EP3767603A1

EP3767603A1 - Helmet-mounted emergency evacuation warning device, and emergency evacuation warning system

Info

Publication number: EP3767603A1
Application number: EP19768334.5A
Authority: EP
Inventors: Makoto Nozawa; Takashi Masuko; Takatomo SHIMBO; Shuichi TAKASUGI
Original assignee: Midori Anzen Co Ltd
Current assignee: Midori Anzen Co Ltd
Priority date: 2018-03-13
Filing date: 2019-03-13
Publication date: 2021-01-20
Also published as: CN111837169A; JPWO2019177007A1; JP7055193B2; EP3767603A4; WO2019177007A1

Abstract

The present invention addresses the problem of providing an emergency evacuation warning device capable of effectively transferring vibrations to the head of a user, even if a helmet is interposed therebetween, and an emergency evacuation warning system. This emergency evacuation warning device for prompting a related person in a work area to carry out an evacuation action immediately is provided with: a casing which vibrates by means of the movement of an inbuilt vibrator; an elastic fixing band which detachably fixes the casing to a helmet of the related person, and which extends in two directions from the casing and is wound around the helmet along the surface of the helmet; and a supporting unit which partially supports the casing on the surface of the helmet in such a way that the helmet oscillates together with the casing by means of the vibrations of the vibrator, which moves in conjunction with a wireless warning signal providing notification of a danger approaching the work area.

Description

Technical Field

The present invention relates to an emergency evacuation alert device mountable on a helmet and an emergency evacuation alert system.

Background Art

PTL 1 and PTL 2 disclose helmets with an alert function each including a vibrator on the inner side surface of the helmet shell. The helmet also has a reception function arranged at the top in the helmet shell. PTL 3 discloses an information transmission device including a hammering sound generating unit on the outside of the occipital section of the helmet shell. This device includes a reception function for recognizing a fall of a worker. PTL 4 discloses a system for monitoring an abnormality such as a fall of a traffic cone or other sign on a highway, for example. PTL 5 discloses a disaster-prevention alert helmet that has a vibrator attached to the chin strap of the helmet. A receiver for activating the vibrator is provided as a separate unit. These conventional examples are designed to provide functions and systems that notify workers of an emergency at work sites, but further improvements are required.

Documents of Prior Arts

Patent document

[PTL 1] Japanese Patent Application Publication No. 2009-167587
[PTL 2] Japanese Patent Application Publication No. 2007-247097
[PTL 3] Japanese Patent Application Publication No. 2014-153876
[PTL 4] Japanese Patent Application Publication No. 2013-238058
[PTL 5] Japanese Utility Model Registration No. 3200747

Summary of the Invention

Problems to be solved by the invention

In dangerous operations, such as road work on highways, work in tunnels, and firefighting, and operations on alert for disasters, such as volcanic eruptions and tsunamis, information on danger must reach the workers on the front line quickly and reliably to prompt them to evacuate immediately. An objective of the present invention is to provide an emergency evacuation alert device that is to be mounted on a helmet, which is worn by most people at such sites, to ensure that the wearer recognizes alert information by a vibration.
The most important objective is to ensure that the worker recognizes the vibration of the emergency evacuation alert device mounted on the helmet shell through the helmet shell and the interior parts.
Another objective is to provide an emergency evacuation alert system with transmission and reception functions that achieve reliable transmission of alert information and activation of the emergency evacuation alert device.

Solution to Problem

An objective of the present invention is to provide an emergency evacuation alert device for prompting a participant in an operation area to evacuate immediately. The device includes: a housing that is configured to vibrate by movement of a vibrating element installed in the housing; an elastic fixing band for removably fixing the housing to a helmet of the participant, the fixing band extending from the housing in two directions and being configured to wrap around a surface of the helmet; and a support portion configured to partially support the housing on the surface of the helmet such that the helmet oscillates together with the housing by vibration of the vibrating element that moves in response to a radio alert signal for alerting the participant of an imminent danger in the operation area.
The support portion may be formed by a part of the fixing band.
The support portion may include a first support portion and a second support portion that are configured to be disposed between the surface of the helmet and the housing and support the housing at two positions on the surface of the helmet.
When the housing is fixed to the helmet and viewed facing the surface of the helmet, the vibrating element may be disposed in an area that is between the first and second support portions and is not sandwiched by parts directly joined to the helmet shell.
The first support portion may be disposed at a position where the fixing band extends from the housing in one direction, and the second support portion may be disposed at a position where the fixing band extends from the housing in another direction.
The housing may be configured to be fixed to an occipital section of the helmet.
The device may further include: an antenna configured to receive a radio wave of the alert signal; and a control unit configured to activate a motor for moving the vibrating element when the antenna receives the alert signal.
The control unit may activate the motor for moving the vibrating element when identification information in the alert signal received by the antenna is identical with identification information that is registered to the control unit through pairing in advance.
The device may further include a power supply unit configured to supply electric power to the control unit.
The device may further include: a power button for creating a state in which the electric power of the power supply unit is supplied to the control unit; and a battery check button for checking an amount of remaining battery charge of the power supply unit.
A further objective of the present invention is to provide an emergency evacuation alert system that includes the emergency evacuation alert device described above and a transmitter configured to wirelessly transmit the alert signal to the emergency evacuation alert device.
The transmitter may be a device that is to be carried by a participant, the device sending an alert signal, and includes an alert button for wirelessly sending the alert signal.
The transmitter may have a sensor for detecting an occurrence of a dangerous situation and be configured to be attached to an installed object.
The system may further include a repeater configured to relay the alert signal wirelessly transmitted from the transmitter to the emergency evacuation alert device.

Effects of the Invention

The above-mentioned emergency evacuation alert device, which can be removably mounted on the helmet shell, is capable of transmitting an alert signal in a reliable manner even under various adverse conditions. The emergency evacuation alert device can apply a sufficient vibration as an alert signal to the worker's head through the helmet shell and the interior parts. To ensure the activation of the emergency evacuation alert device, an alert signal needs to be transmitted and received reliably by the emergency evacuation alert device. To this end, an emergency evacuation alert system with reliable transmission and reception functions is provided.

Brief Description of Drawings

[Fig. 1]
Fig. 1 is a diagram showing an evaluation of means of emergency evacuation notification.
[Fig. 2]
Fig. 2 is a diagram showing the external appearance of an emergency evacuation alert device of an embodiment.
[Fig. 3]
Fig. 3 is a diagram showing the internal structure of the emergency evacuation alert device of the embodiment.
[Fig. 4]
Fig. 4 is a diagram showing the external appearance of the emergency evacuation alert device of the embodiment that is mounted on a helmet and a human head model.
[Fig. 5]
Fig. 5 is a diagram showing a state of the vibrating emergency evacuation alert device.
[Fig. 6]
Fig. 6 is a diagram showing the external appearance of a transmitter of an embodiment.
[Fig. 7]
Fig. 7 is a diagram showing an example of an operation area.
[Fig. 8]
Fig. 8 is a diagram showing the first example of immediate evacuation achieved with the emergency evacuation alert system.
[Fig. 9]
Fig. 9 is a diagram showing the second example of immediate evacuation achieved with the emergency evacuation alert system.

Description of Embodiments

An embodiment of the present invention is now described. The embodiment described below is an example of an embodiment of the present invention, and the technical scope of the present invention is not limited to the embodiments described below.

An emergency evacuation alert device is mounted on a helmet, receives an alert signal from the outside, and generates vibration with a vibration unit arranged in the device to prompt the helmet wearer to urgently evacuate.
Fig. 2 is a diagram showing the external appearance of an emergency evacuation alert device of the present embodiment. An emergency evacuation alert device 1 has an antenna 10, a housing 2, which substantially has the shape of a rounded rectangular prism and has fixing belt holes 11 and 12 on either end, and a fixing belt (fixing band) 18 for fixing to a helmet. The outer surface of the emergency evacuation alert device 1 includes an operation unit 5, which includes a power button 7 and a battery check button 6, a pairing LED 8 for displaying pairing status, and a power LED 9 for displaying power status.
Fig. 3 shows a control circuit 13, which is arranged in a position corresponding to the operation unit 5, batteries 14 and 15 serving as the power source of the emergency evacuation alert device 1, and a vibrating element 17, which is rotated by a motor 16. These components are arranged in the interior. The control circuit 13 is formed by implementing on an electronic board the antenna 10 for receiving radio waves, an integrated circuit for signal processing in wireless communication and controlling of the motor 16, a light emitting diode for status display, and push button switches positioned corresponding to the battery check button 6 and the power button 7.
Examples of means to notify workers at a dangerous worksite of emergency evacuation include sound (e.g., siren), light (e.g., warning lamp), and a vibrator attached to each worker. Based on the results of evaluation of means of emergency evacuation notification shown in Fig. 1, vibration is considered as the optimal means usable under various conditions. A vibrator can be attached to the waist, an arm, or the head, for example. Given the degree of interference with the operation, and reliable recognition of the vibration by the worker, the shell of a helmet, which is generally worn on the worker's head, is determined to be a suitable position for removably mounting the vibrator. However, a helmet is designed to limit the transmission of an external impact to the head and thus inherently has a structure for mitigating an impact received on the surface of the helmet. For this reason, when a vibrator is mounted on the surface of a helmet having such a structure, it can be difficult to effectively transmit the vibrations caused by the vibrator to the worker's head.

(1) Vibration Unit

The vibration unit includes the motor 16 and the vibrating element 17 and is designed to allow the wearer to perceive strong vibrations on the head through the helmet and thus evacuate immediately.

(a) Setting of Vibration Level Perceived by Human

First, the vibration level that humans can reliably perceive is examined.
The vibration unit is adjusted so that the vibration is propagated to a person's head with a frequency band of 20 to 80 Hz, which is the vibration frequency range that is easily perceived by humans. This level is selected referring to the frequency weighting factors described in "Vertical head vibration in supine position" of JIS B 7760-1 Whole-body vibration, which indicates that a vibration frequency of 8 Hz or less, or 80 Hz or more results in reduced human perception at the same acceleration due to the significant negative weighting applied to the frequency. Additionally, the level is selected referring to the Body Acoustic Laboratory describing that the range of 20 to 150 Hz is an "effective frequency band for Body Sonic (sensory acoustic system)".
The vibration is adjusted to be propagated through a helmet to a person's head with a vibration acceleration in the range of 5 to 42.4 m/s².
The lower limit is set such that the helmet wearer who is engaged with an operation involving strong vibrations can distinguish and recognize the vibration for emergency evacuation from these strong vibrations. The lower limit is set to a vibration acceleration of 5 m/s², which is recognizable even when a person is exposed to whole-body vibrations with the maximum vibration acceleration of 3.46 m/s² (10 minutes/day) defined in the "Standard for permissible whole-body vibration" stipulated by the Research Society of Vibration Syndrome. An impact for a short duration, such as 5 to 10 seconds per impact, is outside the application scope of the "Standard for permissible whole-body vibration". As such, a short impact having a vibration acceleration higher than the maximum vibration acceleration is considered as harmless.
The upper limit is set to a value that does not impose vibration-induced disorder to the helmet wearer who receives a vibration for emergency evacuation. The exposure action value for the amount of vibration exposure per day (daily vibration exposure) specified in "For prevention of vibration-induced disorders" by the Ministry of Health, Labor and Welfare is 2.5 m/s². The estimated daily usage hour of the emergency evacuation alert device of the present application is 0.028 hr (10 seconds per use × 10 times). Based on these values, the vibration acceleration of 42.4 m/s² calculated by the expression below is used as the upper limit. $\begin{array}{l} E xpression : D aily vibration exposure A (8) = α \times \sqrt{T / 8 (m / s^{2})} \\ α : vibration acceleration, T : viration eposure duration per day \end{array}$
In the range described above, the vibration accelerations 7.9 m/s², 9.1 m/s², and 12.0 m/s² were subjected to sensory evaluations with a panel of eight to ten people. The panel was asked to rate the intensity of the vibration of each acceleration on four scales, 1: imperceptible, 2: weak, 3: neither weak nor strong, and 4: strong. The average rate was 2.75 for 7.9 m/s², 3.1 for 9.1 m/s², 3.7 for 12.0 m/s², and the panel commented that a slightly stronger vibration would be more appropriate. As such, the target range of the vibration acceleration on the head of the helmet wearer is set to the range of 12 m/s² or more.

(b) Design of Vibration Unit

The vibration unit was then studied to set the vibration acceleration on the head of the helmet wearer in the range described above. The vibration unit was evaluated specifically taking into account that the vibration of the vibration unit is dampened considerably before it propagates to the wearer's head.

[Table 1]

			Prototype 1	Prototype 2	Prototype 3
Vibrator product name (manufactured by Tokyo Parts Industrial Co., Ltd.)			PM01K	PM11K	Improved PM11K
Vibrating element	Shape		Semicircle	Semicircle	Semicircle
	Radius [mm]		10.5	6.0	10.0
	Weight[g]		13.00	6. 25	7. 80
	Center of gravity [mm]		4. 20	3. 18	3. 93
Motor	Weight[g]		46.5	10.3	10. 3
Vibration capability	Frequency [Hz]		56. 30	64. 40	81. 25
	Amplitude [mm]	X-axis	0. 246	0.132	0. 166
		Y-axis	0. 266	0.125	0. 185
		Z-axis	0. 014	0. 010	0.120
	Acceleration [m/s²]	X-axis	30. 80	21.60	43. 39
		Y-axis	33. 30	20. 50	48. 31
		Z-axis	1.80	1. 60	31.40
		Triaxial total acceleration	45. 40	29. 80	72. 10

Note 1: With respect to the helmet wearer, the X-axis extends in the front-rear direction, the Y-axis extends in the left-right direction, and the Z-axis extends in the up-down direction.
Note 2: The triaxial total acceleration is obtained by combining the values along the three axes X, Y, and Z by the following expression.

E xpression : T riaxial total acceleration = \sqrt{{(X - axis)}^{2} - {(Y - axis)}^{2} + {(Z - axis)}^{2}}

Prototype 1 had the vibration capability sufficient for the helmet wearer to perceive the emergency alert on the head. However, Prototype 1 was determined to be too heavy.
With Prototype 2, the vibration acceleration perceived by the helmet wearer was expected to be about 12 m/s². Prototype 2 is therefore usable. However, since an emergency alert may require a higher vibration capability, the vibration acceleration expected to be perceived by the helmet wearer was increased to about 24 m/s² by slightly increasing the weight and radius of the vibrating element and moving the center of gravity to the outer side. The vibration capability of such a value is considered to be suitable for the perception of the emergency alert by the helmet wearer. The normal balance of the motor 16 and the vibrating element 17 is disturbed by the modification. Also, the modified design is specific to the emergency evacuation alert device mountable on a helmet and has a slightly shorter service life. However, this will not cause any problems because the device is used for a short time in an emergency.

(c) Vibrating Element

As shown in Fig. 3, the vibrating element 17 is fixed to the rotation shaft of the motor 16. As shown in the top view in Fig. 3, the vibrating element 17 has the shape of a semicircle substantially corresponding to a half of a circle having the rotation shaft of the motor 16 in its center. Thus, the vibrating element 17 is fixed to the rotation shaft of the motor 16 that is eccentric to the center of gravity of the vibrating element 17. When the motor 16 rotates the vibrating element 17, the center of gravity of the vibrating element 17 moves around the rotation shaft of the motor 16, thereby vibrating the housing 2. Further, as shown in the front view in Fig. 3, the vibrating element 17 is arranged above the center in the up-down direction of the housing 2. Consequently, the rotation of the vibrating element 17 vibrates the housing 2 as described below.
Fig. 5 is a diagram showing states of the emergency evacuation alert device 1 in which the motor 16 is activated. As described above, the vibrating element 17 is arranged above the center of the housing 2 in the up-down direction. Accordingly, when the motor 16 is activated and rotates the center of gravity of the vibrating element 17 around the rotation shaft of the motor 16, a force is created in a position within the housing 2 that is above the center of the housing 2. This force moves the housing 2 back and forth and left and right. The housing 2 is fixed to the surface of the helmet by the support portions 3 and 4. In other words, the housing 2 is substantially fixed with the fixing belt (fixing band) 18, which extends through the central sections in the right and left ends of the front surface of the housing 2, in contact with the surface 23. The other sections of the housing 2 are not supported. As a result, the housing 2 is fixed to the surface of the helmet such that slight expansion and contraction of the fixing belt (fixing band) 18, which is inserted in the fixing belt holes 11 and 12 of the support portions 3 and 4, respectively, permit the housing 2 to slightly rotate around the axis connecting the support portions 3 and 4. The support portions 3 and 4 and the fixing belt (fixing band) 18 limit rotational movements of the housing 2 around an axis in the front-rear direction and an axis in the up-down direction. However, slight rotational movements of the housing 2 are permitted around an axis in the left-right direction. When the motor 16 is activated, the housing 2 is therefore repeatedly positioned in "State 1" and "State 2" shown in Fig. 5. In other words, the activation of the motor 16 creates rotational oscillation of the housing 2 around an axis in the left-right direction.
When the housing 2 is fixed to the helmet 21 and viewed facing the helmet surface 23, the vibrating element 17 is disposed in an area that is not located between the sections of the fixing belt (fixing band) 18 that are joined to the support portions 3 and 4. That is, the vibrating element 17 of the emergency evacuation alert device 1 may be placed at a position in the housing 2 that is near the upper edge of the housing 2 or near the lower edge of the housing 2. When the vibrating element 17 is located at such a position in the housing 2, the rotational vibration of the housing 2 around an axis in the left-right direction caused by the rotating vibrating element 17 is less likely to be limited as compared to the embodiment described above. The vibration is thus effectively transmitted to the wearer's head.
Nevertheless, the vibrating element 17 may be placed in an area located between the sections of the fixing belt (fixing band) 18 that are joined to the support portion 3 and the support portion 4.

(2) Housing

The housing 2 enclosing the vibration unit is substantially shaped as a rounded rectangular prism. The housing 2 includes the support portions 3 and 4 at the left and right ends of the front surface that faces the helmet. When the housing 2 is mounted on a helmet, the support portions 3 and 4 are disposed between the surface of the helmet and the housing 2, and there is a gap between the other section of the front surface and the helmet surface. Further, the support portions 3 and 4 include the fixing belt holes 11 and 12, which receive the fixing band 18 that is to be wrapped around the helmet for fixing. The support portions 3 and 4 and the fixing belt holes 11 and 12 may each have any length between the upper and lower edges of the housing 2, as long as the length has its midpoint in the central section in the corresponding end of the front surface of the housing 2. The support portions 3 and 4 at the left and right ends of the housing 2 are supported at two positions on the surface of the helmet by the fixing belt 18, which is inserted in the fixing belt holes 11 and 12.
The joining of the housing 2, which includes the vibration unit, to a helmet shell is the most important issue in propagating the vibration of the emergency evacuation alert device 1 to be mounted on the helmet to the worker's head without damping. The results of Experiments 1 and 2 in evaluation tests, which are described below, show that the two-point joining described above propagates the vibration with the lowest degree of damping of the vibration capability of the vibration unit. Also, except for the method that brings the entire surface of the housing 2 into contact with the helmet, the methods of bringing the housing 2 partially into contact with the helmet, such as the one-point joining, three-point joining, and four-point joining, are verified to be usable.
In this embodiment, the emergency evacuation alert device 1 is supported (joined) at two positions on the helmet shell. In this emergency evacuation alert device 1, the support portions 3 and 4 are disposed between the housing 2 and the surface of the helmet. Additionally, the emergency evacuation alert device 1 is fixed to the helmet by an elastic body (the fixing belt 18). Since the elastic body is elastically deformed under a force, the two support portions 3 and 4 (the first and second support portions) substantially determine the positional relationship between the helmet and the emergency evacuation alert device 1. Since the first and second support portions support the emergency evacuation alert device 1 at two positions on the helmet surface, the slight rotational movement around the axis connecting these two positions is more likely to be permitted as compared to a configuration in which the vibration unit is supported at three or more positions, although it depends on the structure of the first and second support portions and the structure of the elastic body. That is, the emergency evacuation alert device 1 described above is permitted to move slightly relative to the helmet. Thus, when the vibration unit vibrates, the emergency evacuation alert device 1 vibrates with a higher amplitude than a device that is supported at three or more positions on the helmet surface. A higher amplitude of the emergency evacuation alert device 1 increases the amplitude of the helmet that receives the vibration of the emergency evacuation alert device 1 through the first and second support portions. A higher amplitude of the helmet increases the vibration transmitted to the head of the helmet wearer from the vibration unit. Thus, the vibrating device described above effectively transmits its vibration to the wearer's head through the helmet.

(3) Fixing Band

The fixing band 18, which is an elastic body, is inserted in the fixing belt holes 11 and 12 in the support portions 3 and 4 of the housing 2 to fix the emergency evacuation alert device 1 to the helmet. The fixing band 18 used in this embodiment is a silicone band that is manufactured by Kontec Co., Ltd. and has a width of 25 mm and a thickness of 2 mm. This band is verified to have a tensile strength of 20 kgf or more using a force gauge manufactured by IMADA Co., Ltd. However, any rubber band with an equivalent elasticity may also be used. The fixing band 18 is folded back at the fixing belt holes 11 and 12 and fastened by ABS buckles 19 and 20. The fixing band 18 is wrapped around the surface of the helmet to fix the emergency evacuation alert device 1. When the emergency evacuation alert device 1 is thus fixed to the elastic body, which can undergo a sufficient degree of expansion and contraction, the vibration of the emergency evacuation alert device 1 is less likely to be restricted. This achieves the effective transmission of the vibration of the vibration portion to the worker's head.
As described above, the fixing band 18 is inserted in the fixing belt holes 11 and 12 provided in the support portions 3 and 4 and folded back. The fixing band 18 is joined to the housing 2 of the vibration portion and the helmet shell surface along its width and thus supports the emergency evacuation alert device 1 at the two positions on the left and right. According to Experiment 5 described below, the fixing band 3 and 4 may have any width between 10 to 50 mm. The fixing band holes 11 and 12 in the support portions 3 and 4 of the housing 2 have a width that is suited to receive the fixing band 18 with a chosen width such that the fixing band 18 is positioned at the center of each side of the housing 2.
The emergency evacuation alert device 1 of the present embodiment is fixed to the occipital section of a helmet. Thus, the load caused by the weight of the emergency evacuation alert device 1 acts to tilt the helmet in the direction from the frontal section to the occipital section of the helmet, thereby reducing the possibility that the helmet interferes with the wearer's view. According to the results of Experiment 3 described below, the vibration acceleration is almost the same on the frontal section and the occipital section, and lower on the temporal section.

(4) Control Unit

The control unit (control circuit) 13 shown in Fig. 3 is an electronic circuit board that controls all operations of the emergency evacuation alert device 1. When the antenna 10 receives an alert signal, the control unit 13 drives the vibration unit. In the present embodiment, when an alert signal is received, the vibration continues for about 5 to 7 seconds. When the transmitter 31 sends an alert signal continuously, the present embodiment remains vibrating until the alert signal stops. The wearer cannot stop this vibration.
Further, the control unit 13 controls the following functions in response to operations on the operation unit 5. To avoid interference, the control unit 13 functions to perform pairing so as to issue an alert only for an alert signal sent from a specific transmitter 31. In addition, the control unit 13 turns the power on and off and check the remaining power.

(5) Operation Unit and Antenna

The operation unit 5 shown in Fig. 2 includes the power button 7 and the battery check button 6. Further, there are the pairing LED 8 and the power LED 9.
When the power button 7 is held down for two seconds or longer, the emergency evacuation alert device 1 is turned on. Given the working hours of a day, the power LED 9 turns green when the emergency evacuation alert device 1 is usable for 10 hours or longer. As the remaining usable time becomes shorter, the wearer is informed with the blinking of the power LED 9 and a buzzer on four levels.
The battery check button 6 and the power button 7 are used for pairing with a transmitter 31 before enabling the use of the emergency evacuation alert device 1. The completion of pairing is checked with the orange pairing LED 8. To enable use, the emergency evacuation alert device 1 is restarted after completing the pairing.
The antenna 10 shown in Fig. 2 uses the 920 MHz band, which is allocated for specified low-power radio stations, and is a wire having a length of about 8 cm accordingly. The antenna 10 projects from the housing 2 by about 6 cm to increase the sensitivity. The projecting section is covered with ethylene propylene diene rubber (EPDM rubber) to resist breaking.

(6) Power Supply Unit

The power supply units (batteries) 14 and 15 shown in Fig. 3 use two AA-size nickel metal hydride rechargeable batteries as the power source. The run time of the battery is about 15 hours. This is sufficient as the power source considering the power consumption of the emergency evacuation alert device 1. A lithium-ion rechargeable battery can also be used, but its large electric capacity poses difficulties in handling. Factors such as an external impact, any issues in charging and discharging conditions, and severe environments may cause an accident, such as ignition or explosion. For this reason, a lithium-ion battery may be unsafe for the helmet 21, which is likely to receive external impacts. Nickel metal hydride rechargeable batteries are therefore used. Further, the power supply units 14 and 15 do not have to be in the housing 2 and may be formed separately.

The emergency evacuation alert device 1 to be mounted on a helmet ensures that the worker recognizes an emergency evacuation alert by its vibration even under a variety of bad conditions. Further, a system is required that reliably transmits information on imminent danger to the emergency evacuation alert device 1. The emergency evacuation alert system of the present embodiment includes a transmitter 31, which sends an alert signal wirelessly from a person or a sensor that has sensed an imminent danger, and the reception function of the emergency evacuation alert device 1 that reliably receives the alert signal. The system may also include a repeater when there is an obstacle in between. In this system, the selection of wireless communication and the actual setting of the system by pairing are important.

(1) Wireless Communication

The emergency evacuation alert system of the present embodiment uses the 920 MHz band allocated for specified low-power radio stations. A band for specified low-power radio stations is used because it is available to all workers without requiring a license. Among the four frequency bands allocated for specified low-power radio stations, the 920 MHz band is selected in consideration of factors including the communication distance, downsizing of devices, and the amount of data that can be transmitted. The system of the present application is designed for work on highways and therefore uses a wireless module with an output of 10 mW in the 920 MHz band. The communication distance is about 7 km. When a longer communication distance is required for other operations, an output of 20 mW will increase the communication distance by about 1.4 times. However, this distance may be achievable only under optimum conditions without obstacles or factors that absorb or diffuse the radio waves, such as rain, snow, or fog, around the wireless module. In the system of the present application, the main body of the wireless module is housed in the housing 2, with other components including the control circuits 13, mechanical parts, and the power supply batteries 14 and 15 placed around the wireless module, and the antenna 10 is encased in resin. Such conditions may shorten the wireless transmission/reception distance. The upper limit of the communication distance of the system of the present application is set to about 300 m with a margin of safety because the system may be used in a life-threatening situation. In theory, the 920 MHz band allows the antenna to have a length of about 8 cm (1/4 of the wavelength), which is advantageous in terms of downsizing of the device. The 920 MHz band has a wide usable frequency bandwidth (13.8 MHz) allowing for transmission of a larger amount of data. Data of up to 64 bits per unit can be transmitted at a rate of 1250 bits per second. Although the system of the present application does not use a large amount of data, a larger capacity is advantageous when the system is used with various functions.

(2) Pairing Function

Before the operation, the emergency evacuation alert system of the present application is set by combining multiple emergency evacuation alert devices 1 and transmitters 31 according to the specific conditions of the worksite. That is, a process of pairing between emergency evacuation alert devices 1 and transmitters 31 is performed.
In the present embodiment, up to 64 transmitters 31 can send an alert signal from a person or sensor that has sensed danger to each worker who has an emergency evacuation alert device 1 on the helmet. There is no limit to the number of emergency evacuation alert devices 1 that receive an alert signal simultaneously (the number of workers who receive the alert signal). Various systems may be constructed by combining these devices according to the situation at the worksite.
Under the existing conditions, the system of the present application is believed to avoid interference with other groups. Each transmitter 31 is assigned with a 16-bit identification number (one of 65,536 combinations), which is stored on the emergency evacuation alert device 1. The transmitter 31 sends its identification number, a given 8-bit node number, and an alert code (four characters). The receiver that receives an alert radio wave from a transmitter 31 compares the stored identification number with the identification number in the received radio wave and starts vibration to give an alert only when the numbers match. There are 65,536 combinations for identification numbers, and the alert code is unique, minimizing the possibility of interference.
The pairing of an emergency evacuation alert device 1 and a transmitter 31 is registered with the emergency evacuation alert device 1 before use. First, before turning on the power, the battery check button 6 and then the power button 7 of the operation unit 5 are held down to enter the pairing setting mode. In this mode, the transmitter 31 to be registered sends an alert signal to the emergency evacuation alert device 1, thereby completing the registration of the transmitter 31 to the emergency evacuation alert device 1. To cancel the registration, the emergency evacuation alert device 1 is returned to the pairing mode, and the battery check button 6 is held down. Completion of registration can be recognized with the orange pairing LED 8 lighting up.
The pairing setting mode ends when the power is turned off. The emergency evacuation alert system becomes usable when the power is turned on again. Once registered, the pairing remains until canceled. However, the emergency evacuation alert device 1 does not display whether the registration of pairing has been performed. As such, after registration, the emergency evacuation alert device 1 needs to be checked at least once whether it vibrates.

(3) Transmitter

Fig. 6 shows a transmitter 31 that transmits an alert signal to emergency evacuation alert devices 1 attached to workers when an emergency occurs. The present embodiment uses a manual button transmitter.
The manual button transmitter is a device that is manually operated to send an alert signal by an administrator (supervisor) who has visually recognized an emergency. Fig. 6 shows its external appearance. The front surface of the housing includes an emergency button 35 and a battery check button 36, which serve as an operation unit. The housing 32 has fixing belt holes 33 and 34 in the sides and a clip on the back surface, and is thus attachable to an upper arm or a pocket of a worker.
Pressing the emergency button 35 will send an alert signal from the transmission antenna 38 provided on the top of the housing 32. A short push on the emergency button 35 causes immediate activation and transmission of an alert signal. A green transmission LED 37 above the emergency button illuminates and a buzzer sounds while the emergency button 35 is held down, indicating the successful transmission of the signal. The other operation buttons of the present system require being held down to activate.
Two AA nickel metal hydride rechargeable batteries are used as the power source, and the batteries can be used for about 168 hours on a single charge. The system does not have a power button and automatically starts to operate when rechargeable batteries are set. To check the remaining capacity of the battery, the battery check button is pressed to illuminate the green transmission LED 37 and sound the buzzer. When the remaining usage time becomes less than 10 hours, the transmission LED 37 automatically blinks and the buzzer sounds to ensure that the user recognizes the low charge state.
Additionally, the transmitter 31 may automatically send an alert signal when a sensor detects an abnormality. The sensor may be a fall sensor or an impact sensor (an acceleration sensor).

(4) Repeater

A repeater may be arranged to pass on an alert signal from the transmitter 31 to the emergency evacuation alert device 1. The communication distance of the system of the present application is set to 300 m. A repeater is used to accommodate a longer distance or to ensure the transmission of an alert signal when there is a concrete wall or other obstacles that may hinder the communication.
The repeater includes a reception unit, which receives radio waves, a transmission unit, which sends radio waves, and a power supply unit. When receiving a radio wave, the repeater generates a radio wave of the same specifications to relay the radio wave of the transmitter 31. The information sent by the repeater includes the identification number of the transmitter 31, eliminating the need for cancellation or change of the pairing registration between the transmitter 31 and the emergency evacuation alert device 1.
Repeaters may be arranged according to the specific worksite environments, and may be connected by wire if necessary. Repeaters are particularly advantageous for communication across multiple floors in a building with considerable interference and large operation areas.

(5) Example of Immediate Evacuation Achieved with Emergency Evacuation Alert System

The system of the present application aims to protect the life of an operation participant 102 who is in an operation area in imminent danger by prompting the operation participant 102 to evacuate immediately.
The operation participant 102 is a concept including workers 104 who work in the operation area, supervisors 103 who supervise the workers, guards 105 who are positioned in the operation area, visitors who visit the operation area, and others who enter the operation area. The participant in the operation area is a concept including people who are present around the operation area and is not limited to the people within the operation area where the entry of unauthorized people and vehicles is restricted by construction barricades, for example. When the operation area is exposed to imminent danger, the system of the present application prompts the participants to evacuate immediately. The system thus minimizes fatal or injury accidents, which would otherwise occur due to a momentary delay, such as a one-second delay, of escaping, and therefore contributes to the important social mission of protecting the safety of life. An example of immediate evacuation achieved with the emergency evacuation alert system in a dangerous operation on a highway is described below.
Fig. 7 is a diagram showing an example of an operation area. For example, in an operation area of road construction, operation participants including a supervisor 103, workers 104, and a guard 105 work inside and outside the operation area. Typically, for such an operation area, pylons 106 and arrow signboards 107 may block the entry of unauthorized people or vehicles. However, on rare occasions, a driver of a passing vehicle may accidentally maneuver the vehicle into a restricted operation area. To avoid such an accident, construction signboards, revolving lights, guide lights, and a vehicle with cautionary signs, for example, are usually placed at the entrance of the restricted zone. Nevertheless, various factors, including low visibility due to dense fog and drowsy driving of an overtired driver, prevent complete elimination of accidental entry of a vehicle into an operation area.
Fig. 8 is a diagram showing the first example of immediate evacuation that can be achieved with the system of the present application. The supervisor carries a transmitter 31, and each worker in the operation area has an emergency evacuation alert device 1 mounted on the helmet. In this example, the supervisor notices a vehicle accidentally entering the operation area and presses the emergency button 35 of the transmitter 31, causing the emergency evacuation alert devices 1 of the workers to vibrate and oscillate the helmets. Upon recognition of imminent danger in the operation area by the oscillation of the helmets, the workers 104 immediately evacuate to protect themselves. This allows the workers 104 to dodge the vehicle accidentally entering the operation area, avoiding contact with the vehicle.
Fig. 9 is a diagram showing the second example of immediate evacuation that can be achieved with the system of the present application. In addition to the transmitter 31 described above, the configuration of the system of the present application may include, as transmitters 31 for issuing an alert signal, transmitters with built-in sensors for detecting a fall or impact, for example. These transmitters with built-in sensors may be attached to pylons 106 and arrow signboards 107. As shown in Fig. 9, when the sensor of a transmitter detects contact between a vehicle and the pylon 106 or the arrow signboard 107, the transmitter sends an alert signal, thereby vibrating the emergency evacuation alert devices 1 on the workers 104 in the operation area and thus oscillating their helmets. With the configuration of the system of the present application that includes such transmitters with built-in sensors, a transmitter with a built-in sensor can send an alert signal before a person carrying a transmitter 31 presses the alert button 35 of the transmitter 31. This allows the workers to evacuate earlier.
The system of the present application is not limited to the operation area of road construction as described above. The system of the present application is applicable to various operation areas including a building construction site, a factory, a plant, a coastal area, a fire site, and a mountain area. The use of repeaters as described above allows the system to be used on disaster restoration sites, disaster monitoring bases, and construction and demolition sites of buildings in disastrous situations such as earthquakes, floods, and volcanic eruptions, where obstacles and poor visibility are expected. On these sites, the system can be used to issue evacuation alerts for additional damage (foreshock and expansion of the disaster) and secondary disasters, and to issue evacuation alerts in the event of a building fire or collapse. For underground sites and sites covering multiple floors, where radio wave transmission can be difficult, repeaters may be placed (e.g., by a window on each floor), or the repeaters may be partially supplemented with transmission wiring in between. These measures allow the system to be used at a variety of sites including construction sites of buildings (condominiums), tunnels, and subways, and work sites such as coal mines and underground lifelines.

The emergency evacuation alert device 1 is to be mounted on the helmet surface 23 of the shell of a helmet 21. To ensure that the worker recognizes an emergency evacuation alert by vibration, the greatest concern was how to transmit the vibration capability of the emergency evacuation alert device 1 to the person's head with minimum damping. For this reason, the following experiments were conducted. In these experiments, firstly, the vibration capability achieved by the device that is not mounted on the helmet 21 was measured at the center of the housing (measurement point A). Then, the vibration capability was measured at the center of the housing of the emergency evacuation alert device 1 when the helmet 21 is mounted on a human head model M as shown in Fig. 4 (measurement point B). Lastly, the vibration capability was measured at the suspension leg joint section of the helmet 21 mounted on the human head model M (measurement point C). The vibrations were thus measured at three measurement points. A clearance of 40 to 45 mm typically separates the suspension leg joint section from the helmet top, and the suspension is in direct contact with the head. As such, the vibration at the measurement point C may be considered as the vibration that is directly perceived by the worker on the head. The measurement factors were frequency, amplitude, and acceleration, and these factors were measured in the front-rear direction (X-axis), the left-right direction (Y-axis), and the up-down direction (Z-axis) for the helmet wearer. Then, the triaxial total acceleration was calculated. For the measurement points B and C, the experiments were performed with the helmet shell, shock-absorbing liner, suspension, headband, ear straps, and chin strap of the helmet 21 actually mounted on the human head model. The experiments described below evaluated five types of methods for joining the vibrating device to the helmet shell. Of these methods, the whole-surface joining used a rubber sheet to bring the entire surface into contact with the helmet shell, and the one-point joining, three-point joining, and four-point joining used small pieces arranged between the surface and the helmet shell. The two-point joining used the fixing belt 18 mounted on the

support portions

3 and 4 of the housing 2. The following four helmets manufactured by Midori Anzen Co., Ltd. were used.

[Table 2]

Helmet model	A: SC-12PCL	B: SC-13PCL	C: SC-MPC	D: SC-13PCLV
Shell shape	With brim	With brim	Without brim	With brim
Shock-absorbing liner	KP (for SC-11)	KP (for SC-13PCLV)	KP (for SC-11)	KP (for SC-13PCLV)
Suspension	Eight resin bands	Four resin bands	Eight resin bands	Four -point tape
Headband	Dial-fit	Ratchet adjuster band	Ratchet adjuster band	Ratchet adjuster band
Mass	430 g	430 g	370 g	440 g

(1) Experiment 1

This experiment was conducted to evaluate the methods for joining the emergency evacuation alert device 1 to the helmet shell and how the vibrations are transmitted to the human head. The evaluated joining methods include joining of the entire surface of the vibrating device to the helmet shell, joining at four positions, and joining at two positions. The vibrating element used was Prototype 2, and the helmet was A:SC-12PCL. The mounting position was the occipital section, the vibration measurement positions were the measurement points A and C, and the width of the fixing belt 18 was 25 mm.

Table 3 shows the results of Experiment 1.

[Table 3]

Joining to helmet		Not mounted	Whole-surface joining		Four-point joining		Two-point joining
Measurement point		A	C		C		C
		Measurement value	Measurement value	Variation [%]	Measurement value	Variation [%]	Measurement value	Variation [%]
Frequency [Hz]	X-axis	64.4	58. 1	-10%	64. 0	-1%	46. 3	-28%
	Y-axis	64. 4	58. 1	-10%	64. 0	-1%	46. 3	-28%
	Z-axis	64.4	58. 1	-10%	64. 0	-1%	46. 3	-28%
Amplitude [mm]	X-axis	0. 132	0. 056	-58%	0. 056	-58%	0. 141	7%
	Y-axis	0. 125	0. 039	-69%	0.05	-60%	0. 035	-72%
	Z-axis	0.010	0. 007	-30%	0. 011	10%	0.034	240%
Acceleration [m/s²]	X-axis	21. 613	7. 463	-65%	9. 055	-58%	11.933	-45%
	Y-axis	20. 466	5. 197	-75%	8. 085	-60%	2. 962	-86%
	Z-axis	1. 637	0. 933	-43%	1. 779	9%	2. 877	76%
	Triaxial total acceleration	29.81	9.140	-69%	12.270	-59%	12.630	-58%

The results of this experiment show that the vibration capability of the emergency evacuation alert device 1 was considerably damped before reaching the human head model through the helmet 21. Of the joining methods, the whole-surface joining suffered the highest damping. With the vibration capability of Prototype 2 used in this experiment, the target triaxial total acceleration of 12 m/s² was barely achieved with the four-point joining and the two-point joining. Table 3 shows that the four-point joining and two-point joining met the target triaxial total acceleration of 12 m/s², but the whole-surface joining failed to achieve the target.
The experiment is now examined in detail. As for the frequencies along the three axes (X, Y, and Z) measured with a sensor at the measurement point C, the percentages of change between the frequencies at the measurement point A and the frequencies with the four-point joining were about -1%. The percentages of change between the frequencies at the measurement point A and the frequencies with the whole-surface joining were about -15%. The percentages of change between the frequencies at the measurement point A and the frequencies with the two-point joining were about -30%. The experiment demonstrates that the two-point joining tends to lower the frequencies as compared to the four-point joining and the whole-surface joining.
As for the amplitudes along the Y-axis among the three axes measured with the sensor at the measurement point C, the percentages of change between the amplitude at the measurement point A and the amplitudes with the two-point joining, the four-point joining, and the whole-surface joining were about -60% to -70%. The experiment demonstrates that the two-point joining, four-point joining, and whole-surface joining tend to significantly lower the amplitude in the Y-axis direction from the amplitude at the measurement point A. It is assumed that this reduction occurred because the vibration in the Y-axis direction created by the emergency evacuation alert device 1, which is mounted on the occipital section of the helmet 21, was converted into the rotational movement of the helmet 21 around the center axis in the up-down direction of the human head model M. In other words, the vibration was converted into the movement that oscillates the helmet 21 in the left-right rotational direction, and therefore did not create vibrations that move the helmet 21 in the Y-axis direction.
As for the amplitudes along the X-axis among the three axes measured with the sensor at the measurement point C, the percentages of change between the amplitude at the measurement point A and the amplitudes with the four-point joining and the whole-surface joining were about -60%. In contrast, the variation (%) between the amplitude in the X-axis direction at the measurement point A and the amplitude with the two-point joining of the embodiment described above was about +7%. The experiment demonstrates that the four-point joining and the whole-surface joining tend to dampen the amplitude in the X-axis direction, whereas the two-point joining of the present embodiment tends to amplify the amplitude in the X-axis direction.
As for the amplitudes along the Z-axis among the three axes measured with the sensor at the measurement point C, no remarkable tendency was identified since the motor 16 in the emergency evacuation alert device 1 has a rotation shaft extending in the Z-axis direction.
The evaluation results show that the two-point joining applied a higher amplitude in the X-axis direction to the human head model M than the four-point joining and the whole-surface joining. This is because the two-point joining facilitates the movement of the vibrating device relative to the helmet as compared to the four-point joining and the whole-surface joining, and the vibration of the emergency evacuation alert device 1 is not restricted. The evaluation results show that the two-point joining effectively transmits vibrations to the user's head through the helmet 21.

(2) Experiment 2

As with Experiment 1, this experiment was conducted to evaluate methods for joining the emergency evacuation alert device 1 to the helmet shell 23 and how the vibrations are transmitted to the human head. For evaluation, the emergency evacuation alert device 1 was joined to the helmet shell 23 at one to four positions. The vibrating element used was Prototype 3, which is an improved version of Prototype 2 and has a higher vibration capability, and the helmet was B:SC-13PCL. The mounting position was the occipital section, the vibration measurement positions were the measurement points A, B, and C, and the width of the fixing belt 18 was 25 mm.

Table 4 shows the results of Experiment 2.

[Table 4]

Joining to helmet		Not mounted	One-point joining		Two-point joining
Measurement point		A	B	C	B	C
Frequency [Hz]	X-axis	81.250	45.000	45.000	50.000	50.000
	Y-axis	81.250	43.750	43.750	50.000	50.000
	Z-axis	81.250	44.375	44.375	50.625	50.625
Acceleration [m/s²]	X-axis	43.390	11.790	17.020	16.700	22.170
	Y-axis	48.310	5.100	4.316	9.205	2.202
	Z-axis	31.400	15.690	6.341	21.460	5.600
	Triaxial total acceleration	72.100	20.300	18.700	28.700	23.000

Joining to helmet		Not mounted	Three-point joining		Four-point joining
Measurement point		A	B	C	B	C
Frequency [Hz]	X-axis	81.250	69.375	69.375	69.375	69.375
	Y-axis	81.250	70.000	70.000	70.000	70.000
	Z-axis	81.250	70.000	70.000	71.875	71.875
Acceleration [m/s²]	X-axis	43.390	7.234	9.230	10.390	8.058
	Y-axis	48.310	13.910	7.029	19.530	9.384
	Z-axis	31.400	9.300	6.398	4.612	4.767
	Triaxial total acceleration	72.100	18.200	13.200	22.600	13.300

The results of the experiment show that, as for the triaxial total accelerations measured at the measurement position of the suspension leg joint section, the acceleration was the largest with the two-point joining and 23 m/s², followed by 18.7 m/s² with the one-point joining. The accelerations were about 13 m/s² with the three-point joining and four-point joining, indicating the greatest degree of damping. Nevertheless, all the values are at least 12 m/s², which is the lowest level set in the present application. The triaxial total accelerations at the measurement point B were larger than those at the measurement point C.

(3) Experiment 3

This experiment was conducted to compare the vibration capabilities obtained when the emergency evacuation alert device 1 of Prototype 3 was mounted on the helmet 21 with the two-point joining in the frontal section, occipital section, and temporal section of the helmet. The helmet used was B:SC-13PCL, the vibration measurement positions were the measurement points A, B, and C, and the width of the fixing belt 18 was 25 mm.

Table 5 shows the results of Experiment 3.

[Table 5]

Mounting position on helmet		Not mounted	Occipital section		Frontal section		Temporal section
Measurement point		A	B	C	B	C	B	C
Frequency [Hz]	X-axis	81.250	50.000	50.000	56.250	56.250	56.875	56.875
	Y-axis	81.250	50.000	50.000	55.625	55.625	56.875	56.875
	Z-axis	81.250	50.625	50.625	56.875	56.875	58.125	58.125
Acceleration [m/s²]	X-axis	43.390	16.700	22.170	18.690	20.230	11.640	10.300
	Y-axis	48.310	9.205	2.202	11.880	9.481	17.680	11.970
	Z-axis	31.400	21.460	5.600	22.350	8.068	23.890	3.128
	Triaxial total acceleration	72.100	28.700	23.000	31.500	23.800	31.900	16.100

The results of this experiment show that high triaxial total accelerations of about 23 m/s² were measured at the measurement point C when the device was mounted on the frontal section and the occipital section. In contrast, the triaxial total acceleration was low and 16 m/s² when the device was in the temporal section. At any position, the acceleration was greater than the target of 12 m/s² of the present application.
However, with overall consideration given to factors, such as the handling and the weight balance of the helmet to which the vibration unit is mounted, the effect of the vibration on the wearer's visual field when the vibration unit is mounted on the frontal section, and the effect of the vibration on the wearer's semicircular canal when the vibration unit is mounted on the temporal section, the occipital section of the helmet is considered to be an optimal position for mounting.

(4) Experiment 4

The device is to be mounted on a helmet 21 when an operation is performed under conditions that may require emergency evacuation. For this reason, this experiment is conducted to evaluate the vibration capability on four types of helmets to identify whether the device is usable with general helmets irrespective of their types. In this experiment, the vibrating device of Prototype 3 was mounted on the occipital section of the helmet 21 by the two-point joining, and the width of the fixing belt 18 was 25 mm.

Table 6 shows the results of Experiment 4.

[Table 6]

Helmet model		Not mounted	A: SC-12PCL		B: SC-13PCL		C: SC-MPC		D: SC-13PCLV
Measurement point		A	B	C	B	C	B	C	B	C
Frequency [Hz]	X-axis	81.250	58.125	58.125	50.000	50.000	60.000	60.000	64.375	64.375
	Y-axis	81.250	58.750	58.750	50.000	50.000	60.625	60.625	63.750	63.750
	Z-axis	81.250	58.750	58.750	50.625	50.625	61.250	61.250	64.375	64.375
Acceleration [m/s²]	X-axis	43.390	4.670	10.720	16.700	22.170	4.261	12.560	10.690	13.700
	Y-axis	48.310	6.269	12.560	9.205	2.202	9.767	16.130	13.920	16.100
	Z-axis	31.400	30.380	8.153	21.460	5.600	32.610	7.326	38.030	0.001
	Triaxial total acceleration	72.100	31.400	18.400	28.700	23.000	34.300	21.700	41.900	21.100

The results of this experiment show that, according to the triaxial total accelerations at the measurement point C, sufficient vibration capabilities were achieved with all four types of helmets. The four types of helmets varied in the shape of the shell, the engagement points between the suspension and the shell (four points and eight points), materials (resin and tape), the shock-absorbing liner, the shape of the headband, and the overall helmet weight. The experiment demonstrated that these helmets all transmitted the vibrations to the human head model.

(5) Experiment 5

When the emergency evacuation alert device 1 is joined to the helmet shell 23 at two positions, it is the fixing band 18 that is actually joined to the helmet shell. For this reason, this experiment was conducted to evaluate whether the width of the fixing band 18 affects the propagation of vibration. This experiment used the emergency evacuation alert device 1 of Prototype 3, which was mounted on the occipital section of the helmet B:SC-13PCL. The widths of the fixing belts 18 were 10 mm to 50 mm.
Table 7 shows the results of Experiment 5.
The results of this experiment show that, according to the triaxial total accelerations at the measurement point C, the vibrations of the vibration unit were sufficiently transmitted to the human head model, although the acceleration was slightly low with 10 mm. Of these widths, the 25 mm width is considered to be most suitable in consideration of the ease of mounting on the helmet and the balance with the housing of the vibration unit.

Reference Signs List

1: Emergency evacuation alert device
2: Housing
3: Support portion
4: Support portion
5: Operation unit
6: Battery check button
7: Power button
8: Pairing LED
9: Power LED
10: Antenna
11: Fixing belt hole
12: Fixing belt hole
13: Control circuit
14: Battery
15: Battery
16: Motor
17: Vibrating element
18: Fixing belt (fixing band)
19: Buckle
20: Buckle
21: Helmet
22: Brim
23: Helmet surface
31: Transmitter
32: Housing
33: Fixing belt hole
34: Fixing belt hole
35: Emergency button
36: Battery check button
37: Transmission LED
38: Antenna
39: Fixing belt (fixing band)
102: Operation participant
103: Supervisor
104: Worker
105: Guard
106: Pylon
107: Arrow signboard
M: Human head model

Claims

An emergency evacuation alert device for prompting a participant in an operation area to evacuate immediately, the device comprising:
a housing that is configured to vibrate by movement of a vibrating element installed in the housing;

an elastic fixing band for removably fixing the housing to a helmet of the participant, the fixing band extending from the housing in two directions and being configured to wrap around a surface of the helmet; and

a support portion configured to partially support the housing on the surface of the helmet such that the helmet oscillates together with the housing by vibration of the vibrating element that moves in response to a radio alert signal for alerting the participant of an imminent danger in the operation area.
The emergency evacuation alert device according to claim 1, wherein
the support portion is formed by a part of the fixing band.
The emergency evacuation alert device according to claim 1 or 2, wherein
the support portion includes a first support portion and a second support portion that are configured to be disposed between the surface of the helmet and the housing and support the housing at two positions on the surface of the helmet.
The emergency evacuation alert device according to claim 3, wherein
when the housing is fixed to the helmet and viewed facing the surface of the helmet, the vibrating element is disposed in an area that is between the first and second support portions and is not sandwiched by parts directly joined to the helmet shell.
The emergency evacuation alert device according to claim 3 or 4, wherein
the first support portion is disposed at a position where the fixing band extends from the housing in one direction, and
the second support portion is disposed at a position where the fixing band extends from the housing in another direction.
The emergency evacuation alert device according to any one of claims 1 to 5, wherein
the housing is configured to be fixed to an occipital section of the helmet.
The emergency evacuation alert device according to any one of claims 1 to 6, further comprising:
an antenna configured to receive a radio wave of the alert signal; and

a control unit configured to activate a motor for moving the vibrating element when the antenna receives the alert signal.
The emergency evacuation alert device according to claim 7, wherein
the control unit activates the motor for moving the vibrating element when identification information in the alert signal received by the antenna is identical with identification information that is registered to the control unit through pairing in advance.
The emergency evacuation alert device according to claim 7 or 8, further comprising
a power supply unit configured to supply electric power to the control unit.
The emergency evacuation alert device according to claim 9, further comprising:
a power button for creating a state in which the electric power of the power supply unit is supplied to the control unit; and

a battery check button for checking an amount of remaining battery charge of the power supply unit.
An emergency evacuation alert system comprising:
the emergency evacuation alert device according to any one of claims 1 to 10; and

a transmitter configured to wirelessly transmit the alert signal to the emergency evacuation alert device.
The emergency evacuation alert system according to claim 11, wherein
the transmitter is a device that is to be carried by a participant, the device sending an alert signal, and includes an alert button for wirelessly sending the alert signal.
The emergency evacuation alert system according to claim 11, wherein
the transmitter includes a sensor for detecting an occurrence of a dangerous situation and is configured to be attached to an installed object.
The emergency evacuation alert system according to any one of claims 11 to 13, further comprising:
a repeater configured to relay the alert signal wirelessly transmitted from the transmitter to the emergency evacuation alert device.