High place work alerting system

Abstract

To further enhance the safety of high place work by persuading a worker to use both a fall arrest device and work positioning instrument at a time of high place work.SOLUTION: A high place work alerting system 1 includes a control unit 33 that, when it is determined based on a detection value of an atmospheric pressure outputted from a worker side atmospheric pressure sensor 21 that a worker exists in a high place which is higher than a reference height by a predetermined amount or more, and it is determined based on a condition of a hook detected by a hook sensor 20 and at least one of information on posture of the hook and information on the position of the hook that a fall arrest device is unused, estimates that the worker is in an unsafe condition and notifies of a fact that the worker is in the unsafe condition.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a high-altitude work warning system that warns workers when working on a pole, for example. [Background technology]

[0002] Traditionally, fall arrest devices and work positioning devices are used when working at height. Fall arrest devices consist of a waist belt worn around the waist, shoulder belts worn around the shoulders, thigh belts worn around the thighs, and a lanyard. On the other hand, work positioning devices consist of a waist belt and a rope wound around a pillar or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-142047 [Patent Document 2] Patent Publication No. 2021-104139 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to further increase the safety of workers working at height, it is preferable to use a fall arrest device and a work positioning device together. By using a fall arrest device and a work positioning device together, for example, when a worker climbs a pillar or when changing the work positioning device, the fall arrest device can be used to prevent a fall in the event of an accident.

[0005] However, there is a risk that workers may not use the fall arrest device and work positioning device together correctly. For example, if a worker switches to a work positioning device without ensuring safety with the fall arrest device, there will be an unsafe period in which both the fall arrest device and the work positioning device are not providing safety, and during this unsafe period, the worker may fall for some reason.

[0006] To prevent this, workers should always be careful not to forget to ensure their safety with fall prevention equipment, but it is possible that they may forget to do so due to, for example, becoming accustomed to the work.

[0007] The present disclosure has been made in consideration of such points, and its purpose is to further increase the safety of working at heights by having workers use fall prevention equipment and work positioning equipment together when working at heights. [Means for solving the problem]

[0008] In order to achieve the above-mentioned objective, one aspect of the present disclosure can be based on a high-altitude work warning system for warning workers who are working at height while wearing fall prevention equipment and work positioning equipment.

[0009] The height-work warning system comprises a worker-side atmospheric pressure sensor worn by the worker and detecting the atmospheric pressure around the worker; a hook sensor that detects whether the hook of the fall arrest device is engaged; a hook state detection unit that acquires at least one of information regarding the posture of the hook and information regarding the position of the hook; an alarm unit that alerts the worker that he is working at height in an unsafe state; and a control unit that, when it is determined that the worker is at a height that is higher than a reference height by a predetermined amount based on the detected value of the atmospheric pressure output from the worker-side atmospheric pressure sensor and it is determined that the fall arrest device is not being used based on the state of the hook detected by the hook sensor and at least one of information regarding the posture of the hook and information regarding the position of the hook detected by the hook state detection unit, presumes that the worker is in an unsafe state and alerts the alarm unit that the worker is in an unsafe state.

[0010] With this configuration, when a worker wearing a fall arrest device and a work positioning device is at a high altitude (for example, 2 m or more above the reference height), the control unit determines that the worker is at a high altitude based on the atmospheric pressure value output from the worker-side atmospheric pressure sensor. Also, it is possible to determine whether the fall arrest device is being used based on the state of the hook of the fall arrest device and at least one of information related to the attitude of the hook and information related to the position of the hook.

[0011] For example, if the hook is never engaged while moving from the reference height to a higher elevation, it can be determined that the hook is not engaged with a fall prevention device, such as a handrail or rope, at the higher elevation. In this case, it can be inferred that the worker is in an unsafe condition. Furthermore, if the worker moves from the reference height to a higher elevation while the hook is still attached to the worker's chest, it can be determined that the hook is not engaged with a fall prevention device. In this case, it can also be inferred that the worker is in an unsafe condition. In this way, based on information on whether the hook is engaged and at least one of information on the hook's posture and information on the hook's position, it is possible to accurately infer whether the worker is in an unsafe condition. Furthermore, if the control unit detects an unsafe condition while the worker is working at a height, it can cause the alarm unit to notify the worker, thereby alerting the worker. It is also possible to notify, for example, a supervisor or manager, that the worker's work at a height is unsafe. This allows the worker to be warned to correct the unsafe condition.

[0012] For example, the control unit determines the time it takes for the worker to move from the reference height to the high place based on the detected atmospheric pressure value output from the worker-side atmospheric pressure sensor, and if the hook sensor detects that the hook was not attached while the worker was moving from the reference height to the high place, it can infer that the worker is in an unsafe state.

[0013] For example, if the control unit determines that the worker is at a height that is a predetermined level or more higher than the reference height and determines that the hook sensor has not engaged for a predetermined period of time or more, it can infer that the worker is in an unsafe state.

[0014] For example, if the control unit determines that the worker is at a height that is a predetermined height or more higher than the reference height and determines that the position of the hook detected by the hook state detection unit is at a position where it is hung on the worker's waist, it can infer that the worker is in an unsafe state.

[0015] The hook state detection unit may include an acceleration sensor fixed to the hook, in which case the acceleration sensor can output a measured value of acceleration as information relating to the attitude of the hook.

[0016] In addition, the hook state detection unit can also generate information regarding the position of the hook based on the strength of radio waves during communication between the hook-side wireless communication unit provided on the hook and the belt-side wireless communication unit provided on the worker's waist belt in the work positioning device. [Effects of the Invention]

[0017] As described above, when an unsafe condition is estimated to exist during work at height, the worker can be warned, thereby improving the safety of work at height. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing a worker performing work on a pole. [Figure 2] FIG. 2 is a schematic diagram of the height work warning system. [Figure 3] FIG. 3 is a flowchart showing an example of the flow of the main process. [Figure 4] FIG. 4 is a flowchart showing an example of the flow of the receive interrupt process. [Figure 5] FIG. 5 is a flowchart showing an example of the flow of the reception determination process. [Figure 6] FIG. 6 is a flowchart showing an example of the flow of the state determination process. [Figure 7] FIG. 7 is a flowchart showing an example of the flow of the HIGH1 process. [Figure 8] FIG. 8 is a flowchart showing an example of the flow of the HIGH1 (bucket vehicle) process. [Figure 9] FIG. 9 is a flowchart showing an example of the flow of the HIGH2 process. [Figure 10]FIG. 10 is a flowchart showing an example of the flow of the HIGH3 process. [Figure 11] FIG. 11 is a flowchart showing an example of the flow of the HIGH4 process. [Figure 12] FIG. 12 is a flowchart showing an example of the flow of the HIGH5 process. [Figure 13] FIG. 13 is a flowchart showing an example of the flow of the HIGH6 process. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

[0020] FIG. 1 shows a situation in which a worker A is performing pole-top work at a work site where a work-at-height warning system 1 (shown in FIG. 2) according to an embodiment of the present invention is used. As shown in this figure, work-at-height refers to the act of worker A climbing, for example, a utility pole B to perform various tasks such as electrical work and wiring work. Work-at-height also refers to the act of climbing, for example, a steel tower or a support pillar, in addition to utility pole B, to perform various tasks. Use of the work-at-height warning system 1 can alert worker A to the need for work-at-height and also manage worker A's safety. The work-at-height warning system 1 is a system for alerting worker A when working-at-height, and can also be called a safety management system. Work-at-height can be defined as work performed at a height that is, for example, 1.5 m or 2.0 m or higher above the reference height (a height higher than a specified height), for example, when the height of the floor or ground is taken as the reference height, and may follow the definition in the Industrial Safety and Health Act.

[0021] When working on a pole, worker A wears fall arrest device 100 and work positioning device 200. By using fall arrest device 100 and work positioning device 200 together, safety can be ensured by fall arrest device 100 and by work positioning device 200. For example, when worker A climbs utility pole B or the like, he may need to change work positioning device 200, and when changing work positioning device 200, fall arrest device 100 can be used to prevent a fall in the unlikely event of a fall.

[0022] The fall arrest device 100 is a typical full-body harness-type fall arrest device and includes a waist belt 101 wrapped around the waist of worker A, shoulder belts 102 worn on worker A's shoulders, thigh belts 103 worn on worker A's thighs, and a lanyard 104. The base end of the lanyard 104 is connected to, for example, the waist belt 101. A hook 105 is provided at the tip of the lanyard 104. The hook 105 is a member that can be hooked onto, for example, a fall prevention member B1 when working at height. The fall prevention member B1 may be part of the utility pole B or may be a separate member from the utility pole B, and is made of a high-strength member that will not fall off or be damaged even when the weight of worker B is applied to it. The fall prevention member B1 may also be provided midway along the height of the utility pole B. Although not shown, fall prevention members may also be provided on steel towers and the like.

[0023] The work positioning device 200 is a device that is generally used when working on a pole, and is equipped with a waist belt 201 that is wrapped around the waist of worker A, and a rope 202 that is wrapped around utility pole B. The rope 202 is connected to the waist belt 201.

[0024] FIG. 2 shows an example of the configuration of the high-altitude work warning system 1, and is a schematic diagram of the high-altitude work warning system 1. The high-altitude work warning system 1 includes a slave unit 2, a slave unit repeater 3, a master unit 4, and an administrator terminal 5. The slave unit 2 and the slave unit repeater 3 are configured to communicate with each other using a communication device of a wireless communication standard that can calculate the distance between them based on the radio wave intensity during communication. Examples of such standards include, but are not limited to, a short-range wireless communication standard such as Bluetooth (registered trademark). The slave unit repeater 3 and the master unit 4 are configured to communicate with each other using, for example, short-range wireless communication such as LPWA (Low Power Wide Area). The master unit 4 and the administrator terminal 5 are configured to communicate with each other using a communication device of a short-range wireless communication standard such as Bluetooth. The communication mode between the slave unit 2, the slave unit repeater 3, the master unit 4, and the administrator terminal 5 is not limited to the above example, and communication can be via, for example, the Internet or a local area network. Furthermore, communication can also be via a commercial public line if necessary. Furthermore, the master device 4 and the administrator terminal 5 may be integrated into one unit.

[0025] (Configuration of handset 2) The slave unit 2 is provided on the fall arrest device 100. In this embodiment, an example in which the slave unit 2 is provided on the hook 105 will be described, but this is not limiting and the slave unit 2 may be provided on any of the waist belt 101, shoulder belt 102, thigh belt 103, and lanyard 104 of the fall arrest device 100. The hook 105 is configured to be able to be hung on a fall prevention member B1 or the like, and when the worker A performs an opening operation, the hook 105 can be hung on the fall prevention member B1 or the like, and when the worker A performs a closing operation while the hook is hung on the fall prevention member B1 or the like, the hung state can be maintained.

[0026] The slave unit 2 is equipped with a hook sensor 20 that detects whether the hook 105 of the fall arrest device 100 is hooked onto a fall prevention member B1 or the like, a worker-side atmospheric pressure sensor 21, a slave-side transmitter 22, a slave-side microcomputer 23, a battery 24, and an acceleration sensor 25. The hook sensor 20 and the worker-side atmospheric pressure sensor 21 can be separated, and the worker-side atmospheric pressure sensor 21 can also be attached to the worker A's helmet, for example.

[0027] The hook sensor 20 is configured, for example, by a photoelectric sensor, a limit switch, or the like. The photoelectric sensor reacts to the fall prevention member B1 or the like and outputs an ON signal when the hook 105 is hung on the fall prevention member B1 or the like, but does not react and outputs an OFF signal when the hook 105 is not hung on. The limit switch outputs an ON signal when the hook 105 is hung on the fall prevention member B1 or the like, but outputs an OFF signal when the hook 105 is not hung on. Note that the hook sensor 20 may be configured by something other than a photoelectric sensor or a limit switch.

[0028] All or part of the worker-side atmospheric pressure sensor 21, slave-side transmitter 22, slave-side microcomputer 23, and battery 24 are built into the hook 105. The worker-side atmospheric pressure sensor 21 is worn by worker A and detects the atmospheric pressure around worker A, and is configured using a conventionally known atmospheric pressure sensor. In this embodiment, the worker-side atmospheric pressure sensor 21 is built into the hook 105. However, since the hook 105 and worker A are not very far apart in the vertical direction and the hook 105 is generally placed at approximately the same height as worker A, the atmospheric pressure detected by the worker-side atmospheric pressure sensor 21 is equal to the atmospheric pressure at the height where worker A is located. The worker-side atmospheric pressure sensor 21 may also be attached to worker A's helmet, waist belt 101, etc., and in this case, the worker-side atmospheric pressure sensor 21 can also detect the atmospheric pressure at the height where worker A is located. From the viewpoint of the safety of worker A, it is preferable that the worker-side atmospheric pressure sensor 21 has a short atmospheric pressure detection cycle, but taking into consideration the consumption of battery 24, it is preferable that the worker-side atmospheric pressure sensor 21 detects atmospheric pressure at a cycle of, for example, about once per second and outputs the detected value (atmospheric pressure value). The worker-side atmospheric pressure sensor 21 is connected to the slave-side microcomputer 23, and the detected value by the worker-side atmospheric pressure sensor 21 is input to the slave-side microcomputer 23.

[0029] The acceleration sensor 25 is fixed so as not to move relative to the hook 105. The acceleration sensor 25 measures acceleration in two horizontal and perpendicular directions (X direction and Y direction) and in the Z direction (vertical direction) which is perpendicular to the X direction and Y direction. The acceleration detection cycle (measurement cycle) by the acceleration sensor 25 may be set to be the same as the atmospheric pressure detection cycle by the worker-side atmospheric pressure sensor 21, or may be shorter or longer than the atmospheric pressure detection cycle by the worker-side atmospheric pressure sensor 21. The acceleration sensor 25 sequentially outputs acceleration measurement values.

[0030] Because the acceleration sensor 25 is fixed to the hook 105, the detection value of the acceleration sensor 25 changes as the posture of the hook 105 changes. This makes it possible to detect whether the hook 105 is facing upward (upward) as shown in FIG. 2, rotated 90° to the right from the posture shown in FIG. 2, rotated 180° to the right from the posture shown in FIG. 2 (downward), or rotated 90° to the left from the posture shown in FIG. 2. That is, the acceleration sensor 25 is included in a hook state detection unit that acquires information about the posture of the hook, and outputs acceleration as information about the posture of the hook 105. The downward posture is the posture that the hook 105 takes when worker A ascends to a high place using a bucket truck, and this posture is determined in advance by rules, etc. Furthermore, the upward posture of the hook 105 shown in FIG. 2 is the posture in which the hook 105 is suspended from a ring around worker A's chest or waist, etc.

[0031] The slave-side transmitter 22 is a hook-side wireless communication unit provided on the hook 105. The slave-side transmitter 22 is a part that transmits the atmospheric pressure value output from the worker-side atmospheric pressure sensor 21, the detection result of the hook sensor 20, and the acceleration measurement value output from the acceleration sensor 25. The slave-side transmitter 22 is composed of a communication module or the like capable of short-range wireless communication, and specifically, is composed of a communication module that satisfies the above-mentioned Bluetooth communication standard.

[0032] The slave-side microcomputer 23 controls the slave-side transmitter 22. When a detection value is input from the worker-side atmospheric pressure sensor 21, the slave-side microcomputer 23 outputs the detection value from the worker-side atmospheric pressure sensor 21 to the slave-side transmitter 22 at a predetermined timing, and causes the slave-side transmitter 22 to transmit the detection value from the worker-side atmospheric pressure sensor 21 to the slave-side repeater 3. Furthermore, each time an acceleration measurement value is input from the acceleration sensor 25, the slave-side microcomputer 23 calculates an inclination angle (roll, pitch, yaw) from the measurement value of the acceleration sensor 25, outputs the calculated inclination angle to the slave-side transmitter 22, and causes the slave-side transmitter 22 to transmit the acceleration measurement value to the slave-side repeater 3. Furthermore, the slave-side microcomputer 23 outputs the detection result of the hook sensor 20 to the slave-side transmitter 22, and causes the slave-side transmitter 22 to transmit the detection result of the hook sensor 20 to the slave-side transmitter 22. The detection result of the hook sensor 20 may include, for example, an ON / OFF signal of the hook sensor 20. In addition, the handset 2 has an address as identification information for identifying the handset 2, and various information transmitted from the handset 2 is assigned an address for identifying which handset 2 transmitted the information.

[0033] The battery 24 is used to supply power to the hook sensor 20, the worker-side atmospheric pressure sensor 21, the slave-side transmitter 22, the slave-side microcomputer 23, and the acceleration sensor 25. The battery 24 may be a rechargeable battery or a replaceable dry cell battery.

[0034] (Configuration of repeater 3) The slave repeater 3 is attached to the waist belt 201 of the work positioning device 200. Therefore, the slave repeater 3 is worn by the worker A. The slave repeater 3 may also be attached to the clothing of the worker A or the waist belt 101 of the fall arrest device 100.

[0035] The slave repeater 3 includes a buzzer 30 as an alarm unit that alerts worker A that working at height is in an unsafe condition, a repeater receiving unit 31, a repeater transmitting unit 32, a repeater microcomputer (control unit) 33, a battery 34, and a distance estimating unit 35. The battery 34 can be configured with the same battery as the battery 24 of the slave 2. The buzzer 30, repeater receiving unit 31, repeater transmitting unit 32, repeater microcomputer 33, battery 34, and distance estimating unit 35 can be housed and integrated in a single housing 3A, or only some of them can be housed in the housing 3A and the rest can be housed in a separate housing (not shown).

[0036] The repeater-side receiving unit 31 is a belt-side wireless communication unit, and is configured with a communication module capable of communicating with the slave-side transmitting unit 22, specifically a communication module of the same standard as the slave-side transmitting unit 22. The repeater-side receiving unit 31 receives the detected value of atmospheric pressure transmitted from the slave-side transmitting unit 22, i.e., the detected value of atmospheric pressure detected by the worker-side atmospheric pressure sensor 21 of the slave 2, as well as the detection result of the hook sensor 20 and the acceleration measurement value output from the acceleration sensor 25.

[0037] The repeater side transmitter 32, which will be described later, is a part that outputs a notification signal output from the repeater side microcomputer 33. The repeater side transmitter 32 may be configured with a communication module similar to the slave side transmitter 22, or may be configured with a communication module capable of wireless communication with an Internet line or a local area network line.

[0038] When the slave-side transmitter 22 and the repeater-side receiver 31 are configured with communication modules that comply with the Bluetooth communication standard, the distance between the slave-side transmitter 22 and the repeater-side receiver 31 can be calculated based on the strength of the radio waves used in communication between the slave-side transmitter 22 and the repeater-side receiver 31 (radio wave strength during communication). The distance between the slave-side transmitter 22 and the repeater-side receiver 31 is estimated by the distance estimation unit 35. Specifically, the distance estimation unit 35 acquires the strength of the radio waves used in communication between the slave-side transmitter 22 and the repeater-side receiver 31, and estimates that the higher the radio wave strength, the closer the distance between the slave-side transmitter 22 and the repeater-side receiver 31 is, while the lower the radio wave strength, the farther the distance between the slave-side transmitter 22 and the repeater-side receiver 31 is. In other words, the distance estimation unit 35 can estimate how far the slave 2 is from the slave-side repeater 3. The relationship between the strength of radio waves during communication and the distance between the slave device 2 and the slave device repeater 3 can be obtained in advance, and the distance between the slave device 2 and the slave device repeater 3 can be estimated based on this relationship.

[0039] The repeater side receiving unit 31 is attached to the waist belt 201 of the work positioning device 200, and therefore can be said to be in close contact with the worker A. On the other hand, the slave side transmitting unit 22 is attached to the hook 105, and therefore may be several tens of centimeters or more away from the worker A. When the worker A is on the ground, for example, if the hook 105 is hung on a ring (not shown) near the waist belt 101 of the worker A, the distance between the slave side transmitting unit 22 attached to the hook 105 and the repeater side receiving unit 31 attached to the waist belt 201 becomes extremely short, and the strength of the radio waves becomes the strongest. The position of the hook 105 at this time is referred to as the waist position. It is predetermined by the rules that the hook 105 must be at the waist position before climbing the utility pole B.

[0040] Furthermore, when worker A is on the ground, for example, if he has hook 105 attached to a ring (not shown) near his chest, the distance between slave unit transmitter 22 provided on hook 105 and repeater unit receiver 31 attached to waist belt 201 will be greater than at the waist position, and the strength of the radio waves will be lower than at the waist position. The position of hook 105 in this case is called the chest position. When not climbing utility pole B, it is permitted by the rules to keep hook 105 at the chest position.

[0041] Furthermore, when worker A is at a high place and has hook 105 hooked onto fall prevention member B1, the distance between slave unit transmitter 22 provided on hook 105 and repeater unit receiver 31 attached to waist belt 201 is greater than the chest position, and the strength of the radio waves is therefore lower than at the chest position. The position of hook 105 at this time is called the use position.

[0042] The above-described radio wave strength and the positional relationship between the slave unit transmitter 22 and the repeater unit receiver 31 can be acquired in advance and then stored in the distance estimation unit 35. The distance estimation unit 35 acquires the radio wave strength in real time and uses the above-described positional relationship to estimate whether the hook 105 is located at the waist position, the chest position, or the use position. In this way, the distance estimation unit 35 generates and acquires information regarding the position of the hook 105. The distance estimation unit 35 corresponds to the hook state detection unit of the present invention.

[0043] The repeater side microcomputer 33 is a part that estimates whether or not worker A is in an unsafe state when working at height, and if it is estimated that worker A is in an unsafe state, it causes the buzzer 30 to notify that worker A is in an unsafe state. Specific processing by the repeater side microcomputer 33 will be described later.

[0044] (Configuration of base unit 4) The base unit 4 is worn by a supervisor or manager on the ground. Therefore, the base unit 4 will be continuously placed at a substantially constant height regardless of the worker A, whether the worker A is at a high place or not. The base unit 4 only needs to be installed so that it hardly moves in the vertical direction, and movement in the horizontal direction is not an issue. The base unit 4 may be installed on the ground, for example, or on various equipment on the ground.

[0045] The master unit 4 includes a reference atmospheric pressure sensor 40, a master unit receiving unit 41, a master unit transmitting unit 42, a master unit microcomputer 43, and a battery 44. The battery 44 can be the same as the battery 24 of the slave unit 2. As shown in FIG. 2, the reference atmospheric pressure sensor 40, the master unit receiving unit 41, the master unit transmitting unit 42, the master unit microcomputer 43, and the battery 44 can be housed and integrated in a single housing 4A, or only some of them can be housed in the housing 4A and the rest can be housed in a separate housing (not shown).

[0046] The reference atmospheric pressure sensor 40 is connected to the main unit microcomputer 43 and is configured separately from the worker-side atmospheric pressure sensor 21 of the slave unit 2. It is installed at a reference height that serves as a basis for determining whether worker A is at a high altitude, and is a sensor that detects atmospheric pressure at that reference height. The reference atmospheric pressure sensor 40 itself can be configured with the same atmospheric pressure sensor that constitutes the worker-side atmospheric pressure sensor 21. Because the reference atmospheric pressure sensor 40 is installed in the main unit 4, it is positioned away from the worker-side atmospheric pressure sensor 21 of the slave unit 2 when worker A is working, and detects atmospheric pressure at a different height from the worker-side atmospheric pressure sensor 21 of the slave unit 2. Specifically, because the main unit 4 is installed in a location where the height hardly changes, it continues to detect atmospheric pressure at the same height while worker A is working.

[0047] The parent device side receiving unit 41 is a communication module capable of communicating with the child device side transmitting unit 22, and specifically, is configured as a communication module of the same standard as the child device side transmitting unit 22. The parent device side receiving unit 41 receives the notification signal transmitted from the child device side transmitting unit 22.

[0048] The master transmitter 42 may be configured with a communication module similar to that of the slave transmitter 22, or may be configured with a communication module capable of wireless communication with the Internet or a local area network. The master transmitter 42 transmits the atmospheric pressure detected by the reference atmospheric pressure sensor 40 to the slave repeater 3.

[0049] When the parent unit side microcomputer 43 receives a detection value from the reference atmospheric pressure sensor 40, it outputs the detection value to the parent unit side transmitter 42 at a predetermined timing, causing the parent unit side transmitter 42 to transmit the detection value to the child unit repeater 3.

[0050] (Configuration of administrator terminal 5) The manager terminal 5 is configured as an information terminal carried by the manager. Examples of the manager terminal 5 include, but are not limited to, a smartphone, a tablet terminal, a notebook personal computer, etc., and the manager terminal 5 may also be configured as, for example, a desktop personal computer. The manager is, for example, a person who manages a work site or a supervisor who supervises the work site, and does not necessarily have to be at the work site, but may be, for example, in a management office.

[0051] The administrator terminal 5 includes a display unit 50, an operation unit 51, a speaker 52, an administrator-side receiving unit 53, an administrator-side microcomputer 54, and a battery 55. The display unit 50, the operation unit 51, and the speaker 52 are communicatively connected to the administrator-side microcomputer 54. The battery 55 can be the same as the battery 24 of the slave unit 2.

[0052] The display unit 50 is provided in the housing 5A of the administrator terminal 5, and is configured, for example, with a liquid crystal display or an organic EL display. The operation unit 51 is configured, for example, with a pressure-sensitive touch panel that can be operated by touch, buttons, switches, etc. In the case of a pressure-sensitive touch panel, it can be provided overlapping the display unit 50. The speaker 52 is capable of emitting various sounds.

[0053] The manager-side receiving unit 53 is a communication module capable of communicating with the base unit-side transmitting unit 42, and specifically, is configured with a communication module of the same standard as the base unit-side transmitting unit 42. The manager-side receiving unit 53 receives alarm signals and the like transmitted from the base unit-side transmitting unit 42. Although details will be described later, the alarm signal is a signal transmitted from the slave unit repeater 3 when it is estimated that the worker is in an unsafe state, and is received by the manager-side receiving unit 53 after being relayed by the base unit 4.

[0054] The manager-side microcomputer 54 is a component that accepts operation of the operating unit 51 and input of a notification signal received by the manager-side receiving unit 53, and also controls the display unit 50 and the speaker 52. Specifically, upon receiving the notification signal received by the manager-side receiving unit 53, the manager-side microcomputer 54 causes the display unit 50 to notify that worker A's work at height is in an unsafe state. Examples of notification by the display unit 50 include displaying a sentence on the display unit 50, such as "Hook not fastened while working at height," or displaying a symbol or mark indicating an unsafe state. Furthermore, upon receiving the notification signal received by the manager-side receiving unit 53, the manager-side microcomputer 54 causes the speaker 52 to notify that worker A's work at height is in an unsafe state. Examples of notification by the speaker 52 include sound, such as "Hook not fastened while working at height," or generating various warning sounds (alarm sounds). The display unit 50 and speaker 52 are examples of a notification unit that notifies that the worker A's work at height is in an unsafe state. Only one of the display unit 50 and speaker 52 may be provided. The notification unit may also be configured, for example, with a vibration generator that generates a predetermined vibration.

[0055] With the above configuration, when the repeater side microcomputer 33 determines that worker A is in an unsafe state, it can control the display unit 50 and speaker 52 of the manager terminal 5 to notify the manager or the like that worker A is in an unsafe state.

[0056] The display unit 50 and speaker 52 as the notification unit may be provided in the slave unit 2 or the slave unit repeater 3 in addition to the manager terminal 5. Although not shown, a speaker and a vibration generator may be provided in the slave unit 2, and when the repeater side microcomputer 33 determines that the worker A is in an unsafe state, a notification signal is transmitted to the slave unit 2, whereby the speaker and the vibration generator can notify the worker A that he is in an unsafe state.

[0057] (Details of the process by the repeater side microcomputer 33) Next, the details of the processing by the repeater-side microcomputer 33 will be described. The repeater-side microcomputer 33 can operate at a frequency of, for example, 32 Hz, but the operating frequency is not limited to this. FIG. 3 is a flowchart showing an example of the main processing flow by the repeater-side microcomputer 33. This flowchart starts when the slave unit 2, slave unit repeater 3, master unit 4, and manager terminal 5 of the work at height warning system 1 are powered on before starting work at height. In step SA1, initial configuration is performed. In the initial configuration, the slave unit 2, slave unit repeater 3, master unit 4, and manager terminal 5 are paired to enable communication with each other. In addition, in this initial configuration, an offset value, which is the difference between the detection value of the worker-side atmospheric pressure sensor 21 of the slave unit 2 and the detection value of the reference atmospheric pressure sensor 40, which is detected approximately simultaneously with the worker-side atmospheric pressure sensor 21, is also measured and stored in the repeater-side microcomputer 33.

[0058] That is, when setting up the height work warning system 1, first, the base unit 4 is installed at the installation location, the sub-unit 2 and sub-unit repeater 3 are attached to worker A, and worker A wearing the sub-unit 2 is made to stand at the same height as the installation location of the base unit 4. Note that the difference from the reference height due to worker A's height can be absorbed by an offset value, so the heights do not have to be the same.

[0059] The detection values ​​of the worker-side atmospheric pressure sensor 21 and the reference atmospheric pressure sensor 40 are then input to the repeater-side microcomputer 33. The repeater-side microcomputer 33 subtracts the detection value of the reference atmospheric pressure sensor 40 from the detection value of the worker-side atmospheric pressure sensor 21. The value obtained by this subtraction process is the offset value. Even if the worker-side atmospheric pressure sensor 21 and the reference atmospheric pressure sensor 40 are configured using the same atmospheric pressure sensor, variations are unavoidable. For example, differences in the detected values ​​may occur even when atmospheric pressure is detected at the same height and timing. Furthermore, the height of the worker-side atmospheric pressure sensor 21 worn by worker A may be higher than that of the reference atmospheric pressure sensor 40, even if worker A is standing at the same height as the installation location of the base unit 4. To prevent errors in high-altitude determination due to the above-mentioned sensor variations and errors in high-altitude determination due to the actual height of the worker-side atmospheric pressure sensor 21, an offset value is calculated in advance. In other words, a vertical origin correction is performed through calibration. For example, if the detection value of the worker-side atmospheric pressure sensor 21 of the slave unit 2 is 10601.234 Pa and the detection value of the reference atmospheric pressure sensor 40 of the master unit 4 is 10625.678 Pa, the offset value will be the value obtained by subtracting the detection value of the reference atmospheric pressure sensor 40 from the detection value of the worker-side atmospheric pressure sensor 21, i.e., -24.444 Pa.

[0060] When pairing the master unit 4 and the slave unit 2 to obtain the offset value, the slave unit 2 and the master unit 4 use the detection value obtained by detecting the atmospheric pressure at approximately the same time while the worker A is standing on the floor or ground at the same height as the master unit 4. For example, the slave unit 2 and the master unit 4 are each provided with a pairing switch (not shown), and the offset value can be calculated by storing the detection value of the worker-side atmospheric pressure sensor 21 and the detection value of the reference atmospheric pressure sensor 40 at the time the pairing switch of the slave unit 2 and the master unit 4 is pressed.

[0061] Once the initial settings are complete, the process proceeds to step SA2, where the repeater microcomputer 33 performs the calculation of cycle counter = cycle counter + 1. In step SA3, the repeater microcomputer 33 determines whether the transmission flag is ON. The transmission flag is a flag that is turned ON when the repeater microcomputer 33 transmits a warning signal when it is estimated that the worker is in an unsafe state. Therefore, when the worker is not in an unsafe state, the transmission flag remains OFF.

[0062] If the determination in step SA3 is YES and the transmission flag is ON, the process proceeds to step SA4, where the slave repeater 3 transmits to the master 4 an address for identifying the slave 2, the status of the slave 2 indicating that it is in an unsafe state, the detection value of the worker-side atmospheric pressure sensor 21, and the detection result of the hook sensor 20. Note that transmission of the detection result of the hook sensor 20 is not essential.

[0063] In step SA5, the repeater-side microcomputer 33 turns off the transmission flag. Then, the process proceeds to step SA6, where the repeater-side microcomputer 33 determines whether the remainder when dividing the period counter by 320 is 0. Here, the current status is transmitted, for example, every 10 seconds. If the remainder when dividing the period counter by 320 is 0, the process proceeds to step SA7, where the slave repeater 3 transmits to the master unit 4 an address for identifying the slave unit 2, the status of the slave unit 2 indicating that it is in a safe state, the detection value of the worker-side atmospheric pressure sensor 21, and the detection result of the hook sensor 20. Note that transmitting the detection result of the hook sensor 20 is not essential.

[0064] In step SA8, the repeater microcomputer 33 determines whether the remainder when dividing the period counter by 8 is 0. Here, for example, the current status is transmitted every 0.25 seconds. That is, the process proceeds to step SA9, where the repeater microcomputer 33 acquires the detection value of the worker-side atmospheric pressure sensor 21 and the detection value of the reference atmospheric pressure sensor 40. In step SA10, the repeater microcomputer 33 acquires the detection value of the acceleration sensor 25. In step SA11, the repeater microcomputer 33 performs LPF (low-pass filter) processing on the detection values ​​acquired in step SA9 and the detection values ​​acquired in step SA10.

[0065] In step SA12, the repeater microcomputer 33 calculates the attitude of the hook 105, i.e., the tilt angles (roll, pitch, yaw), based on the detection value of the acceleration sensor 25 that was LPF processed in step SA11. This allows the repeater microcomputer 33 to obtain the current attitude of the hook 105. Also, in step SA13, based on the signal output from the hook out sensor 20, the repeater microcomputer 33 determines whether the hook 105 is engaged or not, and obtains this information.

[0066] In step SA14, a reception determination process, which will be described later, is executed. In addition, in step SA15, a state determination process, which will be described later, is executed. The flow in Fig. 3 continues to be executed until the work at height warning system 1 is turned off, and when the work at height warning system 1 is turned off, the flow ends at that point.

[0067] 4 is a flowchart showing an example of the flow of reception interrupt processing. This flow starts when a detected value of atmospheric pressure is input. In step SB1, the repeater microcomputer 33 determines whether the detected value of atmospheric pressure was input from the parent unit 4 or from the child unit 2. If it was input from the parent unit 4, the process proceeds to step SB2, where the repeater microcomputer 33 acquires the detected value of the reference atmospheric pressure sensor 40 that has been subjected to LPF processing. Note that here, the detected value of the reference atmospheric pressure sensor 40 is referred to as the LPF-processed value. Specifically, it is the value obtained by inputting the detected value of the reference atmospheric pressure sensor 40 to a low-pass filter and processing it.

[0068] In step SB3, the reception flag is set to the parent unit, and the reception interrupt process is terminated. On the other hand, if the input is from the child unit 2, the process proceeds to step SB4, where the repeater unit microcomputer 33 acquires the LPF-processed detection value of the worker's atmospheric pressure sensor 21. In step SB5, the reception flag is set to the child unit, and the reception interrupt process is terminated.

[0069] FIG. 5 is a flowchart showing an example of the flow of the reception determination process. This process starts after step SA13 shown in FIG. 3. In step SC1, the repeater microcomputer 33 determines whether the reception flag in the reception interrupt process indicates the master unit. If the reception flag indicates the master unit, the process proceeds to step SC2, where the repeater microcomputer 33 acquires the detection value of the reference atmospheric pressure sensor 40 that has been subjected to LPF processing. In step SC3, the repeater microcomputer 33 determines whether the reception flag in the reception interrupt process indicates the slave unit. If the reception flag indicates the slave unit, the process proceeds to step SC4. In step SC4, the distance estimation unit 35 acquires the strength of the radio waves used in communication between the slave unit transmitter 22 and the repeater unit receiver 31 and estimates the position of the slave unit 2 based on the acquired radio wave strength. This allows the hook 105 to be determined as being at the waist position, chest position, or use position.

[0070] In step SC5, the LPF-processed detection value of the worker-side atmospheric pressure sensor 21 is set to "A." In step SC6, the LPF-processed detection value of the reference atmospheric pressure sensor 40 is subtracted by the high altitude threshold value and set to "B."

[0071] In step SC7, a high altitude determination is performed based on "A" set in step SC5 and "B" set in step SC6. Specifically, the repeater-side microcomputer 33 determines whether worker A is at a high altitude based on the value obtained by subtracting the detection value of the worker-side atmospheric pressure sensor 21 of the slave unit 2, the offset value, and a predetermined threshold (high altitude threshold) from the detection value of the reference atmospheric pressure sensor 40 of the master unit 4. The high altitude threshold for determining whether worker A is at a high altitude is 20.0 Pa if work at a height of 2 m or more is defined as a high altitude. The high altitude threshold can be set arbitrarily depending on the height at which the work is determined to be a high altitude. Also, assume that the detection value of the reference atmospheric pressure sensor 40 of the master unit 4 is 10611.234 Pa.

[0072] When worker A wearing slave unit 2 is standing at the reference height, let's say the detection value of the worker-side atmospheric pressure sensor 21 of slave unit 2 is 10593.678 Pa. In this case, the repeater unit microcomputer 33 executes the following calculation: subtract the detection value of the reference atmospheric pressure sensor 40 of the master unit 4, the offset value, and the high altitude threshold value from the detection value of the worker-side atmospheric pressure sensor 21 of slave unit 2. The obtained value (Z) is 20.888 Pa. Since Z > 0, the repeater unit microcomputer 33 determines that worker A is at a lower altitude than that defined as a high altitude.

[0073] On the other hand, when worker A wearing handset 2 is climbing utility pole B, let's say the detection value of worker-side atmospheric pressure sensor 21 of handset 2 is 10566.945 Pa. In this case, repeater-side microcomputer 33 performs the following calculation: subtract the detection value of reference atmospheric pressure sensor 40 of base unit 4, the offset value, and the high altitude threshold from the detection value of worker-side atmospheric pressure sensor 21 of handset 2. The obtained value (Z) is -49.033 Pa. Since Z<0, repeater-side microcomputer 33 determines that worker A is at a location defined as high altitude. Note that if the result of the above calculation were Z=0, this includes an error and is basically impossible, so repeater-side microcomputer 33 determines that base unit 4 is at a lower position than handset 2.

[0074] If it is determined in step SC7 that worker A is in a low place, the process proceeds to step SC8, where the repeater microcomputer 33 sets the status to "LOW (low place)." Since worker A is safe when he is in a low place, the process proceeds to step SC9, where the slave unit status, i.e., the worker's current status, is set to "safe." Thereafter, the process proceeds to step SC10, where the reception flag is cleared and the reception determination process ends.

[0075] If it is determined in step SC7 that worker A is at a high place, the process proceeds to step SC11, where it is determined whether or not the status is "LOW." If the status is other than "LOW," the process proceeds to step SC10. On the other hand, if the status is "LOW," the process proceeds to step SC12, where it is determined whether or not the hook 105 is engaged. If the hook 105 is engaged, the process proceeds to step SC13, where it is determined the posture of the hook 105. If the hook 105 has rotated 180 degrees from the posture shown in FIG. 2 and is facing downward, the process proceeds to step SC15. This downward posture is the posture adopted when a bucket truck is used to ascend to a high place, so in step SC15, the relay unit side microcomputer 33 sets the status to "HIGH1 (bucket truck)."

[0076] If it is determined in step SC13 that the hook 105 is in a position other than downward, the process proceeds to step SC14, where the repeater-side microcomputer 33 sets the status to "HIGH1." Then, the process proceeds to step SC16. If it is determined in step SC12 that the hook 105 is not engaged, the process proceeds directly to step SC16. In step SC16, the safety timer is cleared.

[0077] FIG. 6 is a flowchart showing an example of the flow of the state determination process. This process starts after step SA14 shown in FIG. 3. In step SD1, the relay microcomputer 33 determines whether the state status is "HIGH1." If the state status is "HIGH1," the process proceeds to step SD2. In step SD3, the relay microcomputer 33 determines whether the state status is "HIGH1 (bucket truck)." If the state status is "HIGH1 (bucket truck)," the process proceeds to step SD4. In step SD5, the relay microcomputer 33 determines whether the state status is "HIGH2." If the state status is "HIGH2," the process proceeds to step SD6. "HIGH2" can be determined by the relay microcomputer 33, as will be described later.

[0078] In step SD7, the repeater microcomputer 33 determines whether the status is "HIGH3." If the status is "HIGH3," the process proceeds to step SD8. Whether the status is "HIGH3" can be determined by the repeater microcomputer 33, as will be described later.

[0079] In step SD9, the repeater microcomputer 33 determines whether the status is "HIGH4." If the status is "HIGH4," the process proceeds to step SD10. Whether the status is "HIGH4" can be determined by the repeater microcomputer 33, as will be described later.

[0080] In step SD11, the repeater microcomputer 33 determines whether the status is "HIGH5." If the status is "HIGH5," the process proceeds to step SD12. Whether the status is "HIGH5" can be determined by the repeater microcomputer 33, as will be described later.

[0081] In step SD13, the repeater microcomputer 33 determines whether the status is "HIGH6." If the status is "HIGH6," the process proceeds to step SD14. Whether the status is "HIGH6" can be determined by the repeater microcomputer 33, as will be described later.

[0082] 7 is a flowchart showing an example of the flow of the HIGH1 process of step SD2 in FIG. 6. In step SE1 after start, the repeater microcomputer 33 executes the calculation of safety timer = safety timer + 1. In step SE2, the repeater microcomputer 33 determines whether the safety timer is 0, that is, whether the remainder when calculating safety timer / (32 × set seconds 1) is 0 (for example, if the safety timer counts up 32 times per second, and the set seconds is 10 seconds, the remainder becomes 0 every 10 seconds). Alternatively, the repeater microcomputer 33 determines whether the position of the slave unit 2 is close to the worker A (whether it is at chest level).

[0083] If the remainder when calculating the safety timer divided by (32 × set number of seconds 1) is 0, or if the position of the slave unit 2 is close to the worker A, the process proceeds to step SE3, where the slave unit status is set to a dangerous state, i.e., an unsafe state. For example, if the safety timer is exceeded, it is presumed that the worker has moved to the top of the utility pole B to work without changing the hook 105, and in such a case the slave unit status can be set to a dangerous state. Also, if the hook 105 is at chest level, it is presumed that the hook 105 is not hooked on the fall prevention member B1, and in such a case the slave unit status can be set to a dangerous state.

[0084] In step SE4, it is determined whether or not something is hooked on the hook 105. If the hook 105 is hooked on something, the process proceeds to step SE5, where the posture of the hook 105 is determined. If the hook 105 is facing downward, the process proceeds to step SE6, where the relay-side microcomputer 33 sets the status to "HIGH1 (bucket truck)."

[0085] If it is determined in step SE4 that the hook 105 is not engaged, the process proceeds to step SE7, where the status is set to "HIGH2." In step SE8, the slave unit status is set to safe, and in step SE9, the safety timer is cleared. In step SE10, it is determined whether the slave unit status is safe. If the slave unit status is safe, the process proceeds to step SE11, where no notification is given to worker A or the manager, etc., but if the slave unit status is unsafe, the process proceeds to step SE12, where a notification signal is sent to notify worker A, the manager, etc. In step SE13, the transmission flag is turned ON.

[0086] Fig. 8 is a flowchart showing an example of the flow of the HIGH1 (bucket truck) processing in step SD4 in Fig. 6. In step SF1 after the start, it is determined whether the hook 105 is engaged. If the hook 105 is engaged, this flow ends. If the hook 105 is not engaged, the flow proceeds to step SF2, and the status is set to "HIGT2." In step SF3, the slave status is set to safe.

[0087] 9 is a flowchart showing an example of the flow of the HIGH2 process of step SD6 in FIG. 6. In step SG1 after start, the repeater-side microcomputer 33 executes a calculation of safety timer = safety timer + 1. In step SG2, the repeater-side microcomputer 33 determines whether the safety timer is 0, that is, whether the remainder when calculating safety timer ÷ (32 × set number of seconds 2) is 0. If the remainder when calculating safety timer ÷ (32 × set number of seconds 2) is 0, the process proceeds to step SG3, where the slave unit status is set to a dangerous state, i.e., an unsafe state. That is, since it is estimated that the hook 105 was not hooked onto the fall prevention member B1 within the specified time after being released from the fall prevention member B1, the slave unit status can be set to a dangerous state in such a case.

[0088] In step SG4, it is determined whether or not the hook 105 is hung. If the hook 105 is hung on something, the process proceeds to step SG5 to determine the position of the handset 2. On the other hand, if the hook 105 is not hung on something, the process proceeds to step SG12.

[0089] If it is determined in step SG5 that the slave unit 2 is located far away from the worker A, the process proceeds to step SG7, where the posture of the hook 105 is determined. If the hook 105 is in a horizontal posture (a posture rotated 90° to the right or left from the posture shown in FIG. 2), the process proceeds to step SG9, where the repeater-side microcomputer 33 sets the status to "HIGH6." If the hook 105 is in an upward posture (the posture shown in FIG. 2), the process proceeds to step SG8, ​​where the repeater-side microcomputer 33 sets the status to "HIGH3."

[0090] If it is determined in step SG5 that the slave unit 2 is close to worker A, the process proceeds to step SG6, where the repeater side microcomputer 33 sets the status to "HIGH1." In step SG10, the slave unit status is set to safe. In step SG11, the safety timer is cleared. In step SG12, it is determined whether the slave unit status is safe. If the slave unit status is safe, the process proceeds to step SG13, where no notification is given to worker A or the manager, etc., but if the slave unit status is unsafe, the process proceeds to step SG14, where a notification signal is sent to notify worker A, the manager, etc. In step SG15, the transmission flag is turned ON.

[0091] Figure 10 is a flowchart showing an example of the flow of the HIGH3 process in step SD8 in Figure 6. In step SH1 after starting, it is determined whether or not the hook 105 is hooked on something. If the hook 105 is hooked on something, this flow ends. If the hook 105 is not hooked, the flow proceeds to step SH2, and the state status is set to "HIGT4." In step SH3, the safety timer is cleared.

[0092] 11 is a flowchart showing an example of the flow of the HIGH4 process of step SD10 in FIG. 6. In step SJ1 after start, the repeater microcomputer 33 executes a calculation of safety timer = safety timer + 1. In step SJ2, the repeater microcomputer 33 determines whether the remainder when calculating safety timer ÷ (32 × set number of seconds 3) is 0. If the remainder when calculating safety timer ÷ (32 × set number of seconds 3) is 0, the process proceeds to step SJ3, where the slave unit status is set to a dangerous state, i.e., an unsafe state. That is, since it is estimated that the hook 105 was not hooked onto the fall prevention member B1 within the specified time after being removed from the fall prevention member B1, the slave unit status can be set to a dangerous state in such a case.

[0093] In step SJ4, it is determined whether or not the hook 105 is hung on something. If the hook 105 is hung on something, the process proceeds to step SJ5 to determine the position of the handset 2. On the other hand, if the hook 105 is not hung on something, the process proceeds to step SJ12.

[0094] If it is determined in step SJ5 that the slave unit 2 is far away from the worker A, the process proceeds to step SJ7 to determine the posture of the hook 105. If the hook 105 is horizontal, the process proceeds to step SJ9, where the repeater microcomputer 33 sets the status to "HIGH6." If the hook 105 is facing upward, the process proceeds to step SJ8, where the repeater microcomputer 33 sets the status to "HIGH3."

[0095] If it is determined in step SJ5 that the slave unit 2 is close to worker A, the process proceeds to step SJ6, where the repeater side microcomputer 33 sets the status to "HIGH5." In step SJ10, the slave unit status is set to safe. In step SJ11, the safety timer is cleared. In step SJ12, it is determined whether the slave unit status is safe. If the slave unit status is safe, the process proceeds to step SJ13, where no notification is given to worker A or the manager, etc., but if the slave unit status is unsafe, the process proceeds to step SJ14, where a notification signal is sent to notify worker A, the manager, etc. In step SJ15, the transmission flag is turned ON.

[0096] 12 is a flowchart showing an example of the flow of the HIGH5 process in step SD12 in FIG. 6. In step SK1 after start, the repeater-side microcomputer 33 executes a calculation of safety timer = safety timer + 1. In step SK2, the repeater-side microcomputer 33 determines whether the remainder when dividing the safety timer by (32 × set seconds 4) is 0. Alternatively, the repeater-side microcomputer 33 determines whether the position of the slave unit 2 is close to the worker A (whether it is at chest level). If the remainder when dividing the safety timer by (32 × set seconds 4) is 0, and the position of the slave unit 2 is close to the worker A, the process proceeds to step SK3, where the slave unit status is set to a dangerous state, i.e., an unsafe state. That is, if there is a remainder when dividing the safety timer by (32 × set seconds 4), it is estimated that the worker has moved to the upper part of the utility pole B and is working without changing the hook 105. In such a case, the slave unit status can be set to a dangerous state. Also, when the hook 105 is at the chest position, it is assumed that the hook 105 is not hooked on the fall prevention member B1, and in such a case, the handset status can be set to a dangerous state.

[0097] In step SK4, it is determined whether or not the hook 105 is engaged. If the hook 105 is engaged, the process proceeds to step SK8. If it is determined in step SK4 that the hook 105 is not engaged, the process proceeds to step SK5, where the status is set to "HIGH4." In step SK6, the slave unit status is set to safe, and in step SK7, the safety timer is cleared. In step SK8, it is determined whether or not the slave unit status is safe. If the slave unit status is safe, the process proceeds to step SK9, where no notification is given to worker A or the manager, etc., but if the slave unit status is unsafe, the process proceeds to step SK10, where a notification signal is sent to notify worker A, the manager, etc. In step SK11, the transmission flag is turned ON.

[0098] Figure 13 is a flowchart showing an example of the flow of the HIGH6 process in step SD14 in Figure 6. In step SL1 after the start, it is determined whether the hook 105 is engaged. If the hook 105 is engaged, this flow ends. If the hook 105 is not engaged, the flow proceeds to step SL2, and the status is set to "HIGT4." In step SL3, the safety timer is cleared.

[0099] As described above, the repeater-side microcomputer 33 can determine whether or not the worker A is at a height that is a predetermined level higher than the reference height based on the detected atmospheric pressure value output from the worker-side atmospheric pressure sensor 21. The repeater-side microcomputer 33 can also determine whether or not the fall arrest device 100 is being used based on the state of the hook 105 detected by the hook sensor 20 and at least one of information regarding the attitude of the hook 105 and information regarding the position of the hook 105.

[0100] Then, when the repeater side microcomputer 33 determines that worker A is at a high altitude and that the fall arrest device 100 is not being used, it estimates that worker A is in an unsafe state and can cause the buzzer 30 to alert that worker A is in an unsafe state.

[0101] The repeater-side microcomputer 33 can determine the time during which worker A moves from the reference height to a higher place based on the detected value of atmospheric pressure output from the worker-side atmospheric pressure sensor 21. For example, if the detected value of atmospheric pressure output from the worker-side atmospheric pressure sensor 21 is decreasing, it can be determined that worker A is moving from the reference height to a higher place, and if the hook sensor 20 detects that the hook 105 was not hooked while worker A was moving from the reference height to a higher place, it means that worker A has not hooked the hook 105 to the fall prevention member B1, and in this case, it is estimated that an unsafe state exists.

[0102] Furthermore, the repeater-side microcomputer 33 can measure the time when the hook 105 is not engaged or the time when the hook 105 is engaged by the hook sensor 20. When it is determined that the worker A is at a height higher than the reference height by a predetermined amount or more and the hook sensor 20 determines that the time when the hook 105 is not engaged has continued for a predetermined amount or more, or when it is determined that the worker A is at a height higher than the reference height by a predetermined amount or more and the hook sensor 20 determines that the time when the hook 105 is engaged has continued for a predetermined amount or more, the repeater-side microcomputer 33 can estimate that the worker A is in an unsafe state.

[0103] Furthermore, if the repeater side microcomputer 33 determines that worker A is at a height that is a predetermined height or more higher than the reference height and determines that the position of the hook 105 is at a position where it is hung on worker A's waist (waist position), it can infer that worker A is in an unsafe state.

[0104] According to this embodiment, when it is estimated that an unsafe condition exists during work at height, a warning can be given to worker A, thereby improving the safety of work at height.

[0105] The above-described embodiments are merely examples in all respects and should not be construed as limiting. Furthermore, all modifications and variations within the scope of the claims are within the scope of the present invention. [Industrial Applicability]

[0106] As described above, the height-work warning system according to the present disclosure can be used, for example, during work on poles or towers. [Explanation of symbols]

[0107] 1. Height work warning system 20 Hook Sensor 21 Worker side atmospheric pressure sensor 22 Sub-unit transmitter (hook-side wireless communication unit) 25 Acceleration sensor (hook state detection section) 30 Buzzer (alarm unit) 31 Repeater side receiving unit (belt side wireless communication unit) 33 Repeater side microcomputer (control unit) 35 Distance estimation unit (hook state detection unit) 100 Fall arrest equipment 200 Work Positioning Equipment

Claims

1. A height-work warning system for warning a worker who wears a fall prevention device and a work positioning device and works at height, an operator-side atmospheric pressure sensor that is worn by the operator and detects the atmospheric pressure around the operator; a hook sensor for detecting whether the hook of the fall arrest device is engaged; a hook state detection unit that acquires at least one of information about the attitude of the hook and information about the position of the hook; a notification unit that notifies a worker that work at height is in an unsafe state; A height-work warning system comprising a control unit that, when it is determined that the worker is at a height that is a predetermined height or more higher than the reference height based on the detected atmospheric pressure value output from the worker-side atmospheric pressure sensor, and when it is determined that the fall arrest equipment is not in use based on the state of the hook detected by the hook sensor and at least one of the information regarding the posture of the hook and the information regarding the position of the hook detected by the hook state detection unit, estimates that the worker is in an unsafe state and alerts the alarm unit that the worker is in an unsafe state.

2. The height-work warning system according to claim 1, The control unit determines the time it takes for the worker to move from the reference height to the high place based on the detected atmospheric pressure value output from the worker-side atmospheric pressure sensor, and if the hook sensor detects that the hook is not attached while the worker is moving from the reference height to the high place, it presumes that the worker is in an unsafe state.

3. The height-work warning system according to claim 1, The control unit is a height-work warning system that estimates that the worker is in an unsafe condition when it determines that the worker is at a height that is a predetermined height or more higher than the reference height and when it determines that the hook sensor has determined that the hook has not been attached for a predetermined period of time or more.

4. The height-work warning system according to claim 1, The control unit is a height-work warning system that estimates that the worker is in an unsafe state when it determines that the worker is at a height that is a predetermined height or more higher than the reference height and when it determines that the position of the hook detected by the hook state detection unit is in a position where it is attached to the worker's waist.

5. The height-work warning system according to claim 1, The hook state detection unit includes an acceleration sensor fixed to the hook, and the acceleration sensor outputs a measured acceleration value as information regarding the posture of the hook.

6. The height-work warning system according to claim 1, The hook state detection unit generates information regarding the position of the hook based on the strength of radio waves during communication between a hook-side wireless communication unit provided on the hook and a belt-side wireless communication unit provided on the worker's waist belt in the work positioning device, in a height-work warning system.

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