A stroboscopic control and camera trigger delay adaptive synchronization control device and a synchronization method thereof

Abstract

The application discloses a stroboscopic control and camera trigger delay adaptive synchronization method, comprising the following steps: S1, presetting the range of the adaptive light source delay value, inputting the light source delay value into the light source one by one and controlling the stroboscopic of the light source, and using the camera to collect the image of the object in each stroboscopic process; S2, capturing the capture area of the image and calculating the average gray value of the capture area; S3, recording the average gray value corresponding to each light source delay value, comparing the average gray values corresponding to two light source delay values, when the average gray value corresponding to the light source delay value is less than the average gray value corresponding to the other light source delay value, stopping the adaptation, and saving the average gray value of this time as the best light source delay value, which is used as the delay value of the light source stroboscopic in subsequent work, otherwise, repeating the above steps. The application improves the ease of use of the stroboscopic / strobe controller, reduces the cost of manual debugging, and improves the debugging efficiency of the machine.

Description

Technical Field

[0001] This invention relates to the field of detection light source technology, and in particular to a strobe control and camera trigger delay adaptive synchronization control device and its synchronization method. Background Technology

[0002] Strobe / flicker is a design scheme that can temporarily increase the brightness of a light source by outputting a high voltage to the LED chip for a short time.

[0003] Considering the lifespan of the light source, sufficient heat dissipation time is generally required for the LED beads, meaning a certain time interval is needed for triggering. To better adapt to the camera's image acquisition and make good use of the light source's brightness enhancement time, the camera and the strobe / flash controller need to be synchronized. LED light sources have a fast response time, on the order of nanoseconds. Traditional synchronization methods involve manually adjusting the trigger delay of the light source to achieve synchronization with the camera's acquisition time. Even for machines with the same configuration, each machine needs to be adjusted individually, which is time-consuming, labor-intensive, and inefficient. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a strobe control and camera trigger delay adaptive synchronization control device and its synchronization method. This invention achieves precise matching of camera shutter speed and light source strobe frequency, and can complete the configuration without manual intervention, thereby significantly improving the ease of use of the strobe / strobe controller, effectively reducing the cost and time consumption of manual debugging, and greatly improving the debugging efficiency of the machine and the overall production efficiency.

[0005] To achieve the above objectives, the present invention provides a method for adaptive synchronization of strobe control and camera trigger delay, comprising the following steps:

[0006] S1. Preset the range of the adaptive light source delay value, input the light source delay value into the light source one by one and control the light source to flicker. Use the camera to capture the image of the detected object during each flicker.

[0007] S2. Capture the capture area of ​​the above image and calculate the average gray value of the capture area;

[0008] S3. Record the average gray value corresponding to each light source delay value. Compare the average gray values ​​corresponding to two light source delay values. When the average gray value corresponding to the light source delay value is less than the average gray value corresponding to the other light source delay value, stop the adaptation and save the light source delay value of this time as the optimal light source delay value for use as the delay value of light source flicker in subsequent operations. Otherwise, repeat the above steps.

[0009] Furthermore, the light source delay value is controlled within the range of 0 to 999 microseconds. Within this range, the light source delay value is adjusted in preset increments, which meets the response requirements of most cameras and light sources currently on the market, ensuring synchronization accuracy.

[0010] Furthermore, in step S1, the step size for each change in the input light source delay value is 1 microsecond, ensuring a balance between accuracy and response speed. By adjusting the image grayscale changes microsecond by microsecond and providing real-time feedback, the system automatically identifies the delay parameter that optimizes the imaging brightness, avoiding synchronization deviations caused by manual adjustments.

[0011] Furthermore, in step S2, the image capture area is the region corresponding to the center point of the image. The grayscale changes in this region best reflect the peak response of the illumination intensity, thereby ensuring the representativeness and stability of the feedback data.

[0012] Furthermore, in step S2, the image capture area is determined as follows: In image processing, the image is first divided into multiple sub-regions, then the brightness value of each sub-region is calculated, and finally, the sub-region with the highest brightness value is selected as the capture area. By dynamically selecting the brightest area as the capture target, uneven lighting or occlusion interference that may exist in a fixed area is effectively avoided, thus improving the accuracy of grayscale feedback.

[0013] Furthermore, the size of the capture area is one-tenth of the number of pixels. This size ensures sufficient sampling accuracy while reducing computational load and improving system response efficiency.

[0014] Furthermore, the capture area can be rectangular, circular, or polygonal. The shape of the capture area can be flexibly configured to match the contour features of the target object, further improving the capture accuracy of the illumination response, depending on the imaging requirements of different application scenarios.

[0015] Furthermore, in step S3, the average grayscale values ​​corresponding to the two light source delay values ​​are compared. This comparison is based on the average grayscale values ​​of the capture area of ​​the image obtained after two consecutive flashes. Specifically, when the average grayscale value of the capture area obtained by the Nth light source delay value is less than the average grayscale value of the capture area obtained by the (N-1)th light source delay value, the adaptation process stops, and the (N-1)th light source delay value is recorded as the optimal light source delay value. By successively approximating the lowest grayscale response point, the light source flash and camera exposure are ensured to reach optimal synchronization, thereby maximizing image contrast and detection stability.

[0016] Furthermore, the average grayscale value comparison process in step S3 is executed in real time after each strobe trigger to ensure that changes in ambient light or shifts in the target object's position do not affect the synchronization accuracy. At the same time, the system automatically records the grayscale data for subsequent analysis and optimization.

[0017] A strobe control and camera trigger delay adaptive synchronization control device includes:

[0018] The communication module is used to realize the dynamic adjustment and feedback control of the light source delay parameters;

[0019] The processing module is connected to the communication module and is used to perform logic for recognizing the image capture area, calculating the average gray value, and adaptively adjusting the light source delay value.

[0020] The storage module is used to save the grayscale data and delay parameters corresponding to each strobe flash;

[0021] The output control module is used to generate stable trigger commands based on the optimal light source delay value, ensuring precise synchronization between the camera and the stroboscopic light source.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] The synchronization method of this invention can automatically traverse preset delay values ​​and make judgments based on the objective "average gray value" index, realizing a fully automatic calibration process. This reduces the technical requirements for operators and ensures the objectivity and repeatability of each calibration result.

[0024] In practical applications, this invention can automatically adapt to and synchronize the working times of different brands and models of cameras with different LED strobe / burst sources, achieving precise matching of camera shutter speed and light source strobe frequency. Configuration can be completed without manual intervention, significantly improving the ease of use of the strobe / burst controller, effectively reducing the cost and time of manual debugging, and greatly improving machine debugging efficiency and overall production efficiency. Simultaneously, this adaptive synchronization mechanism can effectively cope with dynamic interference in complex industrial environments, such as power fluctuations, ambient light changes, and equipment aging, ensuring synchronization stability during long-term operation and further improving product quality and testing accuracy. Attached Figure Description

[0025] To more clearly illustrate the technology in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a flowchart illustrating a method for adaptive synchronization of strobe control and camera trigger delay according to the present invention. Detailed Implementation

[0027] The technology of this embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiment is one embodiment of the present invention, and not all embodiments thereof. Based on this embodiment of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0029] Furthermore, if the embodiments of the present invention involve descriptions such as "first" or "second", such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0030] like Figure 1 The present invention discloses a method for adaptive synchronization of strobe control and camera trigger delay, comprising the following steps:

[0031] S1. Preset the range of the adaptive light source delay value, input the light source delay value into the light source one by one and control the light source to flicker. Use the camera to capture the image of the detected object during each flicker.

[0032] The specific execution steps are as follows: First, the range of light source delay parameters is preset in the controller, which is usually set between 0 and 999 microseconds. The controller will automatically and sequentially increase the delay value within this range with a basic step size of 1 microsecond. At each set delay value, the controller will accurately output a trigger signal to the light source driving circuit, instructing the light source to perform a strobe / flash operation. At the same time, the controller will send an exposure synchronization signal to the camera at the instant of outputting the light source trigger signal. After receiving this synchronization signal, the camera will immediately start the exposure process and acquire a single frame image at the current moment. The acquired image data is then transmitted in real time to the back-end image processing module for analysis or storage through a high-speed interface. This cyclic process is repeated for each delay value to achieve accurate photoelectric synchronization testing and data acquisition.

[0033] S2. Capture the capture area of ​​the above image and calculate the average gray value of the capture area;

[0034] When the image processing module receives each frame of image, it first divides the image into regions and selects the capture region. For the capture region, the present invention can select the region corresponding to the center point of the image as the main sub-region. Of course, in other embodiments, the image can be divided into multiple sub-regions, and the brightness value of each sub-region can be calculated. By comparing the brightness values ​​of each sub-region, the region with the highest brightness value is selected as the capture region.

[0035] Preferably, the size of the above-mentioned capture area is one-tenth of the number of pixels, that is, based on one-tenth of the total number of pixels in the image, to ensure that the area size is moderate, which can reflect local features and has sufficient statistical representativeness. For example, for a 1280×1024 resolution image (total pixels of about 1.3 million), the capture area is set to 360×360 pixels (about 129,600 pixels, close to one-tenth), which will not cause excessive fluctuation of grayscale values ​​due to the area being too small, nor will it contain too much background noise due to the area being too large.

[0036] Preferably, the capture area can be a rectangular area, or it can be set to a circle or polygon according to the shape of the actual target to maximize the coverage of the effective feature area.

[0037] Subsequently, the grayscale values ​​of all pixels within the selected capture area are summed and the average value is calculated, which is recorded as the average grayscale value of the corresponding image under that delay value.

[0038] S3. Record the average gray value corresponding to each light source delay value. Compare the average gray values ​​corresponding to two light source delay values. When the average gray value corresponding to the light source delay value is less than the average gray value corresponding to the other light source delay value, stop the adaptation and save the average gray value of this time as the optimal light source delay value for use as the delay value of light source flicker in subsequent operations. Otherwise, repeat the above steps.

[0039] Specifically, starting from a delay value of 0 microseconds, the delay is gradually increased in steps of 1 microsecond, and image acquisition and average gray value calculation are continuously performed until the average gray value under the current delay is lower than the average gray value under the previous delay. That is, the comparison of the average gray value is based on the comparison of the average gray value of the captured area of ​​the image obtained after flickering under two consecutive light source delay values. That is, when the average gray value of the captured area obtained by the Nth light source delay value is less than the average gray value of the captured area obtained by the N-1th light source delay value, the adaptation process stops, and the N-1th light source delay value is recorded as the optimal light source delay value.

[0040] Furthermore, this invention incorporates a real-time comparison mechanism for average grayscale values. This mechanism effectively addresses dynamic interference: if the target object experiences a slight shift due to vibration (shift less than 10 pixels), the system will recalculate the average grayscale value of the current capture area (adjusted according to the target object's shift) after the next strobe trigger and compare it with the previous data. The system will not stop adapting due to changes in the target object's position. If the ambient light suddenly increases (e.g., due to external lighting), the grayscale value of the Nth strobe may be slightly higher than that of the N-1th strobe, but the system will still continue to iterate until the grayscale value meets the requirements, ensuring the accuracy of the optimal delay value.

[0041] Preferably, the average grayscale value comparison process in step S3 is executed in real time after each strobe trigger to ensure that changes in ambient light or shifts in the target object's position do not affect the synchronization accuracy. At the same time, the system automatically records the grayscale data for subsequent analysis and optimization.

[0042] 1. Use an industrial camera and lens to photograph a workpiece to be inspected. Set the image resolution to 1280×1024. Set the capture area of ​​the image center point to a rectangular area of ​​360×360 pixels. Set the light source delay value range to 0~999µs. Start the operation.

[0043] 2. Set the light source delay value to 0, and the image processing module obtains the average gray value (assumed to be 120) at the center of the image, denoted as G0;

[0044] 3. Set the light source delay value to 1, and the image processing module obtains the average gray value of the image center (assumed to be 125), denoted as G1;

[0045] 4. Compare G1 and G0. Since G1 is greater than G0, continue to increase the delay.

[0046] (Keep trying)...

[0047] 5. Set the light source delay value to 100, and the image processing module obtains the average grayscale value (assuming it is 220) at the center of the image, denoted as G. 100 ;

[0048] 6. Set the light source delay value to 101, and the image processing module obtains the average gray value (assuming it is 218) at the center of the image, denoted as G. 101 ;

[0049] 7. Compare G101 and G100, because G 101 Less than G 100 The adaptation process has stopped.

[0050] 8. The light source delay value at the 100th microsecond is determined as the optimal delay parameter, and the adaptive configuration is completed. The system automatically saves this parameter and applies it to subsequent shooting tasks, while performing a quick verification every time it starts.

[0051] A strobe control and camera trigger delay adaptive synchronization control device includes:

[0052] The communication module specifically includes: 1. A light source communication interface, which is usually a digital I / O (such as TTL signal), RS-232, RS-485, Ethernet (such as PoE) or a dedicated light source controller network, used to realize dynamic adjustment and feedback control of light source delay parameters.

[0053] 2. A corresponding number of camera communication interfaces, typically using standard industrial camera protocols such as GigEVision, USB3Vision, and CameraLink, to send soft trigger commands to the camera and receive image data acquired by the camera.

[0054] The storage module is used to save the optimal light source delay parameters determined by the processing module and the average gray value corresponding to each delay value, so that the system can quickly read and verify the effectiveness when it starts up.

[0055] Specifically, it includes a parameter configuration area, a process data cache area, and an optimal parameter storage area;

[0056] The above parameter configuration area includes preset delay search range (maximum value, minimum value, step value), coordinates of the capture area, grayscale calculation threshold, control algorithm parameters, etc.

[0057] The process data cache area, as a cache area, is mainly used to record the [light source delay value, average gray value] of each test. This data is used for comparison in decision-making logic and can also be used for subsequent analysis.

[0058] The optimal parameter storage area is used to persistently store the optimal delay value determined through iteration;

[0059] Preferably, the optimal parameter storage area uses non-volatile storage technology to ensure that calibration results can still be retained after power failure or system restart, avoiding repeated calibration.

[0060] The processing module performs grayscale analysis on the captured area of ​​the image and transmits the results to the storage module in real time. It also calls the nearest light source delay value from the storage module to issue commands in conjunction with the output control module. In practical applications, to increase the efficiency of image processing, a host computer can be connected via TCP / IP, RS-232, or other protocols to achieve more efficient collaborative control and data transmission. It also supports remote monitoring and parameter adjustment. The host computer can be used to view the grayscale change trend and the results of each delay matching in real time, which is convenient for system debugging and optimization.

[0061] The output control module is connected to both the communication module and the processing module. It generates stable trigger commands based on the optimal light source delay value to ensure precise synchronization between the camera and the stroboscopic light source.

[0062] The working process of the control device of the present invention is as follows:

[0063] Calibration phase:

[0064] The user initiates a calibration command;

[0065] The processing module controls the system through the communication module and performs scanning tests within a preset delay range; for each light source delay value, it acquires images, calculates the average gray value, and stores them in the storage module.

[0066] The processing module's dynamic logic compares grayscale value changes in real time. Once the set threshold is met, it stops immediately and stores the optimal value in the storage module.

[0067] Assignment phase:

[0068] The output control module reads the saved optimal light source delay value from the storage module.

[0069] Whenever a trigger signal arrives, the module precisely controls the camera and light source to work synchronously according to a fixed and optimized timing sequence, ensuring that stable and high-quality images are obtained for every shot. This process does not require manual intervention, significantly improving the system's automation level and imaging consistency. Through a real-time comparison mechanism, the device can adapt to parameter drift caused by factors such as changes in ambient light and equipment aging, and has long-term operational stability.

[0070] Practical applications show that the device can complete calibration within 30 seconds with a synchronization accuracy of ±0.5 microseconds, effectively ensuring the clear imaging requirements of high-speed moving objects. In a 72-hour continuous stability test, the device did not exhibit synchronization deviation or parameter drift, and the grayscale value fluctuation range was always controlled within ±3, verifying its excellent environmental adaptability and reliability.

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A stroboscopic control and camera trigger delay adaptive synchronization method, characterized in that, Includes the following steps: S1. Preset the range of the adaptive light source delay value, input the light source delay value into the light source one by one and control the light source to flicker. Use the camera to capture the image of the detected object during each flicker. In step S1, the controller inputs the light source delay value into the light source one by one and controls the light source to flicker. The controller will send an exposure synchronization signal to the camera at the moment of outputting the light source trigger signal. After receiving the exposure synchronization signal, the camera will immediately start the exposure and capture a single frame image at the current moment. S2. Capture the capture area of ​​the above image and calculate the average gray value of the capture area; S3. Record the average grayscale value corresponding to each light source delay value. Compare the average grayscale values ​​corresponding to two light source delay values. When the average grayscale value corresponding to one light source delay value is less than the average grayscale value corresponding to another light source delay value, stop the adaptation and save the average grayscale value of this operation as the optimal light source delay value for use as the delay value of light source flicker in subsequent operations. Otherwise, repeat the above steps. The comparison of the average gray values ​​corresponding to the two light source delay values ​​is based on the comparison of the average gray values ​​of the capture area of ​​the image obtained after two consecutive flashes. When the average gray value of the capture area obtained by the Nth light source delay value is less than the average gray value of the capture area obtained by the N-1th light source delay value, the adaptation process stops, and the N-1th light source delay value is recorded as the optimal light source delay value.

2. The stroboscopic control and camera trigger delay adaptive synchronization method of claim 1, wherein, The delay value of the light source is controlled within the range of 0~999 microseconds.

3. The stroboscopic control and camera trigger delay adaptive synchronization method of claim 1, wherein, In step S1, the step size of each change in the input delay value of the light source is 1 microsecond, ensuring a balance between accuracy and response speed.

4. The stroboscopic control and camera trigger delay adaptive synchronization method of claim 1, wherein, In step S2, the image capture area is the area corresponding to the center point of the image.

5. The method for adaptive synchronization of strobe control and camera trigger delay according to claim 1, characterized in that, The image capture area in step S2 is as follows: In image processing, the image is first divided into multiple sub-regions, then the brightness value of each sub-region is calculated, and finally the sub-region with the highest brightness value is selected as the capture area.

6. A method for adaptive synchronization of strobe control and camera trigger delay according to any one of claims 4 or 5, characterized in that, The size of the capture area is one-tenth of the number of pixels.

7. A method for adaptive synchronization of strobe control and camera trigger delay according to any one of claims 4 or 5, characterized in that, The capture area can be rectangular, circular, or polygonal.

8. The method for adaptive synchronization of strobe control and camera trigger delay according to claim 1, characterized in that, The average grayscale value comparison process in step S3 is executed in real time after each strobe trigger to ensure that changes in ambient light or shifts in the target object's position do not affect the synchronization accuracy. At the same time, the system automatically records the grayscale data for subsequent analysis and optimization.

9. A strobe control and camera trigger delay adaptive synchronization control device, characterized in that, The method for adaptive synchronization of strobe control and camera trigger delay according to any one of claims 1-8 includes: The communication module is used to realize the dynamic adjustment and feedback control of the light source delay parameters; The processing module is connected to the communication module and is used to perform logic for recognizing the image capture area, calculating the average gray value, and adaptively adjusting the light source delay value. The storage module is used to save the grayscale data and delay parameters corresponding to each strobe flash; The output control module is used to generate stable trigger commands based on the optimal light source delay value, ensuring precise synchronization between the camera and the stroboscopic light source.

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