RU220409U1 - REMOTE CONTROLLED DEVICE FOR SEARCHING FOR VICTIMS IN SNOW BARS AND AVALANCHES - Google Patents

Abstract

The utility model relates to the field of search and detection of victims under snow rubble and avalanches and can be used during search and rescue operations by search and rescue units of the Russian Ministry of Emergency Situations.

A remote-controlled device for searching for victims in snow debris and avalanches contains a receiving and transmitting antenna unit, which is located on a radio-controlled transportation platform and consists of a metal case, the internal volume of which is filled with radio-absorbing material. A control board is installed on top of the case, and a transmitting and receiving resistive-loaded antenna based on foiled fiberglass laminate is fixed in the lower part. The control board is connected to the receiver and transmitter using connectors and secured to the housing using stands and screws. An antenna amplifier as part of the receiver and a pulse generator as part of the transmitter, the components of which are located in plastic cases attached to a metal case, are connected to the input contacts of the antenna using mechanical catchers. On the outside, the antenna module is covered with a plastic case on which connectors for connecting a laptop and a power supply are located. On the inner surface of the plastic case there is a switching board on which the Wi-Fi wireless communication module is located. The receiving and transmitting antenna is designed to transmit and receive an ultra-wideband signal, and the transmitting and receiving parts of the antenna are weakly directional and represent a bistatic antenna system in which the transmitting and receiving parts are separated. The radio-controlled transport platform contains a platform control signal receiver, an actuator for the platform control receiver, and two wheel pairs. The rear wheel set is responsible for moving back and forth and is mounted on an axle, which is connected to an electric motor through a worm gear. The electric motor is controlled from the actuator of the platform control receiver, and at the same time is a displacement sensor. The front wheel pair is responsible for turning left and right and is mechanically connected to the control unit.

The technical result is to ensure the safety of rescuers searching for and detecting victims under snow rubble and avalanches (who have a high risk of failure) during search and rescue operations by search and rescue units of the Russian Ministry of Emergency Situations. 5 ill.

Description

The technical field to which the utility model belongs.

The utility model relates to the field of solving problems of searching and detecting victims under snow rubble and avalanches and can be used during search and rescue operations by search and rescue units of the Russian Ministry of Emergency Situations.

State of the art.

Russian rescuers have been using avalanche probes for a long time to probe the thickness of snow. Their length can be very different: from 2 to 4 meters. Both independent collapsible structures and combinations of ski poles are made from alloy steel, aluminum alloy, fiberglass and carbon /1,2,3,4,5/.

A more advanced way to search for victims in avalanches is to use so-called beepers /6,7,8,9,10,11/.

There are two types of beepers: analog and digital. Analog beepers capture the signal without any processing. The louder the sound, the closer the target. Digital devices, having received a signal, process it according to a certain algorithm. As a result, the distance and direction to the signal source are calculated. Very often, digital instruments show the wrong direction and the distance is determined with a large error.

An alternative radio search scheme is used during search and rescue operations using devices developed by Recco 712,13,14,15,16,17/.

A special radio wave reflector is attached to clothing, shoes and other equipment. It's essentially a piece of metalized plastic. The search party is equipped with a portable radar. However, as the experience of using these devices to search for victims in avalanches has shown, the number of false alarms when searching for victims is quite large, as a result of which the search time increases.

The closest analogue of the proposed utility model is a mobile device for searching for victims in snow debris and avalanches, the operation of which is based on radar sounding of snow cover (RU 205767).

The main disadvantage of these technical means is the fact that to conduct search operations it is necessary that the victim be equipped with the above sensors, which is not always possible in real life. In addition, the use of these methods and technical means to search for victims in avalanches is associated with significant difficulties due to a large number of various interferences, which in turn predetermines low reliability of detection of victims and a decrease in the pace of search work.

However, the most significant drawback of all the proposed technical means of searching for victims in snow rubble and avalanches is the very high risk of rescuers conducting the search falling into crevices covered with snow.

Disclosure of utility model

The operation of a remote-controlled device for searching for victims in snow debris and avalanches is based on radar sensing of the snow cover using a special radio-controlled transportation platform.

Existing search devices require direct contact between the rescuer and the search device.

Classic radar of air targets uses radio pulses with a carrier frequency from a few to tens of GHz using various types of modulation as sounding signals. In radar sounding of snow avalanches, this type of signal using such high frequencies cannot be used due to the strong attenuation of radio waves in the sounded medium.

A remotely controlled device, unlike other search tools, will allow you to obtain in real time the necessary information about the nature and depth of the location of the objects you are looking for in a relatively homogeneous environment.

In addition, the spatial extent of radio pulses, which determines the range resolution, in narrowband locators is tens and hundreds of meters. Therefore, this type of sounding signals is not applicable in the radio engineering complex, since the achieved resolution does not ensure the task of sensing snow avalanches to depths of up to the required 2-3 meters with the required depth resolution of 10-15 cm.

Therefore, to solve the problem of detecting victims at close range with high resolution, special ultra-wideband (hereinafter referred to as UWB) radars are used.

The process of searching for victims in snow debris is carried out by controlling the movement of the search device along the surface of the snow block via a radio channel. In the absence of foreign objects in the snow blockage structure, the signal transmitted to the display device will have constant parameters throughout the entire time of scanning the snow blockage. If the victim is in the snow, the probing signal will be reflected from him as long as the mobile device is above its surface. Based on the path traveled by the mobile device, one can judge the size of the victim and thus select him from foreign objects.

The fundamental performance of the proposed mobile device was demonstrated during tests in the Elbrus high-mountain search and rescue team.

The technical task of this utility model is to develop a device that would provide a technical result, which consists in ensuring the safety of rescuers searching for and detecting victims under snow rubble and avalanches (who have a high risk of failure) during search and rescue operations by search and rescue units of the Ministry of Emergency Situations Russia.

The technical problem is solved due to the fact that a remotely controlled device for searching for victims in snow rubble and avalanches contains a receiving and transmitting antenna unit consisting of a metal case, on top of which there is a control board, which is connected to the receiver and transmitter using connectors and is fixed on the case with using racks and screws, and in the lower part there is a transmitting and receiving resistive-loaded antenna based on foil fiberglass, to the input contacts of which an antenna amplifier as part of the receiver and a pulse generator as part of the transmitter, the components of which are located in plastic cases, are connected using mechanical catchers, attached to a metal case, the internal volume of which is filled with radio-absorbing material, on the outside the antenna module is covered with a plastic case on which connectors for connecting a laptop and a power supply are located, on the inner surface of the plastic case there is a switching board on which the Wi-Fi wireless communication module is located, with In this case, the receiving and transmitting antenna is designed to transmit and receive an ultra-wideband signal, and the transmitting and receiving parts of the antenna are weakly directional and represent a bistatic antenna system in which the transmitting and receiving parts are separated. The novelty lies in the fact that, unlike the prototype, in the proposed device, on a special radio-controlled transport platform, a platform control signal receiver, an actuator for the platform control receiver, two wheel pairs are placed, and the rear wheel pair is responsible for moving back and forth and is mounted on an axle, which is connected through a worm gear to an electric motor, the electric motor is controlled from the actuator of the platform control receiver and is at the same time a displacement sensor, the front wheel pair is responsible for turning left and right and is mechanically connected to the control unit.

Brief description of drawings

In fig. 1 shows a remote-controlled device for searching for victims in snow debris and avalanches.

In fig. Figure 2 shows a block diagram of a remotely controlled device for searching for victims in snow debris and avalanches.

In fig. Figure 3 shows the UWB radar trace (a), the depth section of the profile (b) and the time section of the profile (c).

In fig. Figure 4 shows an example of a georadar profile.

In fig. Figure 5 shows an example of a radargram obtained during a passage in the area of the Elbrus peak.

As shown in FIG. 1 and 2, a remote-controlled device for searching for victims in snow debris and avalanches contains a special radio-controlled transport platform 1 on which a platform control signal receiver 2, an actuator for the platform control receiver 3, two wheel pairs 4 and 4', a UWB radar 5, and a power supply are located 6.

UWB radar 5 consists of a pulse generator 7, a receiver with a stroboscopic converter and an ADC 8, transmitting and receiving antennas 9 and 10, a control unit 11 and a display device 12.

Structurally, a receiver with a stroboscopic converter and an ADC 8 and a pulse generator 7 are combined with receiving and transmitting antennas 9 and 10 and form the so-called antenna unit 13 (Fig. 2).

The rear wheel pair 4' is responsible for moving back and forth and is mounted on an axle, which is connected to an electric motor through a worm gear. The electric motor is controlled from the actuator of the platform control receiver 3. The rear wheel pair 4' is also a displacement sensor.

The front wheel pair 4 is responsible for turning left and right and is mechanically connected to the control unit 11, which is driven by the actuator of the platform control receiver 3.

The basis of the antenna unit 13 is an antenna module consisting of a metal casing, in the lower part of which a transmitting and receiving resistive-loaded antenna based on foil fiberglass is fixed. To ensure the required level of antenna damping, the internal volume of the housing is filled with radio-absorbing material.

The antenna amplifier of the receiver and the pulse generator of the transmitter are connected to the input contacts of the antennas using mechanical catchers. To eliminate the influence of absorbing material on electronic components, the receiver and transmitter are located in plastic housings attached to a metal housing.

A control board is installed on top of the metal case, which is connected to the receiver and transmitter using connectors. The control board is secured to the housing using stands and screws.

On the outside, the antenna module is covered with a plastic case on which connectors for connecting a laptop and a power supply 6 are located.

On the inner surface of the plastic case there is a switching board on which the Wi-Fi wireless communication module is located.

The connection between the external connectors, the wireless communication module and the control board is carried out using a wire harness attached to the inner surface of the plastic cover.

The combination of these design features is novel, has significant differences and contributes to achieving the goal - increasing the safety of rescuers during the work of searching for victims in snow debris.

The absence of one of the design elements either significantly reduces the efficiency of the mobile device or makes it impossible to function as intended.

Implementation of a utility model

The process of searching for victims in snow debris and avalanches is carried out using the claimed utility model by controlling the movement of the search device along the surface of the snow block via a radio channel. In the absence of foreign objects in the snow blockage structure, the signal transmitted to the display device will have constant parameters throughout the entire time of scanning the snow blockage. If the victim is in the snow, the probing signal will be reflected from him as long as the mobile device is above its surface. Based on the path traveled by the mobile device, one can judge the size of the victim and thus select him from foreign objects. Unlike other technical search tools, it will significantly increase the safety of rescuers when searching for victims in avalanches and rubble.

The rescuer, being at a distance from the UWB radar 5, through the control unit 11, the platform control signal receiver 2 and the actuator of the platform control receiver 3, controls the radio-controlled transport platform 1 via a radio channel, moving it along the surface of a snow block or avalanche back and forth and to the left. to the right.

The transmitting antenna 9 of the UWB radar 5 emits probing electromagnetic pulses into the body of the avalanche, where the victim may be located, which, in order to obtain high resolution, have a very short duration (units and fractions of a nanosecond) and a fairly wide spectrum of radiation. The choice of pulse duration is a compromise between the required probing depth and the resolution of the device. To generate probing pulses, the transmitting antenna 9 is excited by a voltage drop.

The electromagnetic pulse emitted by the transmitting antenna 9 into the snow mass is reflected from the objects in it, including the body of the victim.

As a result, a signal is received at the input of the receiving antenna 10, which is a superposition of the signal emitted by the transmitting antenna 9 and falling directly into the receiving antenna 10 (direct transmission signal or direct wave), and signals reflected from the victim’s body. This resulting signal is called a trace (Fig. 3.a).

Since when solving the problem of searching for victims in snow rubble and avalanches, it is necessary to detect victims at shallow depths, the presence of a dead zone caused by switching from the transmitting mode to the receiving mode is unacceptable for the UWB radar. Therefore, the proposed subsurface radar uses bistatic antenna systems in which the transmitting and receiving antennas are separated by a short distance, called the system base. When bistatic sounding is used to detect victims located at shallow depths, it is necessary to ensure the maximum dimensions of the observation zone of reflected signals. This means that the emission and reception zones of the UWB radar antennas should have the maximum possible angular dimensions, i.e. UWB radar antennas must be substantially directional.

To visualize the obtained information, a method called the vertical time method is used, according to which the observed picture is a vertical section of the environment, or profile. The UWB radar moves along the profile and after a certain distance one path is recorded (Fig. 3. b). As a result, a set of received traces is displayed on the monitor screen - a radargram, from which you can determine the location of the victim, his depth and size (Fig. 3. c).

Due to the wide radiation pattern of the UWB radar, local objects are observed not only at the point directly under the UWB radar, but also at some distance in both directions. In this case, the distance to the object is described by a hyperbola, forming a so-called diffracted wave (Fig. 3.c).

To improve visibility in subsurface radar, the brightness method of displaying a radargram, borrowed from seismic exploration, is also used. In accordance with this method, the entire amplitude range of the received signal is divided into intervals, and each interval is assigned its own color. If the amplitude of the received signal at a given point in depth falls within a certain interval, it is assigned this color. As a result, each profile trace is a vertical line with a changing color. The radargram that uses a palette with gradations of gray color is the most visual, and its brightness will change. In practice, in most cases, it is the brightness method of displaying the radargram that is used, because it is most convenient for interpretation (Fig. 4).

As for a classic radar, the main parameters for a UWB radar are the radiated power, the sensitivity of the receiving device, the dynamic range, and the frequency band.

From a practical point of view, the most important parameters of a UWB radar are the sounding depth (depth) and depth resolution.

Depth resolution is the minimum vertical distance between two objects at which separate observation of these objects is possible. Resolution depends on the duration of the probing pulse - the shorter the pulse duration, the higher the resolution.

The sounding depth depends both on the technical characteristics of the UWB radar (emitted power, sensitivity, etc.) and on the electrical properties of the snow cover. When an electromagnetic wave propagates in snow, conduction currents spread throughout the volume, leading to attenuation of the electromagnetic wave. Therefore, the most important characteristic affecting the probing depth is the specific attenuation in the medium.

The probed media have a significant spread in specific attenuation, which depends on the spectrum of the probe electromagnetic wave, the type of the probed medium, its mineralization and moisture saturation. A feature of almost all natural and artificial environments is a significant increase in specific attenuation with increasing frequency of the carrier oscillation. Therefore, when designing UWB radars, in order to increase the sensing depth, they strive to use the lowest possible frequencies, and to maintain resolution, they reduce the pulse duration, ultimately arriving at signals that have almost one period of the carrier oscillation. For such signals, the spectrum width Δƒ is comparable to its central frequency ƒ ₀ (Δƒ≈ƒ ₀ ), and they are called ultra-wideband.

It should be noted that the process of radar observation when using UWB signals differs significantly from a similar process when using traditional narrowband signals. In a UWB radar, the signal repeatedly changes its shape as it is emitted, reflected from a target, and received. Some of these changes (during emission, reception, formation of the radiation pattern) can be calculated, others (during reflection from a target, passing through a medium) as a rule remain unknown. As a result, the shape of the received signal becomes unknown. Therefore, classical optimal processing of this signal using a matched filter or correlator becomes impossible.

Since the distances to the detected victims are small and often comparable to the size of the objects themselves, these objects can no longer be considered as reflecting points or even collections of such points. Most often, objects need to be considered as distributed and the phenomena of diffraction on the corresponding reflective surfaces must be taken into account. To date, the calculation of the effective scattering area of a victim irradiated by a UWB signal has been carried out only for the simplest forms.

To illustrate the possibility of achieving this goal when identifying potentially dangerous areas hidden under snow, a radargram obtained during a passage in the area of the peak of Elbrus is shown (Fig. 5).

Claims (1)

A remotely controlled device for searching for victims in snow debris and avalanches, containing a receiving and transmitting antenna unit consisting of a metal case, on top of which there is a control board, which is connected to the receiver and transmitter using connectors and fixed to the case using stands and screws, and in the lower part there is a transmitting and receiving resistive-loaded antenna based on foil fiberglass, to the input contacts of which an antenna amplifier as part of the receiver and a pulse generator as part of the transmitter are connected to the input contacts using mechanical catchers, the components of which are located in plastic cases attached to a metal case, internal the volume of which is filled with radio-absorbing material, the outside of the antenna module is covered with a plastic case, on which connectors for connecting a laptop and a power supply are located, on the inner surface of the plastic case there is a switching board on which the Wi-Fi wireless communication module is located, while the receiving and transmitting antenna is made with the ability to transmit and receive an ultra-wideband signal, and the transmitting and receiving parts of the antenna are made weakly directional and represent a bistatic antenna system in which the transmitting and receiving parts are separated, characterized in that the transmitting and receiving antenna unit is located on a radio-controlled transport platform on which the receiver is located platform control signals, an actuator of the platform control receiver, two wheelsets, wherein the rear wheel pair is responsible for moving back and forth and is mounted on an axle that is connected to an electric motor through a worm gear, the electric motor is controlled by the actuator of the platform control receiver, and at the same time it is a motion sensor, the front wheel pair is responsible for turning left and right and is mechanically connected to the control unit.

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