Access control device

Abstract

To prevent misidentification of equipment worn by the foremost worker among workers photographed at the same time when a plurality of workers enter a work area one by one, due to another worker being photographed behind the foremost worker. [Solution] When multiple workers enter the work area one by one through an aisle 13, multiple types of equipment worn by the foremost worker among the workers photographed simultaneously by a camera 11 are selected by an equipment selection process by a control device 12. Whether each of the multiple types of equipment thus selected is designated equipment or not and whether it is not worn or not is determined by an equipment determination process by the control device 12. Therefore, even if another worker is photographed behind the foremost worker in the image information photographed by the camera 11, it is possible to accurately determine whether each of the multiple types of equipment worn by the foremost worker is designated equipment or not.

Description

[Technical field]

[0001] The present invention relates to an access control device. [Background technology]

[0002] Workers who work in designated work areas of nuclear power plants, etc., are required to wear designated equipment. For this reason, access control devices are installed at the passages to the work areas to allow only workers wearing the designated equipment to enter the work areas.

[0003] As such an entry control device, Patent Document 1 describes a device that takes a picture of a worker with a camera before he or she enters a work area and judges whether or not the worker is wearing clothes designated for entering the work area based on the color of the clothes, etc. If the device determines that the worker is not wearing clothes designated for entering the work area, the worker is prohibited from entering the work area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4781042 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a worker enters a work area, due to the passage space, multiple workers may line up and enter the work area one by one through the passage. In this case, when a worker is photographed by the camera of the entry management device, there is a risk that another worker may be photographed behind the worker. If another worker is photographed behind the worker photographed by the camera, the following may occur, for example. That is, the equipment, such as clothing, worn by a worker behind the worker closest to the camera may be mistaken for the equipment worn by the closest worker. In this case, it may not be possible to correctly determine whether the closest worker is wearing the specified equipment, which may lead to an erroneous determination. [Means for solving the problem]

[0006] Various aspects of the access control device that solves the above problems will be described below. (Aspect 1) In an entry control device comprising an image input unit which inputs image information of a plurality of workers taken simultaneously as the workers enter a work area one by one, and a determination unit which determines whether the worker in the image information inputted to the image input unit is wearing designated equipment, the determination unit prohibits the worker from entering the work area when it determines that the worker is not wearing the equipment, and permits the worker from entering the work area when it determines that the worker is wearing the equipment, the worker enters the work area wearing a plurality of types of designated equipment, and the determination unit executes an equipment detection process, an equipment selection process, an equipment determination process, and an entry permission determination process, the equipment detection process is a process of detecting position coordinates within the image information inputted to the image input unit of the equipment, and the equipment selection process is a process of detecting the position coordinates of the equipment of the worker in the image information inputted to the image input unit, and the equipment selection process is a process of detecting the position coordinates of the equipment of the worker in the image information inputted to the image input unit, an entry management device which selects a plurality of types of equipment worn by the foremost worker, the equipment determination process being a process of determining whether or not at least one of the plurality of types of equipment to be worn by the foremost worker is not worn, and determining whether or not each of the plurality of types of equipment selected by the equipment selection process is a designated piece of equipment, and the entry permission determination process is a process of prohibiting entry of the worker into the work area when it is determined by the equipment determination process that at least one of the plurality of types of equipment to be worn by the foremost worker is not worn, or when it is determined that at least one of the selected plurality of types of equipment is not designated equipment, and allowing entry of the worker into the work area when it is determined by the equipment determination process that all of the plurality of types of equipment to be worn by the foremost worker are worn, and all of the selected plurality of types of equipment are designated equipment.

[0007] According to the above configuration, when multiple workers enter the work area one by one, image information of the workers photographed at the same time is input to the image input unit.Then, the determination unit determines whether the workers in the image information input to the image input unit are wearing multiple types of specified equipment.In detail, the determination unit executes the above determination through an equipment detection process, an equipment selection process, an equipment determination process, and an entry permission determination process.

[0008] The equipment detection process detects the position coordinates of the equipment of the worker in the image information input to the image input unit.The equipment selection process selects multiple types of equipment worn by the foremost worker from the equipment whose position coordinates have been detected by the equipment detection process.The equipment determination process determines whether at least one of the multiple types of equipment that should be worn by the foremost worker is not worn, and determines whether each of the multiple types of equipment selected by the equipment selection process is specified equipment.

[0009] The equipment determination process determining that at least one of the multiple types of equipment that the nearest worker should wear is not worn, or that at least one of the selected multiple types of equipment is not the designated equipment, means that it has been determined that the nearest worker is not wearing the designated equipment. In this case, the entry permission determination process prohibits the worker from entering the worker area based on the determination by the equipment determination process. Furthermore, the equipment determination process determining that all of the multiple types of equipment that the nearest worker should wear is worn, and that all of the selected multiple types of equipment are the designated equipment, means that it has been determined that the nearest worker is wearing the designated equipment. In this case, the entry permission determination process permits the worker to enter the work area based on the determination by the equipment determination process.

[0010] As described above, when multiple workers enter the work area one by one, the multiple types of equipment worn by the foremost worker among the workers photographed at the same time are selected by the equipment selection process. Whether each of the multiple types of equipment selected in this way is the designated equipment and whether it is not worn is determined through the equipment determination process. Therefore, even if another worker is photographed behind the foremost worker in the above image information, it is possible to accurately determine whether each of the multiple types of equipment worn by the foremost worker is the designated equipment. In other words, it is possible to suppress erroneous determinations regarding whether each of the multiple types of equipment worn by the foremost worker is the designated equipment due to the presence of another worker behind the foremost worker.

[0011] (Aspect 2) The equipment detection process obtains a similarity score representing the degree to which the equipment, whose position coordinates have been detected in the image information, matches a specified equipment, and the equipment selection process obtains a rectangular size representing the size of the equipment, whose position coordinates have been detected by the equipment detection process, and selects equipment whose similarity score and rectangular size are equal to or greater than a pre-registered reference value as a candidate for equipment worn by the foremost worker, and, in the case of multiple candidates of the same type of equipment among the multiple types of selected candidates for equipment, the candidate with the largest rectangular size representing the size of the equipment is retained and the other candidates are excluded (as described in embodiment 1).

[0012] According to the above configuration, the equipment whose similarity score and rectangular size are equal to or greater than the preregistered reference value is selected by the equipment selection process as a candidate for the equipment worn by the foremost worker. If another worker is photographed behind the foremost worker, many candidates may be selected. In the equipment selection process, when there are multiple candidates of the same type of equipment among the multiple types of selected candidates for equipment, the candidate with the largest rectangular size is selected and other candidates are excluded. For example, the equipment candidates are selected as described above for each type until the upper limit number of each type of equipment worn by one worker is reached, and other candidates that are not selected are excluded. Therefore, when multiple workers enter the work area one by one, the multiple types of equipment worn by the foremost worker among the workers photographed at the same time can be accurately selected by the equipment selection process.

[0013] (Aspect 3) The equipment selection process selects multiple types of equipment worn by the foremost worker by eliminating combinations of equipment that are impossible for the worker's body structure based on the geometric relationship of the positions of the equipment when worn by the worker, from among the multiple types of equipment whose position coordinates are detected in the image information by the equipment detection process (access control device described in embodiment 1).

[0014] According to the above configuration, the position coordinates of the equipment of the worker in the image information input to the image input unit are detected by the equipment detection process. In the above image information, when another worker is photographed behind the foreground worker, a large number of equipment items of multiple types may be detected by the equipment detection means. However, the equipment selection process eliminates combinations of equipment items that are impossible for the worker's body structure from the geometric relationship of the positions of the equipment items when worn by the worker, among the multiple types of equipment items whose position coordinates have been detected. As a result, the multiple types of equipment items worn by the foreground worker are selected by the equipment discrimination process. Therefore, when multiple workers enter the work area one by one, the multiple types of equipment items worn by the foreground worker among the workers photographed at the same time can be accurately selected by the equipment selection process.

[0015] (Aspect 4) The equipment determination process initiates a determination when a worker determined to be the foremost worker in the image information input to the image input unit makes a pre-registered body gesture. An entry control device according to any one of (Aspect 1) to (Aspect 3).

[0016] According to the above configuration, when the worker who is determined to be the foremost in the image information input to the image input unit makes a pre-registered body gesture, the equipment determination process starts the determination, allowing the worker to stably start the equipment determination process at a timing desired by the worker.

[0017] (Aspect 5) The equipment detection process calculates a similarity score representing the degree to which the equipment, whose position information has been detected within the image information, matches a designated equipment, and the equipment determination process counts, among n frames consisting of the image information input to the image input unit during a specified time, the number of frames in which the similarity score for one of the selected multiple types of equipment is equal to or greater than a threshold as x, and determines that the one piece of equipment is the designated equipment based on the evaluation value calculated using x and n being equal to or greater than a pre-registered determination value, while determining that the one piece of equipment is not the designated equipment based on the evaluation value being less than the determination value, and these determinations are also performed on other pieces of equipment among all the selected types of equipment (an entry control device described in any one of (Aspect 1) to (Aspect 4).

[0018] According to the above configuration, by adjusting both the judgment value and the threshold value, it is possible to finely adjust the judgment sensitivity for judging whether the item selected as one of the multiple types of equipment worn by the nearest worker is the specified equipment or not, which makes it easier to adjust the judgment sensitivity to an appropriate level that achieves both accuracy and speed of the judgment.

[0019] (Aspect 6) The judgment unit executes a negative example judgment process to judge whether or not the equipment of the worker determined to be the foremost in the image information input to the image input unit is a pre-registered negative example equipment, and the entry permissibility judgment process immediately prohibits the worker from entering the work area when the negative example judgment process judges that the equipment of the worker determined to be the foremost in the image information is the negative example equipment. (An entry management device described in any one of Aspects 1) to 5.

[0020] According to the above configuration, when the equipment worn by the worker at the forefront in the image information input to the image input unit is the equipment of the negative example, and the equipment of the worker is determined to be the equipment of the negative example by the negative example determination process, the entry of the worker into the work area is immediately prohibited. Examples of situations in which the equipment of the worker becomes the equipment of the negative example include a situation in which the worker is only wearing a dedicated underwear worn under a radiation protection suit, or a situation in which the part of the body of the worker where the equipment is worn is exposed. In such a situation, the entry of the worker into the work area is immediately prohibited, so that a worker who is not wearing a radiation protection suit or who is not wearing equipment and has an exposed body can be prevented from entering the work area. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic diagram showing an overall configuration of an access control device. [Diagram 2] 4 is a flowchart showing a procedure for permitting or prohibiting entry of a worker into a work area by the entry control device of FIG. 1. [Diagram 3] 13 is an explanatory diagram showing a rectangle size representing the size of an equipment item whose position coordinates have been detected. FIG. [Figure 4] 4 is an explanatory diagram showing the rectangular size of an equipment item selected as the equipment worn by the foremost worker based on the rectangular sizes in FIG. 3. [Diagram 5] FIG. 5 is an explanatory diagram showing the sizes of the rectangles in FIG. 4 together with the types of equipment. [Figure 6] 1 when selecting a plurality of types of equipment worn by a worker. FIG. [Figure 7] 1 when selecting a plurality of types of equipment worn by a worker. FIG. [Figure 8] 1 when the worker makes a body gesture to start a determination by the equipment determination process. FIG. [Figure 9]1 when a result of the determination made by the equipment determination process is displayed. FIG. [Figure 10] 1 when a result of the determination made by the equipment determination process is displayed. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, one embodiment of the entrance control device will be described with reference to Figs. As shown in FIG. 1, the entry control device includes a camera 11, a control device 12, and a gate 16. The camera 11 photographs workers as they enter one by one through a passage 13 into a work area of ​​a nuclear power plant or the like. The camera 11 simultaneously outputs image information of the workers photographed to the control device 12. The control device 12 serves as an image input unit that inputs the image information. The gate 16 is installed in the passage 13. The gate 16 opens and closes to prohibit or permit the worker from entering the work area through the passage 13. The opening and closing operation of the gate 16 is performed by a drive unit 17 such as a motor.

[0023] The control device 12 is a computer having a CPU, RAM, ROM, etc., and serves as a determination unit that determines whether or not the worker in the image information is wearing the specified equipment. The control device 12 is capable of taking in the image taken by the camera 11 and displaying the image in a left-right inverted (mirror) manner on the display 15. The display 15 is positioned so that the worker photographed by the camera 11 can visually check his or her own image. The control device 12 operates the drive unit 17 to control the opening and closing operation of the gate 16.

[0024] <Prohibition and permission of workers to enter the work area> A worker enters a work area wearing multiple types of designated equipment, such as a cap, left and right gloves, a dosimeter, a radiation protection suit, and left and right socks. The entry control device allows only workers who are wearing all of the designated equipment to enter the work area, and prohibits workers who are not wearing any one of the designated equipment from entering the work area.

[0025] When such an entry control device prohibits or permits a worker to enter a work area, the control device 12 judges the equipment worn by the worker as follows: That is, when a worker stands in front of the camera 11 in the passage 13, the worker is captured in the image information input from the camera 11 to the control device 12. The control device 12 judges whether or not the worker closest to the camera 11 is wearing all of the multiple types of specified equipment in the input image information.

[0026] However, due to the space of the passage 13, a number of workers may line up and enter the work area one by one through the passage 13. In this case, when a worker is photographed by the camera 11, there is a risk that another worker may be photographed behind the worker. If another worker is photographed behind a worker photographed by the camera 11, the equipment worn by the worker behind may be mistaken for the equipment worn by the worker closest to the camera 11. In this case, there is a risk of an erroneous determination being made as to whether or not the closest worker is wearing the designated equipment.

[0027] In order to deal with this situation, the control device 12 sequentially executes an equipment detection process, an equipment selection process, an equipment determination process, and an entry permission determination process. The equipment detection process is a process for detecting the position coordinates of the equipment of the worker in the image information input to the control device 12. The equipment selection process is a process for selecting multiple types of equipment worn by the foremost worker from among the equipment whose position coordinates have been detected by the equipment detection process. The equipment determination process is a process for determining whether each of the multiple types of equipment selected by the equipment selection process is a specified piece of equipment. The equipment determination process is also a process for determining whether at least one of the multiple types of equipment that should be worn by the foremost worker is not worn.

[0028] The entry permission determination process is a process for prohibiting the worker from entering the work area when the equipment determination process determines either (A) or (B) below: (A) When the equipment determination process determines that at least one of the multiple types of equipment that the foremost worker should wear is not wearing, (B) When the equipment determination process determines that at least one of the multiple types of equipment selected by the equipment selection process is not the designated equipment.

[0029] The fact that the equipment determination process has determined that the worker closest to the operator is not wearing the designated equipment means that the equipment determination process has determined that the worker is not wearing the designated equipment. In this case, the entry permission determination process prohibits the worker from entering the operator area based on the determination by the equipment determination process. The prohibition of the worker from entering the work area is performed by closing the gate 16 through the drive unit 17 driven by the control device 12.

[0030] The entry permission determination process is a process for permitting entry of the worker into the work area when the equipment determination process makes the following determinations (C) and (D): (C) When the equipment determination process determines that the foremost worker is wearing all of the multiple types of equipment that should be worn by the worker. (D) When the equipment determination process determines that all of the multiple types of equipment selected by the equipment selection process are designated equipment.

[0031] The fact that the equipment determination process has determined that the worker closest to the operator is wearing the designated equipment means that the equipment determination process has determined that the operator is wearing the designated equipment. In this case, the entry permission determination process permits the operator to enter the work area based on the determination of the equipment determination process. The entry permission of the operator to the work area is granted by opening the gate 16 for a predetermined period of time through the driving of the driving unit 17 by the control device 12.

[0032] As described above, when multiple workers enter the work area one by one, the multiple types of equipment worn by the worker closest to the worker photographed at the same time are selected by the equipment selection process. The multiple types of equipment thus selected are then judged through the equipment judgment process as to whether they are designated equipment or not and whether they are not worn at all.

[0033] Therefore, even if another worker is shown behind the foremost worker in the image information, it is possible to accurately determine whether each of the multiple types of equipment worn by the foremost worker is the designated equipment. In other words, it is possible to prevent erroneous determinations from occurring in determining whether each of the multiple types of equipment worn by the foremost worker is the designated equipment, due to the presence of another worker behind the foremost worker.

[0034] 2 is a flowchart showing the procedure for permitting or prohibiting entry of a worker into a work area. In this flowchart, the process of step 101 (S101) corresponds to the above-mentioned equipment detection process, and the process of S102 corresponds to the above-mentioned equipment selection process. Moreover, the processes of S103 to S105 correspond to the above-mentioned equipment determination process, and the processes of S106 to S108 correspond to the above-mentioned entry permission determination process.

[0035] The control device 12 determines whether a predetermined time has elapsed since the start of the previous determination by the equipment determination process, as the process of S100 in Fig. 2. The predetermined time here is the time required for the previous determination by the equipment determination process to end, for example, 4 seconds. If it is determined in S100 that the predetermined time has not elapsed, the process of S100 is looped and executed until the predetermined time has elapsed. If it is determined in S100 that the predetermined time has elapsed, the process proceeds to S101.

[0036] <Equipment detection process (S101)> As the process of S101, the control device 12 detects position coordinates within the image information input from the camera 11 of the worker and the equipment. As the process of S101, the control device 12 calculates a similarity score representing the degree to which the worker, whose position coordinates are detected in the image information, is a true worker, for the worker. More specifically, the control device 12 calculates the similarity score from the image data of the worker, whose position coordinates are detected in the image information, using a learning model consisting of a multi-layer neural network. Furthermore, as the process of S101, the control device 12 calculates a similarity score representing the degree to which the equipment, whose position coordinates are detected in the image information, matches a specified equipment. More specifically, the control device 12 calculates the similarity score from the image data of the equipment, whose position coordinates are detected in the image information, using a learning model consisting of a multi-layer neural network.

[0037] <Equipment selection process (S102)> In the process of S102, the control device 12 obtains a rectangular size representing the size of the worker whose position coordinates were detected in S101, and obtains a rectangular size representing the size of each piece of equipment of the worker. The similarity scores of the workers and their equipment whose rectangular sizes have been obtained in this manner are obtained as described above. The multiple squares in Fig. 3 represent the rectangular sizes of the workers and their equipment whose similarity scores are equal to or greater than a preregistered reference value among the rectangular sizes obtained by the control device 12. In the notation "HxW" for the rectangles in Fig. 3, "H" represents the height (pixel value) of the rectangle, and "W" represents the width (pixel value) of the rectangle size.

[0038] The control device 12 selects the worker with the largest rectangular size as the worker closest to the camera 11 from among the candidate workers whose similarity scores are equal to or greater than a preregistered reference value. Furthermore, the control device 12 selects equipment whose position coordinates are within the rectangular size of the worker set as the worker closest to the camera 11 as candidates for multiple types of equipment worn by the worker closest to the camera 11. Examples of the candidates for equipment selected in this way include a cap, left and right gloves, a dosimeter, a radiation protection suit, and left and right socks.

[0039] In the process of S102, the control device 12 selects the candidate with the largest rectangular size for the selected multiple types of equipment when there are multiple candidates for the same type of equipment. In detail, the control device 12 selects the candidates for equipment for each type as described above until the maximum number of each type of equipment worn by one worker is reached, and excludes the other candidates that are not included in the selection. Note that the maximum numbers of the cap, gloves, dosimeter, radiation protection suit, and socks as the above-mentioned equipment are 1, 2, 1, 1, and 2, respectively.

[0040] The multiple squares in Fig. 4 indicate multiple types of equipment after the control device 12 has eliminated the above-mentioned candidates. These pieces of equipment are treated as multiple types of equipment worn by the worker at the forefront, that is, a cap, left and right gloves, a dosimeter, a radiation protection suit, and left and right socks, as shown in Fig. 5. In the notation "HxW" for the rectangles in Fig. 4, "H" represents the height of the rectangle (pixel value), and "W" represents the width of the rectangle (pixel value).

[0041] FIG. 6 shows the display on the display 15 when the multiple types of equipment worn by the foremost worker are selected using the above-mentioned method. As can be seen from FIG. 6, the display 15 displays an image of the foremost worker photographed by the camera 11. Furthermore, the display 15 also displays images of the multiple types of equipment worn by the worker, that is, a cap, left and right gloves, a dosimeter, a radiation protection suit, and left and right socks. The control device 12 displays the rectangular sizes of the items selected as the multiple types of equipment worn by the foremost worker on the display 15 as square frames surrounding the items of equipment. Furthermore, the control device 12 displays the names of the multiple types of equipment near the frames and displays the similarity scores of the items of equipment in %. The similarity scores are displayed in % by values ​​within a range of 0 to 100%.

[0042] Although the image in FIG. 6 shows another worker behind the foreground worker, the above-mentioned method can be used to prevent the equipment worn by the other worker from being selected as being worn by the foreground worker.

[0043] It is possible to adopt a method other than the above-mentioned method for selecting the multiple types of equipment worn by the nearest worker. For example, the control device 12 eliminates combinations that are impossible for the worker's body structure from among the multiple types of equipment whose position coordinates are detected in the image information, based on the geometric relationship of the positions when worn by the worker. In this way, the multiple types of equipment worn by the nearest worker may be selected from among the multiple types of equipment whose position coordinates are detected in the image information.

[0044] Fig. 7 shows the result when the control device 12 uses such a method to select multiple types of equipment worn by the foremost worker. In Fig. 7, since there is another worker behind the foremost worker, the size of the equipment worn by the other worker, specifically the size of the left and right gloves, is displayed as a rectangle size (pixel value on the screen) surrounding those gloves. The name of the equipment and the similarity score are displayed near the rectangle size. However, by using the above-mentioned method, it is possible to prevent equipment worn by another worker from being selected as being worn by the foremost worker.

[0045] <Equipment determination process (S103 to S105)> The control device 12 starts a judgment by the equipment judgment process when the worker who is determined to be the foremost in the image information performs a pre-registered body gesture, for example, a gesture that is not usually performed such as raising a hand until it enters the upper area of ​​the image information. In detail, the control device 12 judges whether or not the foremost worker in the image information performs the body gesture, i.e., a judgment start motion, as the process of S103. FIG. 8 shows the display of the display 15 when the worker performs the body gesture as the judgment start motion. The upper area of ​​the image in FIG. 8 is indicated by a two-dot chain line. Then, if it is determined in S103 of FIG. 2 that the judgment start motion has not been performed, the process proceeds to S108. If it is determined in S103 that the judgment start motion has been performed, the process proceeds to S104.

[0046] The control device 12 performs a determination by an equipment determination process as the process of S104. In detail, the control device 12 counts, as x, the number of frames in which the similarity score of one of the selected multiple types of equipment is equal to or greater than a threshold value, among n frames composed of image information input from the camera 11 to the control device 12 during a specified time. The control device 12 determines that the one piece of equipment is the designated equipment based on an evaluation value calculated using x and n, for example, x / n being equal to or greater than a determination value. The control device 12 also determines that the one piece of equipment is not the designated equipment based on an evaluation value calculated using x and n being less than a determination value. The control device 12 also performs these determinations on other pieces of equipment among the selected multiple types of equipment. Furthermore, as the process of S104, when there is a type of equipment that is insufficient as equipment that should be worn by the worker among the selected multiple types of equipment, the control device 12 determines that at least one of the multiple types of equipment that should be worn by the worker is not worn.

[0047] In the process of S104, when it is determined that at least one of the multiple types of equipment that the worker should wear is not worn, this means that the above-mentioned determination (A) has been made. Also, in the process of S104, when it is determined that one of the selected multiple types of equipment is not the designated equipment, this means that the above-mentioned determination (B) has been made. In the process of S104, when it is determined that all of the multiple types of equipment that the worker should wear are worn, this means that the above-mentioned determination (C) has been made. Also, in the process of S104, when it is determined that all of the selected multiple types of equipment are the designated equipment, this means that the above-mentioned determination (D) has been made.

[0048] The control device 12 displays the result of the judgment made by the above-mentioned equipment judgment process on the display 15 as the next process of S105. Fig. 9 and Fig. 10 show examples of the display on the display 15 at this time. In the process of S104, if the judgment of (C) above is made and the judgment of (D) above is made, that is, if an OK judgment is made, this is displayed on the display 15 as shown in Fig. 9. Also, in the process of S104, if the judgment of (A) above or the judgment of (B) above is made, that is, if an NG judgment is made, this is displayed on the display 15 as shown in Fig. 10. In Figs. 9 and 10, the notations "right hand" and "left hand" correspond to gloves, and the notations "right foot" and "left foot" correspond to socks.

[0049] The control device 12 also performs a negative example determination process as the process of S104 described above. The negative example determination process is a process for determining whether or not the equipment of the worker determined to be the foremost in the image information input to the control device 12 is a preregistered negative example equipment. Examples of situations in which the equipment of the worker is determined to be a negative example by the negative example determination process include a situation in which the worker is wearing only a dedicated underwear worn under a radiation protection suit, or a situation in which the part of the worker's body where the equipment is worn is exposed.

[0050] As a negative example determination process, the control device 12 uses a learning model for negative example determination to determine whether or not the equipment of the worker is a negative example from image data of multiple types of equipment worn by the foremost worker in the image information. The learning model for negative example determination may be a learning model composed of a multi-layer neural network. When the control device 12 determines that the equipment of the worker is a negative example, it immediately performs an NG determination. Furthermore, in the subsequent process of S105, the control device 12 displays an NG determination on the display 15.

[0051] <Entry permission determination process (S106 to S108)> The control device 12 determines whether or not the above-mentioned OK judgment has been made as the process of S106. If it is determined in S106 that the OK judgment has been made, the process proceeds to S107. As the process of S107, the control device 12 opens the gate 16 for a predetermined time by driving the drive unit 17, and closes the gate 16 by driving the drive unit 17 after the predetermined time has elapsed. By opening the gate 16 in this manner, the worker is permitted to enter the work area. Note that the above-mentioned predetermined time can be set, for example, to a time that allows the worker to pass through the open gate 16.

[0052] If it is determined in S106 that the OK judgment has not been made, in other words that the NG judgment has been made, the process proceeds to S108. In the process of S108, the control device 12 drives the drive unit 17 to close the gate 16. As a result, the worker is prohibited from entering the work area.

[0053] Next, the effects of the entry control device of this embodiment will be described. (1) It is possible to prevent erroneous determinations from occurring in determining whether each of multiple types of equipment worn by the foremost worker is a specified piece of equipment, which may occur when another worker is captured behind the foremost worker in the image information captured by camera 11.

[0054] (2) In the equipment selection process executed by the control device 12, multiple types of equipment worn by the worker closest to the camera 11 are selected using a method corresponding to Fig. 6 or a method corresponding to Fig. 7. As a result, when a worker enters a work area, multiple types of equipment worn by the worker closest to the camera 11 can be accurately selected from the equipment photographed by the camera 11.

[0055] (3) When the worker closest to the operator in the image information input to the control device 12 makes a gesture that is not usually made, such as raising his / her hand, as a pre-registered physical gesture, the equipment determination process is started. This allows the operator to stably start the equipment determination process at a timing that suits him / her.

[0056] (4) In the equipment detection process executed by the control device 12, a similarity score is calculated to indicate the degree to which the equipment, the position information of which is detected, matches the designated equipment in the image information input to the control device 12. In the equipment determination process executed by the control device 12, the number of frames in which the similarity score of one of the selected types of equipment is equal to or greater than a threshold is counted as x, out of n frames composed of the image information during a specified time. The control device 12 determines that the one piece of equipment is the designated equipment based on an evaluation value calculated using x and n, for example, x / n being equal to or greater than a determination value. The control device 12 also determines that the one piece of equipment is not the designated equipment based on x / n being less than the determination value. The control device 12 also performs these determinations on other pieces of equipment among all the selected types of equipment.

[0057] In the judgment by the equipment judgment process, by adjusting both the judgment value and the threshold value, it is possible to finely adjust the judgment sensitivity for judging whether the equipment selected as one of the multiple types of equipment worn by the foremost worker is the specified equipment or not. This makes it easier to adjust the judgment sensitivity to an appropriate level that achieves both accuracy and speed of the judgment.

[0058] (5) When the equipment worn by the foremost worker in the image information input to the control device 12 is the equipment of a negative example, and the negative example determination process determines that the equipment of the worker is the equipment of a negative example, an NG determination is immediately made. The control device 12 immediately prohibits the entry of the worker into the work area by closing the gate 16 based on the NG determination. Examples of situations in which the equipment of the worker becomes the equipment of a negative example include a situation in which the worker is wearing only a dedicated underwear worn under a radiation protection suit, or a situation in which the part of the body of the worker where the equipment is worn is exposed. In such a situation, the entry of the worker into the work area is immediately prohibited as described above, so that a worker who is not wearing a radiation protection suit or who is not wearing equipment and has an exposed body can be prevented from entering the work area.

[0059] The above embodiment can be modified, for example, as follows: The above embodiment and the following modified examples can be combined with each other to the extent that no technical contradiction occurs. In the equipment judgment process, it is not necessary to judge whether the clothes worn by the worker at the forefront are the specified equipment (radiation protection suit). For example, in a work area where radiation protection suit is not required, a worker may wear his / her own work suit. In such a case, by omitting the judgment, it is possible to prevent unnecessary NG judgments about the worker's clothes.

[0060] It is not necessary to perform negative example determination processing on worker clothes. Although the example given above shows a gesture of raising one's hand as a pre-registered physical gesture to indicate the start of the equipment determination process when the worker starts the equipment determination process, other physical gestures may also be used.

[0061] Although x / n is used as an example of the evaluation value in the equipment judgment process, other evaluation values ​​may be used. For example, an evaluation value (x / n)+b with a constant b added, or an evaluation value such as log(x / n) may be used.

[0062] The display 15 does not necessarily have to be provided. [Explanation of symbols]

[0063] 11. Camera 12...Control device 13...Aisle 15…Display 16…Gate 17...Drive unit

Claims

1. an image input unit that inputs image information of a plurality of workers that are simultaneously photographed when the workers enter a work area one by one; and a determination unit that determines whether the workers in the image information input to the image input unit are wearing designated equipment, In the entry management device, the determination unit prohibits the worker from entering the work area when it is determined that the worker is not wearing the equipment, and allows the worker to enter the work area when it is determined that the worker is wearing the equipment, The worker enters the work area wearing a plurality of types of designated equipment, The determination unit executes an equipment detection process, an equipment selection process, an equipment determination process, and an entry permission determination process, the accessory detection process is a process of detecting position coordinates of an accessory of a worker within the image information inputted to the image input unit, The equipment selection process is a process of selecting a plurality of types of equipment worn by a foremost worker from among the equipment whose position coordinates have been detected by the equipment detection process, The equipment determination process is a process for determining whether or not at least one of a plurality of types of equipment to be worn by the foremost worker is not worn, and for determining whether or not each of the plurality of types of equipment selected by the equipment selection process is a designated equipment, The entry permission determination process is a process of prohibiting the worker from entering the work area when the equipment determination process determines that at least one of the multiple types of equipment that the foremost worker should wear is not wearing, or when it determines that at least one of the multiple types of equipment selected is not designated equipment, and of allowing the worker to enter the work area when the equipment determination process determines that all of the multiple types of equipment that the foremost worker should wear are wearing and all of the selected multiple types of equipment are designated equipment.

2. The equipment detection process calculates a similarity score representing a degree to which the equipment, the position coordinates of which are detected in the image information, matches a specified equipment, 2. The access control device of claim 1, wherein the equipment selection process determines a rectangular size representing the size of the equipment whose position coordinates have been detected by the equipment detection process, selects equipment whose similarity score and rectangular size are equal to or greater than a preregistered reference value as a candidate for equipment worn by the foremost worker, and, for those of the same type of equipment among the selected candidates for the multiple types of equipment, keeps the candidate with the largest rectangular size representing the size of the equipment and excludes the other candidates.

3. The access control device of claim 1, wherein the equipment selection process selects multiple types of equipment worn by the foremost worker by eliminating combinations of equipment that are impossible for the worker's body structure based on the geometric relationship of the positions of the equipment when worn by the worker, from among multiple types of equipment whose position coordinates are detected in the image information by the equipment detection process.

4. The entry control device according to any one of claims 1 to 3, wherein the equipment determination process starts a determination when a worker determined to be the foremost worker in the image information input to the image input unit makes a pre-registered body gesture.

5. The equipment detection process calculates a similarity score representing a degree to which the equipment, the position information of which is detected within the image information, matches a specified equipment, The equipment determination process counts, among n frames composed of the image information input to the image input unit during a specified time, the number of frames in which the similarity score for one of the selected multiple types of equipment is equal to or greater than a threshold as x, and determines that the one piece of equipment is a designated equipment if an evaluation value calculated using x and n is equal to or greater than a pre-registered judgment value, while determining that the one piece of equipment is not a designated equipment if the evaluation value is less than the judgment value, and performs these judgments on other equipment among all the selected types of equipment.

6. The determination unit executes a negative example determination process, The negative example determination process determines whether or not an equipment of a worker determined to be the foremost in the image information input to the image input unit is an equipment of a pre-registered negative example, The entry management device according to any one of claims 1 to 3, wherein the entry permissibility determination process immediately prohibits the worker from entering the work area when the negative example determination process determines that the equipment of the worker closest to the front in the image information is the negative example equipment.

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