Safety belt usage status management system

Abstract

To provide a safety belt use state management system capable of managing a use state of a hook of a safety belt simply and reliably.SOLUTION: A safety belt use state management system 100 includes: an image acquisition unit 110 for acquiring a site image capturing a site where an operator works; a hook position specification unit 130 for specifying the position of a hook of a safety belt from the site image; a support body position specification unit 140 for specifying the position of support bodies from the site image; a main rope route specification unit 160 for specifying the route of a main rope stretched between the support bodies from the site image; a main rope range setting part 150 for setting the range of the route where the main rope can be stretched on the basis of the position of the support bodies; a virtual main rope estimation unit 170 for estimating the range of a route of a virtual main rope on the assumption that the main rope exists in the set range of the route when the route of the main rope cannot be specified from the site image; and a determination unit 180 for determining whether or not the hook is hooked on the main rope or the virtual main rope from the positional relationships between the specified route of the main rope or the range of the route of the virtual main rope and the position of the hook.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a safety belt use status management system. [Background technology]

[0002] Workers working at heights wear safety harnesses, which are fall prevention devices, and attach the hooks on the harness to the lifeline while working to prevent falls. Workers move around the work site while working, and as they do so, they change the hooks on the safety harness. This type of hook change needs to be done properly, but it is a task that is performed frequently, making it difficult for managers to constantly monitor it.

[0003] To reduce the management burden on managers, technology has been proposed to check the usage status of safety harnesses by incorporating switches and cameras into the hooks of safety harnesses (see, for example, Patent Documents 1 and 2). However, this requires all workers to wear dedicated safety harnesses, which is expensive. Also, because the hooks are frequently hooked onto the lifeline, there is a risk that the switches and cameras may break down due to impacts.

[0004] Therefore, a technology has been proposed to monitor the use of safety belts from on-site images taken at the work site. For example, Patent Document 3 describes a technology in which the hook of the safety belt and the life rope or handrail are each colored differently throughout, and when the color image of the hook intersects with the color image of the life rope or handrail, it is determined that the hook is in use. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6409748 [Patent Document 2] Patent No. 6505555 [Patent Document 3] Patent Publication No. 2021-129953 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology described in Patent Document 3 requires that the life rope and handrail be uniformly colored over their entire surface, and if the color peels off or becomes dirty due to friction or other reasons, there is a risk of erroneous judgment.

[0007] In view of the above, an object of the present invention is to provide a safety belt usage status management system and method that can easily and reliably manage the usage status of safety belt hooks. [Means for solving the problem]

[0008] The safety harness usage status management system of the present invention is characterized by comprising an image acquisition unit that acquires a site image of a site where a worker wearing a safety harness is working, a hook position identification unit that identifies the position of a hook on the safety harness from the site image, a support position identification unit that identifies the position of a support between which the main harness to which the hook is attached is hung from the site image, a main harness path identification unit that identifies the path of the main harness hung between the supports from the site image, a main harness range setting unit that sets the range of a path over which the main harness can be hung between the supports based on the positions of the supports, a virtual main harness estimation unit that, if the main harness path cannot be identified within the range of the path from the site image, estimates the range of a virtual main harness path that assumes that the main harness exists within the range of the path, and a discrimination unit that determines whether the hook is attached to the main harness or the virtual main harness from the positional relationship between the identified main harness path or the range of the virtual main harness path and the position of the hook.

[0009] The safety harness usage management method of the present invention is characterized by comprising the steps of: acquiring a site image of a work site where a worker wearing a safety harness is working; identifying the position of a hook on the safety harness from the site image; identifying the position of a support body between which a main rope to which the hook is attached is hung from the site image; identifying the route of the main rope hung between the supports from the site image; setting the range of the route over which the main rope can be hung between the supports based on the positions of the supports; if the main rope route cannot be identified within the range of the route from the site image, estimating the range of a virtual main rope route assuming that the main rope exists within the range of the route; and determining whether the hook is attached to the main rope or the virtual main rope from the positional relationship between the identified main rope route or the range of the virtual main rope route and the position of the hook.

[0010] According to the safety harness usage management system and method of the present invention, even if the route of the lifeline cannot be identified from the site image, it is possible to determine whether the hook is attached to the lifeline based on the range of the virtual lifeline route and the positional relationship between the hook. This makes it possible to easily and reliably determine the usage status of the hook even if the image of the lifeline cannot be identified from the site image due to weather conditions such as backlighting or background images.

[0011] In the safety belt use status management system of the present invention, for example, the range of the route is a range in which the life ropes, one end of which is supported by the support body, can exist. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a construction site managed using a safety belt usage status management system according to an embodiment of the present invention. [Figure 2] Block diagram of a safety belt usage status management system. [Figure 3] 3 is a flowchart showing a safety belt use status management method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] A safety harness usage status management system 100 according to an embodiment of the present invention will be described. The safety harness usage status management system 100 is a system for managing the usage status of a safety harness, which is a fall prevention device worn by a worker performing work at height.

[0014] First, a construction site managed using a safety belt usage status management system 100 will be described with reference to Fig. 1. This construction site is a site where workers A perform high-altitude work, and each worker A wears a safety belt 10.

[0015] The safety belt 10 comprises a belt 11 for wearing on the human body, a rope 12 as a lifeline connected at one end to the back part of the belt 11, and a hook 13 connected to the other end of the rope 12. The safety belt 10 has two sets of ropes 12 and hooks 13, and by always having at least one of the hooks 13 attached to a main rope 30 stretched between posts 20 or the like, worker A is prevented from falling or falling. The posts 20 are fixed to the frame of a building or temporary scaffolding, and are configured to be able to support the load on the main rope 30 if worker A falls.

[0016] The safety belt 10 preferably includes a full harness type belt 11 that supports the entire body by passing the belt around the thighs, shoulders, etc. in addition to the waist belt. In the case of a full harness type, it is recommended that the hook 13 be hooked onto the shoulder belt and positioned around the chest when not working at height.

[0017] The lifeline 30 is usually stretched between the two posts 20 at a predetermined height, about waist-high for worker A. The lifeline 30 is made up of a rope 32 with hooks 31 attached to both ends. It is preferable to use a tensioner (not shown) to reduce the slack in the lifeline 30 stretched between the posts 20.

[0018] The support pole 20 comprises a support pole body 21 extending vertically and an annular retaining metal fitting 22 provided at the upper end of the support pole body 21 for hanging the hook portion of the life rope 20. Although not shown, the lower end of the support pole body 21 is attached using a vice-like fixing jig or the like to a flange portion of a steel frame that constitutes the framework of a building or temporary scaffolding.

[0019] Although not shown, the main rope 30 may be configured so that the hook portion 31 can be hooked onto a retaining bracket installed on the steel frame of a building or temporary scaffolding, for example, using an H-shaped steel steel clamp or a single-tube pipe clamp with a ring-shaped retaining bracket.

[0020] In this way, the hook portions 31 at both ends of the main rope 30 are supported by the retaining fittings 22 of the support pole 20 or by retaining fittings provided on clamps (not shown). These retaining fittings 22 correspond to the support body and supporting portion of the present invention. Below, we will explain the case where the hook portion 31 of the main rope 30 is supported by the retaining fittings 22 of the support pole 20, and the retaining fittings 22 will also be called the support body 22.

[0021] Here, an identification portion 40 is provided on the upper portion of the support 22. The identification portion 40 allows the identification portion 40 to be easily distinguished from other components in an image captured at the site. The identification portion 40 is, for example, a colored portion of the support 22, or a component of a different color from the support 22 and installed on the upper portion of the support 22. The identification portion 40 is preferably colored in a color not commonly used for components used at the site, such as a fluorescent color, or is easily attached and detached, such as a fluorescent magnet, sticker, or ribbon. The identification portion 40 may also be provided on other portions of the support 20, such as the lower portion or end portion of the support 22, or may be provided on a portion of the upper portion of the support body 21.

[0022] Furthermore, the identification section 40 may be provided at a portion that is located at a predetermined distance from the support 22. In this case, it is preferable that this portion be located at a position that makes it possible to identify the path of the life rope 30 when the life rope 30 is strung between the supports 20. For example, a member or the like may be provided on the top of the support 22, and the identification section 40 may be provided by coloring a portion of this member that is a predetermined distance away from the support 22. Furthermore, the identification section 40 may be provided on a steel frame that is a predetermined distance away from the clamp.

[0023] Furthermore, the identification part 40 may be provided on the hook part 31 of the master rope 30 supported by the support body 22. Also, the identification part 40 may be provided on a part of the rope 32 that is a predetermined distance away from the hook part 31 of the master rope 30.

[0024] It is preferable that the positional relationship of the identifier 40 with respect to the support 22 is the same at sites where the same imaging device 50 is used to capture images. If the positional relationship in which the identifier 40 is provided varies, it is preferable that the color or shape of the identifier 40 differs depending on the positional relationship in which the identifier 40 is provided. For example, it is preferable that the identifier 40 provided on the support 22 and the identifier 40 provided on the clamp be different colors, such as yellow fluorescent and orange fluorescent, or rectangular and triangular. It is to be noted that in this specification, the terms "positional relationship" and "position" can also mean directions.

[0025] An imaging device 50 is installed at the work site to capture images of the work site where high-altitude work is being performed. It is preferable to provide multiple imaging devices 50, such as cameras or video cameras, and capture images of the work site from multiple directions, making it possible to obtain the three-dimensional position of the imaging target. Alternatively, a three-dimensional camera or three-dimensional video camera capable of obtaining the three-dimensional position of the imaging target may be used.

[0026] 2, the safety belt use status management system 100 manages the use status of the safety belt 10 using on-site images captured by an imaging device 50 and transmitted via a network N. The network N may be either wired or wireless, and any type of communication network such as the Internet, a LAN (Local Area Network), or a VPN (Virtual Private Network) may be used.

[0027] The safety belt usage status management system 100 is composed of a computer such as a PC computer, which is realized by a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) executing a program stored in an internal storage device using RAM as a working area.

[0028] The safety belt usage status management system 100 comprises an image acquisition unit 110, a worker position identification unit 120, a hook position identification unit 130, a support body position identification unit 140, a main rope range setting unit 150, a main rope path identification unit 160, a virtual main rope estimation unit 170, a judgment unit 160, and a warning unit 190. The processing in the worker position identification unit 120, the hook position identification unit 130, the support body position identification unit 140, the main rope range setting unit 150, the main rope path identification unit 160, the virtual main rope estimation unit 170, and the judgment unit 180 may be performed using AI.

[0029] The image acquisition unit 110 acquires, via the network N, site images captured by the imaging device 50 of the site where the worker A wearing the safety belt 10 is working.

[0030] The worker position identification unit 120 identifies the worker A from the site image acquired by the image acquisition unit 110 and identifies the position of the worker A. The image of the worker A can be identified using existing image identification technology, but the worker A can be easily identified by focusing on the helmet and safety belt 10 worn by the worker A. Note that when there are multiple workers A, it is not necessary to distinguish between each worker A; it is sufficient to check whether each worker A is using the safety belt 10 appropriately and identify the worker A who is not using it appropriately.

[0031] It is possible to identify worker A within the entire range that appears in the site image captured above a predetermined height, or it is also possible to identify worker A only within a predetermined range. When identifying the range in this way, the range for identifying worker A may be set based on the position of the supports 22 identified by the support position identifying unit 140. This is because, since the main rope 30 is strung between the supports 22, it is considered that safety assurance by the main rope 30 is not necessary in the work range where there are no supports 22.

[0032] However, in order to install the lifeline 30 in a work area where there is a risk of falling or tripping, a support 22 is installed, and an identification unit 40 is installed to easily and reliably identify the position of this support 22. Therefore, in a work area where the risk of the worker falling or tripping has disappeared as the work progresses and the lifeline 30 is no longer needed, it is preferable to remove the identification unit 40 and then detach the lifeline. However, in some cases, the identification unit 40 and lifeline 30 may remain in an area where the lifeline 30 is no longer needed. Therefore, it is preferable for the administrator to check the setting of the range for identifying worker A.

[0033] Furthermore, even when working above a certain height, there may be a work range where safety is not required using the safety harness 10, depending on the installation conditions of the deck slab, formwork, etc. In such cases, the manager or the like may set the work range, and the worker A within this work range may not be identified.

[0034] The hook position identifying unit 130 identifies the hook 13 provided on the safety belt 10 worn by the worker A identified by the worker position identifying unit 120 from the site image acquired by the image acquiring unit 110, and identifies the position of the hook 13. Existing image identification technology can be used to identify the hook 13, and since the hook 13 is large, identification is relatively easy. Note that coloring the hook 13 with a fluorescent color or the like makes identification even easier. Since the safety belt 10 worn by the worker A is equipped with two hooks 13, the positions of the two hooks 13 are identified for each identified worker A.

[0035] The support position identifying unit 140 identifies the identification unit 40 from the site image acquired by the image acquisition unit 110, and identifies the position of the support 22 based on the identified position of the identification unit 40. The support position identifying unit 140 first identifies the image of the identification unit 40 from the site image and identifies the position of the identification unit 40. The identification unit 40 is colored or otherwise applied so that it can be easily identified by image compared to other parts of the construction site. Therefore, it is possible to easily identify the image of the identification unit 40 from the site image using existing image identification technology. Note that if the hook 13 is colored, it is preferable to color the identification unit 40 a different color.

[0036] As described above, the positional relationship between the identifier 40 and the support 22 is known, so the position of the support 22 can be identified from the identified position of the identifier 40.

[0037] The main rope range setting unit 150 determines the range in which the main rope 30 may exist based on the position of the support 22 identified by the support position identifying unit 140 from the site image acquired by the image acquiring unit 110.

[0038] The lifeline 30 is stretched between adjacent supports 22. Therefore, based on the identified positions of the supports 22, the range in which the lifeline 30 is estimated to be present so that it is stretched between the supports 22 is identified. By limiting it to this range, it is possible to simplify and speed up the work required for identification compared to identifying an image of the lifeline 30 from the entire site image. The lifeline 30 is thin, and identification can be difficult depending on weather conditions such as backlighting and the background image, but within a specified range, it is possible to identify it with high accuracy.

[0039] Here, the range in which the image of the master rope 30 can be identified is between the supports 22, but because the master rope 30 hangs down due to its own weight, it is never located above the supports 22, but is located at its lowest point near the center of adjacent supports 22, and is located slightly below the supports 22 in the parts close to the supports 22. Furthermore, because the master rope 30 is stretched while being taut using a tensioner or the like, it does not bend significantly downward, and furthermore, it appears straight when viewed from above. Therefore, the range in which the master rope 30 can exist can be estimated to be a predetermined narrow range.

[0040] The master rope path identification unit 160 determines the path of the master rope 30 within the range set by the master rope range setting unit 150 from the site images acquired by the image acquisition unit 110. Note that if the master rope range setting unit 150 does not exist, the master rope path identification unit 160 may directly identify the master rope 30 from the site images acquired by the image acquisition unit 110 and determine the path of the master rope 30.

[0041] In addition, identification parts may be provided by coloring predetermined areas of the rope 32 of the main rope 30, such as both ends or the center, and the route of the main rope 30 may be identified by identifying these identification parts from images of the site. However, if the rope 32 is colored, it is preferable to color it a color different from that of the hook 13 and the support 22.

[0042] If the master rope path identification unit 160 cannot identify the path of the master rope 30 within the range set by the master rope range setting unit 150, the virtual master rope position estimation unit 170 estimates the range of the path of the virtual master rope, assuming that the master rope 30 exists within the range.

[0043] As mentioned above, the main rope 30 is difficult to distinguish from site images, so there are cases where the main rope 30 cannot be identified from site images within the range set by the main rope range setting unit 150. However, the identification unit 40 is provided to indicate that the hook portion 31 of the main rope 30 is hooked on the support body 22 identified by this identification unit 40. Therefore, even if the main rope 30 cannot be identified from site images, it is possible to estimate that the hook portion 31 of the main rope 30 is hooked on the support body 22 identified by the identified identification unit 40.

[0044] Therefore, if the master rope 30 cannot be recognized within the range set by the master rope range setting unit 150, the path of the virtual master rope is estimated by assuming that the master rope 30 is stretched between adjacent supports 22. At this time, the master rope 30 is estimated to be present within a predetermined range, assuming that it is stretched between adjacent supports 22 with a predetermined range of bending. Note that the range of bending may be changed depending on the spacing between the supports 22. The range set by the master rope range setting unit 150 may also be estimated as the range of the path of the virtual master rope.

[0045] In addition, the virtual main rope may be used not only when the main rope 30 stretched between two supports 22 cannot be identified at all, but also when the main rope 30 cannot be identified partially, by assuming that the main rope 30 exists within a specified range connecting the identified main ropes 30, and estimating a partial path of the virtual main rope.

[0046] The determination unit 180 determines whether the hook 13 is caught on the main rope 30 or virtual main rope from the positional relationship between the position of the main rope 30 or virtual main rope and the position of the hook 13. Based on these positional relationships, it may be determined that the hook 13 is caught not only when it is definitely caught, but also when there is some error in these positional relationships. This is because, for worker A wearing the safety belt 10, there is a large difference in height between the hook 13 and the main rope 30 except when the hook 13 of the safety belt 10 is caught on the main rope 30 or is about to be caught on it.

[0047] The warning unit 190 issues a warning based on the result of the judgment by the judgment unit 180. If the judgment unit judges that either one or neither of the two hooks 13 of the safety belt 10 is caught on the life rope 30, it issues a warning to the worker A wearing the safety belt 10 or to the manager. The warning is given by emitting a warning sound, instruction, warning light, etc. from a speaker or warning light, not shown, attached to the work site, the worker, the management building, etc. Furthermore, the warning unit 190 may display warning information, etc. on a display unit such as a liquid crystal display.

[0048] Hereinafter, a safety belt use status management method according to an embodiment of the present invention using the above-described safety belt use status management system 100 will be described with reference to FIG.

[0049] First, an image acquisition step (S1) is performed in which the image acquisition unit 110 acquires an on-site image captured by the imaging device 50.

[0050] Next, a worker position specifying step (S2) is performed in which worker A is identified from the site image acquired by the image acquisition unit 110 and the position of worker A is specified.

[0051] Next, a hook position specifying step (S3) is performed in which the hook 13 provided on the safety belt 10 worn by the worker A identified by the worker position identifying unit 120 is identified from the site image acquired by the image acquiring unit 110, and the position of the hook 13 is specified. Then, a support position specifying step (S4) is performed in which the identifier 40 is identified from the site image acquired by the image acquiring unit 110, and the position of the support 22 is specified based on the position of the identified identifier 40. Furthermore, a main rope range setting step (S5) is performed in which the range in which the main rope 30 can exist is determined based on the position of the support 22 identified by the support position identifying unit 140 from the site image acquired by the image acquiring unit 110.

[0052] Next, a master rope path identification step (S6) is performed to determine the path of the master rope 30 within the range set by the master rope range setting unit 150 from the site images acquired by the image acquisition unit 110. Then, if the master rope path identification unit 160 cannot identify the path of the master rope 30 within the range set by the master rope range setting unit 150 (S6: NO), a virtual master rope position estimation step (S7) is performed to estimate the range of the path of a virtual master rope assuming that the master rope 30 exists within the range.

[0053] Next, a determination process (S8) is performed to determine whether both or at least one of the hooks 13 of the safety belt 10 worn by each worker A is caught on the main rope 30 or virtual main rope based on the positional relationship between the position of the main rope 30 or virtual main rope and the position of the hook 13.

[0054] If it is determined that both or at least one of the hooks 13 of the safety belts 10 worn by each worker A are caught on the main rope 30 or virtual main rope (S8: YES), it is determined that all safety belts 10 are being used properly, and the image acquisition process (S1) and subsequent steps are repeated.

[0055] If it is determined that both or at least one of the hooks 13 of any of the safety belts 10 worn by worker A is not caught on the main rope 30 or the virtual main rope (S8: NO), a warning process (S9) is performed to issue a warning.

[0056] Note that even if the main rope 30 is not present within the specified work area, the main rope will remain in that work area until safety is ensured. In other words, the main rope 30 will continue to exist on the same path until the manager issues an instruction to remove the main rope 30. Therefore, until the main rope 30 is removed, the position of the support 22 identified by the support position identifying unit 140, the range in which the main rope 30 may exist set by the main rope range setting unit 150, and the path of the main rope 30 identified by the main rope path identifying unit 160 will not change. Therefore, the support position identifying process (S4) through the virtual main rope position estimating process (S7) may be omitted until the main rope 30 is removed.

[0057] Furthermore, even if the main rope path identification unit 160 cannot identify the path of the main rope 30 within the range set by the main rope range setting unit 150 (S6: NO), as long as the main rope 30 does not change, the path of the main rope 30 identified previously may be used as the path of the virtual main rope.

[0058] According to the safety harness usage status management system 100 and the safety harness usage status management method using the same, the positions of the supports 22 are identified from site images based on the positions of identification parts that are easily identifiable from site images. Therefore, the supports 22 across which the life rope 30 is stretched can be identified based on the presence or absence of the identification part 40. This makes it possible to identify the supports 22 that actually support the life rope 30, excluding the supports 22 that do not support the life rope 30 depending on the progress of the work, etc., and therefore makes it possible to easily and reliably identify the route of the life rope 30.

[0059] Furthermore, even if the route of the main rope 30 cannot be identified from the site image, it is possible to determine whether the hook 13 is caught on the main rope 30 from the range of the route of the virtual main rope estimated by the virtual main rope estimation unit 170 and the positional relationship between the hook 13. This makes it possible to easily and reliably determine the usage status of the hook 13 even if the image of the main rope 30 cannot be identified from the site image due to weather conditions such as backlighting or the background image.

[0060] The present invention is not limited to the above-described embodiment and can be modified as appropriate. For example, the present invention has been described with reference to a case in which the position of each support 22 is identified from an on-site image by identifying the identification unit 40 installed on each support 22. However, the present invention is not limited to this, and the support 22 may be identified directly from an on-site image without installing the identification unit 40. [Explanation of symbols]

[0061] 10...safety belt, 11...belt, 12...rope, 13...hook, 20...support, 21...support body, 22...retaining fitting, support body (support part), 30...main rope, 31...hook part, 32...rope, 40...identification part, 50...imaging device, 100...safety belt usage status management system, 110...image acquisition part, 120...worker position identification part, 130...hook position identification part, 140...support body position identification part, 150...main rope range setting part, 160...main rope path identification part, 170...virtual main rope estimation part, 180...judgment part, 190...warning part, A...worker, N...network.

Claims

1. an image acquisition unit that acquires site images of a site where a worker wearing a safety belt is working; a hook position identifying unit that identifies the position of a hook provided on the safety belt from the site image; a support position identifying unit that identifies the position of a support between which a life rope on which the hook is attached is stretched, from the on-site image; a lifeline range setting unit that sets a range of a route in which the lifeline can be stretched between the supports based on the positions of the supports; a lifeline path specifying unit that specifies the path of the lifeline stretched between the supports within the range of the path set by the lifeline range setting unit from the site image; a determination unit that determines whether the hook is hooked on the main rope based on the positional relationship between the specified main rope path and the position of the hook; A safety belt use status management system comprising: The system further includes a virtual lifeline estimation unit that, when at least a portion of the lifeline path cannot be identified within the range of the path from the on-site image, estimates the range of the path of a virtual lifeline in which the lifeline is assumed to exist within the range of the path based on the interval between adjacent supports, A safety belt usage status management system characterized in that the determination unit determines whether the hook is hooked on the virtual life rope based on the positional relationship between the range of the path of the virtual life rope and the position of the hook.

2. 2. A safety belt use status management system according to claim 1, wherein the range of the route is a range in which the life ropes each having one end supported by the support body can exist.

3. an image acquisition step of acquiring site images of a site where a worker wearing a safety belt is working; a hook position specifying step of specifying the position of a hook provided on the safety belt from the site image; a support position identifying step of identifying, from the on-site image, the position of a support between which a life rope on which the hook is attached is stretched; a life rope range setting step for setting a range of a route in which the life rope can be stretched between the supports based on the positions of the supports; a lifeline path specifying step of specifying, from the on-site image, the path of the lifeline stretched between the supports within the range of the path set in the lifeline range setting step; a determination step of determining whether or not the hook is hooked on the life rope based on the positional relationship between the specified life rope path and the position of the hook; A safety belt use status management method including: If at least a portion of the path of the lifeline cannot be identified within the range of the path from the on-site image, the method further includes a virtual lifeline estimation step of estimating the range of the path of a virtual lifeline in which the lifeline is assumed to exist within the range of the path based on the spacing between adjacent supports, A safety belt usage status management method characterized in that in the determination step, it is determined whether or not the hook is hooked on the virtual life rope based on the positional relationship between the range of the path of the virtual life rope and the position of the hook.

Images