Monitoring method, monitoring device, and computer storage medium

Abstract

A monitoring method for monitoring a cleanroom interior in which removable floor tiles are arranged on the floor, said method comprising a step for detecting, on the basis of three-dimensional data for the cleanroom interior generated from the results of a distance measurement using electromagnetic waves, an opening from which a floor tile has been removed, wherein said detection step comprises a step for comparing a reference height determined in advance on the basis of three-dimensional data for the cleanroom interior generated in advance, with the height of each part of the cleanroom interior indicated by the three-dimensional data of the cleanroom interior generated during monitoring, and determining the presence or absence of said opening on the basis of the results of the comparison.

Description

Monitoring method, monitoring device, and computer storage medium

[0001] The present disclosure relates to a monitoring method, a monitoring device, and a computer storage medium.

[0002] Patent Literature 1 discloses a clean room monitoring device for monitoring the interior of a clean room having a removable floor panel. The monitoring device includes a monitoring camera that captures images of the floor panel along a passageway through which workers can pass. The monitoring device also includes a monitoring unit that detects the presence or absence of an opening where the floor panel has been removed from an image signal obtained by the monitoring camera, and if an opening is present, detects the presence or absence of a worker approaching the opening from the image signal from the monitoring camera, and outputs an alarm signal when a worker is detected; and an alarm generating means that receives the alarm signal from the monitoring unit and generates an alarm.

[0003] Patent No. 6018821

[0004] The technology disclosed herein improves worker safety when floor tiles are removed and opened in a clean room without the use of cameras.

[0005] One aspect of the present disclosure is a monitoring method for monitoring the inside of a clean room in which removable floor tiles are placed on the floor, comprising a step of detecting an opening through which the floor tile has been removed based on three-dimensional data of the inside of the clean room generated from distance measurement results using electromagnetic waves, wherein the detecting step includes a step of comparing a predetermined reference height based on the three-dimensional data of the inside of the clean room generated in advance with the height of each part of the clean room indicated by the three-dimensional data of the inside of the clean room generated during monitoring, and determining the presence or absence of the opening based on the comparison result.

[0006] According to the present disclosure, when floor tiles in a clean room are removed and an opening is made, worker safety can be improved without using a camera.

[0007] 1 is a block diagram showing a schematic configuration of a monitoring system having a monitoring device according to a first embodiment. FIG. 2 is a diagram for explaining a LiDAR unit. FIG. 3 is a diagram for explaining a LiDAR unit. FIG. 4 is a functional block diagram of a control unit of a monitoring device relating to monitoring based on three-dimensional data in a clean room. FIG. 5 is a diagram showing an example of an image displayed on the display unit by a display control unit. FIG. 6 is a diagram showing a portion of an image obtained from data processed by a visualization processing unit. FIG. 7 is a flowchart for explaining an example of a flow for determining a reference height by a monitoring device. FIG. 8 is a flowchart for explaining an example of a monitoring flow by a monitoring device. FIG. 9 is a flowchart for explaining an example of a monitoring flow by a monitoring device. FIG. 10 is a functional block diagram of a control unit of a monitoring device according to a second embodiment. FIG. 11 is a flowchart for explaining an example of an alarm generation flow in a monitoring flow according to the second embodiment.

[0008] Conventionally, in semiconductor manufacturing lines for manufacturing semiconductor devices, for example, numerous semiconductor manufacturing devices, such as substrate processing devices, are arranged in clean rooms with a clean atmosphere. In such clean rooms, floor tiles (sometimes called gratings) with numerous lattice-shaped ventilation holes are arranged on the floor. The space below the floor tiles houses pipes, various electrical equipment, pumps, chemical tanks, and the like. For example, when installing, maintaining, or repairing these pipes, various electrical equipment, pumps, and the like, workers must descend into the space below the floor tiles to perform their work. Therefore, the floor tiles are removable.

[0009] In this way, in clean rooms, when floor tiles are removed, workers can descend into the space below the floor tiles to perform their work. However, when floor tiles are removed, openings are created in the floor of the clean room, which are formed by a large number of floor tiles, and there is a risk that workers could fall through these openings into the space below. In particular, workers performing other tasks on the floor tiles may be unaware that openings exist, and so workers have traditionally been warned to be careful.

[0010] The technology described in Patent Document 1 uses a surveillance camera that captures images of the floor tile surface, and based on the image signals obtained by the surveillance camera, detects whether or not there is an opening where a floor tile has been removed, and if there is a worker present, outputs an alarm signal and issues an alarm from an alarm generating means.

[0011] While this technology has improved worker safety, there are some locations where the use of surveillance cameras is not permitted due to concerns about the risk of confidential information being leaked or privacy concerns.

[0012] Therefore, the present disclosure provides a technology that can detect the presence or absence of an opening where a floor tile has been removed without using a camera.

[0013] A monitoring method and a monitoring device according to the present embodiment will be described below with reference to the drawings. In this specification, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0014] (First embodiment) <Monitoring system> Fig. 1 is a block diagram showing a schematic configuration of a monitoring system having a monitoring device according to Embodiment 1. Figs. 2 and 3 are diagrams for explaining a LiDAR (Light Detection and Ranging) unit, which will be described later.

[0015] The monitoring system 1 in FIG. 1 includes a monitoring device 10 for monitoring the inside of a clean room and a LiDAR unit 20.

[0016] The monitoring device 10 includes a main body 11 , a display 12 , an alarm unit 13 , and an input unit 14 .

[0017] The main body 11 is a computer equipped with a processor such as a CPU, a memory, and the like, and includes a storage unit 11a and a control unit 11b. The storage unit 11a stores various information and includes a memory such as a RAM and a storage device such as an HDD. The storage unit 11a stores a program including instructions for executing a monitoring flow described below and a program including instructions for executing a reference height determination flow described below. The programs may be recorded on a computer-readable storage medium H and installed from the storage medium H into the main body 11. The storage medium H may be a medium for temporary storage or a medium for non-temporary storage.

[0018] The display unit 12 displays various images and is configured, for example, by a liquid crystal display, an organic EL display, or the like.

[0019] The alarm unit 13 issues an alarm by means of at least one of light and sound. The sound alarm may be in the form of emitting an alarm sound or reading out a warning message by voice. The alarm unit 13 is provided, for example, in a substrate processing apparatus PA (see FIG. 2) serving as a semiconductor manufacturing apparatus in a clean room to be monitored.

[0020] The input unit 14 is used by an operator to input instructions, and includes, for example, a touch panel and a keyboard.

[0021] The LiDAR unit 20 is an example of a three-dimensional data generation unit.

[0022] The three-dimensional data generation unit, exemplified by the LiDAR unit 20, generates three-dimensional data of the clean room interior from the results of distance measurement using electromagnetic waves. Specifically, the three-dimensional data generation unit includes an output unit, a detection unit (i.e., a sensor), and a calculation unit. In the three-dimensional data generation unit, the output unit outputs electromagnetic waves, and the detection unit detects reflected waves of the electromagnetic waves output from the output unit. The calculation unit of the three-dimensional data generation unit calculates the distance to each measurement point in the clean room based on the detection results from the detection unit and calculates the coordinate values ​​(x, y, z coordinate values) of each measurement point based on the calculation results, thereby generating point cloud data indicating the shape of the clean room interior as three-dimensional data of the clean room interior. The calculation unit of the three-dimensional data generation unit is configured, for example, by a microcontroller.

[0023] The LiDAR unit 20 uses laser light, specifically near-infrared laser light, as the electromagnetic wave. The output section of the LiDAR unit 20, which serves as the output section of the three-dimensional data generation section, includes a laser oscillator that generates a laser and a driver that drives the laser oscillator. The detection section of the LiDAR unit 20, which serves as the detection section of the three-dimensional data generation section, includes a photodiode that receives the laser light.

[0024] 2, LiDAR unit 20 is disposed so that clean room floor Y, to which floor tiles FT are detachably attached, is located within an area AR1 where electromagnetic waves (specifically, laser light) can be irradiated (i.e., an area where point cloud data as three-dimensional data can be generated). Specifically, LiDAR unit 20 is fixed so that at least an area on clean room floor Y where substrate processing equipment PA as semiconductor manufacturing equipment is not placed, i.e., an area where workers pass through, is located within area AR1 where electromagnetic waves can be irradiated (hereinafter referred to as electromagnetic wave irradiation area).

[0025] The LiDAR unit 20 may have an annular electromagnetic wave irradiation area AR1 when viewed from the direction of the axis P of the LiDAR unit, and a non-irradiation area AR2 that is not irradiated with electromagnetic waves and is surrounded by the electromagnetic wave irradiation area AR1 when viewed from the same direction. In this case, the LiDAR unit 20 may be disposed so that the axis P faces the substrate processing apparatus PA. Specifically, the LiDAR unit 20 may be fixed so that the axis P faces the substrate processing apparatus PA and the floor Y of the clean room is located within the electromagnetic wave irradiation area AR1 but not within the non-irradiation area AR2. For example, when the LiDAR unit 20 is attached to the top of the substrate processing apparatus PA, the LiDAR unit 20 may be attached so that it faces diagonally downward so that the substrate processing apparatus PA is located within the non-irradiation area AR2.

[0026] In addition, a plurality of LiDAR units 20 (two in the illustrated example) are arranged so that point cloud data for the entire periphery of the substrate processing apparatus PA can be generated, that is, so that the entire periphery of the substrate processing apparatus PA is surrounded by an electromagnetic wave irradiation area AR1 as shown in FIG. 2. In the following description, one of the two LiDAR units 20 is referred to as the first LiDAR unit 20. １ , and the other is the second LiDAR unit 20 ２ This is what happens.

[0027] For example, the LiDAR unit 20 is attached to the ceiling of a clean room. The LiDAR unit 20 may also be attached to the substrate processing apparatus PA. In this case, for example, the LiDAR unit 20 is attached to a position slightly separated from the substrate processing apparatus PA via an attachment member 30, as shown in FIG. 3 . The LiDAR unit 20 may also be supported by a stand (not shown) serving as a support member placed on the floor of the clean room.

[0028] The three-dimensional data of the clean room interior (specifically, point cloud data showing the shape of the clean room interior) generated or acquired by this LiDAR unit 20 is output to the monitoring device 10 and stored in the memory unit 11a.

[0029] The monitoring device 10 monitors the clean room based on the three-dimensional data of the inside of the clean room generated by each LiDAR unit 20. During monitoring by the monitoring device 10, each LiDAR unit 20 sequentially generates the above three-dimensional data. Furthermore, each LiDAR unit 20 generates the above three-dimensional data at least once before monitoring by the monitoring device 10 in order to determine a reference height, which will be described later.

[0030] <Controller 11b of Monitoring Device 10> Fig. 4 is a functional block diagram of the controller 11b of the monitoring device 10 for monitoring the inside of a clean room based on three-dimensional data. Fig. 5 is a diagram showing an example of an image displayed on the display unit 12 by the display controller 150 (described later). Fig. 6 is a diagram showing a portion of an image obtained from data processed by the visualization processor 160 (described later).

[0031] As shown in FIG. 4, the control unit 11b includes an acquisition unit 100, a detection unit 110, a reference height determination unit 120, an alarm control unit 130, an opening position identification unit 140, a display control unit 150, and a visualization processing unit 160, which are realized by a processor such as a CPU reading and executing a program stored in the memory unit 11a.

[0032] The acquisition unit 100 acquires data to be used for detection by the detection unit 110 during monitoring from the three-dimensional data of the clean room that is stored in the storage unit 11a and sequentially generated by the LiDAR units 20. The acquisition unit 100 acquires, for example, at least the most recent three-dimensional data as the data to be used for detection by the detection unit 110 during monitoring, and specifically, acquires at least the most recent three-dimensional data for each LiDAR unit 20.

[0033] The detection unit 110 detects an opening through which a floor tile FT has been removed based on three-dimensional data of the inside of the clean room. Specifically, the detection unit 110 detects the opening based on the three-dimensional data of the inside of the clean room acquired by the acquisition unit 100. The detection unit 110 has a determination unit 111.

[0034] The determination unit 111 uses a reference height Ts. The reference height Ts is determined in advance before the detection by the detection unit 110 based on three-dimensional data of the interior of the clean room generated in advance before the detection. The determination unit 111 compares this reference height Ts with the height of each part of the clean room indicated by the three-dimensional data of the interior of the clean room generated during monitoring, and determines the presence or absence of an opening based on the comparison result. Specifically, the determination unit 111 compares the reference height Ts with the height of each part of the clean room indicated by the three-dimensional data of the interior of the clean room acquired by the acquisition unit 100, and determines the presence or absence of an opening based on the comparison result.

[0035] For example, the determination unit 111 determines that an opening exists in the clean room when a portion whose height is lower than the reference height Ts by at least a threshold value Th1 is present, i.e., when an opening has been detected. The threshold value Th1 is set to, for example, a value greater than the thickness of the floor tile FT. Specifically, the threshold value Th1 is, for example, 10 cm. The determination unit 111 may also determine that an opening exists when a portion whose height is lower than the reference height Ts by at least a threshold value Th1 is present in the clean room and the area of ​​the mass of the lower portion in a planar view is greater than a threshold value Th2. The area is determined, for example, from a collection of XY coordinates of points in the point cloud data having z coordinate values ​​lower than the reference height Ts by at least a threshold value Th1. The threshold value Th2 is set, for example, based on the area of ​​the floor tile FT. Specifically, the threshold value Th2 is, for example, 25% or more of the area of ​​the floor tile FT. By using the area in this way, it is possible to reduce false detections of openings, such as detecting gaps between floor tiles FT as openings.

[0036] The reference height determiner 120 determines the reference height Ts in advance based on three-dimensional data of the clean room interior generated in advance before detection by the detector 110, i.e., before monitoring by the monitoring device 10 begins. Specifically, the reference height determiner 120 determines the reference height Ts before the determination by the determiner 111, based on three-dimensional data of the clean room interior generated before the determination is started. For example, the reference height determiner 120 automatically determines the height that appears most frequently among the heights in the three-dimensional data of the clean room interior (specifically, the z coordinate value in the point cloud data) as the reference height. The reason for this determination is that the height of the upper surface of the floor tile FT, i.e., the floor surface, is the height that appears most frequently in the clean room.

[0037] The alarm control unit 130 causes the alarm unit 13 to issue an alarm when the detection unit 110 detects an opening. Specifically, the alarm control unit 130 controls the alarm unit 13 to issue an alarm when the determination unit 111 of the detection unit 110 determines that an opening is present. Furthermore, after causing the alarm unit 13 to issue an alarm, the alarm control unit 130 stops the alarm from the alarm unit 13 when the detection unit 110 no longer detects an opening.

[0038] When an opening is detected by the detection unit 110, the opening position identification unit 140 identifies the position of the opening based on three-dimensional data of the interior of the clean room generated during monitoring. Specifically, when an opening is detected by the detection unit 110, the opening position identification unit 140 identifies the position of the opening based on three-dimensional data of the interior of the clean room acquired by the acquisition unit 100. For example, the opening position identification unit 140 calculates the position of the center of gravity (specifically, the horizontal position of the center of gravity, i.e., the x- and y-coordinate values ​​of the center of gravity) of a mass whose height is lower than the reference height Ts by at least a threshold value Th1, and identifies the position of the center of gravity as the position of the opening.

[0039] The display control unit 150 causes the display unit 12 to display an image indicating the position of the opening identified by the opening position identifying unit 140. For example, as shown in FIG. 5 , the image is a top-view image Im1 that schematically illustrates a top view of the floor, with a region R1 corresponding to the opening highlighted. The top-view image Im1 is divided into, for example, multiple regions, with the region R1 corresponding to the position of the opening highlighted. Information correlating the positions of the openings with the positions of the regions in the top-view image Im1 is stored in the storage unit 11a and referenced by the display control unit 150 when generating the top-view image Im1. The top-view image Im1 also includes an image Im11 that simulates the substrate processing apparatus PA. This allows the operator to easily understand the relative positional relationship between the opening and the substrate processing apparatus PA. The top-view image Im1 may also include a warning message Im12 indicating that an opening has been formed.

[0040] The visualization processing unit 160 processes the three-dimensional data of the clean room interior so that it can be visualized. Specifically, the visualization processing unit 160 converts the three-dimensional data of the clean room interior generated by the LiDAR unit 20 into data representing a pseudo-stippled image Im2 of the clean room interior, a portion of which is shown in FIG. 6 . The pseudo-stippled image Im2 is a stippled image of the interior of the clean room as seen from the position of the LiDAR unit 20, and each point in the image corresponds to each point in the point cloud data as three-dimensional data. The visualization processing unit 160 may be omitted.

[0041] <Reference Height Determination Flow> Next, before describing an example of a monitoring flow by the monitoring device 10, an example of a reference height determination flow by the monitoring device 10 will be described with reference to Fig. 7. Fig. 7 is a flowchart for explaining an example of a reference height determination flow by the monitoring device 10. The determination flow is executed prior to the monitoring flow.

[0042] (Step S1: First LiDAR unit 20 １ First, the acquisition unit 100 acquires the point cloud data stored in the storage unit 11a and acquired by the first LiDAR unit 20 before the start of monitoring by the monitoring device 10. １ The data generated by the first LiDAR unit 20 for determining the reference height１ The data is acquired as point cloud data.

[0043] (Step S2: First LiDAR unit 20 １ Next, the reference height determination unit 120 determines the reference height of the first LiDAR unit 20 for determining the reference height acquired by the acquisition unit 100. １ Based on the point cloud data, the first LiDAR unit 20 １ The reference height Ts is determined.

[0044] For example, the reference height determination unit 120 may use the first LiDAR unit 20 for determining the reference height. １ The z-coordinate value with the highest frequency of occurrence among the z-coordinate values ​​in the point cloud data is calculated by the first LiDAR unit 20. １ The reference height Ts is automatically determined.

[0045] First LiDAR unit 20 by reference height determination unit 120 １ The determination of the reference height Ts may be performed as follows. That is, first, the reference height determination unit 120 determines the first LiDAR unit 20 for determining the reference height. １ The z-coordinate value with the highest frequency of occurrence among the z-coordinate values ​​in the point cloud data is calculated by the first LiDAR unit 20. １ At the same time, the visualization processing unit 160 determines the first LiDAR unit 20 for determining the reference height Ts as a candidate for the reference height Ts. １ The display control unit 150 processes the point cloud data in a manner that allows visualization, and generates data showing the pseudo-stippled image Im2 of the inside of the clean room. Based on the determination result by the reference height determination unit 120 and the processing result by the visualization processing unit 160, the display control unit 150 generates a pseudo-stippled image Im2 of the inside of the clean room, which is １ The display unit 12 displays an image highlighting the portion of the image whose height matches the candidate for the reference height Ts of the first LiDAR unit 20 based on the result of input by the operator to the input unit 14 during this display. １ The candidate for the reference height Ts is １This makes it possible to more reliably align the reference height Ts with the height of the upper surface of the floor tile FT, i.e., the floor surface.

[0046] (Step S3: Second LiDAR unit 20 ２ Acquisition of point cloud data) The acquisition unit 100 acquires point cloud data stored in the storage unit 11a and acquired by the second LiDAR unit 20 before the start of monitoring by the monitoring device 10. ２ The data generated by the second LiDAR unit 20 for determining the reference height is ２ The data is acquired as point cloud data.

[0047] (Step S4: Second LiDAR unit 20 ２ Next, the reference height determination unit 120 determines the reference height of the second LiDAR unit 20 for determining the reference height acquired by the acquisition unit 100. ２ Based on the point cloud data, the second LiDAR unit 20 ２ Determine the reference height Ts of the second LiDAR unit 20 ２ A more specific method for determining the reference height Ts is １ This is the same as the reference height Ts.

[0048] In this way, the reference height Ts is determined for each LiDAR unit 20.

[0049] <Monitoring Flow> Next, an example of a monitoring flow by the monitoring device 10 will be described with reference to Fig. 8 and Fig. 9. Fig. 8 and Fig. 9 are flowcharts for explaining an example of a monitoring flow by the monitoring device 10.

[0050] (Step S11: First LiDAR unit 20 １ First, the acquisition unit 100 acquires the point cloud data of the first LiDAR unit 20 stored in the storage unit 11a. １ The first LiDAR unit 20 for monitoring may store, for example, the most recent point cloud data generated by the １ The data is acquired as point cloud data.

[0051] (Step S12: First LiDAR unit 20 １Next, the determination unit 111 determines whether or not there is an opening in the monitoring range using the first LiDAR unit 20 for monitoring acquired by the acquisition unit 100. １ The height of each point in the clean room indicated by the point cloud data and the first LiDAR unit 20 １ The reference height Ts of the first LiDAR unit 20 is compared with the reference height Ts of the first LiDAR unit 20 based on the comparison result. １ The presence or absence of an opening in the monitoring range is determined using the

[0052] For example, the determination unit 111 may determine a set of adjacent points, i.e., a cluster of points, that satisfy the following conditions (A) and (B) as the first LiDAR unit 20 for monitoring. １ When the point cloud data includes １ (A) The height of each point is determined to be within the monitoring range using the first LiDAR unit 20. １ (B) The projected area of ​​the set of points onto the xy plane is greater than a threshold value Th2.

[0053] (Step S13: Second LiDAR unit 20 ２ Acquisition of point cloud data) The acquisition unit 100 also acquires the second LiDAR unit 20 stored in the storage unit 11a. ２ The second LiDAR unit 20 for monitoring may store, for example, the most recent point cloud data generated by the ２ The data is acquired as point cloud data.

[0054] (Step S14: Second LiDAR unit 20 ２ Next, the determination unit 111 determines whether or not there is an opening in the monitoring range using the second LiDAR unit 20 for monitoring acquired by the acquisition unit 100. ２ The height of each point in the clean room indicated by the point cloud data and the second LiDAR unit 20 ２ The reference height Ts of the second LiDAR unit 20 is compared with the reference height Ts of the first LiDAR unit 20 based on the comparison result. ２ The presence or absence of an opening in the monitoring range is determined using the

[0055] For example, the determination unit 111 may determine a set of adjacent points, i.e., a cluster of points, that satisfy the following condition (C) and the above-mentioned condition (B) as the second LiDAR unit 20 for monitoring. ２ When the point cloud data includes ２ (C) It is determined that there is an opening within the monitoring range using the second LiDAR unit 20 ２ is lower than the reference height Ts by a threshold value Th1 or more.

[0056] Then, the first LiDAR unit 20 １ and the second LiDAR unit 20 ２ If there is no opening in any of the monitoring ranges using the first LiDAR unit 20 (NO in step S15), that is, if it is determined that there is no opening in either step S12 or step S14, the monitoring flow returns to step S11. １ and the second LiDAR unit 20 ２ If an opening exists in at least one of the monitoring ranges using (YES in step S15), that is, if it is determined that an opening exists in at least one of step S12 and step S14, the monitoring flow proceeds to step S16 and subsequent steps.

[0057] (Step S16: Alarm) In step S16, the alarm control unit 130 causes the alarm unit 13 to generate an alarm.

[0058] (Step S17: Identifying Aperture Position) The aperture position identifying unit 140 identifies the position of the aperture. For example, the aperture position identifying unit 140 identifies the position of the aperture of the first LiDAR unit 20 for monitoring. １ The set of points included in the point cloud data of the second LiDAR unit 20 for monitoring ２ The opening position specifying unit 140 calculates the center of gravity (more specifically, the x- and y-coordinate values ​​of the center of gravity) of each of the sets of points included in the point cloud data of the image sensor 100. The opening position specifying unit 140 specifies the calculated center of gravity as the position of the opening.

[0059] (Step S18: Displaying a top-view image) Next, the display control unit 150 causes the display unit 12 to display the above-mentioned top-view image Im1 indicating the position of the opening, based on the position of the opening identified by the opening position identifying unit 140. Steps S17 and S18 may be performed before step S16, or may be performed in parallel with step S16.

[0060] After steps S16 to S18, steps S19 to S22 are performed, which are similar to steps S11 to S14 described above.

[0061] First LiDAR unit 20 １ and the second LiDAR unit 20 ２ If an opening still exists in at least one of the monitoring ranges using the first LiDAR unit 20 (YES in step S23), that is, if it is determined that an opening exists in at least one of step S20 and step S22, the monitoring flow returns to steps S16 to S18. １ and the second LiDAR unit 20 ２ If there is no opening in any of the monitoring ranges using (NO in step S23), that is, if it is determined that there is no opening in either step S20 or step S22, the monitoring flow proceeds to step S24 and subsequent steps.

[0062] (Step S24: Stopping Alarm) In step S24, the alarm control unit 130 controls the alarm unit 13 to stop the alarm.

[0063] (Step S25: Stop display of top-view image) The display control unit 150 controls the display unit 12 to stop displaying the above-mentioned top-view image Im1 indicating the position of the opening. Step S25 may be performed before step S24 or in parallel with step S24.

[0064] After steps S24 and S25, the monitoring flow returns to step S1.

[0065] <Main Effects of the First Embodiment> As described above, the monitoring method for a clean room having floor tiles FT arranged on the floor according to this embodiment includes a step of detecting an opening where a floor tile FT has been removed based on three-dimensional data of the clean room. The detection step includes a step of comparing a predetermined reference height Ts based on the three-dimensional data of the clean room generated in advance with the height of each part of the clean room indicated by the three-dimensional data of the clean room generated during monitoring, and determining the presence or absence of an opening based on the comparison result. Therefore, if an opening is found, an alarm can be issued, for example, to allow workers to recognize the existence of an opening, thereby improving worker safety. Furthermore, in this embodiment, the three-dimensional data of the clean room used to detect the opening is generated from the results of distance measurement using electromagnetic waves. That is, in this embodiment, a camera is not required for opening detection. Therefore, even in cases where the use of cameras is not permitted due to concerns about the risk of confidential information leaks or privacy concerns, work safety can be improved.

[0066] (Second embodiment) Fig. 10 is a functional block diagram of a control unit of a monitoring device according to a second embodiment. In this embodiment, as shown in Fig. 10, the control unit 11Ab has an object position identification unit 170 in addition to an acquisition unit 100, a detection unit 110, a reference height determination unit 120, an alarm control unit 130, an opening position identification unit 140, a display control unit 150, and a visualization processing unit 160. The visualization processing unit 160 may be omitted. The object position identification unit 170, like the acquisition unit 100, is realized by a processor such as a CPU reading and executing a program stored in the storage unit 11a.

[0067] The object position identifying unit 170 identifies the position of a portion of the clean room that is higher than the reference height Ts based on three-dimensional data of the clean room that was generated during monitoring. The object position identifying unit 170 calculates the position of the center of gravity of the mass of the portion whose height is higher than the reference height Ts by a threshold value Th3 or more (specifically, the horizontal position of the center of gravity, i.e., the x- and y-coordinate values ​​of the center of gravity), and identifies the position of the center of gravity as the position of the portion (hereinafter, "object") that is higher than the reference height Ts. The threshold value Th3 is, for example, 60 cm.

[0068] In this embodiment, the alarm control unit 130 causes the alarm unit 13 to issue an alarm according to the distance between the position of the object and the position of the opening. For example, when an object is located within a predetermined range from the opening, the alarm control unit 13 causes the alarm unit 13 to issue an alarm that is louder than normal (i.e., when no object is present within the predetermined range from the opening) or an alarm with a different sound from normal. This can further improve the safety of the worker.

[0069] <Warning Generation Flow> Next, an example of a warning generation flow in the monitoring flow according to this embodiment will be described with reference to Fig. 11. Fig. 11 is a flowchart for explaining an example of a warning generation flow according to this embodiment.

[0070] In this embodiment, if an opening is present, the above-described step S17 is performed. That is, if it is determined in at least one of step S12 and step S14 that an opening is present, the opening position identifying unit 140 identifies the position of the opening.

[0071] (Step S31: Identifying Object Position) The object position identifying unit 170 identifies the position of the object. For example, the object position identifying unit 170 identifies the position of the object using the first LiDAR unit 20 for monitoring. １ A set of points that satisfy the following condition (D) contained in the point cloud data, and a second LiDAR unit 20 for monitoring ２ (D) The object position identifying unit 170 calculates the center of gravity position (more specifically, the x-coordinate value and the y-coordinate value of the center of gravity) of any set of points that are included in the point cloud data and that satisfy the following condition (E): １ (E) The height of each point is higher than the reference height Ts of the second LiDAR unit 20 by a threshold value Th3 or more. ２ is higher than the reference height Ts by a threshold value Th3 or more.

[0072] Step S31 may be performed before step S17 or in parallel with step S17.

[0073] <Step S32: Position Determination> Thereafter, the alarm control unit 130 determines whether or not an object is located within a predetermined range from the opening. For example, the alarm control unit 130 first calculates the distance from the opening to the object based on the position of the opening identified in step S17 and the position of the object identified in step S31. Next, the alarm control unit 130 determines whether or not the calculated distance is equal to or less than a predetermined threshold Th4. If the calculated distance exceeds the predetermined threshold Th4, the alarm control unit 130 determines that the object is not located within the predetermined range from the opening, and if the calculated distance is equal to or less than the predetermined threshold Th4, the alarm control unit 130 determines that the object is located within the predetermined range from the opening.

[0074] <Step S33: Normal Alarm> If no object is located within a predetermined range from the opening (NO at step S3), the alarm control unit 130 causes the alarm unit 13 to issue a normal alarm.

[0075] <Step S34: Normal Alarm> If an object is located within a predetermined range from the opening (YES in step S32), the alarm control unit 130 causes the alarm unit 13 to generate an emergency alarm. The emergency alarm may be louder than the normal alarm, or may have a different sound from the normal alarm. The emergency alarm may also be louder than the normal alarm and have a different sound from the normal alarm.

[0076] <Modification of Second Embodiment> When an object is located within a predetermined range from the opening, the alarm control unit 130 may cause the alarm unit 13 to issue an alarm at a louder volume the closer the object is to the opening. According to this, when the object continues to be located within a predetermined range from the opening when the object position identification unit 170 repeatedly identifies the position of the object, the volume of the alarm from the alarm unit 13 becomes louder as the object approaches the opening, and the volume of the alarm from the alarm unit 13 becomes quieter as the object moves away from the opening.

[0077] If an object is located within a predetermined range from the opening and the position of the object does not change for a certain period of time, the alarm control unit 130 may return the alarm from the alarm unit 13 to the normal state.

[0078] The object position identification unit 170 may also determine whether an object located within a predetermined range from the opening is a cone or bar that is recommended for installation around the opening. This determination is made, for example, by pattern matching based on previously acquired information about the shape of the cone or bar. Furthermore, this determination may be made based on a model created in advance by machine learning using point cloud data generated by the LiDAR unit 20. This can improve the accuracy of the determination.

[0079] If the alarm control unit 130 determines that an object located within a predetermined range from the opening is a cone or a bar, it may cause the alarm unit 13 to issue a normal alarm, and if the object is not determined to be a cone or a bar, it may cause the alarm unit 13 to issue an alarm that is louder than normal or that has a different sound than normal.

[0080] Furthermore, when an object is located within a predetermined range from the opening, the alarm control unit 130 may return the alarm from the alarm unit 13 to normal only when the position of the object does not change for a certain period of time and the object is determined to be a cone or a bar.

[0081] <Other Modifications> When determining the presence or absence of an opening and determining the reference height Ts, the three-dimensional data may be masked so that three-dimensional data of only a predetermined portion of the clean room is used for at least one of these purposes. This masking process is performed by a masking unit. The masking unit is implemented by a processor such as a CPU reading and executing a program stored in the storage unit 11a. At least one of the reference height determination unit 120 and the opening position identification unit 140 may also function as the masking unit. Furthermore, the three-dimensional data of only a predetermined portion of the clean room is, for example, three-dimensional data of only a portion of the clean room located within a predetermined distance from the LiDAR unit 20. Since the three-dimensional data generated by the LiDAR unit 20 is more accurate for portions closer to the LiDAR unit 20, by performing the above-described process, the presence or absence of an opening can be determined more accurately, and a more accurate reference height Ts can be obtained. Three-dimensional data used for other purposes may also be masked by the masking unit in a similar manner.

[0082] In some cases, the floor tiles FT attached to the floor of a clean room are transparent. The change in the three-dimensional data generated by the LiDAR unit 20 between a state in which the transparent floor tiles FT are attached and a state in which they are removed and an opening is formed may be small. Specifically, when the electromagnetic waves irradiated by the LiDAR unit 20 are transmitted through the transparent floor tiles FT, the change is small. Therefore, the following polarizing film may be attached to the transparent floor tiles FT. That is, a polarizing film may be attached to the transparent floor tiles FT that reflects the electromagnetic waves irradiated by the LiDAR unit 20 toward the LiDAR unit 20 but transmits visible light from the position of a worker directly facing the transparent grating. This allows for more reliable detection of openings created by the transparent floor tiles FT when monitoring is performed based on the three-dimensional data generated by the LiDAR unit 20.

[0083] In the above, the LiDAR unit 20 that uses light (specifically, near-infrared light) as electromagnetic waves has been given as an example of the three-dimensional data generator, but this is not limiting. For example, the three-dimensional data generator may use millimeter waves as electromagnetic waves.

[0084] In the above, the number of installed LiDAR units 20 is two, but it may be three or more (for example, four). By increasing the number of units, the detection accuracy of the opening can be improved.

[0085] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0086] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0087] The following configuration examples also fall within the technical scope of the present disclosure: (1) A monitoring method for monitoring the interior of a clean room in which removable floor tiles are arranged on the floor, comprising: detecting an opening through which the floor tile has been removed based on three-dimensional data of the interior of the clean room generated from distance measurement results using electromagnetic waves; the detecting step comprising: comparing a reference height determined in advance based on the three-dimensional data of the interior of the clean room generated in advance with the height of each part of the clean room indicated by the three-dimensional data of the interior of the clean room generated during monitoring, and determining the presence or absence of the opening based on the comparison result; (2) The monitoring method described in (1) above, further comprising: determining the reference height based on the three-dimensional data of the interior of the clean room generated in advance before the detecting step; (3) The monitoring method described in (1) or (2) above, wherein the determining step determines that the opening exists when there is a part in the clean room whose height is lower than the reference height by a threshold or more. (4) The monitoring method according to any one of (1) to (3), further comprising the step of issuing an alarm when the opening is detected in the detecting step. (5) The monitoring method according to (4), further comprising the step of stopping the alarm when the opening is no longer detected after issuing the alarm. (6) The monitoring method according to any one of (1) to (5), further comprising the step of identifying the position of the opening based on three-dimensional data of the interior of the clean room generated during the monitoring when the opening is detected in the detecting step. (7) The monitoring method according to (6), further comprising the step of displaying an image showing the position of the opening identified in the identifying step. (8) The monitoring method according to (7), further comprising the step of stopping the display of the image when the opening is no longer detected after displaying the image. (9) A monitoring method described in any one of (1) to (8), further comprising a step of masking the three-dimensional data so that three-dimensional data of only a specified portion within the clean room is used for at least one of determining the reference height and judging the presence or absence of the opening.(10) The monitoring method according to (4) or (5), further comprising the steps of: when the opening is detected in the detecting step, specifying the position of the opening based on three-dimensional data of the interior of the clean room generated during the monitoring; and specifying the position of a portion in the clean room that is higher than the reference height based on the three-dimensional data of the interior of the clean room generated during the monitoring; and the step of issuing an alarm issues the alarm with content according to the distance from the portion that is higher than the reference height to the opening. (11) The monitoring method according to any one of (1) to (10), further comprising the step of processing the three-dimensional data so as to be visualized. (12) A monitoring device for monitoring the inside of a clean room in which removable floor tiles are arranged on the floor, comprising a detection unit that detects an opening through which the floor tile has been removed based on three-dimensional data of the inside of the clean room generated from distance measurement results using electromagnetic waves, the detection unit having a determination unit that compares a reference height determined in advance based on the three-dimensional data of the inside of the clean room generated in advance with the height of each part of the clean room shown in the three-dimensional data of the inside of the clean room generated during monitoring, and determines the presence or absence of the opening based on the comparison result. (13) The monitoring device described in (12) above, further comprising a reference height determination unit that determines the reference height based on the three-dimensional data of the inside of the clean room generated in advance before detection by the detection unit. (14) The monitoring device described in (12) or (13) above, wherein the determination unit determines that the opening is present when there is a part in the clean room whose height is lower than the reference height by a threshold or more. (15) The monitoring device according to any one of (12) to (14), further comprising an alarm control unit that causes an alarm unit to issue an alarm when the opening is detected by the detection unit. (16) The monitoring device according to any one of (12) to (15), further comprising an opening position specifying unit that specifies the position of the opening based on three-dimensional data of the inside of the clean room generated during the monitoring when the opening is detected by the detection unit. (17) The monitoring device according to (16), further comprising a display control unit that displays an image showing the position of the opening specified by the opening position specifying unit on a display unit.(18) The monitoring device according to any one of (12) to (17), further comprising a masking unit that performs a masking process on the three-dimensional data so that three-dimensional data of only a predetermined portion within the clean room is used for at least one of determining the reference height and judging the presence or absence of the opening. (19) The monitoring device according to (15), further comprising: an opening position specifying unit that, when the opening is detected by the detection unit, specifies the position of the opening based on three-dimensional data of the interior of the clean room generated during the monitoring; and an object position specifying unit that specifies the position of a portion within the clean room that is higher than the reference height based on three-dimensional data of the interior of the clean room generated during the monitoring, and the alarm control unit issues the alarm with content corresponding to the distance from the portion that is higher than the reference height to the opening. (20) A readable computer storage medium storing a program running on a computer of a control unit that controls a monitoring device to cause the monitoring device to execute a monitoring method for monitoring the inside of a clean room in which removable floor tiles are placed on the floor, wherein the monitoring method includes a step of detecting an opening through which the floor tile has been removed based on three-dimensional data of the inside of the clean room generated from distance measurement results using electromagnetic waves, and the detecting step includes a step of comparing a predetermined reference height based on the three-dimensional data of the inside of the clean room generated in advance with the height of each part of the clean room indicated by the three-dimensional data of the inside of the clean room generated during monitoring, and determining the presence or absence of the opening based on the comparison result.

[0088] 10 Monitoring device 11b, 11Ab Control unit 110 Detection unit 111 Determination unit FT Floor tile Y Floor unit

Claims

1. A monitoring method for monitoring the inside of a clean room in which removable floor tiles are placed on the floor, comprising a step of detecting an opening through which the floor tile has been removed based on three-dimensional data of the inside of the clean room generated from distance measurements using electromagnetic waves, the step of detecting including a step of comparing a predetermined reference height based on the three-dimensional data of the inside of the clean room generated in advance with the heights of each part in the clean room shown in the three-dimensional data of the inside of the clean room generated during monitoring, and determining the presence or absence of the opening based on the comparison result.

2. The monitoring method according to claim 1, further comprising the step of determining said reference height based on pre-generated three-dimensional data of the interior of said clean room prior to said detecting step.

3. The monitoring method according to claim 1, wherein said determining step determines that said opening is present when there is a portion in said clean room whose height is lower than said reference height by a threshold value or more.

4. The monitoring method of claim 1, further comprising the step of issuing an alarm if said opening is detected in said detecting step.

5. The monitoring method according to claim 4, further comprising the step of terminating said alarm if, after issuing said alarm, said opening is no longer detected.

6. A monitoring method according to any one of claims 1 to 5, further comprising a step of identifying the position of the opening based on three-dimensional data of the inside of the clean room generated during the monitoring when the opening is detected in the detecting step.

7. The monitoring method according to claim 6, further comprising the step of displaying an image showing the location of the opening identified in said identifying step.

8. The monitoring method of claim 7, further comprising the step of ceasing display of said image if, after displaying said image, said opening is no longer detected.

9. A monitoring method according to any one of claims 1 to 5, further comprising a step of masking the three-dimensional data so that three-dimensional data of only a specified portion within the clean room is used for at least one of determining the reference height and judging the presence or absence of the opening.

10. A monitoring method as described in claim 4 or 5, further comprising the steps of: when the opening is detected in the detection step, identifying the position of the opening based on three-dimensional data of the interior of the clean room generated during the monitoring; and identifying the position of a part in the clean room that is higher than the reference height based on the three-dimensional data of the interior of the clean room generated during the monitoring, wherein the issuing of the alarm issues an alarm whose content depends on the distance from the part that is higher than the reference height to the opening.

11. A monitoring method according to any one of claims 1 to 3, further comprising a step of processing the three-dimensional data so as to make it possible to visualize it.

12. A monitoring device for monitoring a clean room in which removable floor tiles are placed on the floor, comprising a detection unit that detects an opening through which the floor tile has been removed based on three-dimensional data of the inside of the clean room generated from distance measurement results using electromagnetic waves, the detection unit having a judgment unit that compares a reference height determined in advance based on the three-dimensional data of the inside of the clean room generated in advance with the heights of each part in the clean room shown in the three-dimensional data of the clean room generated during monitoring, and judges the presence or absence of the opening based on the comparison result.

13. The monitoring device according to claim 12, further comprising a reference height determination unit that determines the reference height based on three-dimensional data of the interior of the clean room that has been generated in advance prior to detection by the detection unit.

14. The monitoring device according to claim 12, wherein the determination unit determines that the opening is present when there is a portion in the clean room whose height is lower than the reference height by a threshold value or more.

15. The monitoring device according to claim 12, further comprising an alarm control unit that causes an alarm unit to issue an alarm when the opening is detected by the detection unit.

16. A monitoring device according to any one of claims 12 to 15, further comprising an opening position identifying unit that, when the opening is detected by the detection unit, identifies the position of the opening based on three-dimensional data of the inside of the clean room generated during the monitoring.

17. The monitoring device according to claim 16, further comprising a display control unit that causes an image showing the position of the opening identified by the opening position identifying unit to be displayed on a display unit.

18. A monitoring device as described in any one of claims 12 to 15, further comprising a masking unit that performs a masking process on the three-dimensional data so that three-dimensional data of only a specified portion within the clean room is used for at least one of determining the reference height and judging the presence or absence of the opening.

19. The monitoring device of claim 15, further comprising: an opening position identification unit that, when the opening is detected by the detection unit, identifies the position of the opening based on three-dimensional data of the interior of the clean room generated during the monitoring; and an object position identification unit that identifies the position of a part in the clean room that is higher than the reference height based on the three-dimensional data of the interior of the clean room generated during the monitoring, wherein the alarm control unit issues the alarm with content according to the distance from the part that is higher than the reference height to the opening.

20. A readable computer storage medium storing a program that runs on a computer of a control unit that controls a monitoring device to cause the monitoring device to execute a monitoring method for monitoring the inside of a clean room in which removable floor tiles are placed on the floor, said monitoring method including the step of detecting an opening through which the floor tile has been removed based on three-dimensional data of the inside of the clean room generated from distance measurement results using electromagnetic waves, said detecting step including the step of comparing a reference height that has been determined in advance based on the three-dimensional data of the inside of the clean room generated in advance with the heights of each part in the clean room shown in the three-dimensional data of the inside of the clean room generated during monitoring, and determining the presence or absence of the opening based on the comparison result.

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