracket is on the object stage. A support frame for supporting the inner frame is formed, a beam-shaped frame is formed above the inner frame, and the bright-field camera and the dark-field camera are movably arranged on the beam-shaped frame.

Further, the shape of the above-mentioned inner bracket is hemispherical, and the inner bracket forms an image capturing gap below the bright field camera and the dark field camera.

Further, the above-mentioned lighting device also includes a distance sensor arranged on the light field camera and the dark field camera, and the distance sensor is used to detect the distance between each of the light field camera and the dark field camera and the workpiece to be measured. relative distance;

The object presentation table includes a clamping component arranged around the area to be measured, a tray positioned below the clamping component for supporting the workpiece to be measured, and an angle adjustment mechanism arranged below the tray, The angle adjustment mechanism includes a telescopic rod, a universal ball connected with the telescopic rod, and a suction cup arranged between the universal ball and the tray, and the suction cup is detachably connected to the tray;

The machine vision detection module is also used to adjust the height of the telescopic rod and the angle of the universal ball, so that the relative distance between the workpiece to be tested and each of the light field cameras and the dark field cameras is preset. within the distance.

Further, the above-mentioned tray is a transparent tray, a telescopic pivot is further provided on the object stage, and a pivot hole corresponding to the telescopic pivot is provided on the side wall of the tray;

The machine vision detection module is also used to control the telescopic pivot to turn over the tray, so as to turn the workpiece to be tested.

Another aspect of the embodiments of the present invention provides an image synthesis method, which is applied to the multi-light source automatic lighting device described in any of the above, including:

Controlling the first controllable light source on the first annular support to be in the state of a normally bright line light source;

Controlling the second controllable light source to sequentially illuminate the workpiece to be tested at multiple preset angles of the second annular support;

Controlling the third controllable light source to sequentially illuminate the workpiece to be tested at multiple preset angles of the third annular support;

When the second controllable light source or the third controllable light source illuminates the workpiece to be tested at different preset angles, the array camera assembly is controlled to obtain an image of the workpiece to be tested, and an image brightness matrix of the workpiece to be tested is generated;

A composite image is generated according to the image brightness matrix of the workpiece to be tested and the image of the workpiece to be tested.

Further, when the second controllable light source or the third controllable light source illuminates the workpiece to be tested at different preset angles, the above-mentioned step of controlling the array camera assembly to obtain the image of the workpiece to be tested to obtain the image brightness matrix of the workpiece to be tested, include:

When the second controllable light source illuminates the workpiece to be tested at different preset angles and the third controllable light source is extinguished, the control array camera assembly is controlled to obtain an image of the workpiece to be tested, and a first image group of the workpiece to be tested is generated;

When the third controllable light source illuminates the workpiece to be tested at different preset angles and the second controllable light source is extinguished, the control array camera assembly is controlled to obtain an image of the workpiece to be tested, and a second image group of the workpiece to be tested is generated;

According to the first image group of the workpiece to be tested and the second image group of the workpiece to be tested, an image brightness matrix of the workpiece to be tested is generated.

I_n为第n幅图像的亮度矩阵，所述根据所述待测工件图像矩阵，生成合成图像的步骤，包括：Further, define the above-mentioned workpiece image brightness matrix to be measured as

I _n is the brightness matrix of the nth image, and the step of generating a composite image according to the described workpiece image matrix to be tested, includes:

确定G值，其中

为已知的光源照射角度矩阵，L_n ^T为第n幅图像对应的光源入射角度；According to the formula

Determine the G value, where

is the known light source illumination angle matrix, L _n ^T is the light source incident angle corresponding to the nth image;

其中k_d＝||G||，生成合成图像。According to the formula

where k _d =||G||, generates a composite image.

In the embodiment of the present invention, a lighting bracket is provided, and at least a first annular bracket, a second annular bracket and a third annular bracket are arranged on the lighting bracket from high to low, and a light source controller is provided to control the lights provided on each annular bracket. The controllable light source illuminates the workpiece to be tested on the stage, so that the illumination is sufficiently uniform, and the relatively fixed first annular bracket, second annular bracket and third annular bracket make the irradiation angle relatively fixed, avoiding the generation of errors At the same time, the invention utilizes the reflection characteristics of the defect target for different light source directions and angles, adjusts the flashing rules of the controllable light source on the ring support, and performs image processing in conjunction with the sequence images obtained by the array camera assembly, so as to realize the detection of subtle defects.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a perspective view of a multi-light source automatic lighting device according to a first embodiment of the present invention;

Fig. 2 is the perspective view of Fig. 1 after removing the stage;

Fig. 3 is the side view of Fig. 2;

4 is a perspective view of the inner support and the array camera assembly according to the first embodiment of the present invention;

5 is a perspective view of a tray and an angle adjustment mechanism according to a second embodiment of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

When ordinal numbers such as "first" and "second" (if any) are mentioned in the embodiments of the present invention, unless they really express the meaning of order according to the context, it should be understood that they are only used for distinction.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" (if any) should be understood in a broad sense, for example, it may be a fixed connection, or It can be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

First embodiment:

Referring to FIGS. 1 to 4 , an embodiment of the present invention discloses a multi-light source automatic lighting device, including:

Lighting bracket 1, the lighting bracket includes at least a first annular bracket 11, a second annular bracket 12 and a third annular bracket 13 located at different heights, and also includes at least a first annular bracket provided on the first annular bracket 11. a controllable light source 14 , a second controllable light source 15 disposed on the second annular support 12 and a third controllable light source 16 disposed on the third annular support 13 ;

The object table 2 is shown as the area to be measured 21 formed by the object table 2 at the bottom of the lighting bracket 1;

The array camera assembly 3 includes a bright field camera 31 and a dark field camera 32 arranged on the top of the lighting bracket;

a light source controller for controlling the illumination angle and illumination range of the first controllable light source 14, the second controllable light source 15 and the third controllable light source 16;

The machine vision detection module is configured to generate a composite image according to the images of the workpiece to be tested obtained by the bright field camera 31 and the dark field camera 32 under different lighting environments.

In this embodiment, the object stage 2 includes a transfer device, and the workpiece to be tested can be transferred to the region to be tested 21 of the object stage through the transfer device. The region to be tested 21 is located on the main axis of the array camera assembly 3, and the brightfield camera 31 It is used to detect defects of the type of absorbing light on the surface of the product, or to detect defects that have a significantly different reflection property from the workpiece to be tested; the dark field camera 32 is used to detect defects of the type of scattered light on the surface of the product, or to detect reflected light Defects whose orientation is significantly different from the smooth surface of the workpiece to be tested. Through the cooperation of the bright field camera 31 and the dark field camera 32 , the composite image of this embodiment is more conducive to the defect detection at the back end.

As a preferred embodiment, the number of the above-mentioned bright field cameras 31 and dark field cameras 32 is two, the light field cameras 31 and dark field cameras 32 are arranged above the area to be measured 21, and the The bright field cameras 31 and the dark field cameras 32 are spaced apart in the circumferential direction.

Meanwhile, the first controllable light source 14 , the second controllable light source 15 and the third controllable light source 16 each include eight fixed light sources uniformly distributed on the circumference. The light source controller can control the illumination angle and illumination range of the light source by controlling the combined illumination mode of the fixed light source.

The above-mentioned lighting bracket includes an outer bracket 4 and an inner bracket 5, and the first annular bracket 11, the second annular bracket 12 and the third annular bracket 13 are formed on the inner bracket 5; A support frame 41 for supporting the inner bracket 5 is formed on the object stage 2, a beam-shaped frame 42 is formed above the inner bracket 5, and the bright field camera 31 and the dark field camera 32 are movably arranged at the position. on the beam-shaped frame 32. The inner bracket 4 can be used to adjust the overall position of the light source, and the outer bracket 5 can be used to adjust the position of the array camera assembly, so that the implementation of the automatic force striking device of the present invention is relatively flexible.

As an example and not limitation, the shape of the inner bracket 5 is hemispherical, and the inner bracket 5 forms an image capturing gap 51 under the bright field camera 31 and the dark field camera 32 . It should be noted that the shape of the inner bracket 5 may also be a polygonal column shape or a polygonal truncated shape.

In the embodiment of the present invention, a lighting bracket is provided, and at least a first annular bracket, a second annular bracket and a third annular bracket are arranged on the lighting bracket from high to low, and a light source controller is provided to control the lights provided on each annular bracket. The controllable light source illuminates the workpiece to be tested on the stage, so that the illumination is sufficiently uniform, and the relatively fixed first annular bracket, second annular bracket and third annular bracket make the irradiation angle relatively fixed, avoiding the generation of errors At the same time, the invention utilizes the reflection characteristics of the defect target for different light source directions and angles, adjusts the flashing rules of the controllable light source on the ring support, and performs image processing in conjunction with the sequence images obtained by the array camera assembly, so as to realize the detection of subtle defects.

Second embodiment:

Different from the above-mentioned first embodiment, in this embodiment, the first controllable light source on the first annular support is a ring-shaped line light source, including a plurality of luminous bodies arranged in a ring; the second controllable light source passes through the The slider is arranged on the second annular bracket and can slide in the chute of the second annular bracket; the third controllable light source is arranged on the third annular bracket through the slider and can slide in the slot of the third annular bracket slide. The light source controller can control the position of the second controllable light source and the third controllable light source corresponding to the slider in the chute, so as to control the irradiation angle of the second controllable light source and the third controllable light source.

At the same time, the above-mentioned lighting device further includes a distance sensor arranged on the light field camera and the dark field camera, and the distance sensor is used to detect the distance between each of the light field camera and the dark field camera and the workpiece to be tested. relative distance;

Referring to FIG. 5 , the object presentation table includes a clamping component 6 disposed around the area to be measured, a tray 7 located below the clamping component 6 for supporting the workpiece to be measured, and a device The angle adjustment mechanism 8 under the tray 7 includes a telescopic rod 81 , a universal ball 82 connected to the telescopic rod 81 , and a suction cup 83 arranged between the universal ball 82 and the tray 7 , the suction cup 83 is detachably connected with the tray 7;

The machine vision detection module is also used to adjust the height of the telescopic rod 81 and the angle of the universal ball 82, so that the relative distance between the workpiece to be tested and each of the light field cameras and the dark field cameras is within within the preset distance.

As a specific implementation solution, the above-mentioned telescopic rod 81 may be a cylinder rod, and an air pump interface 84 for pumping air for the suction cup 83 is provided at the joint of the universal ball 82 and the suction cup 83 . The above distance sensors may be infrared sensors or ultrasonic sensors. Exemplarily, when the number of the bright field cameras and the dark field cameras are two in the first embodiment, four distance sensors are used to obtain the information on the workpiece to be measured. The distance from the four corresponding points to the corresponding camera to obtain the average distance between the workpiece to be measured and the array camera assembly, and the inclination angle of the surface of the workpiece to be measured. When the average distance exceeds the preset distance range, the machine vision detection module adjusts the height of the telescopic rod 81 so that the workpiece to be tested is located within the pre-focusing range of the array camera assembly; when the tilt angle exceeds the preset angle range, the machine vision The detection module adjusts the angle of the universal ball 82 on the telescopic rod 81 so that the surface of the workpiece faces the array camera assembly, so that each controllable light source can illuminate the workpiece to be tested with an inclined or irregular surface, and the array camera assembly can obtain clear images. The front image of the workpiece to be tested.

As an improvement but not a limitation, the above-mentioned tray 7 is a transparent tray, a telescopic pivot is further provided on the object stage, and a pivot hole 71 corresponding to the telescopic pivot is provided on the side wall of the tray;

The machine vision detection module is also used to control the telescopic pivot to turn over the tray 7 to turn the workpiece to be tested.

When the telescopic pivot is extended, the telescopic pivot is inserted into the corresponding pivot hole 71 on the side wall of the tray 7. At this time, the machine vision detection module controls the telescopic pivot to flip the tray so that the back of the workpiece to be tested is facing For the array camera assembly, since the back of the workpiece to be tested is the placement surface, usually the placement surface is a flat surface, the back surface of the workpiece to be tested can be illuminated and images can be acquired by simply flipping the workpiece to be tested, which is simple and convenient. In this embodiment, one of the angle adjustment mechanism 8 and the telescopic pivot is connected to the tray 7, and when the telescopic pivot is retracted, the angle adjustment mechanism can be used to connect with the tray and support the tray.

Because before lighting and image acquisition of the workpiece to be tested, it is usually necessary to use visual standard parts to adjust and focus the array camera components (hereinafter referred to as pre-adjustment), so that the light field cameras and dark field cameras are basically focused at On the workpiece to be tested, in this embodiment, an angle adjustment mechanism is provided, so that the automatic lighting device can automatically identify the thickness of the workpiece to be tested and the smoothness of the surface, and the height of the telescopic rod is adjusted so that the workpiece to be tested is located at the position of the array camera assembly. Within the pre-focusing range, adjust the angle of the universal ball on the telescopic rod so that the surface of the workpiece is roughly facing the array camera assembly, so that each controllable light source can illuminate the workpiece to be tested with an inclined or irregular surface, and the array camera The component obtains a clear frontal image of the workpiece to be tested, avoiding the problem of inefficiency caused by repeated pre-adjustment in the face of different workpieces to be tested. At the same time, in this embodiment, by providing a telescopic pivot and opening a pivot hole on the side wall of the tray, the machine vision detection module can control the telescopic pivot to turn the tray over to perform defect detection on the back surface of the workpiece to be tested, avoiding the need for Manual intervention and fully automated design are easy to operate, saving time and effort.

Third embodiment:

An embodiment of the present invention provides an image synthesis method, which is applied to the multi-light source automatic lighting device described in any of the above embodiments, including:

Controlling the first controllable light source on the first annular support to be in the state of a normally bright line light source;

Controlling the second controllable light source to sequentially illuminate the workpiece to be tested at multiple preset angles of the second annular support;

Controlling the third controllable light source to sequentially illuminate the workpiece to be tested at multiple preset angles of the third annular support;

When the second controllable light source or the third controllable light source illuminates the workpiece to be tested at different preset angles, the array camera assembly is controlled to obtain an image of the workpiece to be tested, and an image brightness matrix of the workpiece to be tested is generated;

A composite image is generated according to the image brightness matrix of the workpiece to be tested and the image of the workpiece to be tested.

In this embodiment, before the step of controlling the first controllable light source to be in the state of a constant-bright line light source on the first annular support, it also includes the step of pre-adjustment:

Use the visual standard to adjust and focus the array camera components, so that each bright field camera and dark field camera focus on the surface of the workpiece to be tested;

Through the preset flashing rules of the light source controller, each of the first controllable light source, the second controllable light source and the third controllable light source is sequentially flashed within a certain brightness range;

Obtain and apply flash rules for array camera assemblies that meet sharpness standards.

As a specific lighting scheme, when the second controllable light source or the third controllable light source illuminates the workpiece to be tested at different preset angles, the array camera assembly is controlled to obtain the image of the workpiece to be tested, and the workpiece to be tested is obtained. The steps of the image brightness matrix, including:

When the second controllable light source illuminates the workpiece to be tested at different preset angles and the third controllable light source is extinguished, the control array camera assembly is controlled to obtain an image of the workpiece to be tested, and a first image group of the workpiece to be tested is generated;

When the third controllable light source illuminates the workpiece to be tested at different preset angles and the second controllable light source is extinguished, the control array camera assembly is controlled to obtain an image of the workpiece to be tested, and a second image group of the workpiece to be tested is generated;

According to the first image group of the workpiece to be tested and the second image group of the workpiece to be tested, an image brightness matrix of the workpiece to be tested is generated.

As an example, compared to the solution in the first embodiment in which each of the first controllable light source, the second controllable light source and the third controllable light source includes eight fixed light sources evenly distributed on the circumference, each camera acquires 16 different Image of the angle of illumination of the light source. The array camera assembly can obtain a total of 64 images of 4*16, of which 2 bright field photos and 2 dark field photos can be obtained under the illumination of the light source at each preset angle. The reliability of the image synthesis method is guaranteed.

I_n为第n幅图像的亮度矩阵，所述根据所述待测工件图像矩阵，生成合成图像的步骤，包括：In order to further reduce the interference of uneven illumination and false defects on high-quality image acquisition, this embodiment defines the image brightness matrix of the workpiece to be tested as:

I _n is the brightness matrix of the nth image, and the step of generating a composite image according to the described workpiece image matrix to be tested, includes:

确定G值，其中

为已知的光源照射角度矩阵，L_n ^T为第n幅图像对应的光源入射角度；According to the formula

Determine the G value, where

is the known light source illumination angle matrix, L _n ^T is the light source incident angle corresponding to the nth image;

其中k_d＝||G||，生成合成图像。According to the formula

where k _d =||G||, generates a composite image.

Through the above synthesis method, the interference of uneven illumination and false defects on high-quality image acquisition can be further reduced, and a highly reliable synthesized image can be obtained.

In the embodiment of the present invention, a lighting bracket is provided, and at least a first annular bracket, a second annular bracket and a third annular bracket are arranged on the lighting bracket from high to low, and a light source controller is provided to control the lights provided on each annular bracket. The controllable light source illuminates the workpiece to be tested on the stage, so that the illumination is sufficiently uniform, and the relatively fixed first annular bracket, second annular bracket and third annular bracket make the irradiation angle relatively fixed, avoiding the generation of errors At the same time, the invention utilizes the reflection characteristics of the defect target for different light source directions and angles, adjusts the flashing rules of the controllable light source on the ring support, and performs image processing in conjunction with the sequence images obtained by the array camera assembly, so as to realize the detection of subtle defects.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. a multi-light source automatic lighting device, is characterized in that, comprises: A lighting bracket, the lighting bracket includes at least a first annular bracket, a second annular bracket and a third annular bracket located at different heights, and at least a first controllable light source arranged on the first annular bracket, a second controllable light source arranged on the second annular support and a third controllable light source arranged on the third annular support; an object table, the object table is the area to be measured formed at the bottom of the lighting bracket; an array camera assembly, including a bright field camera and a dark field camera arranged on the top of the lighting bracket; a light source controller for controlling the illumination angle and illumination range of the first controllable light source, the second controllable light source and the third controllable light source; a machine vision detection module, configured to generate a composite image according to the images of the workpiece to be tested obtained by the light field camera and the dark field camera in different lighting environments; The lighting device further includes a distance sensor arranged on the light field camera and the dark field camera, and the distance sensor is used to detect the relative distance between each of the light field camera and the dark field camera and the workpiece to be measured; The object presentation table includes a clamping component arranged around the area to be measured, a tray positioned below the clamping component for supporting the workpiece to be measured, and an angle adjustment mechanism arranged below the tray, The angle adjustment mechanism includes a telescopic rod, a universal ball connected with the telescopic rod, and a suction cup arranged between the universal ball and the tray, and the suction cup is detachably connected to the tray; The machine vision detection module is also used to adjust the height of the telescopic rod and the angle of the universal ball, so that the relative distance between the workpiece to be tested and each of the light field cameras and the dark field cameras is preset. within the distance; The tray is a transparent tray, a telescopic pivot is further provided on the object stage, and a pivot hole corresponding to the telescopic pivot is provided on the side wall of the tray; The machine vision detection module is also used to control the telescopic pivot to turn over the tray, so as to turn the workpiece to be tested. 2 . The multi-light source automatic lighting device according to claim 1 , wherein the number of the bright-field cameras and the dark-field cameras is two each, and the bright-field cameras and the dark-field cameras are arranged in the waiting area. 3 . above the measurement area, and the bright-field cameras and the dark-field cameras are spaced apart in the circumferential direction. 3. The multi-light source automatic lighting device according to claim 2, wherein the lighting bracket comprises an outer bracket and an inner bracket, and the first annular bracket, the second annular bracket and the third annular bracket are formed in the on the inner bracket; the outer bracket forms a support frame for supporting the inner bracket on the object stage, and a beam-shaped frame is formed above the inner bracket, and the light field camera and the dark field camera can be The movable arrangement is on the beam-like frame. 4 . The multi-light source automatic lighting device according to claim 3 , wherein the shape of the inner bracket is hemispherical, and the inner bracket forms an image acquisition gap below the bright field camera and the dark field camera. 5 . 5. An image synthesis method, characterized in that, applied to the multi-light source automatic lighting device according to any one of claims 1 to 4, comprising: Controlling the first controllable light source on the first annular support to be in the state of a normally bright line light source; Controlling the second controllable light source to sequentially illuminate the workpiece to be tested at multiple preset angles of the second annular support; Controlling the third controllable light source to sequentially illuminate the workpiece to be tested at multiple preset angles of the third annular support; When the second controllable light source or the third controllable light source illuminates the workpiece to be tested at different preset angles, the array camera assembly is controlled to obtain an image of the workpiece to be tested, and an image brightness matrix of the workpiece to be tested is generated; A composite image is generated according to the image brightness matrix of the workpiece to be tested and the image of the workpiece to be tested. 6 . The image synthesis method according to claim 5 , wherein when the second controllable light source or the third controllable light source illuminates the workpiece to be tested at different preset angles, the array camera assembly is controlled to obtain the The steps of measuring the image of the workpiece to obtain the brightness matrix of the image of the workpiece to be measured include: When the second controllable light source illuminates the workpiece to be tested at different preset angles and the third controllable light source is extinguished, the array camera assembly is controlled to obtain an image of the workpiece to be tested, and a first image group of the workpiece to be tested is generated; When the third controllable light source illuminates the workpiece to be tested at different preset angles and the second controllable light source is extinguished, the array camera assembly is controlled to obtain an image of the workpiece to be tested, and a second image group of the workpiece to be tested is generated; According to the first image group of the workpiece to be tested and the second image group of the workpiece to be tested, an image brightness matrix of the workpiece to be tested is generated. 7. The image synthesis method according to claim 6, wherein the image brightness matrix of the workpiece to be measured is defined as

I _n is the brightness matrix of the nth image, and the step of generating a composite image according to the brightness matrix of the workpiece image to be measured, includes: According to the formula

Determine the G value, where

is the known light source illumination angle matrix, L _n ^T is the light source incident angle corresponding to the nth image; According to the formula

where k _d =||G||, generates a composite image.

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