X-ray inspection system and calibration method thereof

Abstract

To provide an X-ray inspection system and a calibration method of the same which enable the fingertip of a robot to accurately follow a work object being conveyed.SOLUTION: An X-ray inspection system comprises: an X-ray inspection device 10; a robot 30 that, upon receiving a trigger signal, performs prescribed work within a prescribed operation area Arw; and a control device 20 connected in a communicable manner with the X-ray inspection device 10 and the robot 30. The X-ray inspection system is configured to: when there is a specific area with a prescribed inspection result in a sequential X-ray image Xi, communication-output to the control device 20 inspection information including at least area positional information of the area; and causes the control device 20 to communication-output, to the robot 30, prescribed work execution position information as a trigger signal, to output, to the robot 30, a signal according to a conveyance movement amount in a period from at least the trigger signal output until when a work target inspection object reaches a prescribed work position within the operation area Arw, so that, after subjected to teaching on the prescribed work position, the robot 30 executes prescribed work.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an X-ray inspection system and a calibration method thereof, and more particularly to an X-ray inspection system including an X-ray inspection device that sequentially X-ray inspects articles being transported on a conveyor and a robot that performs a predetermined task while following the article transport in accordance with the inspection results, and a calibration method thereof. [Background technology]

[0002] In X-ray inspection systems that inspect transported items sequentially, when defective items are removed from the transport path using a sorting machine or the like, the items are often detected by an item detection sensor during transport, and the detection signal is used as a trigger to set the timing for removing the workpieces.

[0003] However, when multiple relatively small items are transported in a scattered state without being aligned (hereinafter referred to as bulk transport), it is not easy to identify defective items by item detection, so a method has been known in which item inspection is performed in units of specified areas on the transport path, and the items to be inspected are selectively removed from the system from the transport path at intervals of a certain transport distance corresponding to that inspection area, depending on whether or not there are defective items.However, when removing defective items, some good items are also removed from the system, which results in poor product yield.

[0004] Therefore, recently, conveyor tracking systems that use robots to follow the transport of goods and remove defective products have become widely used, and vision tracking systems that use industrial television cameras as visual sensors are particularly effective for pinpoint removal.

[0005] In such a tracking system, in addition to calibrating each camera to enable accurate determination of the position, orientation, etc. of the object being imaged from the camera image, calibration is also performed to convert the coordinate values ​​of the camera image obtained from the camera and its image processing device into coordinate values ​​in the robot coordinate system for vision tracking.

[0006] In other words, when conveyor tracking is employed using a robot equipped with a camera, an adjustment called calibration is performed to allow coordinate tracking in the conveying direction. The coordinate values ​​of the camera's field of view image, which becomes the image signal (for example, the origin signal), are converted into coordinate values ​​in the robot coordinate system and input to the robot, and movement in the conveying direction is synchronized with an encoder, enabling linked operation.

[0007] A known calibration method for this type of vision tracking involves, for example, using a first camera whose field of view is the tip of the robot arm, second and third cameras whose field of view covers the workpiece within a predetermined transport section on the conveyor but not the tip of the robot arm, and a calibration workpiece having three holes (referred to here as holes h1, h2, and h3 for convenience) with varying spacing between adjacent holes; the calibration workpiece is positioned so that holes h1 and h2 are within the field of view of the first camera and hole h3 is within the field of view of the second camera; the camera coordinate values ​​of holes h1, h2, and h3 are determined; the robot coordinate values ​​of holes h1 and h2 are determined using a predetermined conversion formula based on the idea that the conversion from camera coordinate values ​​to robot coordinate values ​​is a combination of parallel translation and rotation; the robot coordinate value of h3 is determined from the positional relationship between holes h1, h2, and h3 and the robot coordinate values ​​of holes h1 and h2; and the calibration workpiece is slightly shifted and similar calculations are performed to calibrate the second camera (see Patent Document 1).

[0008] Also known is a system that starts visual recognition processing when a mark plate with a scale enters the visual recognition range, measures the amount of movement due to conveyor transport in accordance with the timing of image capture, and, when the mark plate is at a first position within the robot's operating range, acquires the coordinates of a predetermined scale position on the mark plate that is in contact with the pin using a robot holding a pin that serves as a pointer in its hand, and, when the mark plate is at a second position within the robot's operating range, calculates the coordinate transformation parameters Q, R, and S based on the movement distance (ΔConv) from the first position and the amount of change in each coordinate component (x, y, z) of the scale position that has been similarly read (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 62-214403 [Patent Document 2] Japanese Patent Application Publication No. 6-238584 Summary of the Invention [Problem to be solved by the invention]

[0010] However, when the above-mentioned conveyor tracking is applied to an X-ray inspection system and configured as an X-ray inspection system equipped with an X-ray inspection device with a coordinate output function and a robot with a conveyor tracking function, it is sometimes not possible to align the coordinates of the X-ray image based on each item so that they correspond to the coordinate system of the robot, and therefore the coordinates of the X-ray image cannot be effectively used for conveyor tracking.

[0011] Specifically, in an X-ray inspection device, an X-ray line sensor typically repeatedly acquires X-ray line images at short intervals, and X-ray line image data for a predetermined number of lines is stored in an image memory as the object to be inspected is transported on a conveyor, thereby periodically acquiring X-ray images of a predetermined image size (hereinafter also referred to as sequential X-ray images). Therefore, if the object to be inspected is a product with a fixed shape and is transported in an aligned manner at intervals, the detection signal from the object detection sensor is used as a trigger to acquire sequential X-ray images synchronized with the transport of the object, and the X-ray inspection image of the object, with the tip of the robot arm aligned with the reference position based on the object, can be input to the robot and used for conveyor tracking.

[0012] However, when multiple relatively small items are conveyed in a loose manner without being aligned, it is difficult to identify defective items through item detection. For example, in loose or parallel inspections, where the items to be inspected may be conveyed overlapping each other when viewed across the conveyor's width (the direction perpendicular to the conveyance direction), it is not possible to align each item based on that item. While it is possible to create coordinates for defective items based on sequential X-ray images and align them, it is not possible to synchronize the origin on the X-ray image with the origin of the robot arm's hand, which can result in misalignment between the coordinates on the X-ray image and the coordinates used in vision tracking.

[0013] Therefore, even though the system is configured with an X-ray inspection device that can output X-ray image data that allows for precise coordinate acquisition, it is not possible to acquire X-ray images that are suitable for performing quick and accurate tracking and exclusion operations, and there was an unresolved issue in that X-ray images could not be effectively used in place of images captured by a vision camera.

[0014] Therefore, the present invention aims to provide an X-ray inspection system using an X-ray vision tracking method that performs vision tracking using X-ray images, allowing the robot's hands to accurately track the work object being transported regardless of the item transport form, and a calibration method for the system. [Means for solving the problem]

[0015] To achieve the above object, the X-ray inspection system according to the present invention comprises: (1) an X-ray inspection device that irradiates an inspection object transported by a transport means operating under predetermined transport conditions with X-rays and inspects the inspection object based on an X-ray image obtained by processing detected X-ray transmission data; a robot that receives a trigger signal and performs a predetermined task on the inspection object within a predetermined operating area based on information included in the trigger signal; and a control device that is communicably connected to the X-ray inspection device and the robot, wherein the X-ray inspection device processes the X-ray transmission data detected within a predetermined cycle to generate sequential X-ray images, and when a specific area that is determined to be a specific inspection result is found in the sequential X-ray images, generates at least an area indicating the position of the specific area. The control device is configured to communicate and output inspection information including area position information to the control device, and the control device has a position information output means for communicating and outputting work position information including information indicating the position at which the specified work should be performed to the robot as the trigger signal based on the inspection information, and a transport signal output means for outputting a transport signal to the robot in accordance with the transport movement amount of the inspected object transported by the transport means at least from the time the trigger signal is output until the inspected object at which the robot is to perform the specified work reaches the specified work position within the operating area, and the robot performs the specified work after being instructed of the specified work position corresponding to the area position information.

[0016] With this configuration, in the present invention, the control device acquires inspection information from the X-ray inspection device, including area position information indicating the position of a specific area in sequential X-ray images corresponding to an object to be inspected with a predetermined inspection result, and outputs work position information including information indicating the position where a predetermined task should be performed to the robot based on the inspection information as a trigger signal, and outputs a transport movement amount until the object to be inspected, where the robot is to perform the predetermined task, reaches the predetermined work position within the operating area after outputting the trigger signal, thereby controlling the robot. ToThe system is configured to perform a predetermined task, and as a preliminary task, the robot is instructed to provide coordinates of the task position corresponding to the area position information. When the instructed robot receives a trigger signal, it executes the predetermined task based on the task position information corresponding to the area position information of the work object (the object to be inspected) contained in the trigger signal and the transport movement amount. This enables the position information of the work object to be aligned with the robot's coordinate system, allowing the position information output from the X-ray inspection device to be effectively utilized for vision tracking. Furthermore, by setting an X-ray inspection image size appropriate for the size of the object to be inspected and the robot's operational capabilities for that object, an X-ray image of the object suitable for tracking can be obtained regardless of the transport form of the object, resulting in an X-ray inspection system that can accurately track the coordinates of the work object.

[0017] In a preferred embodiment of the present invention, (2) the position information output means may be configured to output the trigger signal when receiving inspection information including the predetermined inspection result from the inspection information output by the X-ray inspection device, and not output the trigger signal when receiving inspection information not including the predetermined inspection result. In this way, for example, when the inspection is a pass / fail inspection, it is possible to avoid outputting unnecessary signals for the overwhelming majority of pass / fail products.

[0018] In a preferred embodiment of the present invention, (3) the position information output means may be configured to output the trigger signal each time it receives the inspection information including the predetermined inspection result. In this way, each time an object to be inspected is produced, the robot can be made to perform an operation in response to the trigger signal, such as pinpointing and removing a defective object.

[0019] In a preferred embodiment of the present invention, (4) the position information output means may be configured to sequentially store the inspection information including the predetermined inspection results, and read and communicate the inspection information at predetermined timings. In this way, the inspection information can be communicated and output to the robot in a timely manner according to the timing at which the robot is required to perform a task.

[0020] In a preferred embodiment of the present invention, (5) the control device can be configured to execute a teaching mode for teaching the robot a correspondence relationship between the area position information and the predetermined work position, and the robot can store the correspondence relationship. In this case, the correspondence relationship between the area position information and the predetermined work position is taught to the robot in the teaching mode, so that the robot can accurately store the correspondence relationship.

[0021] In a preferred embodiment of the present invention, (6) the control device can be configured to, in the teaching mode, stop transport of the inspection object at a first stop position when receiving the inspection information from the X-ray inspection device, resume transport of the inspection object when communicating and outputting the trigger signal to the robot, stop transport of the inspection object again at a second stop position where the inspection object is included in the operating area of ​​the robot, and then teach the robot the correspondence. In this way, teaching can be performed at the first stop position to convert position information of a specific area resulting in a predetermined inspection result on the X-ray inspection device side into transport position information on the robot side, and the amount of transport movement from the stop position after the teaching to the second stop position can be accurately grasped, and the robot side can be accurately taught a work position where a predetermined work should be performed.

[0022] In a preferred embodiment of the present invention, (7) the control device may be configured to increment the conveying means by a predetermined time each time a predetermined operation input is received, and to convey the inspection object from the first stop position to the second stop position by receiving the operation input multiple times. In this case, the operator can easily and effectively grasp the conveying movement amount from the first stop position to the second stop position based on the number of increments. Note that the conveying signal output means for transmitting the conveying movement distance and direction to the robot may include means for outputting the operation amount or control signal (motor rotation speed, operation pulse signal, etc.) of the conveyor drive source to calculate the conveying movement amount, or means for simply calculating the conveying movement amount from a set belt speed value and elapsed time and outputting the result as a conveying signal may be provided.

[0023] In a preferred embodiment of the present invention, (8) the control device may further include a display means for legibly displaying coordinate data based on the area position information when the object to be inspected is stopped at the second stop position. In this case, when an operator instructs the robot to the coordinates of a work position, the coordinate data is legibly displayed, allowing the operator to accurately grasp the taught position.

[0024] In a preferred embodiment of the present invention, (9) the control device may be configured to display symbols representing positions of the coordinate data on the display means in two-dimensional coordinates, directly or indirectly corresponding to the coordinate data. In this case, multiple teaching positions and their arrangements can be easily recognized from the displayed symbols, improving workability.

[0025] In a preferred embodiment of the present invention, (10) the control device may further comprise a coordinate setting means for receiving input of the coordinate data in order to teach the robot the correspondence, and may be configured to output the coordinate data to the robot via communication. In this case, the work position information whose coordinates have been set on the control device side is transferred from the coordinate setting means to the robot, thereby enabling quick and accurate teaching work on the robot side.

[0026] In a preferred embodiment of the present invention, (11) the control device may be configured to communicate and output coordinate data based on the area position information to the robot when the object to be inspected is stopped at the second stop position, thereby making it possible to easily teach the robot by operating the robot.

[0027] In order to achieve the above-mentioned object, the calibration method for the X-ray inspection system of the present invention is (12) a calibration method implemented using an X-ray inspection system having the configuration of (5) above, in which in the X-ray inspection system of the present invention, the control device is capable of executing a teaching mode for teaching the robot the correspondence between the area position information and the specified work position, and the robot is capable of storing the correspondence, characterized in that the control device is set to the teaching mode, the X-ray inspection device transports the object to be inspected having a plurality of teaching bodies attached thereto for generating the specific area that will be the specified inspection result, and the robot is taught the correspondence.

[0028] With this configuration, the calibration method of the present invention transports an object to be inspected, to which multiple teaching objects are attached for generating specific areas that will be determined as predetermined inspection results by an X-ray inspection device, and teaches the robot the correspondence between area position information indicating the position of the specific area and the predetermined work position where the robot will perform the work. As a result, when a specific area that is determined as the predetermined inspection result is found in an X-ray image obtained during X-ray inspection, it becomes possible to align the specific area with the robot's coordinate system from the area position information indicating the position of the specific area, and regardless of the transport form of the object to be inspected, an X-ray image of the work object that is suitable for tracking can be obtained, allowing the robot's hand to accurately track the work object.

[0029] In a preferred embodiment of the present invention, (13) the teaching body may include at least one base-point teaching body and at least one other-point teaching body. In this case, since teaching is performed using a plurality of teaching bodies, more accurate positioning is possible, and the robot hand can be made to follow the teaching body accurately.

[0030] In a preferred embodiment of the present invention, (14) the corresponding relationship can be taught by teaching the robot the location of the base point teaching body and then teaching the location of the other point teaching body. In this case, the reference of the robot coordinate system can be set based on the base point by teaching the location of at least one, for example, three, base point teaching bodies, and by teaching the location of the other point teaching body, a suitable teaching range can be set according to the operating range of the robot.

[0031] In a preferred embodiment of the present invention, (15) a test chart in which each teaching unit is visibly provided on a single base sheet can be used as the test object. In this case, by using the test chart visibly provided on a single base sheet as the test object for teaching, the operator can perform teaching more efficiently.

[0032] To achieve the above object, (16) an X-ray inspection method according to the present invention includes a step of identifying the position of a predetermined specific area in an X-ray transmission image acquired of an object to be inspected transported on a conveyor and communicating and outputting position information of the specific area, a step of communicating and outputting work position information to a robot based on the position information for causing the robot to perform a predetermined task on the object to be inspected, and a step of causing the robot to perform the predetermined task based on the work position information, the X-ray inspection method further includes a step of transporting a test chart as the object to be inspected, the test chart having a predetermined teaching object that generates the predetermined specific area in the X-ray transmission image, and starting a teaching mode, and acquiring the X-ray transmission image of the test chart and identifying the position of the predetermined specific area in the X-ray transmission image. a step of controlling the conveyor to restart the transport of the test chart and stop the test chart in the operating area of ​​the robot, and outputting a transport signal to the robot indicating the transport movement amount of the test chart at least from when the transport is restarted to when the transport is stopped; a step of instructing the robot of the position of the predetermined teaching body on the test chart in the operating area, calculating and storing the correspondence between the work position information and the position; and a step of terminating the teaching mode.

[0033] With this configuration, the X-ray inspection method of the present invention includes execution of a teaching mode in which a test chart having a predetermined teaching object that produces the predetermined specific area in an X-ray transmission image is transported to acquire the X-ray transmission image, the transport of the test chart is stopped to identify the position of the specific area, and work position information is transmitted and output to the robot to cause the robot to perform the task, the transport of the test chart is resumed and, when the test chart reaches the operating area of ​​the robot, the transport is stopped again and a transport signal indicating the transport movement amount from the restart to the re-stop is output to the robot, and the robot is instructed to the position of the predetermined teaching object on the test chart, and a correspondence between the work position information and the position is calculated and stored. Therefore, when the X-ray image obtained during X-ray inspection contains a specific area that is determined to be a specific inspection result, the area position information indicating the position of the specific area and the transport movement amount can be aligned with the robot's coordinate system based on the correspondence stored in the robot, allowing the robot's hand to accurately follow the work object.

[0034] The test chart according to the present invention (17) is a test chart for causing the X-ray inspection device to generate sequential X-ray images at a predetermined cycle by being conveyed on a belt conveyor of the X-ray inspection device and passing through an X-ray irradiation area, thereby generating a predetermined specific area in the sequential X-ray images, characterized in that the test chart comprises a base sheet having a predetermined X-ray transmittance, and a plurality of shielding bodies fixed at predetermined intervals and having an X-ray shielding rate that provides a predetermined contrast to a portion corresponding to the base sheet in the sequential X-ray images, and the shielding bodies are visible from at least one side of the base sheet.

[0035] With this configuration, the test chart of the present invention has a visible shielding body that serves as a teaching body for teaching the robot the position of a specific area on the X-ray image, so that the test chart can be transported into the robot's operating area, the position of the teaching body on the test chart can be taught, and the robot coordinate values ​​can be input into the robot.

[0036] In a preferred embodiment of the present invention, (18) the test chart may be configured such that the shielding is arranged so as to generate the specific area across a plurality of the sequential X-ray images at any transport timing. This allows simulated specific areas to be distributed within the operating range of a robot that may be required to perform a predetermined task in an arrangement pattern that is effective for the task, thereby enabling the execution of a test that is effective for the predetermined task. [Effects of the Invention]

[0037] According to the present invention, it is possible to provide an X-ray inspection system using an X-ray vision tracking method, which allows the robot's hand to accurately track the transported work object, and a calibration method for the system. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is a schematic configuration diagram of an X-ray inspection system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic block diagram of a control system of the X-ray inspection system according to one embodiment of the present invention. [Figure 3] FIG. 1 is a schematic configuration diagram of a pinpoint rejection robot in an X-ray inspection system according to an embodiment of the present invention. [Figure 4] FIG. 1 is an explanatory diagram of a calibration method for X-ray vision tracking in an X-ray inspection system according to one embodiment of the present invention. FIG. 1(a) shows the step of generating an X-ray image Vp by adjusting the coordinate positions of two X-ray images Xi, which include multiple teaching object images corresponding to the object, among the periodically obtained sequential X-ray images Xi, in the transport direction so that they can be included within a single image area based on the object. FIG. 1(b) shows the step of moving the X-ray image Vp of the object by a predetermined distance Lr in the transport direction and locating it within the operating area of ​​the robot. [Figure 5]This is an explanatory diagram of a test chart used when performing calibration for X-ray vision tracking in an X-ray inspection system according to one embodiment of the present invention, showing the arrangement of multiple teaching objects that allows the coordinates of an appropriate number of object images to be adjusted in the transport direction based on the object, depending on the size of the object and the working capacity of the robot. [Figure 6] (a) is a plan view of an example of a test chart used when performing calibration for X-ray vision tracking in an X-ray inspection system according to one embodiment of the present invention, and (b) is a cross-sectional view taken along the arrows B6-B6 in (a) of the same figure. [Figure 7] 1 is an explanatory diagram showing a setting area of ​​X-ray vision for a defective product, which is a work object, when X-ray vision tracking is performed in an X-ray inspection system according to an embodiment of the present invention. FIG. [Figure 8] 10 is a flowchart showing a calibration procedure for X-ray vision tracking in an X-ray inspection system according to an embodiment of the present invention. [Figure 9] FIG. 10 is an explanatory diagram of a work screen that displays the coordinates of a base point teaching body used in a calibration work for X-ray vision tracking in the X-ray inspection system according to one embodiment of the present invention. [Figure 10] FIG. 10 is an explanatory diagram of another work screen displaying the coordinates of the base point teaching body used in the calibration work for X-ray vision tracking in the X-ray inspection system according to one embodiment of the present invention. [Figure 11] 1 is a flowchart illustrating an X-ray inspection method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0039] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0040] 1 to 10 show an X-ray inspection system according to one embodiment of the present invention.

[0041] First, the configuration will be described.

[0042] 1 to 3, in the X-ray inspection system 1 according to this embodiment, articles Wp to be inspected as they are being transported on a conveyor 11 arranged in an article manufacturing line (not shown) are sequentially inspected by at least an X-ray inspection device 10, while articles Wp determined to be defective by the X-ray inspection device 10 are pinpointed and removed from the conveyor 11 by a robot 30, which is a first sorting device. Furthermore, if an article is determined to be defective by the X-ray inspection device 10 but cannot be handled by pinpoint removal by the robot 30, it is sorted and removed by a downstream sorting conveyor 40 in area units within a predetermined transport section.

[0043] The article Wp may be, for example, food (fresh food or processed food) or medicine that is ingested by humans or animals, or manufactured as a product that is worn or comes into contact with humans or animals, but is not limited to a specific article. Also, in FIG. 1, the conveyor 11 is composed of an upstream conveyor 11A and a downstream conveyor 11B that are driven synchronously with each other, but since these conveyors are driven synchronously to form a single article conveyance path, they may be configured as a single conveyor 11. A single conveyor 11 eliminates positional deviations that occur when transferring between belts, and eliminates the need for interlocking control of conveyance speeds.

[0044] The X-ray inspection system 1 includes an X-ray inspection device 10, such as an X-ray foreign object detector, and inspects the quality condition of each item Wp passing through a predetermined inspection section on the conveyor 11A using a predetermined X-ray inspection method, and is able to determine, for example, whether the item is an OK item (i.e., a non-defective product) or an NG item (i.e., a defective product) based on preset judgment conditions.

[0045] Depending on the inspection content, the X-ray inspection device 10 may not only determine whether the product is good or not, but may also determine whether the product is of a specific rank when the quality state of the product Wp is ranked into multiple stages. The X-ray inspection device 10 may also have the functions of a weighing device that measures the mass of the product Wp, a foreign object detection device that detects any foreign objects that have been mixed in, or an appearance inspection device that detects defects in the product shape or the sealed portion of the packaging bag.

[0046] As shown in Figure 2, the X-ray inspection system 1 also includes an inspection control unit 15 built into the X-ray inspection device 10, and a control unit 20 as a control device that controls the drive of the robot 30 and the sorting conveyor 40.The inspection control unit 15 and the control unit 20 are connected using a predetermined communication method, for example, an Ethernet-based field bus, allowing digital communication between controllers (exchange of control information at lower layers, communication by upper layers to monitor the operating status of lower layers and events in each device, etc.).

[0047] More specifically, the X-ray inspection device 10 irradiates each inspection target object Wp conveyed in a predetermined conveying direction D1 by the conveyor 11A with X-rays from the X-ray irradiator 12, detects the amount of transmitted X-rays at predetermined time intervals using the X-ray line sensor 13, and sequentially stores the detected values ​​in the image memory 14 while the object Wp passes through the inspection area, thereby enabling the inspection control unit 15 to periodically acquire data of sequential X-ray inspection images (hereinafter also referred to as sequential X-ray images) showing the distribution of transmitted X-ray doses of part or all of the object Wp from the image memory 14. Therefore, the sequential X-ray images are periodically generated by accumulating a predetermined number of lines of X-ray data output by the X-ray line sensor 13.

[0048] The inspection control unit 15 has a processor and memory, and various control programs that can be used to perform specified functions.It is composed of an image processing unit 16 that performs image processing functions based on X-ray inspection image data from the image memory 14, a quality judgment unit 17 that performs the function of judging the quality status of the item Wp based on the image processing results by the image processing unit 16, and an operation display unit 19 such as a touch panel that can display the judgment results of the quality judgment unit 17 and input operations.

[0049] The quality judgment unit 17 can judge, for example, the quality state of the article Wp for each predetermined inspection unit area (each of multiple inspection areas equally divided in any direction within a predetermined conveying distance section that is equal to or greater than the length of the article Wp in the conveying direction) based on the image processing results by the image processing unit 16, and is configured to judge, for example, whether or not foreign matter is present in each inspection unit area. Therefore, depending on the size of the article Wp and the conveying interval, multiple articles Wp may fall within the area that serves as the unit of inspection judgment, or only a single article Wp may fall within that area.

[0050] The conveyor 11 is equipped with a rotary encoder 18 (hereinafter simply referred to as the encoder 18) as a conveyance signal output means. This encoder 18 is capable of detecting the conveyance position, displacement in the conveyance direction, and displacement direction of the conveyor 11, and can accurately convey the movement distance and direction of the conveyor 11 to the robot 30. For example, an incremental rotary encoder that outputs A-phase and B-phase signals in which pulses rise at different phases, and a Z-phase signal in which a pulse rises with each rotation, can be used as the conveyance signal output means. Note that the conveyance signal output means may output the operation amount or control signal of the conveyor drive source (such as the motor rotation speed or an operation pulse signal) so that the conveyance movement amount can be calculated. Alternatively, the conveyance signal may simply be a result of calculating the conveyance movement amount from a set belt speed value and elapsed time.

[0051] The control unit 20 is composed of, for example, a PLC (programmable logic controller) or a management PC, and has various control programs built in to use these to perform specified functions, including the drive control functions of the robot 30 and the sorting conveyor 40.

[0052] The control unit 20 may include a tablet-type information terminal that cooperates with the management PC to function as a programming tool for the PLC and a setting input switch. The management PC of the control unit 20 may also monitor the status of the X-ray inspection system 1 and manage the inspection results of the X-ray inspection device 10 associated with the production plan. The control unit 20 may also have an X-ray control function for controlling the operation of the X-ray inspection device, thereby enabling efficient control of a variety of X-ray inspection devices and robots without excessive specification changes.

[0053] The control unit 20 and a robot controller 39 (described later) acquire encoder pulses from the encoder 18 at regular intervals along the conveyor 11, thereby calculating the position of the inspected item Wp in the conveying direction, the period during which the robot 30 will be within a predetermined operating area Arw where pinpoint removal is possible within the movable range of the robot 30, and the transport position during that period. This allows the control unit 20 and a robot controller 39 to calculate the transport distance Lr from the time a trigger signal (hereinafter also referred to as a coordinate transmission trigger signal) is output until the robot 30 reaches a predetermined work position within the robot operating area Arw. The pinpoint removal operation referred to here is a localized removal operation for multiple loose items Wp that are transported within the predetermined operating area Arw, which is a predetermined transport section on the conveyor 11B, as shown in FIG. 7. For example, the pinpoint removal operation is an operation to remove, from the conveyor 11A, a small number of small items (individuals) that are part of the multiple items, or a portion of minced or other separable items Wp that are spread within the operating area Arw.

[0054] The control unit 20 also acquires the inspection judgment results and position information of each inspected item Wp by the quality judgment unit 17 from the inspection control unit 15 of the X-ray inspection device 10, and acquires the X-ray inspection image data together with its coordinate reference data. The control unit 20 then links area position information (e.g., pixel coordinates of the X-ray image) indicating the position of an item Wp judged to be defective or a specific area of ​​an inspection unit in the X-ray inspection image data with changes in the conveyance direction position (x-direction coordinates in FIG. 1) accompanying the conveyance within a predetermined conveyance section on the conveyor 11B that is the inspection section by the X-ray inspection device 10 and the operating area Arw of the pinpoint removal operation by the robot 30. That is, the control unit 20 outputs a coordinate transmission trigger signal containing robot coordinate information of the target object as a trigger signal to the robot 30 based on setting parameters obtained by performing a calibration in advance to convert the region position information of the X-ray inspection device 10 into robot coordinates in the coordinate system used by the robot 30, so that the control unit 20 can obtain a function (tracking function) of causing the position of the pinpoint removal operation of the defective product by the robot 30 to follow the movement of the position of the NG judgment region in the quality judgment unit 17 of the X-ray inspection device 10. Note that the conversion to robot coordinates may be performed by the robot controller, in which case the control unit outputs region position information of the X-ray image of the target object. Here, the region position information indicating the position of the specific region is position information in dot units in the X-ray image. The control unit 20 converts the region position information into position information in mm units by, for example, a PLC constituting the control unit 20, taking into account the magnification ratio of the object in the inspection image and the effects of image correction processing, and can then convert it into coordinates (in mm units) in the robot coordinate system based on instruction information at the first stop position and the second stop position, which will be described later.

[0055] As shown in FIG. 1, the robot 30 has a robot controller 39 that inputs the robot coordinate information of the work object contained in the coordinate transmission trigger signal from the control unit 20, and this robot controller 39 controls the robot 30 to pinpoint and remove an item Wp that has been inspected by the X-ray inspection device 10 in accordance with the results of the inspection by the X-ray inspection device 10, provided that a first pre-set sorting condition is met.

[0056] As shown in Figures 2 and 3, the robot 30 can move, for example, a vacuum head 31 using an articulated robot arm 32 in at least the width direction of the conveying path (the longitudinal direction of the line sensor 13) perpendicular to the item conveying direction, in this case both in the item conveying direction and the width direction of the conveying path, and can discharge the item to a defective item receptacle 34 outside the conveyor 11B (hereinafter also referred to as outside the system).

[0057] More specifically, the vacuum head 31 includes an elevation-type vacuum nozzle 31a having a downward opening at its lower end and a sideways opening at its upper end, a head body 35 that supports the vacuum nozzle 31a so that it can be raised and lowered via an elevation drive shaft 35a, a suction duct 33 connected to the vacuum nozzle 31a, a drive fluid ejection unit 37 having an ejector function that ejects high-pressure drive fluid (here, compressed air) downstream from around the outlet of the suction duct 33 to generate negative pressure in the suction duct 33, and a discharge duct 36 connected to the outlet sides of the suction duct 33 and the drive fluid ejection unit 37 and forming a diffuser passage whose internal cross-sectional area gradually increases toward the defective product receptacle 34. The vacuum head 31 is configured to suck defective articles Wp from the vacuum nozzle 31a into the suction duct 33 and eject them from the discharge duct 36 into the defective product receptacle 34.

[0058] The ejector-type vacuum head 31 is a pinpoint removal means that sucks in specific items Wp whose inspection results deviate from predetermined quality conditions, such as defective items, and removes them from the conveyor 11B. This vacuum head 31 is supported by the robot arm 32, so that when the results of the inspection by the X-ray inspection device 10 deviate from the predetermined quality conditions, it can move in at least a direction perpendicular to the predetermined conveying direction, in this case both in the conveying direction v of the conveyor 11B and in the width direction w perpendicular to that direction, depending on the inspection results.

[0059] In the vacuum head 31, when a defective article Wp is sucked into the vacuum nozzle 31a and passes through its entrance, the article Wp is detected by a small passage detection sensor 31s, such as a reflective laser sensor, attached to the vacuum nozzle 31a or the upstream end of the suction duct 33. Also, when a defective article Wp is sucked into the suction duct 33 and passes to the discharge side, the article Wp is detected by a passage detection sensor 36s attached to the downstream end of the suction duct 33 or near the driving fluid ejection unit 37. The driving fluid ejection unit 37 is connected to a compressed air supply source via a solenoid valve and a filter regulator (not shown).

[0060] Here, the vacuum nozzle 31a can be raised and lowered between an elevated position shown by a solid line in Figure 3 and a lowered position shown by a virtual line in Figure 3 via the elevation drive shaft 35a by an elevation drive mechanism 32f supported integrally on the second arm 32e together with the head body 35, and the height of the lowered position is set for each type of item Wp so that defective items can be pinpointedly sucked in at the lowered position and removed outside the conveyor 11B (hereinafter also referred to as outside the system).

[0061] The robot arm 32 includes, for example, a first arm 32a whose base end is rotatably supported on a support base 32b and which can be rotatably driven via a geared motor 32c, and a second arm 32e which is rotatably supported at the tip of the first arm 32a via a joint having a geared motor 32d. The second arm 32e integrally supports the vacuum head 31, and the robot controller 39 servo-controls the geared motors 32c and 32d to control the drive angle positions of the geared motors 32c and 32d to target values, thereby enabling the vacuum nozzle 31a to move (including conveyance tracking) to any coordinate position within the operating area Arw.

[0062] The sorting conveyor 40 is positioned downstream of the conveyor 11B in a predetermined conveying direction, and is configured to remove items Wp after inspection by the X-ray inspection device 10 in units of area sorting sections of a predetermined conveying distance, depending on the results of the inspection by the X-ray inspection device 10 and predetermined second sorting conditions.

[0063] 2, the sorting conveyor 40 has an up-and-down swinging conveyor 41 having a sorting section in the conveying direction that is shorter than the conveyor 11B, which is the pinpoint removal section used by the robot 30, an up-and-down drive actuator 42 such as an air cylinder that raises the conveyor 41 at one end in the conveying direction, for example, the upstream end 41a, and a defective product receiver 43. The up-and-down drive actuator 42 is connected to an air supply source via a directional control valve, an air supply control valve, a filter regulator, and the like (not shown), and switching the directional control valve switches the control direction of the air supply and exhaust to the up-and-down drive actuator 42, thereby controlling the switching of the operating direction of the up-and-down sorter.

[0064] When the conveyor 41 is tilted upward at the upstream end 41a, the sorting conveyor 40 selectively drops articles Wp that have passed through a predetermined transport section on the conveyor 11B that forms the predetermined operating area Arw of the robot 30, and discharges them into a defective article receptacle 43 outside the conveyor 11B. Note that the sorting conveyor 40 may be of another type, such as a shuttle type whose length extends and retracts horizontally, or a type formed by an inclined chute plate.

[0065] As shown in Figure 2, the control unit 20 has multiple functional units realized by a predetermined control program using a management PC or PLC, including an inspection information input unit 21, a sorting condition setting unit 22, and a sorting request output unit 23.

[0066] The inspection information input unit 21 has a first input means 21a that inputs information related to the judgment results from the image processing unit 16 and the quality judgment unit 17 of the X-ray inspection apparatus 10, a second input means 21b that inputs area position information indicating the position of the article Wp or the inspection unit area in addition to the image information from the image processing unit 16, and a third input means 21c that acquires specific sensor information from the passage detection sensors 31s, 36s that indicates a failure of the pinpoint removal operation by the robot 30. The specific sensor information here indicates that at least one of the passage detection sensors 31s, 36s did not detect the passage of the defective article Wp within a predetermined time from the issuance of a sorting command to the robot 30 (output of a pinpoint removal request Ra), and therefore the pinpoint removal operation by suction failed, or indicates a delay in the elapsed time between the detection of the passage of the article Wp by the passage detection sensor 31s attached to the vacuum nozzle 31a and the detection by the passage detection sensor 36s attached to the downstream end of the suction duct 33, exceeding a preset allowable suction time.

[0067] The sorting condition setting unit 22 determines whether or not a first sorting condition is met based on the information acquired by the inspection information input unit 21, depending on the results of the inspection by the X-ray inspection device 10 and the transport state of the inspected item Wp, and also has a sorting condition determination means 24 that determines whether or not a second sorting condition is met based on whether or not the first sorting condition is met and whether or not the pinpoint exclusion by the robot 30 was successful (whether or not it was successful).

[0068] The sorting request output unit 23 has a pinpoint exclusion request means 23a that outputs a pinpoint exclusion request Ra to the robot 30 and the robot coordinates of successive work objects in accordance with the determination result by the sorting condition determination unit 24 that the first control condition is satisfied, and an out-of-system discharge request means 23b that outputs a direction switching signal equivalent to an area sorting exclusion command to a directional control valve or the like that controls the up-out drive actuator 42 of the sorting conveyor 40 in accordance with the determination result by the sorting condition determination unit 24 that the second control condition is satisfied.

[0069] The sorting condition determination means 24 is configured to determine that the second sorting condition is met if the first sorting condition is not met or if the pinpoint removal operation by the robot 30 is unsuccessful. The first sorting condition is a condition under which all of the articles Wp (defective articles) that do not meet predetermined quality conditions within a predetermined conveying section can be removed within a predetermined sorting period by the pinpoint removal operation by the robot 30, and in this case, the number of defective articles Wp within the predetermined operating area Arw of the robot 30 shown in Fig. 1 does not reach a predetermined upper limit based on the processing capacity of the robot 30, or the position of the defective article Wp to be removed is located forward (upstream) of a predetermined position based on the processing capacity of the robot.

[0070] In addition, if it becomes uncertain whether the removal operation of all defective products within the specified operating area Arw will be completed due to variations in the position or posture of defective products Wp within the specified operating area Arw, failure of the pinpoint removal operation by the robot 30, or delay in the pinpoint removal operation due to clogging of products in the vacuum nozzle 31a, etc., the sorting condition determination means 24 will determine that the pinpoint removal operation by the robot 30 has been unsuccessful and will cause the sorting conveyor 40 to perform reliable removal.

[0071] In other words, when the robot 30 is primarily used, the sorting condition determination means 24 can establish the second sorting condition and operate the sorting conveyor 40 when the first sorting condition is not established, or when the pinpoint removal operation by the robot 30 fails or is not confirmed to be successful within a specified time.

[0072] Of course, whether the robot 30 or the sorting conveyor 40 is used preferentially may be variably set manually or by automatic mode setting according to the type of article Wp.

[0073] The sorting condition setting unit 22 also has a coordinate information acquisition means 25, a coordinate adjustment means 26, and a coordinate value conversion means 27 as means for realizing an X-ray vision tracking function that enables pinpoint removal operations by the robot 30.The coordinate information acquisition means 25, the coordinate adjustment means 26, and the coordinate value conversion means 27 are configured to operate based on various setting parameters obtained as a result of performing a calibration operation in advance using a test chart 60 such as shown in Figures 1 and 6 in order to realize the X-ray vision tracking function in this system.

[0074] When the quality judgment unit 17 notifies the inspection information input unit 21 that the X-ray inspection result is a predetermined result, for example, an NG judgment, the coordinate information acquisition means 25 acquires area position information indicating the position of a specific area included in the image area of ​​the X-ray inspection, i.e., position information (e.g., coordinates of the center of the circumscribed circle, center of gravity, etc.) in the image (work object image) that is the target of the NG judgment. Note that area position information may be acquired by expanding the image area in the transport direction using a series of multiple sequential X-ray images Xi. For example, using the imaging order number n for convenience, the most recent sequential X-ray image resulting in the predetermined inspection result is designated Xi(n) and the sequential X-ray image immediately preceding it is designated Xi(n-1). Then, the sequential X-ray images Xi(n) and Xi(n-1) at the time the predetermined inspection result was obtained and those immediately preceding it can be acquired, and area position information can be acquired for those X-ray images. In addition, the area position information may include information such as the ID of the target image, the number in the order of capture, the ID and weight of a specific area within the same image, etc., and for example, it is possible to pinpoint exclusion by having the selection condition setting unit 22 prioritize specific areas with high weights so that the first selection condition is met.

[0075] The coordinate value conversion means 27 has the function of a conversion means that converts the area position information acquired by the coordinate information acquisition means 25 (for example, the coordinates (x, y) of the work object image Vp) into robot coordinate (xr, yr) values, and functions as position information output means that outputs a coordinate transmission trigger signal to the robot 30 as work position information. If the inspection result is a pass / fail product, the coordinate information acquisition means 25 does not acquire the area position information, so no work position information is output, and for the vast majority of pass / fail products in the case of pass / fail inspection, no unnecessary signals are output. Also, although the function of the conversion means of the coordinate value conversion means 27 has been described as one of the functions of the control unit 20, it may also be configured as a function of the robot controller 39. In this case, the area position information acquired by the coordinate information acquisition means 25 will be included directly in the coordinate transmission trigger signal to the robot 30 and output.

[0076] In a teaching mode in which the robot 30 is set and a calibration operation is performed, the coordinate adjustment means 26 and the coordinate value conversion means 27 convert the coordinate values ​​(Ax, Ay), (Bx, By), (Cx, Cy) of a plurality of reference points, for example, A, B, C, contained in one sequential X-ray image Xi that becomes the work object image Vp, into coordinate values ​​for the test chart 60 on which teaching bodies 61, 62, 64, etc. that serve as reference points for teaching the robot 30 the area position information (x, y) of the work object image Vp are attached so that they can be seen and X-rayed. The conversion means 27 outputs robot coordinate information as work position information in the form of coordinates (Arx, Ary), (Brx, Bry), and (Crx, Cry) in the robot coordinate system, and when the test chart 60 is transported into the working area to teach the coordinates of the work target teaching bodies 61, 62, and 64, the coordinates of the work target image Vp within the working area Arw are input to the robot 30 based on the coordinate values ​​(Arx, Ary), (Brx, Bry), and (Crx, Cry) in the robot coordinate system. Note that the control unit 20 may be provided with a function for receiving input of coordinate data and function as a coordinate setting means for communicating and outputting the input coordinate data to the robot. The coordinate data may not only be coordinates in the robot coordinate system based on the area position information, but also coordinates of the X-ray image based on the area position information before conversion, which may be input or automatically determined and communicated and output to the robot.

[0077] In addition, when the coordinate adjustment means 26 and the coordinate value conversion means 27 are to teach the robot 30 the coordinates of the working position, they start test transport of the test chart 60, which is the object to be inspected by the X-ray inspection device 10, and acquire area position information of the teaching bodies 61, 62, 64. After that, they stop the transport at the first stop position where the trigger signal output position Et0 to the robot 30 in the preset trigger setting area Ats is reached, thereby setting the transport movement amount to zero, and then they resume transport by operation input from the operation display unit 19, and transport the test chart 60 while making increments until it reaches the working position (second stop position) in the operating area Arw, at which point they stop the transport to teach the robot.

[0078] When the test chart 60 is stopped at the second stop position, coordinate information of the robot coordinates (Arx, Ary), (Brx, Bry), and (Crx, Cry) of the teaching objects 61, 62, and 64 is displayed as numerical coordinate data on the operation display unit 19, which is a display means. This display allows the user to teach the robot 30 the coordinates of the work position while checking the teaching objects on the test chart 60. The coordinate data may be displayed as a graphic display such as a coordinate graph or as a code display that can be easily converted, as long as it is legible. In addition to numerical values, two-dimensional coordinates may be displayed on the screen, directly or indirectly corresponding to the coordinate data. The operation input for inching the conveyor 11B and the display of the coordinate data may be displayed on an operation unit or display unit provided in the control unit 20.

[0079] 4(a), the work object image Vp may be adjusted from multiple sequential X-ray images Xi to acquire and teach the teaching object. In this case, the sequential X-ray images Xi(n-1), Xi(n) acquired by the coordinate information acquisition means 25 are used to display reference points, for example, the coordinates (Dx, Dy), (Ex, Ey), (Fx, Fy) of the teaching object images D, E, and F, on the screen from the area position information of the teaching objects 61, 62, and 64. The coordinate (x0) in the transport direction of the origin Ox of the work object image Vp calculated based on the coordinate values ​​of a predetermined number or more of the reference points A, B, and C (corresponding to (Ax, Ay), (Bx, By), and (Cx, Cy)) is set as the trigger signal output position Et0 so that a predetermined number or more of the coordinates of D, E, and F fall within the set size Svp of the work object image Vp (see FIG. 5). Then, the coordinate values ​​Ax, Bx, and Cx are calculated by adjusting the coordinates Dx, Ex, and Fx in the transport direction of the teaching object images D, E, and F of the sequential X-ray images Xi so that they have the same origin Ox. The values ​​are then manipulated so that the work object is positioned within the X-ray imaging pitch Pm, and tracking calibration is performed using the adjusted coordinate values ​​(Ax, Ay), (Bx, By), and (Cx, Cy). This avoids missing teaching object images and enables calibration with fewer teaching objects. The origin Ox may also be set to one of the reference points A, B, or C, corresponding to the trigger signal output position Et0 for identifying the work position of the robot 30.

[0080] The test chart 60 has a base sheet 71, a plurality of teaching bodies 61, 62, 64 arranged in a predetermined arrangement pattern on the base sheet 71 for teaching the robot 30 reference points of the work object image, and a plurality of visible metal (e.g., stainless steel) shielding bodies 72 for forming teaching body images of specific areas in an X-ray image captured by X-rays, allowing the identification of multiple reference points, and may be housed in a protective film or case that is equally or more permeable to X-rays than the base sheet 71.

[0081] Furthermore, as shown in Figure 5, since the contour coordinates of the multiple teaching bodies 61, 62, and 64 within the coordinate search window Vp' are known, the x-direction coordinate component can be adjusted so that the maximum value of their coordinate components in the transport direction is slightly upstream of the position of the origin Ox of the object image Vp in the transport direction, that is, so that the position of the origin Ox of the object image Vp is a position that precedes the most downstream x-direction coordinate component of the contour coordinates of the multiple teaching bodies 61, 62, and 64 in the transport direction, and the coordinate values ​​can be reset using the x-direction coordinate component of the origin Ox as the reference (x0, y0).

[0082] This test chart 60 has a length that spans the entire width direction perpendicular to the conveying direction D1 of the conveyor 11, and has a width in the conveying direction that is more than twice the origin pitch Po of the sequential X-ray images Xi obtained periodically by the X-ray inspection device 10.The set size Svp of the work object image Vp is set to, for example, the size of the sequential X-ray images Xi, but it goes without saying that it is possible to create a test chart that corresponds to an arrangement and quantity that allows a predetermined number or more of reference points with the same origin to be obtained depending on the processing capacity of the robot 30.

[0083] The control unit 20 sets the number and order of pinpoint rejection based on the coordinates of the defective items Wp (NG items) in the work object image Vp and the conveyance movement amount Lr, which is the distance from the trigger signal output position Et0 by the conveyor transport to the work position in the operating area Arw of the robot 30. The number of pinpoint rejection here is less than a set number (for example, 5), and if there are more than the set number of defective items Wp (NG items), the control unit 20 determines that the second sorting condition is met.

[0084] In this embodiment, the system includes an X-ray inspection device 10 that irradiates X-rays onto an object to be inspected Wp being transported in a predetermined transport direction D1 on a conveyor 11, and sequentially inspects the object to be inspected Wp based on periodically obtained sequential X-ray images Xi containing data on the X-rays that have passed through the object to be inspected, and a robot 30 that, when a trigger signal is input, performs a predetermined task on the object to be inspected Wp identified by the position information included in the trigger signal, while following the conveyor transport of the object to be inspected Wp within a predetermined operating area Arw.

[0085] The control unit 20 that controls these acquires area position information in at least one sequential X-ray image Xi corresponding to the item Wp (e.g., an NG item) of the specific inspection result, provided that the X-ray inspection device 10 has obtained such result, and causes the coordinate information acquisition means 25 and the coordinate value conversion means 27 to perform the function of a position information output means that outputs the coordinates of the area position information as work position information of the target item Wp.

[0086] As a result, the control unit 20 sets the transport position (predetermined transport position Tg) of the object Wp to be inspected at the time when the X-ray inspection device 10 is able to output the inspection image and the judgment result as the trigger signal output position Et0, and outputs a coordinate transmission trigger signal to the robot 30. When the trigger signal output position Et0 is set to a predetermined position closer to the robot 30 than the predetermined transport position Tg, the inspection information including the inspection results and area position information may be stored sequentially, and the stored inspection information may be read out and communicated at a predetermined timing when the inspection image is acquired and the set position is reached. In this case, the inspection information may be read out using the ID of the image of the object or the image sequence number included in the area position information.

[0087] Furthermore, the control unit 20 causes the coordinate adjustment means 26 and the coordinate value conversion means 27 to perform the function of the robot coordinate adjustment means by instructing the robot 30 of the coordinates (xr, yr) of the work position corresponding to the area position information (x, y) of the work object image Vp, and after having grasped the movement distance Lr in the transport direction from the trigger signal output position Et0 to the robot 30 to within the operating area Arw of the robot 30, causes the robot 30 to instruct the coordinates (xr, yr) of the work position and input the area position information (x, y) of the work object image Vp into the coordinate values ​​(xr, yr) of the robot's coordinate system.

[0088] Next, a calibration method for the X-ray inspection system 1 of this embodiment, which is executed using the above configuration, will be described with reference to the flow of FIG.

[0089] First, the robot 30 is set to a calibration-enabled state, and a test chart 60 is prepared on which a plurality of base point teaching bodies 61, 62, 64 as shown in FIG. 6 and other point teaching bodies 63, 65 arranged at positions a predetermined distance from the base point teaching bodies 61, 62, 64 are attached so that they can be seen visually and X-ray-imaged. The test chart 60 is test-transported in a predetermined transport direction by the X-ray inspection device 10 in teaching mode, and the area position of each teaching body is obtained from sequential X-ray images Xi obtained by periodically taking X-ray images using the coordinate information acquisition means 25 of the control unit 20 (step S1).

[0090] Next, when the test chart 60 reaches the trigger signal output position Et0 to the robot 30 (for example, the position to which it moves after a predetermined time has passed since the X-ray images were acquired so that the judgment result can be output), work position information converted from the area position of the teaching body of the target image into robot coordinates (for example, robot coordinates based on the area position information of the target image Vp including one or more teaching body images of the base point teaching bodies 61, 62, 64 among the base point teaching bodies 61, 62, 64 and the other point teaching bodies 63, 65) is output (step S2).

[0091] Next, the test chart 60 is moved by the conveyor 11 a predetermined distance Lr from the trigger signal output position Et0 to the robot 30, and the base point teaching bodies 61, 62, 64 and other point teaching bodies 63, 65 are placed within the operating area Arw of the robot 30, and the coordinates of each teaching body that will serve as the reference point for teaching based on the work position information output in step S2 are taught to the robot 30 (step S3).

[0092] The term "teaching" as used herein refers to storing a plurality of coordinates serving as reference points in the robot 30. Teaching to the robot 30 involves moving the robot arm 32 of the robot 30 so that the work center position of the hand coincides with the central coordinates of each of the base point teaching bodies 61, 62, and 64 serving as the reference points, thereby storing the robot coordinates corresponding to the central coordinates of each of the base point teaching bodies 61, 62, and 64 as actual work positions, and storing the centers of the teaching bodies corresponding to the coordinates output in step S2. Alternatively, instead of storing all of the output coordinates, one of the base point teaching bodies may be selected as the origin and stored as the origin of the robot coordinates, and then the coordinates of the other point teaching bodies may be selected and converted into coordinate values ​​from the origin of the robot coordinates and stored. This reduces the number of reference points to be taught.

[0093] Next, the coordinates taught to the robot and the transport distance Lr from the position Et0 where the trigger signal is output to the robot 30 to the position where the conveyor 11 is stopped for teaching within the operating area Arw of the robot 30 are calculated and set as parameters in the robot, thereby completing the calibration work (step S4). When completing the calibration work, the user is prompted to reconfirm whether it is OK to set the calculated data such as various parameters in the robot controller 39, and the results of the calibration work are reflected in the robot 30 by operating a button such as "OK".

[0094] In addition, when conveyance is at a constant speed, the conveyance distance Lr can be measured by inputting a previously measured known distance and speed as parameters, so that the robot 30 can operate within the movement time. In addition, when measuring the conveyance distance Lr with an encoder counter that counts encoder pulses using the encoder 18, the encoder counter is cleared at the trigger signal output position Et0, and the value of the encoder counter at the position where the conveyor 11 is stopped for teaching is set in the robot 30. This allows the conveyance distance Lr to be measured following any fluctuations in the conveyance speed, resulting in stable robot operation.

[0095] Furthermore, the position information output in step S2 may be displayed numerically along with an image in which symbols indicating reference points are arranged on a two-dimensional coordinate system, as shown in FIG. 9(a), so that the coordinates of each reference point can be taught to the robot 30. Alternatively, as shown in FIG. 9(b), the coordinates of each base point may be displayed along with a two-dimensional image in which a teaching object image is superimposed on symbols indicating each reference point, so that the coordinates of each reference point can be taught to the robot 30. By using such a display, it is possible to more reliably teach the robot the coordinates. Furthermore, as shown in FIG. 10, it is also possible to display the coordinates of the reference points on an image obtained by combining multiple sequential X-ray images, so that the coordinates of each reference point can be taught to the robot 30. By using such a display, teaching objects located at the boundaries of multiple sequential X-ray images can be extracted without any missing parts, and the center coordinates of the teaching object can be accurately obtained.

[0096] Next, the X-ray inspection method of this embodiment will be described with reference to the flow of Fig. 11. Note that the same parts as those in the above-mentioned X-ray inspection system will be denoted by the same reference numerals.

[0097] The X-ray inspection method of this embodiment includes the steps of: identifying the position of a predetermined specific area in an X-ray transmission image obtained by irradiating X-rays on an object Wp to be inspected and transported on a conveyor 11; communicating and outputting position information of the predetermined area; communicating and outputting work position information to the robot 30 based on the position information, for causing the object Wp to perform a predetermined task; and causing the robot 30 to perform the predetermined task based on the work position information.The method further includes a step of performing a teaching mode in which the robot 30 is set up as described below, which is a preparatory step for performing the inspection mode in which the above-mentioned steps are performed.

[0098] First, the test chart 60 having a predetermined teaching object that generates a predetermined specific area in the X-ray transmission image is conveyed, and the teaching mode is started (step S11).

[0099] Next, an X-ray image of the test chart 60 is acquired, the position of a predetermined specific area in the X-ray image is identified, and the position information of the specific area is output via communication at a predetermined timing (step S12). Next, the conveyor 11 is controlled to stop the transport of the test chart 60 (step S13), and work position information for the robot is output to the robot 30 by communication based on the position information of the specific area output in step S12 (step S14).

[0100] Next, the conveyor 11 is controlled to resume transport of the test chart 60, stop the test chart 60 in the robot's operating area, and output a transport signal to the robot 30 indicating the transport movement amount of the test chart at least from when transport was resumed to when it was stopped (step S15).

[0101] Next, the robot 30 is instructed as to the location of a specified teaching object on the test chart 60 in the operating area Arw (step S16), and the correspondence between the work position information and the location based on the position information of the specific area output in step S12 is calculated and stored in the robot 30 (step S17), after which the teaching mode is ended and the robot transitions to the inspection mode.

[0102] Next, the operation will be described.

[0103] In the X-ray inspection system 1 of this embodiment configured as described above, the control unit 20 acquires inspection information including area position information indicating the position of a specific area in the sequential X-ray images Xi corresponding to the object under inspection of a predetermined inspection result from the X-ray inspection device 10, and outputs work position information including information indicating the position where a predetermined task should be performed to the robot 30 based on the inspection information as a trigger signal. After outputting the trigger signal, the control unit 20 outputs a transport movement amount Lr until the object under inspection on which the predetermined task should be performed reaches a predetermined work position within the operating area Arw, and the robot 30 performs the predetermined task. Then, as a preparatory task, the robot 30 is instructed to provide area position information of the work object in the coordinate system of the X-ray image, such as (Ax, Ay), (Bx, By), (Cx, Cy), and the work position in the robot coordinate system, such as (Arx, Ary), (Brx, Bry), (Crx, Cry), according to tracking calibration conditions that reflect the calibration results in advance. When the instructed robot 30 receives a trigger signal, it executes the predetermined task based on the work position information of the work object (item Wp to be worked on) and the transport movement amount Lr contained in the trigger signal. This makes it possible to align the coordinates of the area position information of the work object (coordinates in the X-ray image of the work object) with the coordinate system of the robot 30, and X-ray images whose coordinates can be acquired and output from the X-ray inspection device can be effectively used for vision tracking. Furthermore, by setting an appropriate work object image size according to the size of the object to be inspected by X-ray and the work capacity of the robot 30 for that object, an X-ray image of the work object suitable for tracking can be obtained regardless of the transport form of the object to be inspected, and the hands of the robot 30 can be made to accurately track the coordinates of the work object.

[0104] Furthermore, in this embodiment, by using a test chart 60 on which base point teaching bodies 61, 62, 64 for teaching the coordinates of the work object image Vp to the robot 30 are attached so that they can be seen and X-rayed, the test chart 60 is transported into the operating area Arw of the robot 30, and based on the teaching values ​​of the coordinates taught using the center of the base point teaching body as the reference point and the transport distance Lr, the area position information of the work object image Vp can be converted into coordinates in the robot coordinate system and easily and accurately input to the robot 30. Furthermore, by adjusting the size of the teaching bodies on the test chart 60 and the arrangement of multiple teaching bodies, it is possible to acquire a work object image Vp that is suited to the work capabilities of the robot 30.

[0105] Furthermore, in this embodiment, in response to test transport of the test chart 60, an image showing the coordinate position of the teaching body created from the acquired sequential X-ray images Xi is displayed on the calibration work screen 80 by the operation display unit 19 together with the coordinates of the base point teaching bodies 61, 62, 64 for coordinate teaching, and the positioning status of the base point teaching bodies 61, 62, 64 displayed on the screen within the work object image Vp can be confirmed.

[0106] Therefore, it is possible to easily set teaching bodies 61, 62, 64, etc. to be taught to the robot 30 based on the teaching body image position on the test chart 60. Also, when teaching by displaying a plurality of sequential X-ray images Xi as shown in Fig. 10, it is possible to easily select teaching bodies 61, 62, 64, etc. Furthermore, when displaying a plurality of sequential X-ray images Xi and adjusting the work object image Vp, it is possible to set the origin coordinates of the work object image Vp so as to effectively prevent the image of the work object from being cut off at the leading end side of the latest sequential X-ray image Xi(n) and spanning over to the side of the immediately preceding sequential X-ray image Xi(n-1).

[0107] Additionally, in this embodiment, the coordinate value conversion means 27 serving as position information output means outputs a trigger signal each time it receives inspection information including a predetermined inspection result, so that each time an object Wp to be inspected is produced, the robot 30 can perform work in response to the trigger signal to pinpoint and remove, for example, a defective product or defective area. Moreover, the coordinate value conversion means 27 sequentially stores the inspection information and reads and outputs the inspection information at predetermined timings, so that the inspection information can be output to the robot 30 in a timely manner according to the timing at which the robot work is required.

[0108] In the teaching mode, the robot 30 is taught a correspondence between work position information based on area position information and a predetermined work position, allowing the robot 30 to accurately memorize the correspondence. Furthermore, in the teaching mode, the control unit 20 as a control device stops the transport of the inspection object Wp at a first stop position when receiving inspection information from the X-ray inspection device 10, resumes the transport when a trigger signal is transmitted to the robot 30, stops the transport of the inspection object Wp again at a second stop position included in the robot 30 operating area Arw, and then teaches the correspondence to the robot 30. Therefore, the X-ray inspection device 10 can execute teaching that can convert, at the first stop position, the position information of a specific area resulting in a predetermined inspection result into transport position information on the robot 30 side, and accurately grasps the transport movement amount Lr from the stop position after the teaching to the second stop position, and then accurately teaches the robot 30 a work position where a predetermined task should be performed.

[0109] Furthermore, the control unit 20 increments the conveyor 11 for a predetermined time each time a predetermined operation input is received. By receiving multiple operation inputs, the control unit 20 transports the object Wp from the first stop position to the second stop position. This allows the operator to easily and effectively grasp the transport distance Lr from the first stop position to the second stop position based on the number of increments. Furthermore, as illustrated in Figures 9 and 10, coordinate data of the reference point based on the area position information is legibly displayed on the calibration work screen 80, which is a display unit. This allows the operator to accurately grasp the taught position when teaching the robot 30 the coordinates of the work position. Furthermore, since symbols representing the coordinate data positions are displayed in two-dimensional coordinates directly or indirectly corresponding to the coordinate data, multiple taught positions and their locations can be easily visually recognized from the displayed symbols.

[0110] Additionally, in this embodiment, if the control unit 20 is provided with a coordinate setting means for receiving input of coordinate data based on area position information in order to teach the robot 30 the correspondence, the set coordinate data can be output by communication to the robot 30, enabling quick and accurate work on the robot 30 side. Also, if the coordinate data based on the area position information is output by communication to the robot 30 when the inspection object Wp is stopped at the second stop position, teaching to the robot 30 can be easily performed by operating the robot side.

[0111] In the calibration method for X-ray vision tracking in the X-ray inspection system 1 of this embodiment, a test chart 60 serving as a substitute object to be inspected is transported, to which a plurality of teaching bodies 61, 62, 64, 63, and 65 are attached for generating specific areas that are determined to be predetermined inspection results by the X-ray inspection device 10, and the robot 30 is taught the correspondence between area position information indicating the position of the specific area and a predetermined work position where the robot 30 will perform work. As a result, when a specific area that is determined to be the predetermined inspection result is found in an X-ray image obtained during X-ray inspection, it is possible to easily and accurately align the area position information indicating the position of the specific area to correspond to the coordinate system of the robot 30. This makes it possible to obtain an X-ray image of the work object that is suitable for tracking regardless of the form in which the object to be inspected is transported, and to enable the hand of the robot 30 to accurately track the work object.

[0112] Furthermore, the test chart 60 used for calibrating the X-ray inspection system 1 in this embodiment comprises a base sheet 71, a plurality of teaching objects 61, 62, 64 arranged in a predetermined arrangement pattern on the base sheet 71 to teach the robot 30 the coordinates of reference points, and a plurality of shielding objects 72 that are visible and form a plurality of identifiable images in an X-ray image captured by X-ray.

[0113] Therefore, the base point Et0 can be set based on the position of the teaching object image on the test chart 60, and based on the teaching values ​​of the coordinates of the teaching objects 61, 62, and 64 that are taught by transporting the test chart 60 into the operating area of ​​the robot 30 and the transport distance Lr, the coordinates corresponding to the origin Ox of the object image can be converted into coordinates in the robot coordinate system and input to the robot 30 easily and accurately.

[0114] In this way, the X-ray inspection system 1 of this embodiment can provide an X-ray vision tracking type X-ray inspection system and a calibration method thereof that can acquire an object image Vp of a predetermined size that includes a work object suitable for tracking regardless of the transport form of the item Wp, and can accurately track the coordinates of the work object with the robot's hand.

[0115] In the above-described embodiment, the sequential X-ray images Xi are generated periodically by accumulating a predetermined number of lines of X-ray data output by the X-ray line sensor 13. However, the sequential X-ray images Xi may be generated periodically using an X-ray detector that acquires the sequential X-ray images Xi, which are obtained by accumulating a predetermined number of lines of output from the X-ray line sensor 13, as two-dimensional X-ray images.

[0116] Furthermore, although the work object image Vp has been described as being the same size as the sequential X-ray image Xi in the transport direction, if the size of the work object in the transport direction is large and the inspection result is output based on multiple sequential X-ray images, the work object image Vp may be a predetermined multiple of the size of the sequential X-ray image Xi in the transport direction. In this case, for example, if the latest sequential X-ray image Xi(n) and the immediately preceding sequential X-ray image Xi(n-1) are the same size as the inspection image, the position information output means acquires coordinate information for the target image including the even earlier sequential X-ray image Xi(n-2) in order to adjust the image position, thereby effectively preventing the outline of the object from being cut off at the leading edge of the immediately preceding sequential X-ray image Xi(n-1).

[0117] Furthermore, in one embodiment, the coordinate information acquisition means may determine, during the inspection, whether the object to be inspected as a whole is within a predetermined work object image size Svp that is equal to or larger than the size Sxi in the transport direction of the sequential X-ray images Xi, and, depending on the result of this determination, adjust the coordinate values ​​of the acquired sequential X-ray images Xi in the predetermined transport direction so that the object to be inspected as a whole is within the work object image size Svp.

[0118] It is also possible to have an operation display unit 19 that displays the coordinates output by the coordinate value conversion means 27 on a screen, and to display them until it is confirmed that one of the teaching bodies 61, 62, 64 in the object image Vp acquired by capturing an image of the test chart 60 with the X-ray inspection device 10 has reached the trigger setting area Ats (either by a confirmation input or a predetermined time has passed since reaching the area).

[0119] The robot 30 has a vacuum head 31 that is moved by an articulated robot arm 32, but it goes without saying that it is not limited to a vacuum head 31, and may also have a robot hand for handling, a punching head for punching relatively soft ingredients (ground meat, cheese, butter, paste, etc.) that are continuously conveyed, etc.

[0120] As described above, the X-ray inspection system of the present invention can provide an X-ray vision tracking type X-ray inspection system and a calibration method thereof that can accurately track the coordinates of a work object. The present invention is useful for X-ray inspection systems that include an X-ray inspection device that sequentially X-ray inspects items being transported on a conveyor and a robot that performs a predetermined task while following the item transport in accordance with the inspection results, as well as for calibration methods thereof in general. [Explanation of symbols]

[0121] 1 X-ray inspection system 10 X-ray inspection equipment 11 Conveyor 11A Conveyor (X-ray inspection device side conveyor) 11B Conveyor (Robot side conveyor, working area side conveyor) 12 X-ray irradiation section 13 X-ray line sensor 14 Image Memory 15 Inspection control section 16 Image processing section 17 Quality Judgment Department 18 Encoder (Rotary Encoder) 19 Operation display section 20 Control Unit 21 Test information input section 21a First input means 21b second input means 21c Third input means 22 Selection condition setting section 23 Selection request output unit 24 Selection condition determination means 25 Coordinate information acquisition means 26 Coordinate adjustment means (coordinate setting means) 27 Coordinate value conversion means (conversion means, position information output means) 30 Robot 31 Vacuum head 31a Vacuum nozzle 31s, 36s Passage detection sensor 32 Robot Arm 32a First Arm 32b Support stand 32c, 32d geared motor 32e Second Arm 32f Lifting drive mechanism 33, 36 Duct 35 Head body 35a Lifting drive shaft 37 Driving fluid injection unit 39 Robot Controller 40 Sorting conveyor 41 Conveyor 42 Up-out drive actuator 60 Test Charts 61, 62, 64 Base point teaching body (teaching body) 63, 65 Other point teaching body (teaching body) 71 Base sheet 72 Shield 80 Calibration work screen A, B, C, D, E, F coordinates Arw specified operating area Ats Trigger setting area D1 Prescribed transport direction Et0 base point (image trigger base point) Lr Conveying distance (conveying distance) Ox Origin (origin of the work object image, reference position of the object image) Or Origin (the origin of the robot coordinate system of the workpiece image) Svp target image setting size Sxi size (size in the direction of conveyance of sequential X-ray images) Tg Predetermined transport position Vp, Vp(n) Work target image (object image) Vp´ coordinate search window Wp Item (item to be inspected, item to be inspected) Xi, Xi(n), Xi(n-1) sequential X-ray images

Claims

1. an X-ray inspection device (10) that irradiates an inspection object (Wp) conveyed by a conveying means operating under predetermined conveying conditions with X-rays and inspects the inspection object based on an X-ray image obtained by processing detected X-ray transmission data; a robot (30) that receives a trigger signal and performs a predetermined operation on the object to be inspected within a predetermined operating area (Arw) based on information contained in the trigger signal; a control device (20) communicably connected to the X-ray inspection device and the robot; An X-ray inspection system comprising: the X-ray inspection device processes the X-ray transmission data detected within a predetermined period to generate sequential X-ray images (Xi), and when a specific region determined to be a predetermined inspection result is found in the sequential X-ray images, the X-ray inspection device is capable of outputting inspection information including at least region position information indicating the position of the specific region to the control device by communication; The control device position information output means (25, 26) for outputting, as the trigger signal, work position information including information indicating a predetermined work position where the robot should perform the predetermined work based on the inspection information; and a transport signal output means for outputting a transport signal to the robot in accordance with a transport movement amount of the inspection object transported by the transport means at least during the period from when the trigger signal is output until the inspection object, on which the robot is to perform the predetermined task, reaches the predetermined task position within the operating area, the control device is further capable of executing a teaching mode for teaching the robot a correspondence relationship between the area position information and the predetermined work position, The robot is capable of memorizing the correspondence, and performs the specified task after being instructed on the specified task position corresponding to the area position information.

2. 2. The X-ray inspection system according to claim 1, wherein the position information output means outputs the trigger signal when it receives inspection information including the specified inspection result from the inspection information communicated and output from the X-ray inspection device, and does not output the trigger signal when it receives inspection information not including the specified inspection result.

3. 3. The X-ray inspection system according to claim 2, wherein the position information output means outputs the trigger signal every time the inspection information including the predetermined inspection result is received.

4. 3. The X-ray inspection system according to claim 2, wherein the position information output means sequentially stores the inspection information including the predetermined inspection results, and reads out and communicates the inspection information at a predetermined timing.

5. The control device, in the teaching mode, 2. The X-ray inspection system according to claim 1, wherein when the inspection information is received from the X-ray inspection device, transport of the inspection object is stopped at a first stop position, transport of the inspection object is resumed when the trigger signal is communicated to the robot, transport of the inspection object is stopped again at a second stop position where the inspection object is included in the operating area of ​​the robot, and then the robot is taught the correspondence.

6. The X-ray inspection system described in Claim 5, characterized in that the control device increments the conveying means for a predetermined period of time each time it receives a predetermined operation input, and by receiving multiple operation inputs, it conveys the object to be inspected from the first stop position to the second stop position.

7. An X-ray inspection system as described in Claim 5 or 6, characterized in that the control device further has a display means (19) that legibly displays coordinate data based on the area position information when the object to be inspected is stopped at the second stop position.

8. The X-ray inspection system described in Claim 7, characterized in that the control device displays a symbol representing the position of the coordinate data on the display means, directly or indirectly corresponding to the coordinate data in two-dimensional coordinates.

9. The X-ray inspection system described in Claim 7, characterized in that the control device further has a coordinate setting means for accepting input of the coordinate data in order to teach the robot the correspondence, and communicates and outputs the set coordinate data to the robot.

10. 9. The X-ray inspection system according to claim 8, wherein the control device further comprises a coordinate setting means for accepting input of the coordinate data in order to teach the robot the correspondence, and for outputting the set coordinate data to the robot by communication.

11. 7. The X-ray inspection system according to claim 5, wherein the control device communicates and outputs coordinate data based on the area position information to the robot when the object to be inspected is stopped at the second stop position.

12. Using the X-ray inspection system according to claim 1, a control device set to the teaching mode, an object to be inspected having a plurality of teaching bodies attached thereto for generating the specific area that will be the predetermined inspection result by the X-ray inspection device, and a robot taught with the correspondence relationship,

13. 13. The method for calibrating an X-ray inspection system according to claim 12, wherein the teaching bodies include at least one base point teaching body and at least one other point teaching body.

14. 14. The calibration method for an X-ray inspection system according to claim 13, wherein the correspondence is taught to the robot by teaching the position of the base point teaching body and then teaching the position of the other point teaching body to the robot.

15. 15. The method for calibrating an X-ray inspection system according to claim 12, wherein a test chart in which each teaching element is visibly provided on a single base sheet is used as the object to be inspected.

16. a step of identifying a position of a predetermined specific area in an X-ray transmission image acquired of an object to be inspected being transported on a conveyor, and outputting position information of the specific area by communication; a step of communicating and outputting work position information to a robot based on the position information, the work position information being used to cause the robot to perform a predetermined work on the object to be inspected; causing the robot to perform the predetermined task based on the task position information, a step of conveying a test chart having a predetermined teaching object that generates the predetermined specific area in the X-ray transmission image as the inspection object, and starting a teaching mode; acquiring an X-ray transmission image of the test chart, identifying the position of the predetermined specific region in the X-ray transmission image, and outputting the position information by communication at the predetermined timing; controlling the conveyor to stop the transport of the test chart; a step of communicating and outputting the work position information based on the position information; controlling the conveyor to resume transport of the test chart, stop the test chart in the operating area of ​​the robot, and output to the robot a transport signal indicating the amount of transport of the test chart from when the transport was resumed until when the transport was stopped; a step of instructing the robot of the position of the predetermined teaching body on the test chart in the operating area, and calculating and storing a correspondence between the work position information and the position of the predetermined teaching body; and a step of terminating the teaching mode.

17. A test chart for causing the X-ray inspection device to generate sequential X-ray images at a predetermined cycle by being conveyed on a belt conveyor of the X-ray inspection device and passing through an X-ray irradiation area, and for generating a predetermined specific area in the sequential X-ray images, A substrate sheet (71) having a predetermined X-ray transmittance, a test chart characterized in that a plurality of shielding bodies, each having an X-ray shielding rate that provides a predetermined contrast to a portion corresponding to the base sheet in the X-ray sequential images, are fixed at predetermined intervals, and the shielding bodies are visible from at least one side of the base sheet.

18. 18. The test chart according to claim 17, wherein the shielding member is arranged so as to generate the specific region across a plurality of the sequential X-ray images for any given transport timing.

Images