RU2692058C1 - Method of protecting radar stations from small-size unmanned aerial vehicles and device for its implementation - Google Patents

Abstract

FIELD: radar ranging and radio navigation.SUBSTANCE: invention relates to radiolocation and can be used to protect radar stations (RS) from small-size unmanned aerial vehicles (UAV). Technical result is achieved by the fact that in method of radar station protection against small-size unmanned aerial vehicles, based on creation of obstacles, as such vending airflows of vortices are used, at that guarding air flows of vortices are created with the help of airflow generators of vortices, they are arranged around radar station or on the side of expected raid at the distance larger than radius of damaging effect of charge, which may be carried by drone. Device for realizing the method of protecting a radar station from small-size UAV, comprising a radar station, comprising a radiating antenna connected to a receiving-transmitting device, input of which is connected to the first output of the radar control device, generators of the vortex airflows are installed, the inputs of which are connected to the second output of the radar control device.EFFECT: high reliability of protecting the radar station from small-size impact nano- and micro-UAV using mobile devices.2 cl, 3 dwg

Description

The invention relates to the field of radar and can be used to protect radar stations (radar) from small unmanned aerial vehicles (UAVs).

In modern conditions, the task of building a reliable air defense system for troops and infrastructure becomes almost impossible due to the class of small-sized unmanned aerial vehicles that appeared in recent years [Army Bulletin Magazine February 2015. “Small-sized UAVs — a New Problem for Air Defense” p. 1, 5, 6, 7-9, 15]. Small-sized air targets such as guided missiles, planning (guided) aerial bombs, cruise missiles of various types of basing (aviation, ground or sea), anti-radar missiles, etc. For many decades, many difficulties have been delivered to air defense systems with their specific flight-technical characteristics. First of all, these are their small effective areas of dispersion (EPR), a wide range of speeds of movement, making hidden flights at low and extremely low altitudes using terrain, etc. The most massive and cheapest are small-sized UAVs.

The following groups are distinguished among small-sized UAVs: nano-UAVs, weight up to 1 kg, flight duration less than one hour, flight altitude up to 300 m; micro-UAV, weight up to 10 kg, flight time up to one hour, flight altitude up to 1000 m; mini-UAV, weight up to 50 kg, flight time several hours, flight altitude up to 3000-5000 m. All these UAVs can perform reconnaissance and reconnaissance-shock functions. Their speeds can reach 100-150 km / h, and the ESR ranges from 0.01 to 0.1 m ² , with a further decrease in perspective [ibid p. 7].

Basically, UAVs have navigation equipment with reference to the GPS navigation system.

Such characteristics of the UAV led to the fact that the timely detection of traditional location methods and reliable defeat of the UAV is extremely inefficient.

The greatest danger to the radar can be a massive use of nano and micro-UAVs, induced by radar radiation and capable of physically destroying radiating devices, primarily the radar antenna, since nano-UAVs can carry a charge of up to one kg. Therefore, the protection of the radar is reduced to combat UAV.

Known methods of dealing with UAVs in the form of targeted use of interference to navigation systems, flight control and information transmission channels [ibid, p 9]. The disadvantage of these methods of dealing with UAVs is the need to create directional high-power radiation on a UAV, for which it is necessary to detect it, which is a difficult task because of the small EPR of the UAV. In addition, UAVs with homing equipment on radar radiations can be induced on radars without the use of navigation equipment and external control. In this case, there remains the risk of destruction of the antenna by the UAV charges.

It is known that in order to exclude the possibility of the penetration of a hostile not detectable object into the protected zone, a “military fence, artificial obstacles, obstacles created in advance ... in order to inflict losses on the enemy or maneuver of his troops ... obstacles to advance ... aviation flights ... are distinguished by anti-tank, anti-personnel, anti-vehicle, anti-landing and anti-ship ... in the form of minefields, ... wire obstacles, anti-tank ditches and ridges, concrete and wooden fences , Wire networks .... Anti-aircraft military barriers ... for the first time ... were used in 1916 in England, Italy and Paris in the form of aerostatic barriers. ”[TSB, M.“ Soviet Encyclopedia ”, third edition, vol. 9, p. 273]. Military barriers are created, including for the case when a hostile object cannot be detected, but only the possibility of its penetration is assumed. An example of the practical use of anti-aircraft barriers during the Great Patriotic War are the aerostat barriers that were created in 1941-1942. on the approaches to Moscow, blocking the possible routes of penetration of any aircraft beyond the line of defense they create - the barrier. Thus, in cases where an attack on a guarded object is possible from any direction, military barriers are created.

The disadvantage of the known military obstacles is the cumbersomeness of their structures, lack of mobility, or ultimately, the impossibility of their use to protect mobile radars from the UAV.

The technical problem (technical result) posed is reliable protection of the radar from small nano and micro-UAV drums using mobile devices.

The technical problem is solved on the basis of excluding the possibility of UAV penetration to the radar at a distance less than the radius of the explosion of its charge.

The technical problem (technical result) is solved by the fact that in the method of protecting a radar station (radar) from small unmanned aerial vehicles, based on the creation of obstacles, according to the invention, deflecting air currents (SW) are used as such.

The technical problem (technical result) is solved also by the fact that in the method of protecting a radar station from small-sized unmanned aerial vehicles according to the invention, vortex blocking air currents are created using vortex air flow generators, placed around the radar or on the side of the expected attack at a distance greater than radius the damaging effect of a charge that a UAV can carry.

The problem posed (technical result) is solved by the fact that the antenna is connected to a receiver-transmitter device to implement a method for protecting a radar station from small-sized unmanned aerial vehicles, comprising a radar, which includes a radiating antenna, a receiving and transmitting device and a radar control device. the second input of which is connected with the first output of the radar control device, according to the invention, generators of air deflecting vortices are introduced into the device, the generator inputs in connected to the second output of the control device.

The essence of the work of the claimed method and device is that on the path of possible penetration of the UAV create a blocking air flow of the vortices. Possible directions of the UAV can be determined, for example, depending on the position of the radar relative to the boundary line (front line), and also if a probable UAV carrier is found with sufficient equivalent reflecting surface (but not UAV) for which this can be detected UAV launch, or terrain, which may limit the sector of possible directions. If information on the direction of the expected flight is not available, then cover all possible directions.

In the present method of protecting the radar from small-sized UAVs, the well-known property of air vortex rings is used to maintain its geometry and move a long distance [V. Merkulov - Fluid dynamics familiar and unfamiliar M. Science 1989 p. 86-89]. As follows from this source, theoretical and experimental studies of large-scale ring vortices created by an explosion were carried out at the Institute of Hydrodynamics of the Siberian Branch of the Academy of Sciences of the USSR. Since the range of such vortices can reach 1-2 km, the authors suggested using vortices to emit industrial gas at such a height, where they could be carried away by horizontal air flows. To this can be added a large number of other possible areas of application of ring vortices. However, all these projects can be implemented only if ring vortices are created not by an explosion, but by some generator that would create vortices cheaply, without noise, with a large frequency. The law of motion of a single vortex is determined by formula (1) [ibid p. 86]:

Here R ₀ is the initial radius of the vortex, V ₀ = U _p is the initial velocity of the vortex, t is the flight time, α = 6 × 10 ^-3 is the experimental coefficient, L (t) is the current distance from the generator to the vortex. From the above formula it follows that the initial velocity of the vortex is proportional to the initial radius. Formula (1) describes the behavior of a single vortex. However, only continuous air flow vortex generators (ERW) can have practical application. For example, the generator VPV, which uses the energy of the air jet compressor. The vortex generator itself is a high-speed shutter that provides a pulsed air supply in the form of a cylindrical volume of length D equal to the length of the generator tube [ibid p. 87]. FIG. 3b shows a diagram of such a generator containing a nozzle, the output of which is blocked by a high-speed gate, and the input is connected to a compressor.

The expiration time Δt with a quickly open gate will be equal to

where U is the flow rate of air

The behavior of a chain of vortices is different from the behavior of a single vortex. In particular, their range increases. The long-lasting chain of vortices causes the flow of adjacent air towards their flight [ibid p. 86].

In [preprint No. 299, V.I. Boyarintsev, A.S. Savin "Investigation of the motion of vortex rings in homogeneous and stratified media." Institute of Mechanics Problems, USSR Academy of Sciences, M. 1987, p. 9-11, formulas 1.2, 1.3] provide formulas for calculating the parameters of a ring vortex.

The translational speed of a single ring vortex (OKV) U _{p is} calculated by the formula (3)

The momentum of the movement of the OKV is determined by the formulas (4), (5)

, к моменту окончания формирования вихря α≈R/2. Радиус R(t) вихря увеличивается пропорционально пройденному вихрем пути по линейному закону. Геометрический параметр β=Δ_R/Δx, - скорость изменения радиуса вихря от пройденного вихрем пути составляет 0,001-0,01 долю пройденного пути [там же с. 7, 11].where R is the radius of the vortex; G is the circulation of the vortex core, ρ is the specific mass density of air,

, by the end of the formation of the vortex α≈R / 2. The radius R (t) of the vortex increases in proportion to the linear path traveled by the vortex. The geometrical parameter β = Δ _{R / Δx} , - the rate of change of the vortex radius from the path traveled by the vortex is 0.001-0.01 share of the path traveled [ibid p. 7, 11].

From this it follows that the diameter of the vortex core weakly depends on time (the path traveled by the vortex).

A feature of the vortices is that the energy accumulated in the generator volume is transmitted to the vortex (Fig. 3b). The magnitude of this energy is equal to

where Δp is the excess pressure in the generator volume, W is the working volume of the vortex generator. Under the action of this pressure, when the shutter is opened, the air acquires the speed U = (2Δp / ρ) ^1/2 - [N.I. Koshkin and M.G. Shirkevich - Handbook of elementary physics. Ed. "THE SCIENCE". M. 1972 with. 54]. When Δр = 0.156 × 10 ³ n / m ² , the speed will be equal to U≈50 m / s.

An increase in the kinetic energy E _k almost proportionally leads to an increase in the long-range action of the VFW L _max [Akhmetov Darwin Gazizovich - Experimental studies of linear and circular concentrated vortices - fluid, gas and plasma mechanics. Abstract of dissertation for the degree of Doctor of Physical and Mathematical Sciences Novosibirsk 2011].

When designing the proposed remedy, the defining parameters of the vortex blocking air flow are:

- size of the protection zone;

- configuration of the location of the generators of the blocking ERW;

- speed in the vortex core at a given distance;

- power generator flow;

- principles of flow generator control.

The calculation of the parameters of the generators that create ERW to ensure the protection of the radar is an engineering task and can be performed by setting specific conditions for the use of the claimed inventions according to the formulas (1), (2), (3), (4), (5) and (6) . We use the information above and carry out, for example, an estimated calculation of the generated vortices.

R_г=0,25 м, а начальный диаметр вихря

По формуле (5) определим начальную циркуляцию ядра вихря Г_ян Set the radius of the generator nozzle R _g = 0.5 m, the velocity of the air flowing out of the generator nozzle U = 50 m / s. This speed is the linear speed of rotation of the core of the vortex. The diameter of the vortex core will be equal to

R _g = 0.25 m, and the initial diameter of the vortex

According to the formula (5) we define the initial circulation of the vortex core G _yan

According to the formula (3) we find the initial velocity of the vortex

U _extra = 23.8 m / s

Determine at what distance from the generator nozzle will be the first vortex, for example, after 2 seconds by the formula (1)

L (t) ₁ = 30.9 m

будет равно 0,02 с. При периоде повторения 5 Гц удаленность первого вихря через 2,2 с будет равнаIf the length of the nozzle of the vortex generator is equal to D = 1 m, then the expiration of air from the volume of the generator (the time of formation of the vortex) according to the formula (2)

will be 0.02 s. With a repetition period of 5 Hz, the distance of the first vortex in 2.2 s will be equal to

L (t) ₂ = 33 m

The change in the distance L (t) ₂ -L (t) ₁ = 2.158 m occurred in 0.2 s

Consequently, the speed of the vortex will be equal to

U (t) = 2.158 / 0.2 = 10.7 m / s. Those. vortex speed will decrease by 2.55 times. Since the current value of the circulation Г _я (t) in the first approximation is preserved, the approximate formula

[M.A. Lavrentiev, B.V. Shabbat - Problems of hydrodynamics and their mathematical modeling, §37 Formation and motion of a vortex].

From which it is seen that R (t) increases in inverse proportion to the decrease in the velocity of the vortex and for the considered example it will be equal to 0.625 × 2.22 = 1.38 m

From formula (3), assuming that the circulation of the vortex core changes slightly in time, i.e. remains equal to G _yan = 78.5 m / s ² , we find the linear velocity of rotation of the vortex core at a distance of 33 m U _I (t) = 17.9 m / s.

The magnitude of the potential energy E _p stored in the generator is equal to

where Δp is the excess pressure in the generator volume, W is the working volume of the vortex generator (nozzle). Explain this formula. The pressure acting on the piston is Δp xS = F, where S is the area of the piston. Under the action of this pressure, the piston moves a distance D = 1 m, and the work is done (accumulation of potential energy). The product of the area Sx D is equal to the volume of the generator W.

The air at the opening of the shutter gains speed

U = (2Δhrρ) ^1/2

With a mass specific air density ρ = 0.125 kg / m ^3, to create an air flow rate U = 50 m / s, an overpressure Δp = 0.156 x 10 ³ n / m ² will be required.

When the radius of the generator nozzle R _g = 0.5 m, the working volume of the generator with a pipe length D equal to 1 m is equal to W = 1.57 m ³ . The potential energy stored in the generator and calculated by the formula (6) is equal to

E _p = 245.3 j

This energy transmitted by the vortex accumulates in the generator during a time Δt = 0.2 s (at a vortex repetition frequency of 5 Hz) and for the continuous operation of the generator, a compressor power of 1.22 kW is required.

From the estimated estimate, it is clear that even at a distance of 33 m from the generator, the linear velocity of the vortex core is 17.9 m / s, which is more than the permissible speed at which the UAV can fly (10 m / s) [Army Gazette February 2015 "Small-sized drones - a new problem for air defense" p. eight].

The interaction of the UAV with the vortex core is shown in FIG. 3b.

Tipping UAV when exposed to a vortex can be explained as follows. When a UAV propeller enters the vortex core zone, the magnitude of the lift force of this propeller changes abruptly due to the flow incident on it from above or below with the linear velocity of the vortex core U (t) _i . At the same time, an overturning moment almost instantly occurs, which, therefore, cannot be compensated.

The proposed method of protection is based on the property of the UAV, which consists in the fact that the UAV “... has low resistance of the apparatus to physical effects of any kind, from a fragment (bullet) to a strong gust of wind, a whirlwind, resulting in a loss of spatial orientation, a break in a corkscrew. Each significant external disturbance (gust of wind,) with a high probability leads to a loss of orientation of the aircraft and a subsequent accident ”[g. Army Gazette, Feb. 2. 2015, p. 9, 5 paragraph below].

The allowable distance L _additional approach of the UAV to the radar is determined by the power of the charge on the UAV and determines the required range of the ERW, if the ERW generator is located at the radar location. On request, the "range of the explosive charge" on the Internet are examples: when the mass of TNT is one kg (for nano and micro UAVs, the charge weight is 0.5-1 kg [ibid. 5]), the safe distance is 12 m. The principle of cubic similarity allows the calculation of a safe range for any other explosive mass (but the size of the UAV also increases and they can become detectable).

Assuming the finite speed ERW equal to a wind speed at which no longer possible flight of the UAV (10 m. / Sec [ibid, pp. 8]), a known permissible distance R _per = 12 m can calculate the required initial velocity (at a charge of 1 kg capacity) for vortex formation and generators capacity, placing them (for example) in the corners of a regular pentagon, which is inscribed in a circle of radius R _lane (Fig. 2a). The distance AB in the correct pentagon is determined from the formula

[A.A. Ryvkin, A.Z. Ryvkin, L.S. Horseradish - Handbook of mathematics. Ed. Higher school, 1975 167]. The angle of inclination ϕ ₀ WPV to the horizon is chosen equal to 30 °.

For example, the generator is located at point A, with R _g = 0.5 m, R _lane = 12 m, ϕ ₀ = 30 °, U (t) _i = 10 m / s, AB is 25 m, Overlapped by SVW distance L ( t) ₂ = 33 m (Fig. 2b). In this case, from formula (7) with the frequency of repetition of the vortices in a stream of 5 Hz, the power consumption of the compressor Ф _к is equal to 1.22 kW.

The angle ϕ = 30 ° is determined from the condition of guaranteed protection of the radar at a given height of the UAV approach. If the generators are located at the corners of a regular triangle or quadrangle, then the required power of the ERW generators will increase as their number decreases (the required long-range action increases), and if you use 6 or 8 generators, having them in the corners of a regular six or octagon, then the required power ERW generators will decrease. The choice of the number of ERW generators when solving a specific task of protecting the radar from an UAV attack is a purely engineering task and depends on the optimization parameters (total power), the essence of the invention does not change.

Thus, in the inventive method and device provide for the creation around the radar (or its radiating part) of the barrier area of the vortex from the air flow, if the UAV enters into it from any direction, it will be tilted and fall. At the same time, small-sized, low-mass UAVs are particularly susceptible to the physical effects of these factors. Such UAVs cannot function at wind speeds ≥10 m / s [ibid p. 8, 14 line below]. When the UAV approaches the area of the movement of the SVC, the UAV will be affected by both the translational impulse of the amount of movement of the ERW, leading to a change in the direction of movement of the UAV, and the rotational movement of the vortex core in the ERW, causing the UAV to tip over or lose its orientation. At the same time on the perimeter of the radar protection R _ln linear speed of rotation of the core of the vortex VPW U _p must be more than 10 m / s to a given height of the barrier L _extra . In this case, the main role is played by the core of the vortex, in which the main energy of the vortex is concentrated. FIG. 2 shows the organization of radar protection by a system of vortex generators located around it at a distance, ensuring its safety. As was shown above, the energy of the vortex spreads over long distances, while the radius of the vortex core and the radius of the vortex itself increase slightly while maintaining circulation, and therefore the speed inside the vortex core remains above the critical one for the UAV.

If information on the size of the angular sector Δβ from which the UAV launch is possible (terrain, front line, boundary or intelligence data on the position of the UAV carrier) is known and the possible presence in the UAV area is detected, then the sources of the vortex flow should overlap only the angular sector Δβ before the protection zone if the sector is not known, i.e. if an attack is expected from any direction, then ERW generators should be located at the corners of the n-gon (Fig. 2a), built around the perimeter of radar protection with radius R _lane . The power of ERW generators and their number - n should provide around the entire perimeter R _lane and the height L _SS U _p (t) not less than the minimum permissible, at which the UAV cannot fly, i.e. U _p (t) at a range of L _SS should be more than 10 m / s. The above estimate, for example, confirms the possibility of implementing this method of protecting the radar from the UAV.

Switching on (switching off) the ERW generators is carried out manually from the radar in accordance with the instructions, which are developed taking into account the location of the radar and the tactics of its use (since the radar itself cannot detect the nano and micro - UAV plaque). This may take into account the conditions for obtaining information about the likely attack of the UAV, or at the outbreak of hostilities, or when receiving the directive of the higher command to bring the means into combat readiness.

The interaction (connection) of the ERW generators with the work of the radar ensures its functioning and survival under the conditions of a possible UAV attack. In this sense, ERW generators are a necessary component of the radar, they are controlled from the radar. Switching on (switching off) of ERW generators is carried out manually from the control panel of the radar station when the radar is operating and in the presence of a UAV raid threat.

The invention is illustrated by drawings.

FIG. 1 shows the claimed device.

FIG. 2. shows an example of the organization of protection radar with the help of ERW generators.

FIG. 3 shows the interaction of the UAV with the ERW and the diagram of the ERW generator.

The claimed device for implementing the claimed method of protecting the radar from small-sized UAVs (Fig. 1) contains a radar including an antenna 1, a receiving and transmitting device 2, a radar control device 3, and generators VPV A, B, C, D, E, antenna output 1 connected to the first input of the receiving and transmitting device 2, the second input of which is connected to the first output of the radar 3 control device, the second output of the radar 3 control device is connected to the inputs of the SVC A, B, C, D, and E

The operation of the method and device (Fig. 3a) is based on the exploitation of the vulnerability of nano and micro-UAV 3, which consists in the fact that they are extremely unstable to any physical impacts - wind gusts of more than 10 m / s and eddies cause the UAV 3 to lose orientation - off course or falls. In order to physically influence the UAV 3, the RLS1 generators 2 are inserted as ERW, the generators 2 are placed around the RLS 1 at a distance R _lane . When the UAV 3 interacts with the rotating vortex core, they lose their orientation up to tilting, which does not allow the UAV 3 to penetrate the radar 1. The organization of circular radar protection (top view) is shown in (Fig. 2a), and spatial (Fig. 2b) shows orientation of the air currents of the vortices that block from the penetration of the UAV to the radar. The location of ERW at an angle ϕ to the horizon provides the necessary density of ERW at the required height with the required L _aux .

Thus, the technical problem is solved and the technical result is achieved.

Claims (2)

1. A method of protecting a radar station (radar) from small-sized unmanned aerial vehicles (UAVs), based on creating barriers, characterized in that barriers are created using vortex air flow generators that are placed, with the possibility of movement, around the radar or from the expected attack UAV at a distance greater than the range of the effect of the charge available on the UAV, turn on and off the generators of the air flow of the vortexes using the radar control device when the radar is running and if there is a threat of a UAV raid, depending on information coming in the radar about a possible UAV raid, the power of the vortex air flow generators and their number is determined based on the condition of providing radar protection around the perimeter - air velocity of the vortex ≥ 10 m / s, the allowable distance of the UAV approach to the radar, determined by the power of the charge on the UAV, and also from the condition of ensuring the interaction of the UAV with the rotating core of the vortex flow. 2. A device for implementing a method of protecting a radar station (radar) from small unmanned aerial vehicles (UAVs), comprising a radar system that includes a radiating antenna, a receiving and transmitting device and a radar control device, the antenna is connected to a receiving and transmitting device, whose input is connected with the first output of the radar control device, characterized in that the device includes the generators of the air flow of the vortices, which, depending on the information received in the radar about a possible UAV raid, t with the ability to move around the radar or from the expected flight of the UAV at a distance greater than the range of the damaging effect of the UAV charge, while the entrances of the airflow generators of the vortices are connected to the second output of the radar control device, providing, on and off, the generators air flow eddies.

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