JP2019215225A - Image inspection system and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for supporting the cause identification when a defect occurs in a system for acquiring a plurality of inspection images while changing a position of a viewpoint with respect to an inspection object. An image inspection system (1) controls an image capturing unit (10), a moving unit (11) for changing a position of a viewpoint of the image capturing unit with respect to an inspection object (W), and a moving unit and an image capturing unit, so that a plurality of image capturing timings are obtained. Control means for acquiring a plurality of inspection images from the viewpoint and inspection means for executing an inspection of an inspection object using the plurality of inspection images. The control unit acquires the plurality of recording images at the respective viewpoints of the plurality of recording timings by performing the control of performing the image capturing by the image capturing unit at the plurality of recording timings that are different from any of the plurality of capturing timings. [Selection diagram] Figure 1

Description

  The present invention relates to an image inspection system, and more particularly to an image inspection system that performs imaging while relatively moving an imaging device and an inspection target.

  2. Description of the Related Art In FA (Factory Automation), a system in which an object to be inspected is imaged and various measurements and inspections are performed using the obtained image is widely used. In this specification, this type of system is generically called an "image inspection system".

  Patent Literature 1 discloses a system in which a camera and an illuminating device are attached to the end of a robot arm, the camera is moved by the robot, and a workpiece can be photographed from a plurality of viewpoints. Patent Literature 1 also discloses an example of a system in which a camera and a lighting device are fixed to a wall, and a work is moved by a robot so that the work can be photographed from a plurality of viewpoints.

JP 2007-248241 A

  When an unintended failure occurs in the inspection of the production line (for example, NG determination frequently occurs), the person in charge of the line first determines whether the cause of the failure is on the production side or on the inspection side. In this case, a problem in the production process is searched for, and in the latter case, the cause is investigated around the inspection device. At this time, in the case of a system in which inspection is performed at a plurality of locations while moving the camera and the work relative to each other as in Patent Document 1, the system is freer than an inspection apparatus of a type in which the positional relationship between the camera and the work is fixed. Because of the high degree, it is expected that it will be difficult to determine the cause of the malfunction. For example, when a camera or a workpiece is moved by a robot, the viewpoint (field of view) of the camera may be deviated from a desired position for some reason. The environment may change, or light may be specularly reflected on the work surface, causing halation. Alternatively, the program may have a bug, and the robot may not have performed the intended operation. However, in the conventional system, since it is not possible to later confirm what kind of movement the camera or the work has made, it has been difficult to identify the cause of the problem.

  The present invention has been made in view of the above circumstances, and provides a technique for supporting identification of a cause when a failure occurs in a system for acquiring a plurality of inspection images while changing the position of a viewpoint with respect to an inspection object. The purpose is to do.

According to a first aspect of the present invention, there is provided an imaging unit for photographing an inspection target, and a position of a viewpoint of the imaging unit with respect to the inspection target by moving at least one of the inspection target and the imaging unit. Storage means for storing control information for defining a moving means for changing the position, a movement route of the viewpoint with respect to the inspection object, and a plurality of imaging timings at which imaging of the inspection object is performed on the movement route. Means for controlling the moving means and the imaging means in accordance with the control information, thereby obtaining a plurality of inspection images at respective viewpoints of the plurality of photographing timings, and using the plurality of inspection images. Inspection means for performing an inspection of the inspection object by the inspection means, wherein the control means An image characterized by acquiring a plurality of recording images at respective viewpoints of the plurality of recording timings by performing control of performing photographing by the imaging means at a plurality of recording timings different from any of the timings of the recording. Provide an inspection system.

  According to this configuration, shooting is performed at a timing different from the shooting timing of the inspection image, and a plurality of recording images different from the inspection image are obtained. If the image for inspection is photographed at n places and the image for recording is photographed at m places, the image at the viewpoint of (n + m) places is finally obtained. Therefore, by verifying these images, it is possible to confirm changes in the visual field during the inspection process and to confirm whether the environment such as lighting was appropriate, and to easily identify the cause of the defect. Can be expected.

  The present invention may employ any of a configuration in which the inspection object is fixed and the imaging unit is moved, a configuration in which the imaging unit is fixed and the inspection object is moved, and a configuration in which both the inspection object and the imaging unit are moved. Good. An “inspection image” is an image acquired for use in inspection of an inspection object by an inspection unit. On the other hand, the “recording image” is an image obtained solely for verifying the recording and operation of the viewpoint and the visual field, and is not used for inspection by the inspection unit.

  Recording timing determining means for determining the plurality of recording timings so that one or more recording timings are arranged between the photographing timings of the inspection image based on the control information; The means may acquire the plurality of recording images in accordance with the plurality of recording timings determined by the recording timing determining means. By arranging the recording timing between the photographing timings of the inspection image as described above, it is possible to achieve both the photographing of the inspection image and the photographing of the recording image.

  The recording timing determining means may arrange one or more recording timings at a point that equally divides the time between two adjacent photographing timings on a time axis. Thereby, unbiased data logging (recording of the visual field) can be performed for a period between two photographing timings.

  The recording timing determining unit, when an inspection image is acquired at a certain imaging timing, equally divides a time obtained by subtracting a predetermined margin from a time difference between the imaging timing and the next scheduled imaging timing. One or more of the recording timings may be arranged at a point. Since the recording timing is determined based on the actual shooting timing, an image at a more accurate position (field of view) can be obtained.

  The recording timing determining unit may arrange the recording timing such that a time interval between the photographing timing and the recording timing is longer than a time required for acquiring the inspection image by the imaging unit. Good. By satisfying such a constraint, it is possible to acquire a recording image without obstructing acquisition of an inspection image.

  The recording image may be an image having a smaller data size than the inspection image. By reducing the data size, it is possible to reduce the data capacity for storing the recording image.

  The recording image may be an image that requires less time to acquire an image by the imaging unit than the inspection image. This is because, by shortening the capturing time of the recording image, it is easy to satisfy the constraint that the acquisition of the inspection image is not hindered, and the degree of freedom in determining the recording timing of the recording image increases.

  An output unit that displays the plurality of inspection images and the plurality of recording images in chronological order may be provided. As a result, it can be expected that abnormalities in the visual field, changes in the illumination environment, and the like can be easily found, as compared to observing a plurality of images separately.

  The output unit temporally associates the control sequence diagram showing the control of the viewpoint, the imaging timing, and the recording timing on a time axis with the plurality of inspection images and the plurality of recording images. It may be attached and displayed. Thus, it can be expected that abnormalities in the visual field, changes in the lighting environment, and the like can be easily found.

  The output unit may display a first image, which is an image of the inspection object, and a second image, which is an image of a field of view expected at the time of capturing the first image, in a comparable manner. Thus, it can be expected that abnormalities in the visual field, changes in the lighting environment, and the like can be easily found.

  The output unit may notify when a difference between the first image and the second image satisfies a predetermined condition. Thus, it can be expected that abnormalities in the visual field, changes in the lighting environment, and the like can be easily found.

  ADVANTAGE OF THE INVENTION According to this invention, in the system which acquires a some test image while changing the position of the viewpoint with respect to a test object, it can support identification of the cause at the time of a malfunction.

FIG. 1 is a diagram showing an application example of the present invention. FIG. 2 is a diagram illustrating a configuration example of the image inspection system according to the embodiment of the present invention. FIG. 3 is a block diagram illustrating an example of a configuration of the control device. FIG. 4 is a flowchart illustrating an example of the flow of a work inspection process performed by the image inspection system. FIG. 5 is a diagram illustrating an example of a method for determining a recording timing. FIG. 6 is a diagram illustrating an example of a captured image. FIG. 7 is a diagram illustrating an example of a captured image. FIG. 8 is a diagram illustrating an example of a captured image. FIG. 9 is a flowchart illustrating an example of the flow of a work inspection process performed by the image inspection system. FIG. 10 is an example of set values of the photographing timing. FIG. 11 is a diagram illustrating an example of a method for determining a recording timing. 12A to 12C are diagrams illustrating another configuration example of the image inspection system.

<Application example>
FIG. 1 schematically shows one application example of the present invention. The image inspection system 1 illustrated in FIG. 1 is a system that inspects a workpiece W using an image obtained by photographing an inspection site of the workpiece (inspection target) W with a camera (imaging unit) 10. “Inspection” is a process of examining or recognizing the physical state of the work W. For example, detection of abnormalities (scratch, dirt, etc.), determination of good / bad (pass / fail), quality (excellent / good) / Possible / defective) is a typical process, but other than these, two-dimensional or three-dimensional shape measurement, shape recognition, edge detection, number measurement, length measurement, area Measurement, color feature acquisition, labeling, segmentation, object recognition, barcode and two-dimensional code reading, OCR, individual identification, and the like. Such an image inspection system 1 is used, for example, for product inspection and quality control in a production line.

The image inspection system 1 can change the position of the viewpoint of the camera 10 with respect to the work W by moving one or both of the camera 10 and the work W by the robot (moving unit) 11. At the time of inspection, images are captured at a plurality of shooting timings while moving the viewpoint of the camera 10 along a preset movement route R, and these images are stored in a memory or storage as inspection images for use in inspection. The image is stored (FIG. 1 shows an example in which three inspection images are acquired at three imaging timings T _{1 to} T ₃ ). In addition, the image inspection system 1 captures an image from the camera 10 at a timing different from any of the imaging timings of the inspection image (that is, between the imaging timings), and stores these images as a recording image in a memory or storage. To save.

  The recording timing of the recording image is set to a timing that does not hinder imaging of the inspection image (processing such as exposure and reading of data). Here, for example, the recording timing may be arranged at a point where the time between two temporally adjacent shooting timings is equally divided in time. Preferably, when all shooting timings and all recording timings are arranged in chronological order, the recording timings are arranged such that their time intervals are as constant as possible (that is, equal intervals). Is also good.

According to the above configuration, a timing different from the photographing timing of the test image, i.e., as shown in FIG. 1, the point of view of the camera 10 is moved from the photographing timing T ₁ to the next imaging timing T ₂ At the time points T ₁₀ , T ₁₁ , and T ₁₂ during the movement, and at the time points T ₂₀ and T ₂₁ during the movement of the viewpoint of the camera 10 from the photographing time T ₂ to the next photographing time T ₃ , the camera 10 The field of view is recorded. In the example of FIG. 1, since the inspection image is photographed at three places and the recording image is photographed at five places, images at eight viewpoints of 3 + 5 are finally obtained. Therefore, if any defect is found after the inspection, it is possible to verify the images at eight locations on the movement route R, so that changes in the visual field during the inspection process can be confirmed, and the environment such as lighting is appropriate. Can be confirmed, and it can be expected that the cause of the defect can be easily identified.

<System configuration>
FIG. 2 shows a configuration example of the image inspection system 1 according to the embodiment of the present invention. The image inspection system 1 includes a camera 10, a robot 11, an image processing device 12, and a control device 13.

  The camera 10 is a device that captures an image of a work W to be inspected and obtains image data, and includes an optical system such as a lens and an image sensor such as a CCD or a CMOS. If necessary, the camera 10 may be provided with an autofocus mechanism, a pan / tilt / zoom mechanism, a lighting device, and the like. The image captured from the camera 10 may be a monochrome image (grayscale image) or a color image. Further, a special image such as an infrared image may be taken by using illumination other than visible light such as infrared light as the lighting device.

  The robot 11 is, for example, a 6-axis or 7-axis vertical articulated robot. The camera 10 is fixed to the tip of the arm. A motor, an encoder, and a speed reducer (all not shown) are built in the joint portion of the arm. The viewpoint of the camera 10 with respect to the workpiece W can be moved to an arbitrary position by driving the motor of each joint by the control device 13 to move the arm up and down, left and right, expand and contract, and rotate.

The image processing device 12 is a device that performs inspection by image processing using an image of the work W (image for inspection) captured by the camera 10. The image processing device 12 includes, for example, a computer having a processor (CPU), a memory, a storage, a communication module, and an I / O, a display device such as a liquid crystal display, and an input device such as a mouse and a touch panel. Various programs are stored in a storage, and when the image inspection system 1 is operating, necessary programs are loaded into a memory and executed by a processor, so that the processing and functions of the image processing apparatus 12 are provided. Note that at least a part of the processing and functions of the image processing apparatus 12 may be configured by a circuit such as an ASIC or an FPGA, or may be configured by distributed computing or cloud computing.

  The control device 13 is a device that controls the camera 10, the robot 11, and the image processing device 12. The control device 13 includes, for example, a computer having a processor (CPU; control means), a memory, a storage, a communication module, and an I / O, a display device such as a liquid crystal display, and an input device such as a mouse and a touch panel. I have. Various programs are stored in a storage, and when the image inspection system 1 is operating, necessary programs are loaded into a memory and executed by a processor, so that the processing and functions of the control device 13 are provided. The control device 13 may be constituted by a PLC (programmable logic controller) or may be constituted by a general-purpose computer. Note that at least a part of the processing and functions of the control device 13 may be configured by a circuit such as an ASIC or an FPGA, or may be configured by distributed computing or cloud computing. Further, the image processing device 12 and the control device 13 may be configured by one computer.

  FIG. 3 is a block diagram illustrating an example of a configuration of the control device 13. The control device 13 includes a camera control unit 130, a robot control unit 131, a control information storage unit 132, an image acquisition unit 133, an image storage unit 134, a recording timing determination unit 135, and an output unit 136. In the control device 13 of the present embodiment, the camera control unit 130, the robot control unit 131, the image acquisition unit 133, the recording timing determination unit 135, and the output unit 136 are provided by a processor (control unit) executing a program. The control information storage unit 132 and the image storage unit 134 are provided by a non-volatile memory or storage.

  The control information storage unit 132 is a storage unit that stores control information for defining operations of the camera 10 and the robot 11. The control information includes, for example, setting of a shooting timing of an inspection image, a motion program of the robot 11, and the like. These pieces of information are created using, for example, a teaching device, and are registered in the control device 13 in advance (before the start of the inspection process). The camera control unit 130 performs a process of controlling imaging by the camera 10 based on the control information. Further, the robot controller 131 controls the arm of the robot 11 based on the control information, and performs a process of moving the viewpoint of the camera 10 along a predetermined movement route.

  The image acquisition unit 133 performs a process of acquiring data of an image captured by the camera 10 via the image processing device 12. The acquired image data is stored in the image storage unit 134. The recording timing determination unit 135 performs a process of determining the recording timing of a recording image. Regarding the recording timing of the recording image, all recording timings may be determined before the start of the inspection process, or during the execution of the inspection process (for example, in accordance with the timing at which the inspection image was actually captured). T) The recording timing may be determined dynamically. The output unit 136 performs a process of displaying the control sequence diagram, the inspection image, and the recording image in temporal association with each other.

<Inspection processing>
FIG. 4 is a flowchart illustrating an example of the flow of the inspection processing of the work W by the image inspection system 1.

First, in step S40, the recording timing determination unit 135 determines the recording timing of the recording image based on the control information. In the present embodiment, the recording timing of the recording image is determined so that one or more recording images are captured at points that equally divide the time between the imaging timings of the inspection image.

For example, as shown in FIG. 5, when an imaging timing T _i (i = 1,..., N−1) of an inspection image is set between an inspection start time T ₀ and an inspection end time T _{n. Indicates} that the recording timing determination unit 135 determines the recording timing T _ij ,
T _ij = T _i + (T _{i + 1} −T _i ) / m _i × j (j = 1,..., M _i −2)
Ask like.

_mi is the number of divisions of the section between _Ti and _{Ti + 1} , and is an integer of 2 or more. Division number m _i for each section may be set arbitrarily. However, the recording timing determination unit 135 determines that the time interval between the photographing timing and the recording timing temporally adjacent thereto is the time required for acquiring the inspection image by the camera 10 (for example, the time required for exposure and reading of image data). ). By satisfying such a constraint, it is possible to acquire a recording image without obstructing acquisition of an inspection image.

Here, as a photographing time interval _{(T i (j + 1)} -T ij) is as far as possible constant over the entire duration of the test may determine the division number m _i of each section. By keeping the photographing time interval constant, images can be recorded at the same frequency over the entire inspection period, so that data logging with little leakage can be realized, which is useful for searching for a location where a defect has occurred. If the photographing time interval is constant, the group of images is switched and displayed at a constant time interval like a slide show, thereby reproducing the movement of the viewpoint at the same speed (or proportional speed) as that at the time of inspection. Therefore, there is also an advantage that it is easy to grasp the correspondence between the displayed image and the position on the work W.

The information on the recording timing T _ij of the recording image determined as described above is transferred to the camera control unit 130 together with the information on the imaging timing T _i of the inspection image given as control information.

Next, in step S41, the robot control unit 131 reads control information (motion program) from the control information storage unit 132. When the inspection is started in step S42, with the robot control unit 131 starts control of the robot 11 by executing the motion program, the camera control unit 130 is the elapsed time t monitoring from the inspection start time T ₀ by the timer Start.

And the elapsed time t reaches the photographing timing _{T i} (YES in step S43), the camera control unit 130 controls the camera 10, performs photographing of the inspection image (step S44). The inspection image is subjected to necessary processing (for example, white balance adjustment, color adjustment, noise elimination, compression, etc.) in the image processing apparatus 12, and is then taken in by the image acquisition unit 133, and is used to capture a photographing time (time stamp) and a work time. The information is stored in the image storage unit 134 together with the information specifying W. Further, the image processing device 12 performs an inspection process using the inspection image (Step S45). In FIG. 4, the processes of steps S44 to S47 are described as serial processes for convenience of illustration, but the processes of the control device 13 and the processes of the image processing device 12 may be executed in parallel.

When the elapsed time t reaches the recording timing T _ij (YES in step S46), the camera control unit 130 controls the camera 10 to photograph a recording image (step S47). The recording image is subjected to necessary processing (for example, white balance adjustment, color adjustment, noise removal, compression, and the like) in the image processing device 12, and is then captured by the image acquisition unit 133, and is used to capture a shooting time (time stamp) and a work time. The information is stored in the image storage unit 134 together with the information specifying W.

  The recording image may be an image having the same specifications as the inspection image, or may be an image having specifications different from the inspection image. Since the recording image is not used for measurement or inspection, the quality is not required as high as the inspection image. Therefore, the recording image is an image having a smaller data size than the inspection image (for example, an image having a lower resolution than the inspection image, an image having a higher compression ratio than the inspection image, and an image having a smaller field of view than the inspection image). Or an image having a smaller number of channels or colors than the inspection image). By reducing the data size, there is an advantage that the data capacity for storing the recording image can be reduced. Alternatively, the recording image is an image that requires less time to acquire an image with the camera 10 than the inspection image (for example, an image having a lower resolution than the inspection image, an image having a shorter exposure time than the inspection image, or the like). ). This is because, by shortening the capturing time of the recording image, it is easy to satisfy the constraint that the acquisition of the inspection image is not hindered, and the degree of freedom in determining the recording timing of the recording image increases. In addition, the shorter the capturing time of the recording image is, the more the number of recording images can be photographed and there is an advantage that data logging with less leakage is possible.

Steps S43 to S47 are repeated while moving the viewpoint of the camera 10 by the robot 11 to acquire a plurality of inspection images and a plurality of recording images. Then, (YES in step S48) reaches the the inspection end time _{T n,} returns the robot 11 to the home position to end the inspection process.

<Verification of operation>
With reference to FIGS. 6 to 8, a description will be given of a display example of the inspection image and the recording image accumulated in the inspection processing, and a method of verifying an operation using the display image and the recording image. In the present embodiment, since both the inspection image and the recording image are used without distinction when displaying the image and verifying the operation, it is not necessary to distinguish between the inspection image and the recording image in the following description. In the context, the term “captured image” is used as a generic term for both.

  FIG. 6 shows a method of reproducing a stored captured image group like a moving image. Specifically, the output unit 136 reads the data of the captured image from the image storage unit 134 and continuously displays a plurality of captured images while switching the images as in a slide show. Thereby, the temporal change of the visual field of the camera 10 can be observed as if it were a moving image. Therefore, compared to observing a plurality of captured images separately, a visual field abnormality and a change in the lighting environment are reduced. It can be expected that it can be easily found. At this time, the output unit 136 may perform switching display of the captured image at a constant time interval (irrespective of whether the time interval when the captured image is actually captured is constant or uneven). . Alternatively, the output unit 136 refers to the time stamp linked to the captured image and performs playback control so that the image can be switched at the same speed (or proportional speed) as that at the time of inspection (when actually captured). May be.

FIG. 7 shows an example in which a control sequence diagram and a captured image are displayed in a temporally associated manner. The control sequence diagram shows the control of the viewpoint, the shooting timing of the inspection image, and the recording timing of the recording image on the time axis. In the example of FIG. 7, the elapsed time t is plotted on the horizontal axis, and the vertical axis is plotted on the vertical axis. The graphs 70 and 71 (corresponding to the time change of the viewpoint) showing the time change of the encoder value, the imaging timing T _i, and the recording timing T _ij are shown on the two-dimensional coordinates obtained by taking the encoder value of each joint of the robot 11. And drawing. In addition, a time cursor 72 that can be moved by a user operation is displayed, and a captured image 73 corresponding to the time of the time cursor 72 is also displayed. Further, at this time, an expected value image (second image) 74 may be displayed next to the captured image (first image) 73 so that the captured image 73 and the expected value image 74 can be compared and observed. The expected value image 74 is an image of a visual field expected at the photographing time of the photographed image 73 (that is, a visual field of a correct answer). For example, when the image inspection system 1 is adjusted or taught, the master work is photographed. It is good to prepare. Alternatively, the expected value image 74 by computer graphics may be generated by performing a simulation using the three-dimensional shape data of the work W. By displaying the captured image together with the control sequence diagram in this way, it can be expected that abnormalities in the visual field, changes in the illumination environment, etc. can be easily found.

  FIG. 8 shows an example in which a group of photographed images 80 and a group of expected value images 81 are displayed in chronological order while taking temporal correspondence. The horizontal axis indicates the elapsed time t. According to this display, it is possible to check the correctness of the visual field at each timing while observing the temporal change of the visual field, so that it is possible to easily find the location where the viewpoint shift has occurred. Further, the output unit 136 may compare the photographed image at the corresponding time with the expected value image, and notify when the difference between the two images satisfies a predetermined condition. For example, when the sum of the differences between the pixels of the two images is larger than a predetermined threshold, the output unit 136 determines that “there is a possibility of a viewpoint shift”, and highlights 82 as shown in FIG. The user may be alerted by outputting 83 or the like. Such a notification function can assist in finding a viewpoint shift.

  According to the configuration described above, the temporal change of the visual field during the inspection process can be recorded as an image, so that it is easy to find an abnormality in the visual field, a change in the lighting environment, and the like, and to easily identify the cause of the defect. Can be expected.

<Modification>
In the above-described embodiment, the shooting timing and the recording timing are determined based on the elapsed time from the start of the inspection process (Step S40 in FIG. 4). This method does not cause any problem if the robot 11 can realize the positioning according to the program. However, when the position error of the robot 11 cannot be ignored due to the influence of inertia or disturbance, the photographing timing and recording according to the movement of the robot 11 are performed. The timing may be dynamically adjusted.

  9 and 10 show a method of reading an encoder value of the robot 11 and determining a photographing timing and a recording timing based on the value. FIG. 9 is a flowchart showing the flow of the inspection process, and FIG. 10 shows the setting values of the imaging timing registered in the control information storage unit 132. The difference from the above-described embodiment is that the imaging timing is defined not by the elapsed time from the start of the inspection processing but by the position of the viewpoint of the camera 10 (specifically, the encoder value of each joint of the robot 11). It is. Note that a scheduled time of each photographing timing (a time corresponding to the photographing timing when the robot 11 operates ideally) is also set as a reference value because it is necessary for calculating the recording timing.

  In step S90, the robot control unit 131 reads control information (motion program) from the control information storage unit 132. In step S91, the camera control unit 130 reads control information (a set value of a shooting timing) from the control information storage unit 132. When the inspection starts in step S92, the robot control unit 131 executes a motion program to start controlling the robot 11, and the camera control unit 130 starts monitoring encoder values of each axis of the robot 11.

If the encoder value becomes equal to the set value of the photographing timing _{T i} (YES in step S93), the camera control unit 130 controls the camera 10, performs photographing of the inspection image (step S94). Further, the image processing device 12 executes an inspection process using the inspection image (step S95).

In step S96, the recording timing determination unit 135 performs shooting between the current shooting timing and the next shooting timing based on the time at which the shooting in step S93 was performed and the control information (scheduled time for the next shooting timing). The recording timing of the recording image is calculated. Here, as shown in FIG. 11, the time difference between the actual time of the present photographing timing T ₁ until the scheduled time of the next shooting timing T _2, so as to equal the time obtained by subtracting a predetermined margin, 1 One or more recording timings are arranged. The margin is provided in consideration of the possibility that the next shooting timing may deviate from the scheduled time for some reason. The width of the margin may be set to, for example, about several percent of the time interval between the current shooting timing and the next shooting timing.

  When the elapsed time from the photographing time in step S93 reaches the recording timing determined in step S96 (YES in step S97), the camera control unit 130 controls the camera 10 to photograph a recording image (step S98). The subsequent processing is the same as the processing of the above-described embodiment.

  According to the method described above, by determining the shooting timing of the inspection image and the recording timing of the recording image based on the encoder value, it is possible to more precisely match the field of view of the image than the method of the above-described embodiment. .

<Others>
The above embodiment is merely illustrative of the configuration of the present invention. The present invention is not limited to the specific form described above, and various modifications are possible within the scope of the technical idea. For example, in the above embodiment, the recording timing is determined so that the time interval between the captured images is as constant as possible, but the time interval between the captured images may be non-uniform. In the above embodiment, the image data is stored in the control device 13. However, the image data may be stored in the image processing device 12, or may be stored in an external device or a cloud server. Further, in the above-described embodiment, the work W is fixed and the camera 10 is moved. However, the work W may be moved, or both the work W and the camera 10 may be moved. FIGS. 12A to 12C show other configuration examples relating to the relative movement between the workpiece W and the camera 10. FIG. 12A shows a configuration in which the workpiece W is fixed and the camera 10 is moved, and is an example in which a 4-axis (x, y, θ1, θ2) orthogonal robot is used instead of the vertical articulated robot. FIG. 12B shows a configuration in which the camera 10 is fixed and the workpiece W is moved by the vertical articulated robot 11 having six axes (x, y, z, θ1, θ2, θ3). FIG. 12C is an example in which both the work W and the camera 10 are moved. That is, the direction of the work W can be changed by installing the work W on the rotary table 120 of one axis (θ3), and the camera 10 is controlled by the robot 11 of five axes (x, y, z, θ1, θ2). Can change the posture. The configuration illustrated in FIG. 2 and FIGS. 12A to 12C is merely an example, and any configuration may be adopted as long as one or both of the workpiece W and the camera 10 can be moved. 6 to 8 are merely examples of display, and display items and display methods may be appropriately designed.

<Appendix>
(1) imaging means (10) for photographing the inspection object (W);
Moving means (11) for changing at least one of the inspection object (W) and the imaging means (10) to change the position of the viewpoint of the imaging means (10) with respect to the inspection object (W). When,
Storage means for storing control information for defining a movement route of the viewpoint with respect to the inspection object (W) and a plurality of imaging timings at which imaging of the inspection object (W) is performed on the movement route. (132),
A control unit (130, 131) for controlling the moving unit (11) and the imaging unit (10) according to the control information to obtain a plurality of inspection images at respective viewpoints of the plurality of imaging timings;
Inspection means (12) for inspecting the inspection object (W) using the plurality of inspection images,
The control means (130, 131) performs control to execute shooting by the imaging means (10) at a plurality of recording timings which are different from any of the plurality of shooting timings on the movement route. An image inspection system (1), which acquires a plurality of recording images at respective viewpoints at a plurality of recording timings.

1: Image inspection system 10: Camera 11: Robot 12: Image processing device 13: Control device 130: Camera control unit 131: Robot control unit 132: Control information storage unit 133: Image acquisition unit 134: Image storage unit 135: Recording timing Decision unit 136: output unit W: work

Claims (13)

Imaging means for photographing the inspection object;
A moving unit that changes a position of a viewpoint of the imaging unit with respect to the inspection target by moving at least one of the inspection target and the imaging unit;
A storage unit that stores control information for defining a movement route of the viewpoint with respect to the inspection object, and a plurality of imaging timings at which imaging of the inspection object is performed on the movement route,
A control unit configured to control the moving unit and the imaging unit according to the control information to obtain a plurality of inspection images at respective viewpoints of the plurality of imaging timings;
Inspection means for performing inspection of the inspection object using the plurality of inspection images,
The control unit performs control to execute shooting by the imaging unit at a plurality of recording timings that are different from any of the plurality of imaging timings on the movement route, so that each of the plurality of recording timings has a viewpoint. An image inspection system for acquiring a plurality of recording images. Based on the control information, so that one or more of the recording timing is arranged between the shooting timing of the inspection image, the recording timing determining means for determining the plurality of recording timing,
2. The image inspection system according to claim 1, wherein the control unit acquires the plurality of recording images in accordance with the plurality of recording timings determined by the recording timing determining unit. 3. The recording timing deciding unit according to claim 2, wherein the recording timing deciding unit arranges one or more recording timings at a point at which a time between two adjacent photographing timings on a time axis is equally divided. Image inspection system. The recording timing determining unit, when an inspection image is acquired at a certain imaging timing, equally divides a time obtained by subtracting a predetermined margin from a time difference between the imaging timing and the next scheduled imaging timing. The image inspection system according to claim 2, wherein one or more recording timings are arranged at points. The recording timing determination unit may arrange the recording timing such that a time interval between the imaging timing and the recording timing is longer than a time required for acquiring the inspection image by the imaging unit. The image inspection system according to any one of claims 2 to 4, wherein: The image inspection system according to claim 1, wherein the recording image is an image having a smaller data size than the inspection image. The image inspection system according to any one of claims 1 to 6, wherein the recording image is an image that requires a shorter time to acquire an image by the imaging unit than the inspection image. .   The image inspection system according to claim 1, further comprising an output unit configured to display the plurality of inspection images and the plurality of recording images in chronological order. The output unit temporally associates the control sequence diagram showing the control of the viewpoint, the imaging timing, and the recording timing on a time axis with the plurality of inspection images and the plurality of recording images. The image inspection system according to claim 8, wherein the image inspection system is attached and displayed. The output unit displays a first image, which is an image of the inspection object, and a second image, which is an image of a field of view expected at the time of capturing the first image, in a comparable manner. The image inspection system according to claim 8. The image inspection system according to claim 10, wherein the output unit notifies when a difference between the first image and the second image satisfies a predetermined condition. Imaging means for photographing the inspection object;
A moving unit that changes a position of a viewpoint of the imaging unit with respect to the inspection target by moving at least one of the inspection target and the imaging unit;
A storage unit configured to store control information for defining a movement route of the viewpoint with respect to the inspection object and a plurality of imaging timings at which imaging of the inspection object is performed on the movement route. A method of controlling a system,
By controlling the moving unit and the imaging unit according to the control information, a plurality of inspection images are obtained at the viewpoints of the plurality of imaging timings, and any of the plurality of imaging timings on the movement route is obtained. Obtaining a plurality of recording images at respective viewpoints of the plurality of recording timings by performing control of performing photographing by the imaging unit at a plurality of recording timings that are different timings;
Performing an inspection of the inspection object using the plurality of inspection images,
A control method for an image inspection system, comprising:   A program for causing a processor of the image inspection system to execute each step of the method for controlling the image inspection system according to claim 12.

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