JP2018105697A - Mass estimation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable mass estimation device for irradiating an object article with an electromagnetic wave and estimating mass on the basis of the amount of the electromagnetic wave having passed through the object article, with which it is possible to perform mass estimation with high accuracy irrespective of variation in physical quantities such as the mass and size of the object article.SOLUTION: An X-ray inspection device 10 comprises an X-ray irradiation unit 13, an X-ray line sensor 14, a temporary mass calculation unit 21c, a storage unit 22 and a mass estimation unit 21d. The temporary mass calculation unit 21c calculates the temporary mass of an article on the basis of the measurement result of the X-ray line sensor 14. The storage unit 22 stores mass correlation information that represents a correlation between the amount of X-ray and the mass of the article for each mass zone of an object article. The mass estimation unit 21d selects mass correlation information corresponding to a mass zone to which belongs the temporary estimated mass calculated by the temporary mass calculation unit 21c from among the mass correlation information per mass zone stored in the storage unit, and estimates the mass of the article on the basis of the selected mass correlation information and the amount of X-ray.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a mass estimation apparatus that irradiates a target article with electromagnetic waves and estimates mass based on the amount of electromagnetic waves that have passed through the target article.

  2. Description of the Related Art Conventionally, there has been known a mass estimation apparatus that irradiates a target article with electromagnetic waves and performs mass estimation based on the amount of electromagnetic waves that have passed through the target article.

  For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-296022) discloses an apparatus that irradiates an inspection object with X-rays and estimates the mass of the inspection object based on the amount of X-rays that have passed through the inspection object. It is disclosed. Note that the amount of X-rays that pass through the inspection object varies depending on the type of inspection object (composition of the inspection object, etc.) even if the thickness of the inspection object is the same. Therefore, in patent document 1 (Unexamined-Japanese-Patent No. 2002-296022), the mass of the to-be-inspected object is estimated using the relational expression of X-ray transmission amount and mass according to the kind of to-be-inspected object.

  By the way, in an actual mass estimation scene, there is a case where mass estimation is required for an inspection object having a relatively large individual difference in physical quantities such as mass and size. In such a case, a relatively large error occurs between the estimated mass and the actual amount of the inspection object only by using the relational expression between the X-ray transmission amount and the mass corresponding to the type of the inspection object. The present inventor has found that there is a case.

  An object of the present invention is a mass estimation apparatus that irradiates a target article with electromagnetic waves and performs mass estimation based on the amount of electromagnetic waves that have passed through the target article, and relates to variations in physical quantities such as mass and size of the target article. It is an object of the present invention to provide a highly reliable mass estimation apparatus capable of accurately performing mass estimation.

  A mass estimation apparatus according to a first aspect of the present invention includes an irradiation unit, a measurement unit, a temporary physical quantity calculation unit, a storage unit, and a mass estimation unit. The irradiation unit irradiates the target article with electromagnetic waves. The measurement unit measures the amount of electromagnetic waves that have passed through the target article. The temporary physical quantity calculation unit calculates the temporary physical quantity of the target article based on the measurement result of the measurement unit. A memory | storage part memorize | stores the mass correlation information showing the correlation with the quantity of electromagnetic waves, and the mass of a target article for every physical quantity zone | band of a target article. The mass estimation unit selects the mass correlation information corresponding to the physical quantity band to which the temporary physical quantity calculated by the temporary physical quantity calculation unit belongs from the mass correlation information for each physical quantity band stored in the storage unit, and the selected mass correlation information Based on the amount of electromagnetic waves, the mass of the target article is estimated.

  When there is a relatively large individual difference in physical quantity (for example, mass or size (volume, area, article length, circumference length, etc.)) regarding the size of the target article, the target article passes through the target article with respect to the target article having a significantly different physical quantity. It is usually difficult to obtain mass correlation information 1 that accurately represents the correlation between the amount of electromagnetic waves and the mass of the portion through which the electromagnetic waves have passed. For example, even if high-accuracy mass correlation information is obtained for a target article having an average physical quantity, if the physical quantity deviates from the average value, the accuracy may decrease.

  In contrast, the mass estimation apparatus according to the first aspect of the present invention calculates a temporary physical quantity (for example, approximate mass, size (volume, area, article length, circumference length, etc.)) of a target article, and then calculates the provisional physical quantity. The estimated mass of the target article is calculated using the mass correlation information prepared for the physical quantity band to which the physical quantity applies. Therefore, even when the individual difference of the physical quantity related to the size of the target article is relatively large, accurate mass estimation is possible regardless of the physical quantity of the target article.

  In addition, depending on the physical quantity of the target article, in other words, depending on the growth of the target article, etc., natural objects (agricultural products, seafood, livestock products, etc.) that tend to cause differences in the density or composition of the target article are target articles In addition, after calculating the temporary physical quantity of the target article, the estimated mass of the target article is calculated again using the mass correlation information prepared for the physical quantity band to which the temporary physical quantity applies, so the physical quantity related to the size of the target article Regardless of this, accurate mass estimation is possible.

  The mass estimation apparatus according to the second aspect of the present invention is the mass estimation apparatus according to the first aspect, and the storage unit represents the correlation between the amount of electromagnetic waves and the mass of the target article for each type of target article. Further stores approximate mass correlation information. The temporary physical quantity calculation unit calculates the temporary estimated mass of the target article as a temporary physical quantity based on the approximate mass correlation information and the amount of electromagnetic waves.

  In the mass estimation device according to the second aspect of the present invention, the temporary estimated mass, which is a temporary physical quantity, is calculated with a relatively easy configuration, and further, the final mass of the target article is calculated using the mass correlation information prepared for each mass band. Accurate mass can be calculated with high accuracy.

  The mass estimation apparatus according to the third aspect of the present invention is the mass estimation apparatus according to the second aspect, further comprising a correlation information learning unit. The correlation information learning unit derives the mass correlation information and the approximate mass correlation information based on the measurement result of the amount of electromagnetic wave that has passed through the target article whose mass is known.

  In the mass estimation device according to the third aspect of the present invention, the mass correlation information and the approximate mass correlation information are derived based on the actual measurement result of the target article at the time of initial setting or the like, so that the mass of the target article is accurately estimated. Easy to do.

  A mass estimation apparatus according to a fourth aspect of the present invention is the mass estimation apparatus according to the third aspect, wherein the correlation information learning unit detects a target article whose mass is known and whose mass is close to a representative value of the mass of the target article. Based on the measurement result by the measurement unit of the amount of electromagnetic wave that has passed, approximate mass correlation information is derived. The correlation information learning unit derives mass correlation information based on the measurement result of the amount of electromagnetic wave that has passed through three or more target articles having known masses and different masses.

  In the mass estimation apparatus according to the fourth aspect of the present invention, the approximate mass correlation information is derived based on the amount of electromagnetic waves that have passed through the target article whose mass is close to the representative value, so that the approximate mass is determined regardless of the mass of the target article. The temporary mass can be estimated with relatively high accuracy using the correlation information. In addition, by deriving mass correlation information based on the amount of electromagnetic waves that have passed through three or more target articles having different masses, it is possible to derive appropriate mass correlation information for each mass band. The mass can be estimated with high accuracy.

  A mass estimation apparatus according to a fifth aspect of the present invention is the mass estimation apparatus according to the first aspect, and the storage unit represents a correlation between the size of the target article and the mass of the target article for each type of the target article. The size-mass correlation information is further stored. The temporary physical quantity calculation unit determines the size of the target article based on the measurement result of the measurement unit, and calculates the temporary estimated mass of the target article as the temporary physical quantity based on the determined size and the size-mass correlation information.

  In the mass estimation device according to the fifth aspect of the present invention, the temporary estimated mass, which is a temporary physical quantity, is calculated with a relatively easy configuration, and further, the final mass of the target article is calculated using the mass correlation information prepared for each mass band. Accurate mass can be calculated with high accuracy.

  The mass estimation apparatus according to the sixth aspect of the present invention is the mass estimation apparatus according to the first aspect, and the temporary physical quantity calculation unit calculates the size of the target article as the temporary physical quantity.

  In the mass estimation apparatus according to the sixth aspect of the present invention, after calculating the size of the target article, which is a temporary physical quantity, the final mass of the target article is accurately calculated using the mass correlation information prepared for each size band. can do.

  A mass estimation apparatus according to a seventh aspect of the present invention is the mass estimation apparatus according to any one of the first to sixth aspects, and further includes a rank determination unit. The rank determination unit determines the rank of the target article based on the estimated mass of the target article calculated by the mass estimation unit.

  In the mass estimation apparatus according to the seventh aspect of the present invention, the rank can be appropriately determined based on the mass of the target article estimated with high accuracy.

  A mass estimation apparatus according to an eighth aspect of the present invention is the mass estimation apparatus according to any one of the first to seventh aspects, and further includes an input unit that inputs a boundary value of the physical quantity band.

  In the mass estimation apparatus according to the eighth aspect of the present invention, it is possible to appropriately set which mass correlation information should be used for each physical quantity band based on the result of actual mass estimation and the like. Therefore, it is possible to accurately estimate the mass of the target article.

  A mass estimation apparatus according to a ninth aspect of the present invention is the mass estimation apparatus according to any one of the first to eighth aspects, and the electromagnetic wave is an X-ray.

  In the mass estimation apparatus according to the ninth aspect of the present invention, mass estimation can be accurately performed on a wide range of articles by using X-rays having strong penetrating power as electromagnetic waves.

  The mass estimation apparatus according to the present invention calculates the estimated physical mass of the target article using the mass correlation information prepared for the physical quantity band to which the temporary physical quantity applies after calculating the temporary physical quantity of the target article. Therefore, even when the individual difference of the physical quantity related to the size of the target article is relatively large, accurate mass estimation is possible regardless of the physical quantity of the target article.

1 is a schematic configuration diagram of a rank selection system having an X-ray inspection apparatus according to a first embodiment of a mass estimation apparatus of the present invention. It is an external appearance perspective view of the X-ray inspection apparatus of FIG. It is an internal block diagram which showed typically the inside of the shield box of the X-ray inspection apparatus of FIG. It is a figure for demonstrating the measurement of the X-ray which passes the articles | goods by the X-ray line sensor of the X-ray inspection apparatus of FIG. It is a block block diagram of the X-ray inspection apparatus of FIG. It is a flowchart explaining the flow of learning of approximate mass correlation information and mass correlation information for each mass band by the correlation information learning unit of the X-ray inspection apparatus of FIG. It is an example of the approximate mass estimation curve showing the correlation with the brightness | luminance (amount of X-rays) prepared for every kind of articles | goods memorize | stored in the memory | storage part of the X-ray inspection apparatus of FIG. X-ray luminance (amount of X-rays) and mass prepared for each mass band (for each range of provisional estimated mass values) for a certain type of article stored in the storage unit of the X-ray inspection apparatus in FIG. It is an example of the mass estimation curve showing a correlation with. (A) is the mass estimation curve prepared about the mass band (3rd mass band) more than boundary value Y2 in FIG. (B) is a mass estimation curve prepared for a mass band (first mass band) smaller than the boundary value Y1 in FIG. It is a flowchart of the rank determination process of the X-ray inspection apparatus of FIG. It is a block block diagram of the X-ray inspection apparatus which concerns on 2nd Embodiment of the mass estimation apparatus of this invention. It is a flowchart explaining the flow of the learning of the size mass correlation information by the correlation information learning part of the X-ray inspection apparatus of FIG. It is the graph which showed the relationship between the size of the target article of mass estimation by the X-ray inspection apparatus of FIG. 10, and mass. It is a block block diagram of the X-ray inspection apparatus which concerns on 3rd Embodiment of the mass estimation apparatus of this invention. It is a flowchart explaining the flow of the learning of the mass correlation information for every size band by the correlation information learning part of the X-ray inspection apparatus of FIG. It is a flowchart of the rank determination process of the X-ray inspection apparatus of FIG.

  Hereinafter, embodiments of the mass estimation apparatus of the present invention will be described with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention. The following embodiments can be variously modified without departing from the gist of the present invention.

<First Embodiment>
An X-ray inspection apparatus 10 according to a first embodiment of a mass estimation apparatus of the present invention will be described.

(1) Rank selection system provided with X-ray inspection apparatus First, an embodiment of the rank selection system 100 provided with the X-ray inspection apparatus 10 will be described.

  FIG. 1 is a schematic configuration diagram of a rank selection system 100 having an X-ray inspection apparatus 10 according to the first embodiment of the present invention.

  The rank sorting system 100 is a system that calculates an estimated mass of articles such as foods that are successively conveyed, determines the rank of the articles based on the calculated estimated mass, and sorts the articles by rank.

  In the following description, an article for which an estimated mass is calculated in the rank selection system 100 (an object for sorting by rank) is referred to as an article A with reference symbol A. As shown in FIG. 1, the same reference symbol A is attached to all articles for which the estimated mass is calculated, but this does not mean that all the articles are uniform. There are individual differences in the mass of articles. In FIG. 1, the article A is drawn with a square having the same size and the same shape, but there are individual differences in the size (for example, volume, area, article length, circumference length, etc.) and shape of the article A. The article A is a natural product such as an agricultural product, a marine product, or a livestock product.

  The rank selection system 100 mainly includes a front conveyor 70, an X-ray inspection apparatus 10, a rear conveyor 80, and a sorting apparatus 90.

  The front conveyor 70 conveys the article A to the X-ray inspection apparatus 10. The X-ray inspection apparatus 10 calculates the estimated mass of the article A while further conveying the article A that has been conveyed by the front conveyor 70, and determines the rank of the article A based on the calculated estimated mass. The rank determination result of the X-ray inspection apparatus 10 is transmitted to the sorting apparatus 90. The post-stage conveyor 80 conveys the article A after rank determination by the X-ray inspection apparatus 10. The sorting device 90 is provided along the rear conveyor 80. Although the type of the sorting device is not limited, for example, the sorting device 90 includes a plurality of arm members 91 that can rotate so as to project on the conveyance path of the rear conveyor 80. The plurality of arm members 91 are arranged side by side along the rear conveyor 80. Each of the plurality of arm members 91 is associated with a predetermined one rank of the article A. When the rank-determined article A is conveyed by the rear conveyor 80, the sorting device 90 moves the arm member 91 associated with the rank of the article A onto the conveyance path of the rear conveyor 80 according to the result of the rank determination. The article A is extended to guide the article A out of the rear conveyor 80. The article guided to the outside of the rear conveyor 80 by the arm member 91 enters a case corresponding to the arm member 91 (case provided for each rank).

  In the following description, the mass estimation function of the X-ray inspection apparatus 10 and the rank determination function based on the mass will be described. However, the X-ray inspection apparatus 10 has other functions, for example, the inclusion of foreign matter in the article A. It may have an inspection function for presence or absence. Then, the article A determined by the X-ray inspection apparatus 10 as having foreign matters mixed therein may be configured to be discharged out of the rank sorting system 100.

(2) X-ray inspection apparatus The X-ray inspection apparatus 10 will be described below with reference to the drawings.

  FIG. 2 is an external perspective view of the X-ray inspection apparatus 10. FIG. 3 is an internal configuration diagram schematically showing the inside of the shield box 11 of the X-ray inspection apparatus 10. FIG. 4 is a diagram for explaining measurement of X-rays passing through an article by the X-ray line sensor 14 of the X-ray inspection apparatus 10. FIG. 5 is a block configuration diagram of the X-ray inspection apparatus 10.

  In the following description, expressions indicating directions such as “up”, “down”, “left”, “right”, “front (front)”, “rear (back)” may be used. Unless otherwise noted, these directions indicate directions indicated by arrows in FIGS. 2 and 3.

  The X-ray inspection apparatus 10 mainly includes a shield box 11, a conveyor 12, an X-ray irradiator 13, an X-ray line sensor 14, a touch panel monitor 30, and a computer 20 (FIGS. 2, 3, and FIG. 5).

(2-1) Shield Box The shield box 11 is a casing that accommodates various configurations of the X-ray inspection apparatus 10 such as the conveyor 12, the X-ray irradiator 13, the X-ray line sensor 14, and the computer 20.

  A touch panel monitor 30, a switch for operation, and the like are disposed on the upper front portion of the shield box 11 (see FIG. 2).

  Each of the left and right side surfaces of the shield box 11 is formed with an opening 11a for carrying the article A into the shield box 11 (inspection space) and carrying the article A out of the shield box 11 (FIG. 2). The opening 11 a is closed by a shielding noren (not shown) in order to prevent leakage of X-rays to the outside of the shield box 11. The shielding nolen is made of rubber containing lead and tungsten, for example. The shielding nolen is configured to be pushed away by the article A when the article A passes through the opening 11a.

(2-2) Conveyor The conveyor 12 conveys the article A mainly in the shield box 11.

  The conveyor 12 includes a conveyor belt 12a, rollers 12b, a conveyor motor 12c, and an encoder 12d (see FIGS. 3 and 5).

  The conveyor belt 12a is an endless belt. As shown in FIG. 2, the conveyor belt 12 a is disposed so as to penetrate through the openings 11 a formed on both side surfaces of the shield box 11. The conveyor belt 12a is wound around a roller 12b including a driving roller (see FIG. 3). The conveyor belt 12a rotates when the driving roller is driven by the conveyor motor 12c, and conveys the article A placed on the conveyor belt 12a.

  The computer 20, which will be described later, performs inverter control on the conveyor motor 12c so that the conveying speed of the conveyor 12 becomes a predetermined speed. The conveyor motor 12c is equipped with an encoder 12d that detects the conveying speed of the conveyor 12 and sends it to the computer 20 (see FIG. 5).

(2-3) X-ray irradiator The X-ray irradiator 13 is an example of an irradiation unit. The X-ray irradiator 13 irradiates the article A, which is an object of mass estimation, with X-rays as an example of electromagnetic waves.

  As shown in FIG. 2, the X-ray irradiator 13 is disposed above the conveyor 12 that conveys the article A. The X-ray irradiator 13 emits X-rays toward the lower X-ray line sensor 14. The X-ray irradiator 13 irradiates the fan-shaped irradiation range X with X-rays (see FIG. 3).

(2-4) X-ray line sensor The X-ray line sensor 14 is an example of a measurement unit that measures the amount of X-rays that have passed (transmitted) through the article A.

  The X-ray line sensor 14 is disposed below the conveyor 12 that conveys the article A. The X-ray line sensor 14 mainly has a large number of pixel sensors 14a. The pixel sensor 14 a is linearly arranged in a direction orthogonal to the conveyance direction of the conveyor 12. The plurality of pixel sensors 14a are arranged horizontally.

  Each pixel sensor 14a detects X-rays that have passed through the article A and the conveyor 12, and outputs an X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal is a signal indicating the brightness of X-rays. In other words, the X-ray fluoroscopic image signal is a signal corresponding to the amount of detected X-rays that have passed through the article A. That is, the X-ray line sensor 14 measures the amount of X-rays that have passed through the article A.

(2-5) Photoelectric Sensor The photoelectric sensor 15 is a synchronous sensor for detecting the timing when the article A passes through the fan-shaped X-ray irradiation range X (see FIG. 3) (see FIG. 5). The photoelectric sensor 15 is mainly composed of a pair of projectors (not shown) and light receivers (not shown) arranged with the conveyor 12 interposed therebetween.

  In the present embodiment, the timing at which the article A passes the X-ray irradiation range X is detected using the photoelectric sensor 15, but the timing detection method is an example, and the present invention is not limited to this. . For example, the X-ray inspection apparatus 10 may detect the timing at which the article A passes through the X-ray irradiation range X using an X-ray transmission image signal detected by the X-ray line sensor 14.

(2-6) Touch Panel Monitor The touch panel monitor 30 is a full dot display liquid crystal display. The touch panel monitor 30 displays the estimated mass value of the article A calculated by the X-ray inspection apparatus 10, the rank determination result of the article A performed by the X-ray inspection apparatus 10, and the like. Further, the touch panel monitor 30 displays a screen that prompts the operator to input various settings necessary for the X-ray inspection apparatus 10 to perform operations and processes.

  The touch panel monitor 30 is an example of an input unit. The touch panel monitor 30 has a touch panel function and accepts input of various settings by an operator.

(2-7) Computer The computer 20 controls the operation of each part of the X-ray inspection apparatus 10, calculates the estimated mass of the article A, and determines the rank.

  The computer 20 mainly includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, and the like. Further, the computer 20 includes a display control circuit (not shown) that controls data display on the touch panel monitor 30, a key input circuit (not shown) that captures key input data input by the operator via the touch panel monitor 30, and a printer. A communication port (not shown) that enables connection to an external device (not shown) or a network such as a LAN is also provided. Each unit of the computer 20 is connected to each other via a bus line such as an address bus or a data bus.

  The computer 20 is connected to each part of the X-ray inspection apparatus 10 such as a conveyor motor 12c, an encoder 12d, an X-ray irradiator 13, an X-ray line sensor 14, and a photoelectric sensor 15. The computer 20 controls operations of the conveyor motor 12c, the X-ray irradiator 13, and the like. The computer 20 also detects the conveyance speed of the conveyor 12 detected by the encoder 12d, the amount of X-rays (X-ray transmission image signal) passing through the article A measured by the X-ray line sensor 14, and the article A of the photoelectric sensor 15. The detection result is received.

  Various programs including an image generation module, a correlation information learning module, a provisional mass calculation module, a mass estimation module, and a rank determination module are stored in the storage unit 22 of the computer 20 including a ROM, a hard disk, and the like. The CPU executes various programs stored in the storage unit 22 and functions as the control processing unit 21. The storage unit 22 stores various settings necessary for mass estimation and rank determination by the X-ray inspection apparatus 10, and the mass estimation result and rank determination result of the article A. Various settings stored in the storage unit 22 can be changed (set) by input from the touch panel monitor 30.

(2-7-1) Control Processing Unit The control processing unit 21 performs processing such as control of operations of each unit of the X-ray inspection apparatus 10, calculation of estimated mass of the article A, rank determination, and the like.

  Here, among the functions of the control processing unit 21, an image generation function, a correlation information learning function, a provisional mass calculation function, a mass estimation function, and a rank determination function will be described. Here, the function units that perform the image generation function, the correlation information learning function, the provisional mass calculation function, the mass estimation function, and the rank determination function are respectively referred to as an image generation unit 21a, a correlation information learning unit 21b, and a provisional mass calculation unit 21c. These are referred to as mass estimation unit 21d and rank determination unit 21e.

  First, an outline of the function of each functional unit will be described.

  The image generation unit 21 a generates an X-ray transmission image of the article A based on the X-ray fluoroscopic image signal output from the X-ray line sensor 14.

  The provisional mass calculation unit 21 c calculates the provisional estimated mass of the article A based on the measurement result of the amount of X-rays that has passed through the article A of the X-ray line sensor 14. Specifically, the provisional mass calculation unit 21c determines the provisional mass of the article A based on the X-ray transmission image of the article A generated by the image generation unit 21a based on the X-ray transmission image signal of the X-ray line sensor 14 of the article A. Calculate the estimated mass.

  The mass estimation unit 21d estimates the article A based on the measurement result of the amount of X-rays that has passed through the article A of the X-ray line sensor 14 and the provisional estimated mass of the article A calculated by the provisional mass calculation unit 21c. Calculate the mass. Specifically, the mass estimation unit 21d calculates the X-ray transmission image of the article A generated by the image generation unit 21a based on the X-ray transmission image signal of the X-ray line sensor 14 of the article A and the temporary mass calculation unit 21c. Based on the provisional estimated mass of the article A, the estimated mass of the article A is calculated.

  The temporary estimated mass of the article A calculated by the temporary mass calculating unit 21c is used to estimate the final mass of the article A (the mass calculated by the mass estimating unit 21d as the final estimation result of the X-ray inspection apparatus 10). Temporary physical quantity used. Hereinafter, for the purpose of avoiding confusion, the estimated mass of the article A calculated by the provisional mass calculating unit 21c is referred to as a first estimated mass, and the estimated mass of the article A calculated by the mass estimating unit 21d is a second estimated mass. Sometimes called mass.

  The correlation information learning unit 21b learns approximate mass correlation information used by the temporary mass calculation unit 21c to calculate (derived) the temporary estimated mass of the article A. Further, the correlation information learning unit 21b learns (derived) the mass correlation information used by the mass estimation unit 21d to calculate the estimated mass of the article A.

  The rank determination unit 21e determines the rank of the article A based on the estimated mass of the article A calculated by the mass estimation unit 21d.

  Hereinafter, each functional unit will be further described.

(2-7-1-1) Image Generation Unit The image generation unit 21 a generates an X-ray transmission image of the article A based on the X-ray fluoroscopic image signal output from the X-ray line sensor 14. The image generation unit 21a outputs the X-ray fluoroscopic image signal output from each pixel sensor 14a of the X-ray line sensor 14 at a fine time interval when the article A passes through the fan-shaped X-ray irradiation range X (see FIG. 2). An X-ray transmission image of the article A is generated based on the acquired X-ray fluoroscopic image signal. That is, the image generation unit 21a copies the data of the article A by connecting the data for each fine time interval related to the brightness of the X-rays obtained from each pixel sensor 14a of the X-ray line sensor 14 in a matrix in time series. A line transmission image is generated. The timing at which the article A passes through the fan-shaped X-ray irradiation range X is determined by the signal from the photoelectric sensor 15 and the conveyance speed of the conveyor 12.

(2-7-1-2) Correlation Information Learning Unit The correlation information learning unit 21b derives (learns) approximate mass correlation information used by the temporary mass calculation unit 21c to calculate the temporary estimated mass (first estimated mass). . The approximate mass correlation information derived by the correlation information learning unit 21 b is stored in the approximate mass correlation information storage area 22 a of the storage unit 22.

  The correlation information learning unit 21b derives (learns) mass correlation information used by the mass estimation unit 21d to calculate the estimated mass (second estimated mass). The mass correlation information derived by the correlation information learning unit 21 b is stored in the mass correlation information storage area 22 b of the storage unit 22.

  The approximate mass correlation information is information representing the correlation between the amount of X-rays that have passed through the article and the mass of the article that has passed through the X-rays. In the present embodiment, the approximate mass correlation information is a constant of a function that represents the correlation between the amount of X-rays that have passed through the article and the mass of the article that has passed through the X-rays.

  The approximate mass correlation information is learned for each type of article targeted for mass estimation, and stored in the approximate mass correlation information storage area 22a of the storage unit 22 for each type of article. Here, for example, even the same type of article (for example, a vegetable called asparagus) may be handled as a different kind of article depending on the variety, production area, or the like. The correlation information learning unit 21b learns approximate mass correlation information about an article before the mass estimation of a certain kind of article is performed for the first time by the X-ray inspection apparatus 10, for example. Preferably, the correlation information learning unit 21b learns one piece of approximate mass correlation information for each type of article to be inspected.

  The mass correlation information is information representing the correlation between the amount of X-rays that have passed through the article and the mass of the article in the portion through which the X-rays have passed. The mass correlation information is information used to calculate the second estimated mass with higher accuracy than the first estimated mass calculated using the approximate mass correlation information.

  The mass correlation information is learned for each type of article, and further for each mass band of the article (by the range of the provisional estimated mass value), and stored in the mass correlation information storage area 22b of the storage unit 22 for each type of article. Information. For example, in the present embodiment, the correlation information learning unit 21b, as mass correlation information of a certain type of article, first mass correlation information when the mass value is smaller than the boundary value Y1 (first mass band), and mass Second mass correlation information when the value of Y is greater than or equal to Y1 and smaller than Y2 (second mass band) and third mass correlation information when the mass value is Y2 or more (third mass band) are derived . Note that the mass correlation information does not have to be derived for three mass bands, and may be derived for two mass bands or four or more mass bands, for example. In order to accurately estimate the mass of an article, it is preferable to derive mass correlation information for at least three mass bands for each type of article.

  Hereinafter, the learning of the approximate mass correlation information and the mass correlation information for the article A will be described with reference to the flowchart of FIG.

  The learning of the approximate mass correlation information and the mass correlation information is performed, for example, before the X-ray inspection apparatus 10 first estimates the mass of a certain type of article A. In addition, the content of the process demonstrated below is an illustration, Comprising: You may change suitably in the range which does not change the summary of invention. Further, for example, the order of the processes in the flowchart of FIG. 6 may be appropriately changed within a range that does not change the gist of the invention, and some processes are executed simultaneously with other processes without changing the gist of the invention. May be.

  In the present embodiment, the approximate mass correlation information is derived first, and then the mass correlation information is derived. The learning process of the approximate mass correlation information and the mass correlation information is started, for example, in response to a learning process execution command input from the touch panel monitor 30 by the operator.

  First, in step S1, an article A (first sample) whose mass is known (for example, whose mass has been measured with an electronic balance or the like having a higher accuracy than the accuracy of mass estimation required for the X-ray inspection apparatus 10) is a conveyor. 12, the X-ray irradiator 13 irradiates the first sample being conveyed with X-rays. In step S1, the image generation unit 21a performs X-ray fluoroscopy output from each pixel sensor 14a of the X-ray line sensor 14 when the first sample passes through the fan-shaped X-ray irradiation range X (see FIG. 2). An image signal is acquired at fine time intervals, and an X-ray transmission image of the first sample is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the first sample acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the first sample by the X-ray line sensor 14.

  Note that, as the first sample, an article whose mass is close to the representative value of the mass of the article A is preferably used. The representative value of the mass of the article A is a value that represents the mass of the article A, for example, an average value, a median value, a mode value, and the like of a number of randomly selected articles A. Further, here, that the mass is close to the representative value of the mass of the article A means, for example, that the mass value is within a range of ± 10% of the representative value. Here, the mass of the first sample is M1.

  Next, in step S2, the correlation information learning unit 21b derives approximate mass correlation information based on the measurement result by the X-ray line sensor 14 of the amount of X-rays that has passed through the first sample. Specifically, the correlation information learning unit 21b is based on the X-ray transmission image of the first sample generated by the image generation unit 21a based on the X-ray fluoroscopic image signal output from each pixel sensor 14a of the X-ray line sensor 14. Thus, approximate mass correlation information is derived.

  A method for deriving the approximate mass correlation information will be described in detail.

  In the X-ray transmission image generated by the image generation unit 21a, the X-ray brightness indicated by the X-ray fluoroscopic image signal corresponding to the pixel is darker (in other words, the amount of X-ray detected by the pixel sensor 14a is smaller). The lower the brightness, the lower the brightness (darker). If X-rays have passed through the same material, the amount of X-rays detected by the pixel sensor 14a decreases as the material passes through a thicker material in the X-ray irradiation direction, and the X-ray fluoroscopy output from the pixel sensor 14a. The luminance of the pixel corresponding to the image signal is lowered.

Then, the brightness I of the pixel corresponding to the amount of X-rays that have passed through the thickness t portion of the article A on the X-ray transmission image corresponds to the amount of X-rays that have passed through the portion where the article A does not exist. When the brightness of the pixel is I ₀ , it can be expressed by the following equation (1).
I / I ₀ = e ⁻ μ ^t (1)

Here, μ is a linear absorption coefficient determined according to the energy of X-rays and the type of substance. When equation (1) is solved for the thickness t of the substance, the following equation (2) is obtained.
t = −1 / μ × ln (I / I ₀ ) (2)

The mass of the minute part of the article A corresponding to one pixel of the X-ray transmission image is proportional to the thickness of the minute part. Accordingly, the mass m of the minute portion of the content captured by the pixel of brightness I is approximately calculated by the following equation (3) using an appropriate constant α. In addition, if Formula (3) is represented with a graph, it can represent like the approximate mass estimation curve of FIG.
m = −αln (I / I ₀ ) (3)

  If the constant α can be derived, all pixels constituting the article A in the X-ray transmission image of the article A (pixels that are darker than the pixels corresponding to the amount of X-rays that have passed through the part where the article A does not exist) By calculating and adding the corresponding mass m, the mass of the entire article A can be estimated.

  In step S2, the correlation information learning unit 21b derives the value of the constant α in the equation (3) as the approximate mass correlation information. Specifically, the mass M1 of the entire first sample is known, and the value obtained by calculating and adding the mass m corresponding to all the pixels constituting the first sample in the X-ray transmission image of the first sample is The correlation information learning unit 21b derives the value of the constant α using the fact that it becomes equal to the mass M1.

  Note that step S1 and step S2 may be repeated in order to derive accurate mass correlation information with high accuracy. Then, the correlation information learning unit 21b may derive the average value of the constant α obtained in each step S2 as the approximate mass correlation information.

  Next, in step S3, the correlation information learning unit 21b, based on the measurement result of the amount of X-rays that have passed through the first sample by the X-ray line sensor 14, is not less than the boundary value Y1 and the boundary value Y2 (Y2> Y1). The mass correlation information (second mass correlation information) for the smaller mass band (second mass band) is derived.

  The boundary value Y1 is, for example, a value that is 1/3 of the maximum value of the mass of the article A (the maximum mass assumed to be taken by the article A). The boundary value Y2 is a value that is 2/3 of the maximum value of the mass of the article A, for example. Here, the mass M1 of the first sample is a value between the boundary value Y1 and the boundary value Y2. The mass M1 of the first sample is, for example, a value close to the average value of the boundary value Y1 and the boundary value Y2, or a representative value (average value, median value, mode value) of the mass of the article A included in the second mass band. Etc.) is preferable.

  The boundary value Y1 and the boundary value Y2 are preferably configured to be input (changeable) by the operator using the touch panel monitor 30. By making it possible to set the boundary value Y1 and the boundary value Y2 with the touch panel monitor 30, any one of the first mass correlation information, the second mass correlation information, and the third mass correlation information can be selected as to what mass. You can change the usage. As a result, it is possible to improve the accuracy of the mass estimation of the article A by the mass estimation unit 21d.

  The method of deriving the second mass correlation information (the mass correlation information of the second mass band) by the correlation information learning unit 21b is the same as the method of deriving the general mass correlation information described above. Then, the second mass correlation information derived by the correlation information learning unit 21b, that is, the value of the constant α in the equation (3) as the second mass correlation information derived by the correlation information learning unit 21b is the approximate mass correlation information. This is the same as the value of the constant α in the equation (3).

  The method for deriving the second mass correlation information is an example, and is not limited to this. For example, when the mass M1 of the first sample is not included in the second mass band, the average value of the boundary value Y1 and the boundary value Y2 or the representative value of the mass of the article A included in the second mass band is large. If they are different, the same processing as step S1 may be performed using a sample of the article A (fourth sample) different from the first sample. And the correlation information learning part 21b may derive | lead-out 2nd mass correlation information by the process similar to step S2, using the X-ray transmission image of the 4th sample obtained as a result. When the second mass correlation information is derived in this way, the mass of the fourth sample is a value close to the average value of the boundary value Y1 and the boundary value Y2, or the article A included in the second mass band. It is preferably a value close to a representative value (average value, median value, mode value, etc.) of the mass.

  Next, in step S4, an article A (second sample) having a mass different from that of the first sample is conveyed by the conveyor 12, and the X-ray irradiator 13 performs X for the second sample being conveyed. Irradiate the line. In step S4, the image generation unit 21a performs X-ray fluoroscopy output from each pixel sensor 14a of the X-ray line sensor 14 when the second sample passes through the fan-shaped X-ray irradiation range X (see FIG. 2). An image signal is acquired at fine time intervals, and an X-ray transmission image of the second sample is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the second sample acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the second sample by the X-ray line sensor 14.

  In addition, the article A having a mass included in the mass range (third mass band) equal to or higher than the boundary value Y2 is used for the second sample. In particular, the mass M2 of the second sample is included in, for example, a value close to the average value of the maximum value of the mass of the article A (the maximum mass assumed to be taken by the article A) and the boundary value Y2, or the third mass band. It is preferably a value close to a representative value (average value, median value, mode value, etc.) of the mass of the article A to be obtained.

  Next, in step S5, the correlation information learning unit 21b, based on the measurement result of the amount of X-rays that have passed through the second sample by the X-ray line sensor 14, the mass band (third mass band) equal to or greater than the boundary value Y2. The mass correlation information (third mass correlation information) is derived.

  The method for deriving the third mass correlation information by the correlation information learning unit 21b is the same as the method for deriving the approximate mass correlation information in step S2. The third mass correlation information derived by the correlation information learning unit 21b, that is, the value of the constant α in the equation (3) is usually a value different from the approximate mass correlation information. In other words, as shown in FIG. 8A, the mass estimation curve of the third mass band usually does not coincide with the approximate mass estimation curve in the same mass band.

  Note that step S4 and step S5 may be repeated in order to derive accurate third mass correlation information. Then, the correlation information learning unit 21b may derive the average value of the constant α obtained in each step S5 as the third mass correlation information.

  Next, in step S6, an article A (third sample) having a mass different from that of the first sample and the second sample is conveyed by the conveyor 12, and X-ray irradiation is performed on the third sample being conveyed. The instrument 13 emits X-rays. In step S <b> 6, the image generation unit 21 a performs X-ray fluoroscopy that is output from each pixel sensor 14 a of the X-ray line sensor 14 when the third sample passes the fan-shaped X-ray irradiation range X (see FIG. 2). Image signals are acquired at fine time intervals, and an X-ray transmission image of the third sample is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the third sample acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the third sample by the X-ray line sensor 14.

  Note that the article A having a mass included in the mass range (first mass band) smaller than the boundary value Y1 is used for the third sample. In particular, the mass M3 of the third sample is, for example, a value close to ½ of the boundary value Y1 or a representative value (average value, median value, mode value, etc.) of the mass of the article A included in the first mass band. A close value is preferable.

  Next, in step S7, the correlation information learning unit 21b has a mass band (first mass band) smaller than the boundary value Y1 based on the measurement result of the amount of X-rays that have passed through the third sample by the X-ray line sensor 14. The mass correlation information (first mass correlation information) is derived.

  The method for deriving the first mass correlation information by the correlation information learning unit 21b is the same as the method for deriving the approximate mass correlation information in step S2. The first mass correlation information derived by the correlation information learning unit 21b, that is, the value of the constant α in the equation (3) is usually different from the approximate mass correlation information. In other words, as shown in FIG. 8B, the mass estimation curve of the first mass band does not normally match the approximate mass estimation curve in the same mass band.

  Note that step S6 and step S7 may be repeated in order to derive accurate first mass correlation information. Then, the correlation information learning unit 21b may derive the average value of the constant α obtained in each step S7 as the first mass correlation information.

  In the present embodiment, the approximate mass correlation information and the mass correlation information are the constant α of the function (3), but are not limited thereto. For example, the approximate mass correlation information and the mass correlation information (first to third mass correlation information) are a table in which the amount of X-rays transmitted through the article A and the mass of the article A in the portion through which the X-rays are transmitted are associated. It may be.

(2-7-1-3) Provisional Mass Calculation Unit The provisional mass calculation unit 21c is an example of a provisional physical quantity calculation unit. The provisional mass calculation unit 21c is derived by the correlation information learning unit 21b and passes through the approximate mass correlation information stored in the approximate mass correlation information storage region 22a of the storage unit 22 and the article A measured by the X-ray line sensor 14. Based on the amount of X-rays, the provisional estimated mass (first estimated mass) of the article A is calculated as a provisional physical quantity.

  Specifically, the provisional mass calculation unit 21c includes the approximate mass correlation information stored in the approximate mass correlation information storage area 22a of the storage unit 22, and the X-ray transmission image obtained from the measurement result of the X-ray line sensor 14. Based on the above, the first estimated mass of the article A is calculated. More specifically, the provisional mass calculation unit 21c uses the constant α in the equation (3) as the approximate mass correlation information for all the pixels constituting the article A in the X-ray transmission image of the article A. The mass of the minute part of the article A corresponding to each pixel is calculated and added to calculate the temporary estimated mass (first estimated mass) of the article A.

(2-7-1-4) Mass Estimator The mass estimator 21d is derived by the correlation information learning unit 21b and stored in the mass correlation information storage area 22b of the storage unit 22 for each mass band (first correlation). Mass correlation information corresponding to the mass band to which the first estimated mass calculated by the temporary mass calculation unit 21c belongs is selected from (1 mass correlation information to third mass correlation information).

  Then, the mass estimation unit 21d estimates the mass of the article A based on the selected mass correlation information and the amount of X-rays that have passed through the article A measured by the X-ray line sensor 14 (the second estimated mass is calculated). calculate). Specifically, the mass estimation unit 21 d uses the mass correlation information stored in the mass correlation information storage region 22 b of the selected storage unit 22 and the X-ray transmission image obtained from the measurement result of the X-ray line sensor 14. Based on this, the second estimated mass of the article A is calculated. More specifically, the mass estimation unit 21d uses all the pixels constituting the article A in the X-ray transmission image of the article A by using the constant α in the equation (3) as the selected mass correlation information. Then, the mass of the minute part of the article A corresponding to each pixel is calculated and added to estimate the mass of the article A (a second estimated mass is calculated).

(2-7-1-5) Rank determination unit The rank determination unit 21e determines the rank of the article A based on the estimated mass (second estimated mass) of the article A calculated by the mass estimation unit 21d. The rank determination unit 21e determines whether the estimated mass of the article A calculated by the mass estimation unit 21d falls within, for example, five mass ranges set via the touch panel monitor 30, and the mass determined to be applicable. It is determined that the article A belongs to the rank corresponding to the range.

(3) Mass Estimation and Rank Determination by X-ray Inspection Device Hereinafter, the mass estimation and rank determination of the article A performed by the X-ray inspection device 10 will be described with reference to the flowchart of FIG. In addition, the content of the process demonstrated below is an illustration, Comprising: You may change suitably in the range which does not change the summary of invention.

  In addition, when the X-ray inspection apparatus 10 starts mass estimation and rank determination of the article A, the approximate mass correlation information storage area 22a of the storage unit 22 includes approximate mass correlation information, and the mass correlation information storage area 22b includes Assume that mass correlation information is stored.

  First, in step S11, the article A to be inspected (that is, the mass is unknown) is conveyed by the conveyor 12, and the X-ray irradiator 13 irradiates the article A being conveyed with X-rays. In step S11, the image generation unit 21a outputs an X-ray fluoroscopic image output from each pixel sensor 14a of the X-ray line sensor 14 when the article A passes through the fan-shaped X-ray irradiation range X (see FIG. 2). A signal is acquired at fine time intervals, and an X-ray transmission image of the article A is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the article A acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the article A by the X-ray line sensor 14.

  Next, in step S <b> 12, the provisional mass calculation unit 21 c performs the article A based on the approximate mass correlation information stored in the approximate mass correlation information storage area 22 a of the storage unit 22 and the measurement result of the X-ray line sensor 14. The temporary estimated mass (first estimated mass) is calculated. The provisional mass calculation unit 21c is based on the approximate mass correlation information stored in the approximate mass correlation information storage region 22a of the storage unit 22 and the X-ray transmission image generated from the measurement result of the X-ray line sensor 14. A first estimated mass of A is calculated.

  Next, in step S13, the mass estimation unit 21d selects from the mass correlation information (first mass correlation information to third mass correlation information) for each mass band stored in the mass correlation information storage region 22b of the storage unit 22. In step S12, one mass correlation information corresponding to the mass band to which the first estimated mass calculated by the provisional mass calculation unit 21c belongs is selected. Then, the mass estimation unit 21d estimates the mass of the article A based on the selected one mass correlation information and the amount of X-rays measured by the X-ray line sensor 14 (calculates a second estimated mass). ). Specifically, the mass estimation unit 21 d is based on the mass correlation information stored in the mass correlation information storage region 22 b of the selected storage unit 22 and the X-ray transmission image generated from the measurement result of the X-ray line sensor 14. Then, the second estimated mass of the article A is calculated.

  Next, in step S14, the rank determination unit 21e determines the rank of the article A based on the estimated mass (second estimated mass) of the article A calculated by the mass estimation unit 21d.

  Next, in step S15, the rank determination result of the rank determination unit 21e is output to the distribution device 90. In addition, the determination result of the rank determination unit 21e may be displayed on the touch panel monitor 30.

(4) Features (4-1)
The X-ray inspection apparatus 10 of the present embodiment includes an X-ray irradiator 13 as an example of an irradiation unit, an X-ray line sensor 14 as an example of a measurement unit, and a temporary mass calculation unit 21c as an example of a temporary physical quantity calculation unit. And a storage unit 22 and a mass estimation unit 21d. The X-ray irradiator 13 irradiates an article A as a target article with X-rays as an example of electromagnetic waves. The X-ray line sensor 14 measures the amount of X-rays that have passed through the article A. The temporary mass calculation unit 21 c calculates a temporary physical quantity (here, a temporary estimated mass) of the article A based on the measurement result of the X-ray line sensor 14. The storage unit 22 stores mass correlation information representing the correlation between the amount of X-rays and the mass of the article A for each physical quantity band (here, each mass band) of the article A. The mass estimation unit 21d selects mass correlation information corresponding to the physical quantity band to which the temporary physical quantity calculated by the temporary mass calculation unit 21c belongs, from the mass correlation information for each physical quantity band stored in the storage unit 22. The mass estimation unit 21d estimates the mass of the article A based on the selected mass correlation information and the amount of X-rays.

  In the X-ray inspection apparatus 10 of the present embodiment, after calculating the temporary physical quantity (here, temporary estimated mass) of the article A, the mass correlation information prepared for the physical quantity band (mass band) to which the temporary physical quantity applies is used. The estimated mass of the article A is calculated. Therefore, even when the individual difference in physical quantity (here, mass) of the article A is relatively large, accurate mass estimation is possible regardless of the physical quantity of the article A.

  In addition, depending on the physical quantity of the target article, in other words, depending on the growth of the target article, etc., natural objects (agricultural products, seafood, livestock products, etc.) that tend to cause differences in the density or composition of the target article are target articles In addition, after calculating the temporary physical quantity of the target article, the estimated mass of the target article is calculated again using the mass correlation information prepared for the physical quantity band to which the temporary physical quantity applies, so the physical quantity related to the size of the target article Regardless of this, accurate mass estimation is possible.

  Note that the electromagnetic wave in the present embodiment is an X-ray. By using X-rays with strong penetrating power as electromagnetic waves, mass estimation can be accurately performed for a wide range of articles.

(4-2)
In the X-ray inspection apparatus 10 of the present embodiment, the storage unit 22 stores approximate mass correlation information that represents the correlation between the amount of X-rays and the mass of the article A for each type of article A. The temporary mass calculation unit 21c calculates the temporary estimated mass of the article A as a temporary physical quantity based on the approximate mass correlation information and the amount of X-rays.

  In the X-ray inspection apparatus 10 of the present embodiment, a temporary estimated mass that is a temporary physical quantity is calculated with a relatively easy configuration, and further, the final mass of the article A using mass correlation information prepared for each mass band. Can be calculated with high accuracy.

(4-3)
The X-ray inspection apparatus 10 of this embodiment includes a correlation information learning unit 21b. The correlation information learning unit 21b determines the mass correlation information and the approximate mass correlation information based on the measurement result by the X-ray line sensor 14 of the amount of X-rays that have passed through the article A (first sample to third sample) whose mass is known. Is derived.

  In the X-ray inspection apparatus 10 of the present embodiment, the mass correlation information and the approximate mass correlation information are derived based on the measurement results of the actual article A (first sample to third sample) at the time of initial setting or the like. It is easy to accurately estimate the mass of A.

(4-4)
In the X-ray inspection apparatus 10 of the present embodiment, the correlation information learning unit 21b has the mass of X-rays that have passed through the article A (first sample) whose mass is known and whose mass is close to the representative value of the mass of the article A. Based on the measurement result by the X-ray line sensor 14, approximate mass correlation information is derived. The correlation information learning unit 21b has an X-ray quantity X that has passed through three or more articles A (three articles A of the first to third samples in this embodiment) having a known mass and different masses. Based on the measurement result by the line line sensor 14, the mass correlation information is derived.

  In the X-ray inspection apparatus 10 according to the present embodiment, the approximate mass correlation information is derived based on the amount of X-rays that have passed through the article A (first sample) whose mass is close to the representative value. First, the provisional mass can be estimated with relatively high accuracy using the approximate mass correlation information. In addition, by deriving mass correlation information based on the amount of X-rays that have passed through three or more articles A having different masses, it is possible to derive appropriate mass correlation information for each mass band. Can be accurately estimated.

(4-5)
The X-ray inspection apparatus 10 of this embodiment includes a rank determination unit 21e. The rank determination unit 21e determines the rank of the article A based on the estimated mass of the article A calculated by the mass estimation unit 21d.

  In the X-ray inspection apparatus 10 of the present embodiment, it is possible to appropriately determine the rank based on the mass of the article A estimated with high accuracy.

(4-6)
The X-ray inspection apparatus 10 of this embodiment includes a touch panel monitor 30 as an example of an input unit that inputs boundary values Y1 and Y2 of a physical quantity band (mass band).

  In the X-ray inspection apparatus 10 of the present embodiment, it is possible to appropriately set which mass correlation information should be used for each physical quantity band based on the result of actual mass estimation or the like. Therefore, the mass of the article A can be estimated with high accuracy.

Second Embodiment
An X-ray inspection apparatus 110 according to a second embodiment of the mass estimation apparatus of the present invention will be described.

  FIG. 10 is a block configuration diagram of the X-ray inspection apparatus 110. The X-ray inspection apparatus 110 is configured in the same manner as the X-ray inspection apparatus 10 of the first embodiment except for the computer 120. Hereinafter, for simplification of description, only the computer 120 of the X-ray inspection apparatus 110 that is a difference from the X-ray inspection apparatus 10 will be described.

(1) Computer The physical configuration of the computer 120 is the same as that of the computer 20.

  Here, the correlation information learning unit 121b and the provisional mass calculation unit 121c of the control processing unit 21 of the computer 120, which are different from the computer 20, will be mainly described. Note that the image generation unit 21a, the mass estimation unit 21d, and the rank determination unit 21e of the control processing unit 21 of the computer 120 are the same as those in the first embodiment, and thus description thereof is omitted.

  In addition, the storage unit 122 of the computer 120 has a size-mass correlation information storage area 122a that stores a size-mass correlation function instead of the approximate mass correlation information storage area 22a that stores approximate mass correlation information. Since it is the same as the memory | storage part 22 of the computer 20 of embodiment, detailed description is abbreviate | omitted.

(1-1) Correlation Information Learning Unit The correlation information learning unit 121b learns size-mass correlation information used by the provisional mass calculation unit 121c to calculate (derived) the provisional estimated mass of the article A. Further, the correlation information learning unit 121b learns (derived) the mass correlation information used by the mass estimation unit 21d to calculate the estimated mass of the article A. Since the learning of the mass correlation information by the correlation information learning unit 121b is the same as in the first embodiment, the description thereof is omitted here.

  The size-mass correlation information is information representing the correlation between the size of the article A and the mass of the article A. The size of the article A means, for example, a volume, an area, an article length, a perimeter, and the like. In the present embodiment, the size of the article A is the area of the article A (the area of the article A when the article A being conveyed by the conveyor 12 is viewed from above). In addition, it is preferable to select a physical quantity that has a strong correlation with the mass (for example, the physical quantity and the mass are approximately proportional to each other) as the physical quantity used as the size of the article A in the size-mass correlation information.

  The size-mass correlation information is learned for each type of article to be mass estimated, and is stored for each type of article in the size-mass correlation information storage area 122a of the storage unit 22. Here, for example, even the same type of article (for example, a vegetable called asparagus) may be handled as a different kind of article depending on the variety, production area, or the like. The correlation information learning unit 121b learns size-mass correlation information about an article before the mass estimation of a certain kind of article is performed for the first time by the X-ray inspection apparatus 110, for example. Preferably, the correlation information learning unit 121b learns one size-mass correlation information for each type of article to be inspected.

  Hereinafter, learning of the size-mass correlation information for the article A will be described with reference to the flowchart of FIG.

  The learning process of the size-mass correlation information is started in response to a learning process execution command input from the touch panel monitor 30 by the operator, for example.

  First, in step S21, an article A (fifth sample) having a known mass (for example, a mass that has been measured with an electronic balance or the like having a higher accuracy than the accuracy of mass estimation required for the X-ray inspection apparatus 10) is a conveyor. 12, the X-ray irradiator 13 irradiates the fifth sample being conveyed with X-rays. In step S21, the image generation unit 21a performs X-ray fluoroscopy output from each pixel sensor 14a of the X-ray line sensor 14 when the fifth sample passes through the fan-shaped X-ray irradiation range X (see FIG. 2). An image signal is acquired at fine time intervals, and an X-ray transmission image of the fifth sample is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the fifth sample acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the fifth sample by the X-ray line sensor 14.

  Note that, as the fifth sample, an article whose mass is close to the representative value of the mass of the article A is preferably used. The representative value of the mass of the article A is a value that represents the mass of the article A, for example, an average value, a median value, a mode value, and the like of a number of randomly selected articles A. Further, here, that the mass is close to the representative value of the mass of the article A means, for example, that the mass value is within a range of ± 10% of the representative value. The fifth sample and the first sample used to derive the mass correlation information (second mass correlation information) for the second mass band may be the same article A or different articles A. It may be.

  Next, in step S22, the correlation information learning unit 121b calculates the size (here, area) of the fifth sample based on the measurement result of the amount of X-rays that have passed through the fifth sample by the X-ray line sensor 14. . Specifically, the correlation information learning unit 121b uses all the pixels constituting the article A in the X-ray transmission image of the fifth sample (from the pixels corresponding to the amount of X-rays that have passed through the portion where the fifth sample does not exist). The area of the fifth sample is calculated by calculating and adding a small area corresponding to (a dark pixel). Since the mass of the fifth sample is known, for example, if it is known that the area of the article A and the mass of the article A are approximately proportional to each other, the correlation information learning unit 121b determines that the proportional constant in the graph of FIG. Can be derived as size-mass correlation information.

  Note that step S21 and step S22 may be repeated in order to derive accurate size-mass correlation information. And the correlation information learning part 121b may derive | lead-out the average value of the proportionality constant obtained by each step S22 as size mass correlation information.

(1-2) Provisional Mass Calculation Unit The provisional mass calculation unit 121c is configured as follows, based on the measurement result of the amount of X-rays that have passed through the article A of the X-ray line sensor 14, as the provisional estimated mass of the article A. Is calculated.

  First, the temporary mass calculation unit 121c determines the size of the article A based on the measurement result of the X-ray line sensor 14. For example, the provisional mass calculation unit 121c determines, as the size of the article A, all pixels constituting the article A (existence of the article A) in the X-ray transmission image of the article A obtained from the measurement result of the X-ray line sensor 14. The area of the article A is calculated by calculating and adding a small area corresponding to a pixel that is darker than the pixel corresponding to the amount of X-rays that have passed through the portion that is not. Then, the provisional mass calculation unit 121c calculates the provisional estimated mass of the article A as a provisional physical quantity based on the determined size and the size-mass correlation information stored in the size-mass correlation information storage area 122a of the storage unit 122.

(2) Mass estimation and rank determination by X-ray inspection apparatus The processing related to mass estimation and rank determination of the article A performed by the X-ray inspection apparatus 110 is different except that the calculation method of the temporary estimated mass by the temporary mass calculation unit 121c is different. This is the same as the processing related to mass estimation and rank determination of the article A performed by the X-ray inspection apparatus 10 of the first embodiment. Therefore, description is abbreviate | omitted here.

(3) Features The X-ray inspection apparatus 110 of the second embodiment also has the same characteristics as (4-1), (4-5), and (4-6) of the X-ray inspection apparatus 10 of the first embodiment. . The X-ray inspection apparatus 110 has the following features.

(3-1)
In the X-ray inspection apparatus 110 of the present embodiment, the storage unit 122 stores size-mass correlation information that represents the correlation between the size of the article A and the mass of the article A for each type of the article A. The provisional mass calculation unit 121c determines the size of the article A based on the measurement result of the X-ray line sensor 14, and calculates the provisional estimated mass of the article A as a provisional physical quantity based on the determined size and the size-mass correlation information. To do.

  In the X-ray inspection apparatus 110 of the present embodiment, a temporary estimated mass, which is a temporary physical quantity, is calculated with a relatively easy configuration, and the final mass of the article A is further calculated using mass correlation information prepared for each mass band. Can be calculated with high accuracy.

<Third Embodiment>
An X-ray inspection apparatus 210 according to a third embodiment of the mass estimation apparatus of the present invention will be described.

  FIG. 13 is a block configuration diagram of the X-ray inspection apparatus 210. The X-ray inspection apparatus 210 is configured similarly to the X-ray inspection apparatus 10 of the first embodiment except for the computer 220. In the following, for simplification of description, only the computer 220 of the X-ray inspection apparatus 210 that is different from the X-ray inspection apparatus 10 will be described.

(1) Computer The physical configuration of the computer 220 is the same as that of the computer 20.

  Here, the correlation information learning unit 221b, the provisional physical quantity calculation unit 221c, and the mass estimation unit 221d of the control processing unit 21 of the computer 220, which are different from the computer 20, will be mainly described. Note that the image generation unit 21a and the rank determination unit 21e of the control processing unit 21 of the computer 220 are the same as those in the first embodiment, and a description thereof will be omitted.

  The storage unit 222 of the computer 220 is the first implementation except that the mass correlation information stored in the mass correlation information storage area 222b is information for each size band (for each physical quantity band), not for each mass band. Since it is the same as the storage unit 22 of the computer 20 in the embodiment, detailed description thereof is omitted.

(1-1) Correlation Information Learning Unit The correlation information learning unit 221b derives (learns) mass correlation information used by the mass estimation unit 221d to calculate the estimated mass. The mass correlation information derived by the correlation information learning unit 221b is stored in the mass correlation information storage area 222b of the storage unit 222.

  The mass correlation information is information representing the correlation between the amount of X-rays that have passed through the article and the mass of the article in the portion through which the X-rays have passed.

  The mass correlation information is information that is learned for each type of article and for each physical quantity band of the article, and is stored in the mass correlation information storage area 222b of the storage unit 222 for each type of article. Unlike the information for each mass band in the first embodiment and the second embodiment, the mass correlation information in the third embodiment is information for each physical quantity band (here, for each article size band). Note that the size of the article A means, for example, a volume, an area, an article length, a perimeter, and the like. In the present embodiment, the size of the article A is the area of the article A (the area of the article A when the article A being conveyed by the conveyor 12 is viewed from above).

  For example, in the present embodiment, the correlation information learning unit 221b uses the first mass when the size (area in the present embodiment) is smaller than the boundary value Z1 (the first size band) as the mass correlation information of a certain type of article. Correlation information, second mass correlation information when the size is equal to or larger than the boundary value Z1 and smaller than the boundary value Z2 (second size band), and third when the size is equal to or larger than the boundary value Z2 (third size band) Deriving mass correlation information. Note that the mass correlation information does not need to be derived for three size bands, and may be derived for two size bands, or four or more size bands, for example. In order to accurately estimate the mass of an article, it is preferable to derive mass correlation information for at least three size bands for each type of article.

  The boundary value Z1 is, for example, a value that is 1/3 of the maximum value of the size of the article A (the maximum size that the article A is supposed to take). The boundary value Z2 is a value that is 2/3 of the maximum value of the size of the article A, for example.

  The boundary value Z1 and the boundary value Z2 are preferably configured to be input (changeable) by the operator using the touch panel monitor 30. Since the boundary value Z1 and the boundary value Z2 can be set by the touch panel monitor 30, any one of the first mass correlation information, the second mass correlation information, and the third mass correlation information can be selected for any size. You can change the usage. As a result, the accuracy of the mass estimation of the article A by the mass estimation unit 221d can be improved.

  Hereinafter, learning of the mass correlation information for the article A will be described with reference to the flowchart of FIG.

  The learning of the mass correlation information about the article A is performed, for example, before the X-ray inspection apparatus 210 first estimates the mass of a certain kind of article A. In addition, the content of the process demonstrated below is an illustration, Comprising: You may change suitably in the range which does not change the summary of invention. Further, for example, the order of the processes in the flowchart of FIG. 14 may be changed as appropriate within a range that does not change the gist of the invention, and some processes are executed simultaneously with other processes without changing the gist of the invention. May be.

  The learning process of the mass correlation information is started in response to a learning process execution command input from the touch panel monitor 30 by the operator, for example.

  First, in step S31, the article A (sixth sample) whose mass is known (for example, the mass has been measured with an electronic balance or the like having a higher accuracy than the accuracy of mass estimation required for the X-ray inspection apparatus 210) is a conveyor. 12, the X-ray irradiator 13 irradiates the sixth sample being transferred with X-rays. In step S31, the image generation unit 21a performs X-ray fluoroscopy output from each pixel sensor 14a of the X-ray line sensor 14 when the sixth sample passes the fan-shaped X-ray irradiation range X (see FIG. 2). An image signal is acquired at fine time intervals, and an X-ray transmission image of a sixth sample is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the sixth sample acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the sixth sample by the X-ray line sensor 14.

  In the sixth sample, an article A having a size included in a size range (second size band) between the boundary value Z1 and the boundary value Z2 is used. The size of the sixth sample is, for example, a value close to the average value of the boundary value Z1 and the boundary value Z2, or a representative value of the size of the article A included in the second size band (average value, median value, mode value, etc. It is preferable that the value is close to.

  Next, in step S32, the correlation information learning unit 221b determines the mass correlation information (second mass correlation) of the second size band based on the measurement result of the amount of X-rays that have passed through the sixth sample by the X-ray line sensor 14. Information). Note that the method for deriving the second mass correlation information by the correlation information learning unit 221b is the same as the method for deriving the approximate mass correlation information in the first embodiment described above, and thus detailed description thereof is omitted.

  Next, in step S33, the article A (seventh sample) having a known mass is conveyed by the conveyor 12, and the X-ray irradiator 13 irradiates the seventh sample being conveyed with X-rays. In step S33, the image generation unit 21a performs X-ray fluoroscopy output from each pixel sensor 14a of the X-ray line sensor 14 when the seventh sample passes the fan-shaped X-ray irradiation range X (see FIG. 2). An image signal is acquired at fine time intervals, and an X-ray transmission image of a seventh sample is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the seventh sample acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the seventh sample by the X-ray line sensor 14.

  In the seventh sample, an article A having a size included in a size range (third size band) equal to or larger than the boundary value Z2 is used. In particular, the size of the seventh sample is, for example, a value close to the average value of the maximum value of the size of the article A (the maximum size assumed to be taken by the article A) and the boundary value Z2, or included in the third size band. It is preferably a value close to a representative value (average value, median value, mode value, etc.) of the size of the article A.

  Next, in step S34, the correlation information learning unit 221b determines the mass correlation information (third mass correlation) of the third size band based on the measurement result of the amount of X-rays that have passed through the seventh sample by the X-ray line sensor 14. Information). Note that the method for deriving the third mass correlation information by the correlation information learning unit 221b is the same as the method for deriving the general mass correlation information in the first embodiment described above, and thus detailed description thereof is omitted.

  Next, in step S35, the article A (eighth sample) having a known mass is conveyed by the conveyor 12, and the X-ray irradiator 13 irradiates the eighth sample being conveyed with X-rays. In step S35, the image generation unit 21a performs X-ray fluoroscopy output from each pixel sensor 14a of the X-ray line sensor 14 when the eighth sample passes the fan-shaped X-ray irradiation range X (see FIG. 2). An image signal is acquired at fine time intervals, and an X-ray transmission image of the eighth sample is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the eighth sample acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the eighth sample by the X-ray line sensor 14.

  In the eighth sample, an article A having a size included in a size range (first size band) smaller than the boundary value Z1 is used. In particular, the size of the eighth sample is close to, for example, a value close to ½ of the boundary value Z1 or a representative value (average value, median value, mode value, etc.) of the size of the article A included in the first size band. It is preferably a value.

  Next, in step S36, the correlation information learning unit 221b determines the mass correlation information (third mass correlation) of the first size band based on the measurement result by the X-ray line sensor 14 of the amount of X-rays that has passed through the eighth sample. Information). Note that the method for deriving the first mass correlation information by the correlation information learning unit 221b is the same as the method for deriving the approximate mass correlation information in the first embodiment described above, and thus detailed description thereof is omitted.

  Note that, in order to derive accurate mass correlation information, the steps S31 to S36 may be repeated, as in the first embodiment.

(1-2) Temporary Physical Quantity Calculation Unit The temporary physical quantity calculation unit 221c uses the size (here, area) of the article A as a temporary physical quantity based on the amount of X-rays that have passed through the article A measured by the X-ray line sensor 14. calculate.

  Specifically, the provisional physical quantity calculation unit 221c calculates the size (area here) of the article A based on the X-ray transmission image obtained from the measurement result of the X-ray line sensor 14. More specifically, the provisional physical quantity calculation unit 221c sets all the pixels constituting the article A in the X-ray transmission image of the article A obtained from the measurement result of the X-ray line sensor 14 as the size of the article A ( The area of the article A is calculated by calculating and adding a small area corresponding to a pixel darker than the pixel corresponding to the amount of X-rays that have passed through the part where the article A does not exist.

(1-3) Mass Estimation Unit The mass estimation unit 221d is derived by the correlation information learning unit 221b and stored for each size in the mass correlation information storage area 222b of the storage unit 222 (first mass correlation information— The mass correlation information corresponding to the temporary physical quantity band (size band) to which the temporary physical quantity (size) calculated by the temporary physical quantity calculation unit 221c belongs is selected from (third mass correlation information).

  Then, the mass estimation unit 221d estimates the mass of the article A based on the selected mass correlation information and the amount of X-rays that have passed through the article A measured by the X-ray line sensor 14. Specifically, the mass estimation unit 221d uses the mass correlation information stored in the mass correlation information storage region 222b of the selected storage unit 222 and the X-ray transmission image obtained from the measurement result of the X-ray line sensor 14. Based on this, the estimated mass of the article A is calculated. More specifically, the mass estimator 221d uses all the pixels constituting the article A in the X-ray transmission image of the article A using the constant α in the equation (3) as the selected mass correlation information. The mass of the minute part of the article A corresponding to each pixel is calculated and added to estimate the mass of the article A.

(2) Mass estimation and rank determination by X-ray inspection apparatus Hereinafter, mass estimation and rank determination of the article A performed by the X-ray inspection apparatus 10 will be described with reference to the flowchart of FIG. In addition, the content of the process demonstrated below is an illustration, Comprising: You may change suitably in the range which does not change the summary of invention.

  When the X-ray inspection apparatus 10 starts mass estimation and rank determination of the article A, it is assumed that mass correlation information is already stored in the mass correlation information storage area 222b of the storage unit 222.

  First, in step S41, the article A to be inspected (that is, the mass is unknown) is conveyed by the conveyor 12, and the X-ray irradiator 13 irradiates the article A being conveyed with X-rays. Further, in step S41, the X-ray fluoroscopic image output from each pixel sensor 14a of the X-ray line sensor 14 when the image generation unit 21a passes the fan-shaped X-ray irradiation range X (see FIG. 2). A signal is acquired at fine time intervals, and an X-ray transmission image of the article A is generated based on the acquired X-ray fluoroscopic image signal. The X-ray fluoroscopic image signal for the article A acquired by the image generation unit 21 a is a measurement result of the amount of X-rays that have passed through the article A by the X-ray line sensor 14.

  Next, in step S42, the provisional physical quantity calculation unit 221c calculates the size (area here) of the article A based on the measurement result of the X-ray line sensor 14.

  Next, in step S43, the mass estimation unit 221d selects the mass correlation information for each size band (first mass correlation information to third mass correlation information) stored in the mass correlation information storage area 222b of the storage unit 222. In step S42, one piece of mass correlation information corresponding to the size band to which the size calculated by the temporary physical quantity calculation unit 221c belongs is selected. Then, the mass estimation unit 221d estimates the mass of the article A based on the selected 1 mass correlation information and the amount of X-rays measured by the X-ray line sensor 14. Specifically, the mass estimation unit 221d is based on the mass correlation information stored in the mass correlation information storage area 222b of the selected storage unit 222 and the X-ray transmission image generated from the measurement result of the X-ray line sensor 14. Thus, the estimated mass of the article A is calculated.

  Next, in step S44, the rank determination unit 21e determines the rank of the article A based on the estimated mass of the article A calculated by the mass estimation unit 221d.

  Next, in step S45, the rank determination result of the rank determination unit 21e is output to the sorting device 90. In addition, the determination result of the rank determination unit 21e may be displayed on the touch panel monitor 30.

(3) Features The X-ray inspection apparatus 210 of the third embodiment also has the same characteristics as (4-1), (4-5), and (4-6) of the X-ray inspection apparatus 10 of the first embodiment. . The X-ray inspection apparatus 210 has the following features.

(3-1)
In the X-ray inspection apparatus 210 of the present embodiment, the temporary physical quantity calculation unit 221c calculates the size of the article A as a temporary physical quantity.

  In the X-ray inspection apparatus 210 of this embodiment, after calculating the size of the article A, which is a temporary physical quantity, the final mass of the article A is accurately calculated using the mass correlation information prepared for each size band. Can do.

<Modification>
The above embodiments may be appropriately combined within a range that does not contradict each other.

  Below, the modification of the said embodiment is shown. The modified examples may be appropriately combined within a range that does not contradict each other.

(1) Modification A
In the above embodiment, the X-ray inspection apparatuses 10, 110, and 210 are incorporated in the rank sorting system 100 and constitute a part of the rank sorting system 100, but the present invention is not limited to this. For example, the X-ray inspection apparatuses 10, 110, and 210 may be independent apparatuses.

(2) Modification B
In the above embodiment, the correlation information learning units 21b, 121b, and 221b of the X-ray inspection apparatuses 10, 110, and 210 derive mass correlation information, but the present invention is not limited to this. For example, the mass correlation information may be stored in the storage units 22, 122, 222 in advance.

  The same applies to the approximate mass correlation information and the size mass correlation information.

(3) Modification C
In the above embodiment, the electromagnetic wave is an X-ray, but is not limited to this. For example, the electromagnetic waves may be near infrared rays.

(4) Modification D
In the above embodiment, the provisional physical quantity is calculated with a certain degree of accuracy, but the calculation method of the provisional physical quantity is not limited to the above method.

  The provisional physical quantity may be calculated with an accuracy sufficient to determine which physical quantity zone the physical quantity of the article A subject to mass estimation enters in order to select the mass correlation information. For example, if it is 1st Embodiment or 2nd Embodiment, the precision of the grade which only understands that the mass of the article | item A is more than boundary value Y2, more than boundary value Y1, is smaller than boundary value Y2, and is smaller than boundary value Y1. The temporary estimated mass may be calculated.

  The present invention is widely applicable to a mass estimation apparatus that irradiates a target article with electromagnetic waves and estimates mass based on the amount of electromagnetic waves that have passed through the target article.

10, 110, 210 X-ray inspection equipment (mass estimation equipment)
13 X-ray irradiator (irradiation part)
14 X-ray line sensor (measurement unit)
21b, 121b, 221b Correlation information learning unit 21c, 121c Provisional mass calculation unit (provisional physical quantity calculation unit)
21d, 221d Mass estimation unit 21e Rank determination unit 22, 122, 222 Storage unit 30 Touch panel monitor (input unit)
221c Temporary physical quantity calculation unit A article (target article)
Y1, Y2 boundary value (boundary value of mass band)
Z1, Z2 boundary value (boundary value of size band)

JP 2002-296022 A

Claims (9)

An irradiation unit for irradiating the target article with electromagnetic waves;
A measuring unit that measures the amount of the electromagnetic wave that has passed through the target article;
Based on the measurement result of the measurement unit, a temporary physical quantity calculation unit that calculates the temporary physical quantity of the target article;
A storage unit that stores mass correlation information representing a correlation between the amount of the electromagnetic wave and the mass of the target article for each physical quantity band of the target article;
The mass correlation information corresponding to the physical quantity band to which the temporary physical quantity calculated by the temporary physical quantity calculation unit belongs is selected from the mass correlation information for each physical quantity band stored in the storage unit, and the selected mass Based on correlation information and the amount of the electromagnetic wave, a mass estimation unit that estimates the mass of the target article,
A mass estimation apparatus comprising: The storage unit further stores approximate mass correlation information representing a correlation between the amount of the electromagnetic wave and the mass of the target article for each type of the target article,
The temporary physical quantity calculation unit calculates a temporary estimated mass of the target article as the temporary physical quantity based on the approximate mass correlation information and the amount of the electromagnetic wave.
The mass estimation apparatus according to claim 1. A correlation information learning unit for deriving the mass correlation information and the approximate mass correlation information based on a measurement result by the measurement unit of the amount of the electromagnetic wave that has passed through the target article having a known mass;
The mass estimation apparatus according to claim 2. The correlation information learning unit is configured to determine the approximate mass based on a measurement result of the amount of the electromagnetic wave that has passed through the target article whose mass is known and whose mass is close to a representative value of the mass of the target article. Deriving correlation information, and deriving the mass correlation information based on a measurement result of the amount of the electromagnetic wave that has passed through three or more target articles having a known mass and different masses from each other,
The mass estimation apparatus according to claim 3. The storage unit further stores, for each type of the target article, size-mass correlation information indicating a correlation between the size of the target article and the mass of the target article,
The temporary physical quantity calculation unit determines the size of the target article based on a measurement result of the measurement unit, and calculates a temporary estimated mass of the target article based on the determined size and the size mass correlation information. Calculate as a provisional physical quantity,
The mass estimation apparatus according to claim 1. The temporary physical quantity calculation unit calculates the size of the target article as the temporary physical quantity.
The mass estimation apparatus according to claim 1. A rank determination unit that determines a rank of the target article based on the estimated mass of the target article calculated by the mass estimation unit;
The mass estimation apparatus of any one of Claim 1 to 6. An input unit for inputting a boundary value of the physical quantity band;
The mass estimation apparatus of any one of Claim 1 to 7. The electromagnetic wave is X-ray.
The mass estimation apparatus of any one of Claim 1 to 8.

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