Means and systems for protecting the perimeters of objects.

Means and systems for protecting the perimeters of objects.

Means and systems for protecting the perimeters of objects

There is no universal detection system (DS) that would be optimal for the entire territory of Russia and a variety of operating conditions, and it is unlikely that it will be created. The choice of the most effective DS depends on many factors and, above all, on the specific location of the protected facility, its architectural design, the surrounding environment, and much more.

The priority area of ​​activity of the State Unitary Enterprise SNPO «Eleron» is the creation of perimeter means and security systems (PSS) for facilities. The creation of effective PSS is an extremely complex and knowledge-intensive problem. Its successful solution requires long-term experimental studies of the physics of the detection process, collection of information on signals and interference, search for the most effective signal processing algorithms, and careful development of circuit solutions. To conduct research and testing of PSS, we need testing grounds in various climatic zones of the country, a fleet of equipment for recording and processing signals, simulating interference effects, and, most importantly, a team of highly qualified specialists: physicists, researchers, programmers, circuit designers.

Perimeter protection is one of the most important elements of the facility security complex, especially for nuclear or thermal power plants, oil and gas processing plants, oil terminals, airports, finished goods warehouses, etc. In some cases, large facilities have additional protected local zones within the perimeter — the most important and responsible centers (concentration of material assets, etc.). Often there is a task of temporary, short-term protection of small perimeters, for example, when stopping transport with valuable cargo, temporary storage of equipment, construction, etc.

The specificity of domestic conditions for designing and operating perimeter protection systems lies primarily in the wide variety of climatic and soil-geological conditions. Large seasonal temperature fluctuations, heavy snowfalls, snowstorms, wet snow, frequent dense fogs, hurricane winds, heavy rains, ice, frost cause great difficulties in choosing the appropriate alarm system and make it virtually impossible to use any single system for any climatic zone in Russia. Therefore, the designer must be well versed in the existing variety of manufactured systems, alarms, know their features, the scope of the most effective application and the specifics of use.

To correctly select the optimal perimeter protection means, it is necessary to take into account the possibility of allocating an alienation strip (restricted zone) for the placement of alarm systems, the terrain, the topography of the facility, vegetation, the presence of railways and highways near the perimeter, animal migration, the passage of power lines, pipelines, cable lines, etc. Certain difficulties arise when there is a gap in the perimeter for the passage of rail or road transport (installation of gates, barriers, vehicle inspection points). If insufficient attention is paid, they can become sources of increased danger or cause frequent false alarms.

The main tactical and technical characteristics of such perimeter systems are:

• the probability of detection, i.e. the issuance of an alarm signal when a person crosses the detection zone. It determines the «tactical reliability» of the security line and should be no less than 0.9-0.95;

• the false alarm rate is the most important indicator, which largely determines the overall effectiveness of the security system;

• universality and flexibility of the detection means — the ability to work in a wide range of operating conditions in various climatic conditions to protect various objects;

• vulnerability of the system, that is, the ability to overcome the threshold without issuing an alarm signal;

• camouflage (visual and technical) of the detection means. This increases the reliability of the system, since the intruder does not know about the presence of the security alarm, and in addition, it does not distort the architectural appearance of prestigious buildings;

• reliability, durability, ease of installation and operation;

• the price of a linear meter of the security boundary, i.e. the total cost of equipment, sensitive elements, their installation and adjustment, per 1 m of the perimeter length.

To detect the fact of a person's intrusion into a protected area, various physical principles can be used, allowing with varying probability to distinguish a signal from a person against the background of interference effects of the environment. The first alarm systems were devices in the form of a vertical fence made of barbed wire, forming a loop, its resistance was measured by a resistive sensor. The latter gave an alarm signal when the loop was broken or when adjacent wires were shorted.

Although such systems exist today, their modern use is impractical both because of their appearance and because of their low efficiency — the wire becomes covered with a layer of oxide after a few months and the sensor does not work when adjacent wires are short-circuited. The probability of detection in this case drops to 20-30%.

A new step in the development of perimeter detection equipment was the creation in the State Unitary Enterprise SNPO «Eleron» in the 70s of capacitive systems using the effect of changing the characteristics of the electric field near the «antenna system» — a sensitive element in the form of a metal structure placed with the help of insulators on top of a passive fence. The use of domestic know-how — the «security electrode», protected by the USSR copyright certificate — put this development forward as a leader in perimeter alarm systems and ensured its widespread implementation for the protection of hundreds of kilometers of perimeters of a wide variety of objects.

The principle of operation of the capacitive alarm is based on measuring the capacity of the antenna device relative to the ground. In this case, the electronic unit measures only the capacitive component of the antenna impedance and does not respond to changes in resistance (quadrature signal processing using a synchronous detector). The use of an algorithm that analyzes the duration of the signal, its fronts and other characteristic features made it possible to increase the detection probability to 95% with an average false alarm rate of less than one per ten days with a blocked section length of up to 500 m. The design of the antenna device is a metal canopy made in the form of a welded lattice, allows bending in the vertical and horizontal planes, allows tracking the terrain and other topographic features of the object. With the appropriate design, the canopy does not worsen the external architectural appearance of the building.

To date, a whole family of capacitive alarms has been developed — «Radian» (Radian-M, Radian-13, Radian14). The total number of installed devices exceeds 50,000.

Optical beam infrared alarms consist of one or more pairs of «emitter-receiver» that form an invisible beam in the range of 0.8-0.9 microns, the interruption of which causes an alarm signal. The beam system can be installed either on top of the fence or directly on the ground in the form of several beams that form a vertical barrier. Unfortunately, their use in our conditions is associated with many difficulties, since snow drifts, vegetation, fog cause either false alarms or system failure.

More effective are radio beam detection devices that also use a pair of «emitter-receiver», but a different radiation range — microwave. If the detection zone of an IR sensor is with a beam diameter of 1-2 cm, the radio beam has the form of an elongated ellipsoid, the diameter of which in the middle of the zone is from 80 to 500 cm, depending on the size of the antenna and the radiation frequency. The volumetric detection zone is an undoubted advantage of the sensor, it is more difficult to overcome without an alarm signal. The operability of radio beam devices is practically not affected by rain, fog, wind, however, they require the presence of geometrically free space between the emitter and receiver during operation and stop working when snowdrifts form, «shading» the beam.

Another class of systems is vibration systems (sensing the vibration of fence elements or their deformation when trying to overcome them). As a rule, vibration systems use a triboelectric, electret, magnetostrictive or fiber-optic cable as a sensing element, fixed along the top of the fence and in its middle part. Cable deformation (its displacement by 1-2 cm), as well as fence vibrations, cause the appearance of excess charges in the triboelectric or electret cable or a change in the characteristics of the laser radiation propagating in the fiber-optic cable. It is obvious that vibration systems are subject to the influence of a wide variety of interference (wind, microseismic shaking of the soil from the passage of vehicles, hail, etc.). Therefore, to enhance noise immunity, complex recognition algorithms are used, implemented using built-in microprocessors.

A type of radio-type alarm system is the so-called wire-wave system, the sensitive element of which is a two-wire «open antenna», placed on top of the fence with the help of insulating brackets. A VHF generator is connected to one end of the antenna, and a receiver to the other. An electromagnetic field is formed around the wires, forming a detection zone with a diameter of 0.5-0.7 m. When a person appears inside it, the signal level at the receiver input changes and causes an alarm. The antenna system, unlike capacitive sensors, does not require the use of special adapters-insulators, and allows for significant sagging of the wires.

In the early 80s, the first models of detection systems were developed that used a coaxial cable as a sensitive element, the metal braid of which has perforations (holes) along its entire length or is specially thinned. The system consists of two parallel cables placed in the ground at a depth of 0.2-0.3 m along the protected perimeter with a distance of 2-2.5 m between the cables. A VHF generator is connected to one of them, and a receiver to the other. Due to the holes, part of the energy from the generator cable goes to the receiver, forming a detection zone 3-3.5 m wide and 0.7-1 m high. A system of this type is called a leaky wave line, it is completely camouflaged and can be detected only with the help of special equipment. Its use makes sense if the use of a passive barrier is impossible for some reason. The system works reliably in conditions of frozen ground, grass, low bushes, and snow cover.

The class of passive masked detection devices also includes seismic systems, which are multiple geophone sensors connected in a «braid» and placed in the ground at a depth of 0.2-0.3 m. When crossing such a line, microseismic vibrations of the ground occur with each step of a person. They are received by geophones, converted into an electrical signal and, after appropriate processing (counting the number of steps, frequency filtering, etc.), trigger the system. A modification of such a device with a sensitive element in the form of an extended hose filled with antifreeze and connected to a membrane pressure sensor is more noise-resistant. When a person appears directly above the hose, an alarm signal is generated due to a change in pressure. The system has a narrower detection zone (2-3 m) with a sharply decreasing sensitivity at its boundary, due to which noise immunity is increased. However, these systems have not become widespread, since the achieved noise immunity still does not satisfy consumers.

In some cases, a magnetometric detection system with a sensitive element in the form of a multi-wire cable placed in the ground at a depth of 0.15-0.2 m along the protected area may be of interest. All cable cores are connected in series, forming a distributed inductive «coil». The electronic unit measures this inductance and issues an alarm signal when it changes due to a person crossing the zone carrying any metal objects (firearms or bladed weapons, equipment items, etc.). The sensitivity of the system is sufficient to detect the magnetic mass characteristic of a regular pistol and even more so for a machine gun or carbine. At the same time, the system does not react to animals such as wild boars, hares, dogs and cats crossing the zone. It is promising for border protection or in the conditions of northern oil production regions, where migrations of wild animals are inevitable.

For special objects, where an exceptionally high false alarm rate and detection probability are required, the State Unitary Enterprise SNPO «Eleron» has developed a combined system that combines several sensors with different physical operating principles. The location of the sensitive elements is selected in such a way that a signal from human penetration occurs simultaneously in several sensors, while interference that has a different effect on each of them is spaced out in time. This is the «Protvа-4» system, which combines devices with three operating principles — a mesh fence with a triboelectric cable that reacts to vibrations, a radio beam directed parallel to the mesh, and a sensor based on the «leakage wave line», placed in the ground in the immediate vicinity of the mesh fence. The electronic unit processes signals from each sensor in accordance with the logic scheme «2 of 3», i.e. an alarm signal is generated only when any two sensors in the system are triggered simultaneously. This ensures a sharp (by an order of magnitude) reduction in the frequency of false alarms, while maintaining a high probability of detection.

Here is a brief description of the perimeter detection devices developed and mass-produced by GUP SNPO «Eleron».

The capacitive perimeter detector «Radian 14» is the latest modification of the well-known family of capacitive perimeter security alarms. It was developed in 1997 based on the study of long-term operation experience of similar devices «Radian-M» and «Radian-13» and embodied the achievements of circuit design, modern signal processing algorithms and a new element base.

The fundamental difference of the «Radian-14» device, which allowed to significantly increase its noise immunity, is the use of a two-channel signal processing circuit and a «compensation» algorithm. Its essence is that the interference signal in the resistive channel is subtracted from the signal in the capacitive channel and prevents false triggering. The circuit is designed in such a way that the threshold device responds only to one polarity corresponding to the signal in the capacitive channel. Therefore, the interference signal in the resistive channel, no matter how large it is, can only compensate for the capacitive component and will not cause the threshold device to trigger.

A common cause of false alarms is the impact of pulsed electrical interference and especially radio interference, typical for urban conditions of intense «radiosmog». In the new device, pulsed radio interference occurs strictly simultaneously in both channels and is thus compensated (subtracted), which prevents false alarms. Thus, «Radian-14» has the following advantages:

• high noise immunity to rain, wet snow, contaminated insulators, etc.;

• high protection against industrial electrical and radio interference.

This made it possible to achieve an almost tenfold increase in the operating time to false alarm — 2000 hours (instead of 250 hours in the Radian-M device).

In addition, the introduction of a compensating channel made it possible to abandon the mandatory use of special insulator adapters, as well as a protective electrode. Conventional insulators used in electrical installations can be used to install the «Radian-14» device. This significantly reduces the cost of the entire system, provides great opportunities for design and engineering solutions to improve the appearance and camouflage of the antenna system. A version of the antenna canopy system has been developed, which includes installation elements (plastic brackets, steel wire, fasteners) and is supplied together with the electronic unit — the «Yarus» tool.

«Radian 14» is made in the same case as «Radian-13», has the same design and docking parameters. This allows you to easily replace the old device with a new one, and there is no need to reinstall the antenna system, power and signal lines.

The vibration cable detection device «Dolphin-M» consists of an extended sensitive element in the form of a special triboelectric cable and an electronic unit for amplifying and processing the signal. The cable is attached to a passive fence made of metal mesh and converts its vibration, created by the intruder, into an electrical signal, which, after processing in the electronic unit, forms an alarm signal.

«Dolphin-M» is capable of reliably functioning in conditions of strong wind, snow, ice, rain, etc. and industrial interference (nearby traffic, power lines, radio stations). It gives an alarm signal when a person tries to climb over the fence, damage the mesh, bite the wire, cut the cable, etc.

The detection device «Dolphin-M» is widely used to block nuclear power plants, industrial enterprises, banks, administrative buildings.

The sensitive element (SE) of the vibromagnetometric detection device «Drozd» is a system of insulated wires fixed to the passive fence along the entire perimeter section. When overcoming the fence, the intruder causes its vibration (excess noise), which, in turn, leads to the oscillation of the SE wires in the constant magnetic field of the Earth and the generation of electrical signals. They are sent to the processing circuit of the electronic unit of the device and, when certain specified detection criteria are met, cause the output alarm relay to operate.

The Drozd detection system can be installed on the following types of passive fences: concrete, brick, wood, metal mesh (Rabitsa mesh), as well as garden fences made of stamped, welded or forged metal elements.

The Drozd detection system has a number of advantages over known perimeter systems:

• compared to the Dolphin M system, it does not require the mandatory use of a metal mesh fence for the canopy version, which reduces its cost. In addition, the use of inexpensive P-274 wire (volevka) instead of a special triboelectric cable also reduces the cost of the system;

• compared to the «Radian» product, it does not require a «visor» for fastening wires, or the mandatory use of expensive insulator adapters;

• greater versatility of use allows it to be used on almost all types of fences, as well as for protecting overpasses, walls and roofs of buildings;

• high noise immunity: the operation of the device is practically not affected by rain, snow, fog, tall grass or tree branches in the immediate vicinity of the sensitive element (intertwining of the sensitive element wires with bindweed, ivy, etc. is allowed);

• original technical solutions ensure resistance to electromagnetic interference of industrial origin (patent of the Russian Federation No. 2075905 dated 20.03.97).

The two-position radio beam detection device RLD-94 consists of a transmitter and a receiver of microwave energy, installed on special supports at the edges of the blocking line. The transmitter antenna emits a flow of microwave energy directed at the receiver antenna. The appearance of an intruder in the detection zone causes modulation of the received signal. After appropriate processing in the electronic unit, the signal turns on the output relay.

The radio wave two-wire detection device «Uran-M» is designed to block the top of passive fences (concrete, brick, metal), as well as roofs and walls of buildings.

The CO sensitive zone is formed by two parallel wires, fixed along the top of the fence with non-conductive brackets made of plastic or wood. The distance between the wires is 0.4-0.5 m, the length of the blocked section of the perimeter is from 20 to 250 m.

On one side of the area, a generator of probing radio pulses is connected to the wires, on the other — a receiver. Two wires act as an «open antenna». When a person appears in the antenna sensitivity zone, the signal level at the receiver input changes due to the absorption and re-emission of energy, which is a sign of a violation. The sensitivity zone cross-section is an oval with dimensions of 0.7 x 0.4 m. The main advantages of the «Uran-M» security system:

• the ability to track the relief of the security line (fence) — turns, height differences, etc. and, as a result, a decrease in the total number of electronic units;

• an equal cross-section of the detection zone along the entire blocking area;

• ease of installation and maintenance of the linear part of the CO;

• sufficiently high noise immunity to both meteorological factors and industrial interference.

The Binom-M, a camouflaged leaky wave line perimeter protection device, uses a coaxial cable with a perforated metal braid along its entire length as a sensitive element. The device consists of two parallel cables placed in the ground at a depth of 0.2–0.3 m along the protected perimeter with a distance of 2–2.5 m between the cables. A VHF generator is connected to one of them, and a receiver to the other. Due to the holes, part of the energy from the generator cable goes to the receiver, forming a detection zone 3–5 m wide and 0.7–1 m high. The Binom-M should be used if the use of a passive barrier is impossible for some reason, and also if complete camouflage of the CO is required. The system operates reliably in conditions of frozen ground, grass, low bushes, snow cover. The length of the blocking section is up to 250 m, power supply from a 20-30 V DC network, power consumption is no more than 0.7 W.

The combined perimeter system Protvа-4М is a modern, highly effective detection tool for protecting the perimeters of especially important facilities and extended boundaries with increased requirements for security reliability.

The high efficiency of the system is ensured by the combined use of three detection means, built on different physical principles and combined into a single system using the logical scheme «2 out of 3». Combining detection zones ensures the operation of at least two means in any way a person overcomes the blocked zone. At the same time, a false alarm of one of the means does not cause the entire system to be triggered. The use of this design principle allows for an order of magnitude increase in the operating time before a false alarm (up to 5000 hours) and puts the system out of competition with any other perimeter systems.

In addition, the «Protvа-4М» system has a unique property of indicating the direction of the intruder's movement (towards the object or from it).

The system includes the following three different detection means:

•a two-position radio beam means (with a carrier frequency of 735 GHz);

• a radio-technical detection device based on cables buried in the ground with perforated braiding («leakage wave line»);

• a vibration device based on a triboelectric cable fixed to a metal mesh fence.

Along with the linear detection means, the Protvа-4M includes a microprocessor control and indication panel (LUI-12), which combines all the linear units. It controls the entire system and displays alarm and service information. PUI-12 allows you to connect a computer with a graphic image of the blocked boundary of the object displayed on the monitor screen.

The seismomagnetometric detection device «Duplet» is a unique perimeter detection device that has no analogues either in our country or abroad! The only means that allows you to distinguish a person (armed intruder) from animals, including large ones.

«Duplet» can be used to protect (signal blocking) the perimeters of objects that do not have a fence, or act as a preliminary extended signaling security line. It is best used at objects where it is impossible to exclude animal migration.

The operating principle of the «Duplet» is based on the registration, by means of a cable sensitive element, of both seismic signals (ground vibrations) that occur when a person moves, and changes in the magnetic field in the near zone when moving ferromagnetic masses, such as weapons. These signals are converted into electrical signals in electronic units and, after processing according to a specific algorithm, trigger the output alarm relay. A specially developed cable KTPEDEP 10x2x0.5 is used as a sensitive element, the main feature of which is the presence of two screens designed to generate a seismic channel signal. The internal wires are combined into a loop that responds to the magnetic component of the signal.

The CO is resistant to the impact of such natural factors as all types of precipitation, small and medium-sized animals, as well as to the impact of transport and industrial interference.

The rapidly deployable radio beam device «Vitim» is designed for urgent organization of a temporary security line in an unprepared area. It consists of two receiving and transmitting devices in the form of racks. This design allows for their quick installation on any type of soil. In addition, «Vitim» includes a remote indication unit showing the number of the triggered section. Each rack and indication unit have built-in battery power sources. When an intruder crosses the detection zone in the form of an elongated ellipsoid between the racks at a speed of 0.1 to 6 m/s, the system generates an alarm signal and indicates the number of the triggered section on the indication unit. Alarm signals are transmitted via a radio beam, so no cable connections are required. This ensures high speed of system installation: a group of three people can install and adjust the system within an hour. The distance between the racks is 20-120 m, the maximum length of the security line is 1200 m.

SO «Vitim» has no foreign analogues and constantly arouses interest at international exhibitions.

The radio wave detection device «Gazon» is designed to block sections of the perimeter of temporary objects in unprepared terrain with vegetation and complex terrain and configuration of the boundary, as well as to block the top of metal barriers (lattices, nets).

The product is designed to operate in autonomous mode or with a data collection and display system. In autonomous mode, «Gazon» is powered by a 10NKGTS-1D battery, and the operation indication functions using a built-in sound or external indicator controlled by the contacts of the output relay.

The product consists of an electronic unit (EU) and a wire line placed along the blocked section and connected to the EU. The wire line is created using assembly kits (ACS). ACS for soil and asphalt contain dielectric posts installed at intervals of 6-7 m. The upper wire of the line is fixed to the posts at a height of about 1.5 m, the lower wire is laid under the upper wire along the ground or buried to a shallow depth (3-5 cm). The detection zone is formed between the upper wire and the ground surface.

The length of the blocked line when installed on the ground is 40-125 m, on the fence — 40-250 m, the width of the detection zone (on the ground) is no more than 3 m.

Power supply voltage is 10.2-15 V or 20-30 V. The current consumed in standby mode, at a voltage of 12 V is no more than 25 mA.

The TROS-1 camouflaged wire-break alarm is designed to quickly organize a security line for temporary locations of people, equipment, cargo, objects, or the adjacent territory.

The operating principle is to register the integrity of an electric circuit formed by a two-wire microwire. A wire break during an intruder's entry causes an audible signal. The small diameter of the wire ensures a high degree of camouflage on the ground and a high probability of detection. The microwire deployed on the ground is not reused.

The maximum length of the protected line is 1.5 km. It is equipped with two wire cassettes. Power voltage (battery) — 1.5V. Continuous operation time without changing the power source is at least 6 months. Operating temperature range from -50 to +50°C. Dimensions (diameter, length) 53×260 mm.

Thus, the State Unitary Enterprise SNPO «Eleron» has created a wide range of perimeter detection equipment, allowing to solve a wide variety of tasks in protecting virtually any facility.