JP7466298B2 - X-ray inspection equipment - Google Patents

Description

The present invention relates to an X-ray inspection device that inspects an object, the contents of which are packaged in a packaging material, by passing X-rays through the object while transporting it, and in particular to an X-ray inspection device that can calculate the position of the center of gravity of the object and output the position to the outside.

The following Patent Document 1 discloses an invention related to an X-ray inspection device. This X-ray inspection device includes a conveyor 10, an X-ray inspection means 20, an opening/closing cover 32 that covers the transport path 10a of the specified transport section D2 downstream of the inspection area in the transport direction, a sorting and discharge mechanism 40 that selectively discharges the inspected object out of the transport path based on the inspection result of the inspection means, and a discharged object storage box 50 that stores the discharged inspected object W. The opening/closing cover 32 is a front-opening type that opens to the upper surface of the transport path 10a of the specified transport section D2 and its front side in the width direction when opened, and the sorting and discharge mechanism 40 is installed on the inner side of the opening/closing cover 32, and the discharged object storage box 50 is arranged on the rear side of the transport path 10a of the specified transport section D2 in the width direction. According to this X-ray inspection device, there is no need to install a sorting device downstream of the transport path cover near the X-ray inspection means, making it possible to make it compact and facilitating maintenance work from the front side.

JP 2007-033403 A

In conventional X-ray inspection devices such as that disclosed in Patent Document 1, moving means may be used to remove products that are determined to be defective from the transport path and to transport inspected objects that are determined to pass to a specified collection position. Known moving means include a sliding device that pushes the product out of the transport path by the reciprocating motion of a mechanism, and a robot arm that holds the product by chucking or suction and moves it to the desired position.

When moving a product using such a moving means, if the position of the product's center of gravity can be assumed to be at a fixed position based on its appearance, there is little chance of problems occurring with the moving means. For example, when pushing the product out with a sliding device, the product can be moved reliably by pushing the product's center of gravity. Also, when moving a product with a robotic arm, the product can be held reliably by targeting the area near the center of gravity, and problems such as dropping a product held by a robotic arm when moving it are unlikely to occur.

However, if the object to be inspected by the X-ray inspection device is a product whose contents are wrapped in packaging material, problems may arise when moving this product using a moving means. In other words, products in which the position of the contents inside the packaging material is not stable and the position of the contents is difficult to determine from the product's appearance are prone to problems when moved by a moving means. For example, when pushing the product out with a sliding device, there is a possibility that the product's center of gravity may not be pushed and the movement may fail. Furthermore, when moving the product with a robotic arm, there is a possibility that the product may not be held properly if a part other than the center of gravity is targeted, or that even if it is held, it may drop during movement.

The present invention was made in consideration of the problems with the conventional technology described above, and aims to enable an X-ray inspection device that inspects products whose contents are packaged in packaging material to calculate and output the position of the center of gravity of an object after inspection in order to serve some technical purpose, such as ensuring reliable handling of the object after inspection.

The X-ray inspection apparatus 2a, 2b, and 2c described in claim 1 are
An X-ray inspection apparatus comprising: conveying means 3, 4 for conveying an object W, W' to be inspected, the object W, W' being packed with a packaging material Wa and a content Wb; an X-ray generator 6 for irradiating the object W, W' to be inspected conveyed by the conveying means 3, 4 with X-rays; and an X-ray detector 7 for detecting the X-rays transmitted through the object W, W' to be inspected, the X-ray inspection apparatus inspecting the object W, W' to be inspected using an X-ray image acquired from the X-rays detected by the X-ray detector 7,
a content area extraction means for extracting a content area indicating the content on the X-ray image;
A center of gravity calculation means 24 for calculating a center of gravity G of the content area;
a center-of-gravity position output means 25 for determining an origin O representing a reference position on the X-ray image from a preset reference position condition, calculating the position of the center of gravity G relative to the origin O, and outputting the calculated position to a control unit 15 for controlling a robot arm 16 for contacting and holding the position of the center of gravity G to move the inspected objects W, W' to a destination according to the inspection result;
Equipped with
An outer region extraction means 22 is provided for extracting an outer region Sa of the packaging material Wa on the X-ray image,
The reference position condition is characterized in that it is determined as the center of the circumscribing circle C of the outline area Sa.

The X-ray inspection apparatuses 2a, 2b, and 2c described in claim 2 are the X-ray inspection apparatus described in claim 1 ,
The present invention is characterized by having a reference position condition setting means 27 for setting the reference position condition.

According to the X-ray inspection apparatus of claim 1,
The contents area of the contents is extracted on the X-ray image, the center of gravity is calculated from the contents area, an origin representing a reference position on the X-ray image is obtained from preset reference position conditions, the position of the center of gravity of the contents relative to that origin is calculated, and the data (coordinates) of this center of gravity position is output to the control unit of a robot arm positioned downstream of the X-ray inspection device, which contacts and holds the position of the center of gravity and moves the inspected object to a destination according to the inspection results, thereby ensuring reliable handling of the inspected object.
In addition, the outer region of the packaging material and the content region of the content can be extracted on the X-ray image, the center of gravity can be calculated from the content region, an origin that represents a reference position on the X-ray image can be obtained from the reference position condition based on the outer region, and the center of gravity position of the content relative to the origin can be calculated and output to the outside. If this center of gravity position data is used to control a product handling device arranged downstream of the X-ray inspection device, for example, it is possible to obtain effects such as reliable handling of the inspected product.
In addition, by assuming a circumscribing circle circumscribing the outer region on the X-ray image, determining the center of the circumscribing circle, and performing a simple calculation to obtain the center of gravity of the content region with the center as the origin, the center of gravity of the content region can be calculated and output to the outside. When using this data on the center of gravity, if an image of the test object is acquired using an imaging means such as a camera at a later stage of handling the test object, the center of gravity position can be accurately grasped by comparing the X-ray image with the image, which has the effect of enabling reliable handling.

According to the X-ray inspection apparatus of claim 2 ,
The reference position condition setting means makes it possible to easily set the data and instructions required to find the origin that represents the reference position on the X-ray image, so that the origin can be easily re-set even if there is a change, such as replacement or rearrangement, of a product handling device located downstream of the X-ray inspection device.

FIG. 1A is a schematic structural diagram of an X-ray inspection apparatus according to a first embodiment, and FIG. 1B is a diagram showing the positional relationship between an X-ray image of an object to be inspected acquired by the X-ray inspection apparatus and a set origin. 2 is a functional block diagram of a control unit of the X-ray inspection apparatus of the first embodiment. FIG. FIG. 11 is a schematic diagram showing the adsorption and movement operation of an object to be inspected by a robot provided downstream of the X-ray inspection apparatus of the first embodiment, where sub-diagrams (a) to (c) show cases where appropriate handling has been performed after receiving center of gravity position data from the X-ray inspection apparatus of the first embodiment, and sub-diagrams (d) and (e) show examples where a robot that does not receive center of gravity position data from the X-ray inspection apparatus fails to hold the object to be inspected. FIG. 1A is a schematic structural diagram of an X-ray inspection device of the second embodiment, and FIG. 1B is a diagram showing an X-ray image of an object to be inspected acquired by the X-ray inspection device and a camera image of the object to be inspected acquired by a camera set up in a subsequent stage. 13 is an explanatory diagram of a calculation in which a circumscribing circle (ellipse) is set on an acquired X-ray image of an object to be inspected and the center of the ellipse is set as the origin in the X-ray inspection apparatus of the second embodiment. FIG. FIG. 13A is a schematic structural diagram of an X-ray inspection apparatus of the third embodiment, and FIG. 13B is a diagram showing the positional relationship between an X-ray image of an inspection object acquired by the X-ray inspection apparatus and a set origin.

An X-ray inspection system according to a first embodiment will be described with reference to FIGS.
As shown in FIG. 1(a), this X-ray inspection system 1a includes an X-ray inspection device 2a that inspects an object W to be inspected using X-rays while transporting it on a first conveyor 3, a second conveyor 4 as a transport means provided downstream of the X-ray inspection device 2a, and a robot 5 as a handling device provided on the downstream side of the second conveyor 4 for moving the inspected object W to a destination according to the inspection results.

The object W to be inspected by this X-ray inspection system 1a is an object W in which contents Wb are wrapped in packaging material Wa, as shown in the X-ray image in FIG. 1(b), and has the characteristic that the position of the contents Wb is difficult to determine from the appearance of the product. When such an object W to be inspected is moved by a robot 5, the position of the contents Wb in the packaging material Wa is unstable, and therefore, if a part other than the center of gravity G is targeted, it may fail to be held (see FIGS. 3(d) and (e)). Therefore, in the X-ray inspection device 2a of the first embodiment, in order to reliably handle the object W to be inspected by the robot 5 after inspection, the position of the center of gravity G of the inspected object W can be calculated and output to the robot 5.

As shown in FIG. 1(a), the X-ray inspection device 2a includes a first conveyor 3, which is a transport means, an X-ray generator 6 that irradiates X-rays onto an object W to be inspected that is transported by the first conveyor 3, and an X-ray detector 7 that detects the X-rays that have passed through the object W to be inspected.

As shown in FIG. 1(a), the first conveyor 3 has an endless conveyor belt 10 wound around one driving roller 8 and three driven rollers 9. The first conveyor 3 receives the objects W to be inspected from a supply source (not shown) for the objects W provided adjacent to the upstream end in FIG. 1(a). The first conveyor 3 transports the objects W to be inspected in a transport direction (also called the X direction) indicated by a horizontal right-facing arrow in the figure. Note that the direction perpendicular to the transport direction in the horizontal plane and toward the back is called the width direction (also called the Y direction) of the conveyor belt 10. In FIG. 1(a), the width direction is the direction perpendicular to the paper surface on the surface of the conveyor belt 10, and is indicated by a circle with an X placed over it at the starting point of the arrow in the figure.

As shown in FIG. 1(a), the X-ray generator 6 is disposed above the center of the first conveyor 3 with its radiation direction facing downward. The X-rays emitted by the X-ray generator 6 toward the conveyor belt 10 below are shown as straight dashed lines extending in the vertical direction within the plane of FIG. 1(a), but when viewed parallel to the conveyor direction, that is, when viewed horizontally from the side in FIG. 1(a), they appear as a roughly triangular radiation surface with the X-ray generator 6 as its apex.

As shown in FIG. 1(a), the X-ray detector 7 is disposed so as to be in contact with the underside of the upper one of the endless transport belts 10 of the first conveyor 3, and so as to be located directly below the X-ray generator 6. The X-ray detector 7 has an X-ray line sensor 11 in which a large number of detection elements are arranged along the width direction (Y direction). The X-ray line sensor 11 detects X-rays and outputs X-ray transmission data, which is sent to the control unit 20 described later.

As shown in FIG. 1(a), a second conveyor 4 is provided as a transport means downstream of the X-ray inspection device 2a. The second conveyor 4 has a structure in which a transport belt 10 is wound around a drive roller 8 and a driven roller 9. The second conveyor 4 has the same height and transport direction as the first conveyor 3, and receives the inspected object W discharged by the first conveyor 3 and transports it downstream.

1(a), a robot 5 serving as a handling device for an object W to be inspected is provided on one side of the downstream side of the second conveyor 4. The robot 5 has a robot control unit 15. The robot control unit 15 performs control operations using data indicating the position of the center of gravity G of the object W to be inspected provided from a control unit 20 of the X-ray inspection device 2a and a detection timing signal in the X direction of the object W to be inspected sent from a sensor A described later. The robot 5 also has a robot arm 16 controlled by the robot control unit 15, and a suction device 17 serving as a gripping means provided at the tip of the robot arm 16.

As shown in FIG. 1(a), a sensor A is provided on the side of the second conveyor 4 upstream of the robot 5 to detect the object W to be inspected being transported by the second conveyor 4. The sensor A is a transmission type having a light projector and a light receiver, and outputs a detection signal when the object W to be inspected enters between them. The detection signal of the sensor A is input to the robot control unit 15 and is used to control the operating position of the robot 5 so as to match the position data of the center of gravity G in the X direction sent from the control unit 20 of the X-ray inspection device 2a.

Although the details of the control will be described later, the robot 5 can hold the test object W by contacting the air suction port of the suction device 17 with the position of the center of gravity G of the test object W and suctioning it, and can release the holding of the test object W by stopping the suction of air, so that the test object W held at the tip of the robot arm 16 can be reliably moved to a desired position by moving the robot arm 16. Note that, as the form of the gripping means provided at the tip of the robot arm 16, the suction device 17 that sucks and holds the test object W by sucking in air is exemplified, but a clamping device that holds the test object W by pinching two sides of the test object W with multiple claw-like bodies, or a sliding movement device that contacts one side of the test object W and slides it can also be used. The form of the gripping means is preferably selected taking into consideration the shape and weight of the test object W, the direction and distance of movement, and the required moving speed, etc., of the target test object W, and in any form, the action of the gripping means of each form of the robot arm 16 is controlled so as to be appropriately applied to the center of gravity G of the test object W.

The control unit 20 of the X-ray inspection apparatus 2a will be described with reference to FIGS.
1A and 2, the X-ray transmission data output from the X-ray line sensor 11 is input to the control unit 20 of the X-ray inspection apparatus 2a. As shown in Fig. 2, the X-ray transmission data of the inspection object W sent from the X-ray detector 7 is stored in the storage means 21 of the control unit 20. The storage means 21 stores, for example, several hundred pieces of X-ray transmission data corresponding to the number of detection elements per line (Y direction) of the X-ray detector 7, for at least a predetermined number of lines (for example, several hundred lines) corresponding to the length (length from the front end to the rear end) of the inspection object W being transported in the transport direction (X direction).

As shown in FIG. 2, the control unit 20 has an outline region extraction means 22. The outline region extraction means 22 creates an X-ray image of a predetermined size including the inspection object W, from the X-ray transmission data stored in the memory means 21, with density levels corresponding to shading values that become lighter as the amount of transmission increases. FIG. 1(b) is a schematic diagram of this X-ray image. The outline region extraction means 22 extracts from this X-ray image a portion with a density level equal to or greater than a specified threshold as the outline region Sa of the packaging material Wa. In the X-ray image shown in FIG. 1(b), the inner portion of the packaging material Wa that forms the outline of the inspection object W is the outline region Sa.

The outer region extraction means 22 obtains an overall density histogram of the X-ray image created from the X-ray transmission data stored in the memory means 21, and from this density histogram, separates and binarizes the data of the object W to be inspected and the data other than the object W to be inspected (the belt surface). For example, in the overall density histogram, the data is binarized by setting the data of the object W to 255 and the data other than the object W to 0, and from the binarized data, the data of the object W to be inspected can be extracted as the outer region Sa of the packaging material Wa.

As shown in FIG. 2, the control unit 20 has a contents area extraction means 23. The contents area extraction means 23 extracts a portion of the X-ray image within the outer area Sa that has a density level equal to or greater than a specified threshold as a contents area Sb that corresponds to the contents Wb of the inspection object W. In the X-ray image shown in FIG. 1(b), the inner portion of the contents Wb inside the packaging material Wa of the inspection object W is the contents area Sb.

In addition, the content area extraction means 23 may extract X-ray images with a density level exceeding a predetermined threshold as content areas Sb corresponding to the contents Wb of the object W to be inspected, in parallel with the extraction process of the outer shape area Sa.

As shown in FIG. 2, the control unit 20 has a center of gravity calculation means 24 that calculates the center of gravity G. The center of gravity calculation means 24 calculates the center of gravity G of the content area Sb of the X-ray image. Specifically, in the X-ray image shown in FIG. 1(b), provisional center of gravity coordinates relative to a provisional origin are calculated for a plurality of pixels (not shown) that constitute the content area Sb. The coordinates of the provisional origin can be, for example, the minimum and maximum values in the X and Y directions of the content area Sb in a coordinate system in which the lower left corner of the X-ray image is (0,0).

As shown in FIG. 2, the control unit 20 has a reference position condition setting means 27. The reference position condition setting means 27 sets a reference position condition for determining the origin O of the coordinates that serve as the reference for data when calculating data on the position of the center of gravity G of the contents Wb of the inspection object W based on the center of gravity G calculated by the center of gravity calculation means 24 in the X-ray image shown in FIG. 1(b). Note that the reference position condition may be set to a fixed value inside the device if there is no change in the operation of the X-ray inspection system.

First, in the X-ray inspection device 2a of the first embodiment, as shown in FIG. 1(b), a predetermined position L in the width direction of the second conveyor 4 that transports the inspection object W handled by the robot arm 16 is set to the position of the origin O in the Y direction. Specifically, the predetermined position L in the Y direction can be a position of one edge in the width direction of the transport belt 10, or a guide plate (not shown) parallel to the transport direction that is provided along one edge in the width direction of the transport belt 10.

Specifically, the numerical data indicating the distance between a predetermined position L1 in the width direction of the second conveyor 4 and an edge L2 in the Y direction of the X-ray image shown in FIG. 1(b) is set as the reference position condition in the Y direction. The equipment such as the second conveyor 4 and the robot 5 arranged downstream of the X-ray inspection device 2a may be changed to a different model as necessary, in which case the predetermined position L1 in the Y direction of the downstream equipment may also be changed. Therefore, it is convenient to make the numerical data indicating this predetermined position L1 not a fixed value, but to be able to input any numerical value from the reference position condition setting means 27.

In the X-ray inspection device 2a of the first embodiment, as shown in FIG. 1(b), the corner on the downstream side in the X-direction of the outer region Sa of the inspection object W in the X-ray image is set as the reference position condition in the X-direction. The position of the origin O in the X-direction is automatically determined by the control unit 20 acquiring the X-ray image in accordance with this reference position condition.

2, the control unit 20 has a center of gravity position output means 25 that calculates and outputs the position of the center of gravity G. The center of gravity position output means 25 obtains the origin O based on the reference position conditions in the X direction and the reference position conditions in the Y direction described above, and calculates the position of the center of gravity G of the content area Sb relative to the origin O from this origin O and the virtual origin and virtual center of gravity coordinates calculated by the center of gravity calculation means 24. Specifically, in the same coordinate system as the center of gravity calculation means 24, the distance between the specified position L1 and the edge L2, which is the reference position condition in the Y direction, is converted into the number of pixels to obtain the Y coordinate, and the corner on the most downstream side in the X direction is obtained as the X coordinate. Then, the obtained X coordinate and Y coordinate are set as the origin O, and the position of the center of gravity G is calculated by correcting the value of the virtual center of gravity coordinate for the amount of deviation in each direction between the origin O and the virtual origin. The calculated position data of the center of gravity G is output to the robot control unit 15.

As shown in FIG. 1(a), the position data of the center of gravity G output by the control unit 20 of the X-ray inspection device 2a is input to the robot control unit 15. In addition, a detection signal from a sensor A provided on the second conveyor 4 is also input to the robot control unit 15. The detection signal from sensor A indicates that the X-direction position of the origin O set by the control unit 20, i.e., the most downstream corner of the inspected part, has been detected by sensor A on the second conveyor 4 upstream of the robot 5.

As shown in FIG. 2, the control unit 20 has a display unit 26. The display unit 26 can display information necessary for control, such as data and instructions input to the control unit 20, X-ray images acquired by the control unit 20, an origin O set in the control unit 20, and the position of the center of gravity G calculated based on the origin O.

According to the X-ray inspection system 1a configured as above, the following advantageous effects can be obtained.
The object W to be inspected is conveyed by the first conveyor 3, and X-rays irradiated from the X-ray generator 6 pass through the object W to be detected by the X-ray detector 7. The control unit 20 of the X-ray inspection device 2a obtains an X-ray image as shown in FIG. 1(b) from the X-ray transmission data from the X-ray detector 7, and extracts an outer shape area Sa of the packaging material Wa and a content area Sb of the content Wb from the X-ray image. Furthermore, the control unit 20 calculates the center of gravity of the content area Sb, and obtains an origin O representing a reference position on the X-ray image based on the reference position conditions input by the reference position condition setting means 27. The control unit 20 then calculates the center of gravity position of the content relative to the origin O, and outputs position data of the center of gravity G to the robot control unit 15.

After passing through the X-ray inspection device 2a, the object W to be inspected transfers to the second conveyor 4 and passes through sensor A. The robot control unit 15 uses a predetermined position L1 in the width direction of the second conveyor 4, which is the basis of the set reference position condition in the Y direction, as a reference, and measures the timing using the detection signal of sensor A indicating the position of the origin O in the X direction to determine the destination of the suction device 17 of the robot 5 so that it matches the center of gravity position from the X-ray inspection device 2a. This allows the robot 5 to reliably suction and hold the object W to be inspected at the center of gravity position, and to reliably handle the object W, such as moving the object W to a desired position for the packing process without dropping it, or removing it from the second conveyor 4.

Figures 3(a) to (c) are schematic diagrams showing the suction and movement of the inspection object W by the robot 5 in the first embodiment. As described above, the inspection object W targeted by this X-ray inspection system 1a is an object W in which contents Wb are wrapped in packaging material Wa, and the position of the contents Wb is difficult to determine from the appearance of the product. However, the robot 5, which acquires position data of the center of gravity G from the X-ray inspection device 2a, can suction the suction device 17 to a surface position corresponding to the center of gravity G of the inspection object W. Therefore, the suction is reliable and the inspection object W does not fall during movement, allowing proper handling.

In contrast, Figures 3(d) and (e) show a case where the X-ray inspection device 2a cannot output position data of the center of gravity G, i.e., a case where the movement of the object to be inspected W described in the prior art is hindered. If the robot 5 cannot use the position data of the center of gravity G of the object to be inspected W, it becomes difficult for the robot 5 to adhere to the surface of the object to be inspected W at the position of the center of gravity G. Holding the object to be inspected W by suction becomes unreliable, and there is an increased risk that the object to be inspected W will fall when moved.

In the first embodiment described above, the reference position condition in the Y direction is based on a predetermined position L1 in the width direction of the second conveyor 4, which is mechanically fixed, so even if the X-ray image is not particularly clear, at least the origin O in the Y direction can be determined precisely. Therefore, good results can be expected in terms of the calculation accuracy of the position of the center of gravity G of the object W to be output.

The X-ray inspection system 1b of the second embodiment will be described with reference to FIG. 4, focusing on the parts that differ from the first embodiment. The same parts as in the first embodiment (FIG. 1) are assigned the same reference numerals in FIG. 4. For the same configurations and effects as the first embodiment, the description of the first embodiment and FIG. 2 are used.

As shown in FIG. 4(a), in the X-ray inspection system 1b of the second embodiment, a camera 30 serving as an imaging means is provided facing downward above the upstream side of the robot 5 on the second conveyor 4 following the X-ray inspection device 2b. The sensor A of the first embodiment is not present in the second embodiment. The camera image output by the camera 30 is input to the robot control unit 15. The camera image is an image on the XY coordinate plane similar to the X-ray image acquired by the X-ray inspection device 2b.

According to the X-ray inspection device 2b of the second embodiment, the outer region extraction means 22 of the control unit 20 determines the origin O based on the outer region Sa extracted from the X-ray image shown in FIG. 4(b). That is, by operating the reference position condition setting means 27 (see FIG. 2), a part of the outer region Sa of the X-ray image, for example, a part (the lowest corner in this example) located at the minimum value in the Y direction in the same coordinate system as the center of gravity calculation means 24 in the X-ray image of FIG. 4(b) can be set as the reference position condition. In this way, it is convenient to determine in advance which part of the X-ray image is to be the reference position condition, but it may also be set by the reference position condition setting means 27 each time depending on the type of product.

According to the second embodiment of the X-ray inspection device 2b, the center of gravity position output means 25 of the control unit 20 determines the origin O based on the set reference position conditions, and calculates the position of the center of gravity G of the content area Sb of the X-ray image relative to the origin O from this origin and the virtual origin and virtual center of gravity coordinates calculated by the center of gravity calculation means 24, and outputs the position to the robot control unit 15.

As shown in FIG. 4(b), the robot control unit 15 obtains an origin O2 for the camera image sent from the camera 30, which is located at the same position as the origin on the X-ray image based on the external shape of the object W to be inspected, and determines the position of the center of gravity G2 in the camera image based on the origin O2, and determines this as the movement destination of the suction device 17 of the robot 5. The robot arm 16 is operated in accordance with the timing of the camera image acquisition by the camera 30, and the suction device 17 is moved to the position of the center of gravity of the object W to be inspected. This allows the object W to be securely held by suction, and the object W to be moved to a desired position for the boxing process without dropping, or to be removed from the second conveyor 4, thereby enabling reliable handling of the object W.

Figure 5 is a diagram showing a modified example of the method of setting the origin O in the X-ray inspection device 2b of the second embodiment. In this modified example, the control unit 20 of the X-ray inspection device 2b sets a circumscribing circle (ellipse) on the image of the object W in the acquired X-ray image, and sets its center as the origin O. More specifically, in the image of the object W shown in Figure 5, an ellipse (circle) C passing through the four vertices P1, P2, P3, and P4 of the outer shape area Sa, which is the maximum area, is drawn, and the intersection of the major axis and minor axis of the drawn ellipse (circle) C is calculated and set as the origin O. Although the content area Sb is not shown in the image of the object W in Figure 5, the center of gravity G of the content area Sb is calculated based on the set origin O and output to the robot control unit 15.

In the second embodiment (including the modified example) described above, the origin O is determined based on the external shape of the object W in the X-ray image, so favorable results can be obtained when the X-ray image is particularly clear. For example, when the object W is an item with small dimensions in the X-ray irradiation direction (i.e., relatively small height), the spread of the X-rays that pass through the object W is relatively small and the contour of the X-ray image is relatively clear, so that favorable results can be expected in terms of the accuracy of the calculation of the position of the center of gravity G of the contents of the object W in the X-ray image.

The X-ray inspection system 1c of the third embodiment will be described with reference to FIG. 6, focusing on the parts that differ from the first embodiment. The same parts as in the first embodiment (FIG. 1) are assigned the same reference numerals in FIG. 6. For the same configurations and effects as the first embodiment, the description of the first embodiment and FIG. 2 are used.

The third embodiment shown in FIG. 6(a) differs from the first embodiment shown in FIG. 1 in terms of the shape of the object to be inspected W. The object to be inspected W' to which the third embodiment is applied is an object with a large dimension in the direction of X-ray irradiation (i.e., a relatively large height). In the case of such an object to be inspected W', the spread of the X-rays that pass through the object to be inspected W' becomes relatively large, and the contour of the X-ray image becomes blurred and relatively unclear. Therefore, if the origin O is set based on the X-ray image, there is a risk that the accuracy of the position of the center of gravity G of the object to be inspected W' calculated based on this may decrease.

The third embodiment shown in FIG. 6(a) differs from the first embodiment shown in FIG. 1 in that a sensor B is provided on the first conveyor 3 to set the origin O in the X-direction due to the above-mentioned characteristics of the shape of the inspection object W'. That is, the first conveyor 3 is provided with a sensor B downstream of the X-ray detector 7 to detect the inspection object W' being conveyed. This sensor B has the same configuration as the sensor A provided on the second conveyor 4, but the detection signal of the sensor B is input to the center of gravity position output means 25 (see FIG. 2) of the control unit 20 of the X-ray inspection device 2c and is used to obtain the X-direction of the origin O. That is, as shown in FIG. 6(b), the detection signal of the sensor B detects the position of the most downstream edge in the outer region Sa of the X-ray image, and in the X-ray inspection device 2c of the third embodiment, this is set as the origin O in the X-direction. That is, the position in the X-direction corresponding to the input timing of the detection signal of the sensor B becomes the origin O in the X-direction.

As shown in FIG. 6(b), in the X-ray inspection device 2c of the third embodiment, the reference position condition in the Y direction is the numerical data indicating the distance between a predetermined position L1 in the width direction of the second conveyor 4 and an edge L2 parallel to the X direction of the X-ray image. This is the same as in the first embodiment described above, and the origin O in the Y direction is precisely determined.

According to the X-ray inspection system 1c of the third embodiment, the following advantageous effects can be obtained.
The object W' to be inspected is conveyed by the first conveyor 3, and as in the first embodiment, the control unit 20 acquires an X-ray image and extracts from the X-ray image the outer region of the packaging material Wa and the content region Sb of the content Wb. Furthermore, the control unit 20 calculates the center of gravity of the content region Sb and determines an origin O that represents a reference position on the X-ray image based on the reference position conditions input by the reference position condition setting means 27. The control unit 20 then calculates the position of the center of gravity of the content relative to the origin O and outputs position data of the center of gravity G to the robot control unit 15.

After passing through the X-ray inspection device 2c, the object W' to be inspected transfers to the second conveyor 4 and passes through the sensor A. The robot control unit 15 uses the predetermined position L1 in the width direction of the second conveyor 4, which is the basis of the set reference position condition in the Y direction, as a reference, and matches the input timing of the detection signal of the sensor B indicating the position of the origin O in the X direction with the input timing of the object W' to be inspected by the sensor A to determine the center of gravity position from the X-ray inspection device 2c as the destination of the suction device 17 of the robot 5. This allows the robot 5 to reliably suction and hold the object W' to be inspected at the center of gravity position, and to reliably handle the object W', such as moving the object W' to a desired position for the packing process without dropping it, or removing it from the second conveyor 4.

As described above, according to the X-ray inspection device provided in the X-ray inspection system of the embodiment, the outer region of the packaging material and the content region of the contents are extracted from the acquired X-ray image, the center of gravity is calculated from the content region, the origin O representing the reference position on the X-ray image is obtained from the preset reference position condition, and the center of gravity position of the contents relative to the origin O can be calculated and output to the outside. The reference position condition for obtaining the origin O can be set based only on the outer region of the X-ray image, or can be set using a predetermined position on the mechanism of the second conveyor 4 provided in the subsequent stage, or can be set by detecting a specific location corresponding to the outer region of the X-ray image with a sensor B provided on the first conveyor 3. Such reference position conditions can be arbitrarily selected according to the characteristics of the object to be inspected. Then, if the data on the center of gravity position output by the X-ray inspection device is used to control the product handling device arranged in the subsequent stage of the X-ray inspection device, it is possible to obtain effects such as reliable movement and sorting of the object to be inspected.

DESCRIPTION OF SYMBOLS 1a, 1b, 1c...X-ray inspection system 2a, 2b, 2c...X-ray inspection device 3...First conveyor as transport means 4...Second conveyor as transport means 5...Robot as handling device 6...X-ray generator 7...X-ray detector 15...Robot control unit 20...Control unit of X-ray inspection device 22...Outer area extraction means 23...Content area extraction means 24...Center of gravity calculation means 25...Center of gravity position output means 27...Reference position condition setting means 30...Camera A...Sensor B...Sensor C...Ellipse which is a circumscribing circle of the outer area O...Origin G...Center of gravity W, W'...Item to be inspected Wa...Packaging material Wb...Contents Sa...Outer area of packaging material Sb...Content area of contents L1...Predetermined position in the width direction of the transport means

Claims (2)

An X-ray inspection device comprising: conveying means (3, 4) for conveying an object to be inspected (W, W') having contents (Wb) packed in a packaging material (Wa); an X-ray generator (6) for irradiating the object to be inspected conveyed by the conveying means with X-rays; and an X-ray detector (7) for detecting the X-rays transmitted through the object to be inspected, the X-ray inspection device inspecting the object to be inspected using an X-ray image acquired from the X-rays detected by the X-ray detector,
a content area extraction means (23) for extracting a content area (Sb) showing the content on the X-ray image;
A center of gravity calculation means (24) for calculating a center of gravity (G) of the content area;
a center-of-gravity position output means (25) for determining an origin representing a reference position on the X-ray image from a preset reference position condition, calculating the position of the center of gravity relative to the origin, and outputting the calculated position to a control unit (15) for controlling a robot arm (16) for contacting and holding the position of the center of gravity to move the inspected object to a destination according to the inspection result;
Equipped with
An outer region extraction means (22) for extracting an outer region (Sa) of the packaging material on the X-ray image,
An X-ray inspection apparatus (2a, 2b, 2c) characterized in that the reference position condition is determined as the center of a circumscribing circle (C) of the outer shape area . 2. The X-ray inspection apparatus (2a, 2b, 2c) according to claim 1, further comprising a reference position condition setting means (27) for setting the reference position condition.

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