RU2772573C2 - Method for determining directions to exits from premises, corridors, vestibules by a firefighter located at a fire object in low visibility conditions by using a wearable non-linear radar included in the firefighter's equipment and parametric scatterers - Google Patents

Abstract

FIELD: fire extinguishing and rescue operations.

SUBSTANCE: invention relates to methods for improving the efficiency of activities and ensuring the safety of fire departments when extinguishing a fire and conducting rescue operations. The method for determining directions to exits from premises, corridors, vestibules by a firefighter located at a fire object in conditions of reduced visibility by using means of designating evacuation routes is characterized by the fact that a wearable non-linear radar, which is part of the firefighter's equipment, is used as a means of designating evacuation routes, and parametric diffusers are markers of two types, each of which is configured to operate at its own frequency, while the basis of the marker is a semiconductor diode. Markers of the first type are installed above exits from premises to common escape routes, in halls, corridors, lobbies or above windows that can be used for evacuation, markers of the second type are installed above exits from common escape routes to the outside, to a stairwell or to a safe area. Using a non-linear radar, markers are detected that are installed during the construction or operation of a building, or are installed when a firefighter moves deeper into the fire object to further search for the opposite direction, while semiconductor diodes lose their non-linear properties with increasing temperature, which ensures that the fireman chooses a direction that is different from the direction to the high temperature zone.

EFFECT: creation in conditions of limited visibility for the firefighter to directly find directions to the exits leading from the premises of the building to the general evacuation routes, and to find directions to the exits leading from these evacuation routes to the outside, to the stairwell or to another safe area; this excludes the choice of those outlets where the ambient temperature is more than 80-100°С, i.е. close to critical for finding a firefighter.

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Description

A method for determining directions to exits from premises, corridors, lobbies by a firefighter located at a fire object in low visibility conditions by using a wearable non-linear radar included in the firefighter's equipment and parametric scatterers.

The field of technology to which the invention belongs

The invention relates to systems for improving the efficiency of activities and ensuring the safety of fire departments when extinguishing a fire and conducting emergency rescue operations.

State of the art

The ability to confidently navigate in the space of the fire object in the absence of visibility in the smoke is one of the most important components of successful and safe fire suppression and rescue operations at the fire object. The very loss of orientation in the space of the fire object is a harbinger of more dangerous emergencies:

- blockage of structures damaged by fire (with a low fire resistance of structures and a protracted fire);

- depletion of the supply of air (oxygen) in the cylinder (cylinders) of personal respiratory protection (PPE) [Tactical methods of emergency reconnaissance and rescue when extinguishing fires. Educational and methodological manual on the discipline "Organization of fire extinguishing and training of fire and rescue garrisons" / A.N. Denisov, M.M. Danilov, O.I. Stepanov, E.E. Zaitseva - M. : Academy of the State Fire Service of the Ministry of Emergency Situations of Russia, 2020. - 53 p.].

Known specialized lighting equipment for orientation in a smoky space KVAZAR. Designed to indicate escape routes in a smoky or dark room (space) in the absence of other landmarks. It consists of a container with a control unit and coils with a luminous wire. Firefighters roll out the wire as they move deeper into the fire object. The luminous wire is visible in the smoke and serves as a guide for firefighters [https://www.peleng.info/product/quazar50, Tactics for emergency reconnaissance and rescue when fighting fires. Educational and methodological manual on the discipline "Organization of fire extinguishing and training of fire and rescue garrisons" / A.N. Denisov, M.M. Danilov, O.I. Stepanov, E.E. Zaitseva - M .: Academy of the State Fire Service of the Ministry of Emergency Situations of Russia, 2020. - 53 p.]. The difference from the invention is the need to be in close proximity to the luminous wire, the possible loss of orientation when visual contact is lost with it.

Known guide (travel) cable NT-GDZS - textile rope, consisting of an aramid core in a textile sheath with a total diameter of 5.0 mm, placed in a bag. The ends of the rope are closed in thimbles with carabiners. Rope length 50 meters. A thread with a fluorescent effect is woven along the entire length of the cable and beacons of a bright yellow-green color are installed.

Bag - a textile container that can be worn on the shoulder, belt or leg with fastening by means of belts. The bag is designed for laying and carrying the guide cable. The bag has an opening through which the cable, fixed at the security post, unhindered when the GDZS link moves, without interfering with movement. Inside the bag there is a loop for fixing the second end of the cable with a carabiner. On the front side of the bag there is a patch pocket for placing a set of keys for connecting additional guide cables NT-GDZS.

Carabiner - a connecting element for fixing the guide cable.

The beacon is a constructive elliptical thickening on the guide cable, made of plastic materials. Beacons are placed along the entire length of the guide cable in groups of 3 + 1, which facilitates orientation in conditions of limited visibility. Source: https://fireman.club/statyi-polzovateley/putevoy-tros-zvena-gdzs-naznachenie-i-description/. The difference from the invention is the need for direct contact with the rope, the limited movement associated with the length of the rope.

A firefighter orientation system is known based on the installation of radio buoys inside and around the fire object and equipping firefighters with communication devices and data transmission to these buoys with further processing of information in the control center in order to determine the location of firefighters in the local positioning system and in GPS systems [https://engineering .cmu.edu/news-events/magazine/fall-2017/tracking-firefighters-heat-smoke.html]. The difference from the invention is the impossibility of direct determination by the firefighter of the direction to the exit from the premises or from the building.

A known system for positioning firefighters based on the deployment of a local positioning system, consisting of a base station with radio equipment and receivers located at the firefighters. The system allows you to determine the location of a firefighter in the local positioning system [https://www.jpl.nasa.gov/news/pointer-seeing-through-walls-to-help-locate-firefighters]. The difference from the invention is the impossibility of direct determination by the firefighter of the direction to the exit from the premises or from the building.

The closest analogue of the invention is a specialized lighting equipment KVAZAR. The equipment has the following features, similar to the features of the invention: it serves as a means of indicating escape routes, directly, without the mediation of an operator of any system, provides the firefighter with information about finding the exit. The difference from the invention is the need to be close to the luminous cable, the limited length of the cable, the impossibility of detecting entrances to the premises from smoky lobbies and corridors to search for victims who may be present in them.

The invention expands the arsenal of technical means to increase the efficiency and ensure the safety of fire and rescue units when extinguishing fires and conducting emergency rescue operations.

The technical result is the creation in conditions of limited visibility of the possibility for the firefighter to directly find directions to the exits leading from the premises of the building to common escape routes (to corridors, lobbies, then - escape routes), and to find directions to the exits leading from these escape routes to the outside, to the stairwell or other safe area. This eliminates the choice of those outlets where the ambient temperature is more than 80-100°C, i.e. close to critical for finding a firefighter. The technical problem to be solved is the creation of landmarks and a means of searching for these landmarks in conditions of lack of visibility and at a distance exceeding the range of equipment based on guide cables and lighting devices, without the need to specify one's location in an external positioning system and without the need to maintain communication with other fire extinguishing participants .

Disclosure of the essence of the invention

The technical result is achieved by installing non-linear parametric scatterers of two types (hereinafter referred to as markers) in rooms and on escape routes and by a firefighter searching for them using a portable small-sized non-linear radar at his disposal.

In the absence of visibility, the direction to the exit leading to the evacuation route, or the correct direction of movement along the evacuation route, is detected by the signals of a non-linear radar having a narrow radiation pattern and a non-linear marker falls into the irradiation zone of which. The basis of the marker is a semiconductor diode. Semiconductor devices lose their non-linear properties as the temperature increases, therefore, under conditions of elevated temperature, the marker loses the properties of a non-linear parametric scatterer as such and ceases to be detected by a non-linear locator. Thus, the firefighter will not choose the path to the zone of high temperature.

Markers are set using one of the following methods or a combination of them:

- during the construction and operation of the building. Markers are attached above doorways to the surfaces of walls or structures;

- installation of fire safety signs and fire alarms with pre-built markers provided for by fire safety standards;

- during the extinguishing of a fire by the firefighters themselves as part of the fire and rescue divisions when moving deeper into the building. The dimensions of the markers allow firemen to be equipped with markers for placement in the direction of travel. In this case, markers of the same type are installed, allowing you to determine the direction of the return movement to the exit. The markers can be attached to wall surfaces as they are light in weight, or can even be simply dropped on the floor.

Since the markers are passive (they do not have a power supply), their placement does not affect the performance of fire protection systems, engineering systems, communication systems and other building electronic systems.

Method of application of the invention

To apply the invention in rooms, corridors, lobbies of the building, two different types of markers are installed, each of which is configured to operate at its own frequency. Customization is achieved by selecting the semiconductor device and the dimensions of the elements of the contours of the markers. One type of marker (M_P) is used to mark the exits leading from the premises on the evacuation route. Another type of marker (M_E) is used to mark exits leading outside, to a stairwell, to a safe area, as well as to indicate turns and ramifications of escape routes. Installation of markers is made above doorways. In the places where the junctions and turns of the escape routes are marked, the markers are installed on hangers under the ceiling or on the walls at a height corresponding to the installation height of other markers.

Firefighters who go inside the building are provided with non-linear radars that are able to detect the direction separately for each of the two types of markers.

The use of markers of various types for choosing a path is illustrated in the following figures.

Let us assume that the firefighter was in the room when visibility was significantly limited due to the fire smoke spreading through the building. The firefighter is protected by self-contained breathing apparatus, but does not have the ability to visually detect exits.

Figure 1 schematically shows the process of finding a way out of the room with a loss of orientation and limited visibility in the smoke. By adjusting the power and sensitivity of the locator (manual or automatic), by turning the locator, the fireman detects the direction to one of the nearest M_P markers, indicating the door from the room. Moving in this direction, the firefighter enters the corridor and switches the locator to look for markers of a different type.

Figure 2 shows that after leaving the room, if the locator is directed to the dead-end part of the corridor (which does not have access to the stairwell), the firefighter will not receive a signal about the presence of an exit there, since there is no M_E marker in this direction.

Figure 3 shows that when the locator is directed in the opposite direction, compared to Figure 2, the M_E marker appears in the locator coverage area, indicating the direction to the emergency exit, and the fireman selects this direction.

In the absence of markers in a building, firefighters advancing inside the building may leave markers along the path of movement at a distance less than the range of the radar. In practice it will be possible to set markers of only one type, but it will still provide a return path.

The presence of pre-installed markers in the building will allow firefighters moving through the hall, corridor or lobby into the building in low visibility conditions to quickly detect the doors of the premises. This will allow in the shortest possible time to search for people who may have remained in these premises and need to be rescued.

In addition to exits, windows can be marked with markers, the design of which allows them to be opened and evacuated outside.

The current level of development of technology makes it possible to create small-sized markers and small-sized wearable non-linear radars that can be included in the firefighter's equipment.

Implementation of the invention

Markers

To implement the invention, small size markers must be made, which will allow them to be freely placed in the required quantity in the building and to be carried by firefighters engaged in fire fighting and emergency rescue operations.

The use of the invention does not require detection of the marker at a great distance. It is sufficient that the components of the invention (locator and markers) ensure the detection of the marker at a distance of no more than 35-40 m, taking into account the slight attenuation of microwave signals in smoke and the attenuation caused by the placement of markers behind obstacles in the form of plastic cases of fire alarms for various purposes or internal partitions of the building. The sufficiency of this range is due to the fact that the standard length of a dead-end corridor should not exceed 30 m [Table. 6 of the Code of Rules SP1.13130.2020 Fire protection systems. Evacuation routes and exits]. The length of the path along the corridor when located between external exits can be 120 m [Table 1 6 of the Code of Rules SP1.13130.2020], but at the same time, fire safety signs indicating the direction of movement must be installed in the corridor at a distance of 25 m from each other [n . 5.4 Code of Practice SP3.13130.2009 Fire protection systems. Warning system and management of evacuation of people in case of fire]. The installation of these signs should be combined with the installation of M_E markers, which will ensure the possibility of their detection from anywhere in the corridor. Reducing the detection range of the marker by the locator helps to reduce the weight and size parameters, which is very important for wearable equipment.

Passive parametric diffusers are used as markers. The theory and practice of using two types of radio wave scatterers - nonlinear scatterers and parametric scatterers - is well developed [Babanov, N. Yu. Analysis, modeling and synthesis of structures of passive nonlinear and parametric scatterers: specialty 05.12.04 "Radio engineering, including television systems and devices" : dissertation for the degree of Doctor of Technical Sciences, 2016]. The former form the response signal Foc at the frequency of the second harmonic of the locator interrogation signal: Foc=2Fcs , the latter - at a frequency of half the subharmonic of the locator query signal: Foc=0.5 Fcs . In the invention, only parametric diffusers are used, since the electronic devices available in the premises of the building (computers, telephones, fire alarms and detectors, security detectors, LED lighting devices, etc.), being also diffusers, basically do not form a response signal at the subharmonic frequency request signal. Thus, the marker will be the only reference for the search by the locator, which increases the probability of correct and confident detection of the marker.

In general, markers can be made on the basis of patents RU2495450 C1, RU2491573 C1, RU2652150 C2, which show the designs and properties of parametric scatterers based on diodes, and wire-wound inductors and antennas.

The design of M_P and M_E markers ensures the formation of a response signal when only one frequency is irradiated with a request signal (one frequency for M_P markers and another frequency for M_E markers). When such a marker is irradiated with an interrogation signal of a different frequency, the response signal is either absent or too weak to be detected. Setting the marker to the desired frequency is implemented by manufacturing an oscillatory circuit with certain dimensions [Babanov, N.Yu. Analysis, modeling and synthesis of structures of passive non-linear and parametric scatterers: specialty 05.12.04 "Radio engineering, including television systems and devices": dissertation for the degree of Doctor of Technical Sciences, 2016]. The element base of the marker is simple and includes semiconductor diodes, inductances in the form of a part of wire turns (wire arcs), receiving and transmitting antennas. The purposes of the invention are largely met by markers in the form of parametric diffusers with strip type antennas [Design of a strip parametric diffuser-four-terminal / N.Yu. Babanov, A.V. Klyuev, S.V. Lartsov, V.P. Samarin // Radio engineering. - 2020. - T. 84. - No. 12(23). - S. 48-60. - DOI 10.18127/j00338486-202012(23)-06]. Markers of this type have a flat design of small thickness and can be placed directly on various surfaces, including conductive ones.

The design of the marker and its linear dimensions should be selected based on the possibility of preliminary placement in the building, the possibility of equipping firefighters with markers to place them as they move inside the fire object, and the capabilities of radar technology. The invention uses non-linear radars with a fairly narrow radiation pattern. Technically achievable and practically used in wearable radars, the beamwidth of 16 degrees is provided at frequencies of the order of 3.6 GHz (λ = 0.083 m) [https://suritel.ru/catalog/all/apparatura-poiska-kanalov-utechki/nljd /nelineynyy-lokator-lornet-36/]. This beamwidth is acceptable for the purposes of the present invention. With increasing frequency, the width of the radiation pattern decreases, which is even more in line with the objectives of the invention. Thus, it is advisable to build markers of one of the types with a strip antenna length selected for operation at a frequency not lower than the specified one. The response frequency of this marker type is 1.8 GHz.

The size of the strip marker antennas, i.e. the length of the rectangles is 0.49λ, where λ is the wavelength of the request or response signal. Based on a frequency of 3.6 GHz (λ = 0.083 m), the marker will have a receiving strip antenna size of 0.041 m, a transmitting strip antenna of 0.082 m. Depending on the dielectric used, the thickness of the strip antenna can be up to several millimeters. Markers of this size are quite suitable for placement in a building and can be used as M_R markers, which are placed in a building in advance.

For M_E markers, it is necessary to select higher frequencies of the request and response signals, taking into account the frequency range of generation, so that the request signal for the M_P marker does not cause the response signal of the M_E marker. The response signal is re-radiated by the marker in the range of about 300 MHz. Then for the M_E marker, the response signal frequency should be 2.1 Hz (λ=0.142 m), and the request signal frequency 4.2 GHz (λ=0.071 m). In this case, the size of the M_P marker antennas will be: receiving 0.035 m, transmitting 0.069 m. Markers of this size are quite suitable for placement in the building and can be used as M_E markers that are placed in the building in advance, as well as markers that firefighters are equipped to place in the building as you move deeper into the fire object.

The detection range of markers is estimated according to [Babanov, N. Yu. Analysis, modeling and synthesis of structures of passive nonlinear and parametric scatterers: specialty 05.12.04 "Radio engineering, including television systems and devices": dissertation for the degree of Doctor of Technical Sciences, 2016 ] for an interrogation wavelength of 0.1 m (3 GHz). The frequencies of the interrogation signals indicated above, the marker M_P and M_E, lie close enough to this frequency. In addition, there is an extensive selection of microwave diodes required for parametric generation, on the basis of which markers with the required parameters at other frequencies, including the level of oscillation excitation by the irradiating interrogation signal, can be built.

The minimum interrogation power required to drive the token is:

where

Then, for a detection range of 40 m, the required power will be:

This power is quite consistent with the average radiation power of wearable nonlinear locators [https://suritel.ru/catalog/all/apparatura-poiska-kanalov-utechki/nljd/nelineynyy-lokator-lornet-36/].

The power of the received response signal will be:

where

Then the power at the input of the receiver will be:

This power fully corresponds to the sensitivity of wearable nonlinear locators and even exceeds it [https://suritel.ru/catalog/all/apparatura-poiska-kanalov-utechki/nljd/nelineynyy-lokator-lornet-36/]. Thus, there is an energy reserve of the locator-marker-locator radio link, which will allow optimizing the weight and size dimensions of the equipment.

Nonlinear radar

The invention uses a non-linear radar that can operate in continuous or pulsed modes. The radar can emit an interrogation signal at the tuning frequency of the M_P marker or at the frequency of the M_E marker, and, accordingly, receive a half subharmonic from one of these markers. The radar has a directional pattern of 16 degrees or less, which provides the ability to search for a marker in a specific direction. The radar has adjustable sensitivity and radiated power, which is necessary to isolate the strongest signal corresponding to the nearest marker located in the middle of the main lobe of the radiation pattern. The power source of the radar must ensure operation during the time the firefighter works at the fire site, which is no more than 90 minutes.

The radar can be built, among other things, on the basis of the following patents: RU2441253 C1, RU2595775 C1. They propose methods for increasing the sensitivity and noise immunity of radars searching for non-linear markers in order to increase the range of their work. In the invention, this can be used as a means of reducing the mass and size of the radar.

The weight, size and design parameters of the non-linear radar should make it possible for firefighters to have it with them as part of combat equipment. Thus, the weight and size characteristics of the product “Guiding (travel) cable NT-GDZS” are: the mass of the assembly is 1.8 kg, the dimensions of the bag are 172/340/120 mm. The state of the art allows the construction of non-linear radars with similar characteristics to implement the present invention.

Claims (4)

A method for determining directions to exits from premises, corridors, vestibules by a firefighter located at a fire object in conditions of low visibility by using means of indicating escape routes, characterized in that as a means of designating escape routes, a portable non-linear radar is used, which is part of the firefighter's equipment, and parametric diffusers - markers of two types, each of which is configured to operate at its own frequency, while the basis of the marker is a semiconductor diode; markers of the first type are installed above exits from premises to common escape routes, into halls, corridors, lobbies or above windows that can be used for evacuation, markers of the second type are installed above exits from common escape routes to the outside, to a stairwell or to a safe area; using a non-linear radar, markers are detected that are installed during the construction or operation of a building or are installed when a firefighter moves deeper into the fire object to further search for the opposite direction, while semiconductor diodes lose their non-linear properties with increasing temperature, which ensures that the fireman chooses a direction that is different from the direction to high temperature zone.

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