RU2319319C1 - Method for composing wireless information transfer networks and a high-altitude rotary-wing platform for realization of the method - Google Patents

Abstract

FIELD: navigation devices of aerial platforms used for composing wireless information transfer networks and working within range of direct visibility in a given geographical location.

SUBSTANCE: method for composing wireless information transfer networks includes positioning aerial telecommunication platforms at given altitudes by creating a lifting force for keeping them in given points of regional network of geographical location by means of remotely and/or autonomously piloted aircraft, which is kept in given point together with the platform by means of connection to given surface point of geographical region with flexible traction, which is used as a channel for feeding electric power energy to ensure creation of traction vector of aircraft, in accordance to the invention, as electric energy supply channel of the flexible traction an electric conductor is used which may be separated in its middle part, and to ensure lightning protection of information transfer network ends of electric conductor separation section are distanced for not less than value L_br, which is derived from formula

, where E_th - average intensity of electric field in thunderstorm clouds, E_br - intensity of electric breakdown of air, H_al - altitude at which the aircraft is positioned. The high-altitude rotary-wing platform contains a station for receiving and transmitting signals in given geographical location, mounted on an aircraft which has instrument bay and screw propeller in form of electric motor with reducer and traction screw, and connected to a conductor-and-support cable by means of biaxial cardan suspension, second each of the cable is fastened with possible change of cable length in given point of surface of geographical location, and is connected to electric energy supply at that point and has no less than one electro-isolated current conductor for supplying electric energy to electric motor of screw propeller, in accordance to the invention, current conductors are made with separable connector in middle part of cable length with possible movement of at least one end of separable connector along the cable and fastening of separable connector ends at a given distance from each other. Coaxial conductor-and-support cable may contain at least two mutually mobile electro-isolating elements, one of which is in rigid connection with first end of separable connector of current conductor of the cable, and the other one - to second end of separable connector of current conductor. Electro-isolating elements may be positioned inside the coaxial conductor-and-support cable under the layer of external climatic and mechanical protection and/or under isolating layer with possible movement of at least one electro-isolating element along aforementioned layers. External climatic and mechanical protection layer may contain at least one lightning-draining channel, grounded in given point of surface of geographical region.

EFFECT: increased reliability of navigation of high-altitude platforms of telecommunication information network due to increased lightning protection of power supply channel.

2 cl, 3 dwg

Description

The present invention relates to means for providing navigation for high-altitude platforms used to form wireless networks for transmitting information along a line of sight in a given geographical area.

Wireless broadband networks are practically unrivaled in terms of deployment efficiency for geographical areas in which a large territory is combined with a low population density, broadband wireless solutions are of particular importance, as they allow the creation of telecommunication infrastructure in vast territories economically and quickly. This is especially important for informatization of remote and rural regions and solving one of the most important problems of information security - the problem of "information inequality" of the regions.

The use of air platforms provides telecommunication coverage of large geographical regions. Along with the creation of regional data, voice and video information networks, high-altitude platforms can be used for video surveillance within a radius of 70-80 km (for example, in border areas or monitoring traffic flows), forest fire detection, environmental monitoring using sensor networks, geological and geophysical intelligence, radiological monitoring, etc.

Helium airships located at an altitude of 20-22 km, platforms such as a flying wing, airplanes and helicopters are considered as such high-altitude platforms.

Known mobile communication system, including mobile telephones connected by radio to base stations, at least some of which are mobile, connected by radio to a fixed gateway gateway connected via a signal line to a telephone exchange, at least one of mobile base stations are located on an overhead mobile object made in the form of an aerostat (RF patent for utility model No. 28419, 2002).

A omnidirectional high-altitude antenna is known, which is a single-wire transmission line, one end of which is loaded on an agreed load and is mounted on a balloon, and the other end is connected to a transceiver and is attached to the ground with an anchor, which allows to increase the communication range (RF patent No. 2099827, 1994) .

Known balloon antenna in the form of a metal container with radial conductors attached to its body, made in the form of a loop. In this antenna, position stabilization occurs when using at least four special files (RF patent No. 2097880, 1995).

Known antenna wire for an antenna supported in an upright position by an aircraft, comprising a load-carrying cable of synthetic fibers and a conductive braid of aluminum conductors laid on the surface of the cable at an angle (RF patent No. 2030039, 1991). The specified wire does not have sufficient reliability for prolonged use in wireless data transmission networks.

For all of the above analogues, in addition to individual shortcomings, there is a common disadvantage associated with the use of a carrier - an aerostat, which consists in the need to use bulky and relatively expensive berthing devices to lower and hold the aerostat on the ground during storm and lightning warnings.

The duration of navigation when using high-altitude platforms of regional networks at altitudes of up to 1 km in natural environmental conditions in open spaces determines the priority of providing lightning protection for the navigation system of air platforms and the operability of the telecommunication network. It should be borne in mind that thunderstorm activity in central Russia is 2.9 lightning strikes into the Earth’s surface area of 1 square kilometer per year (by year we should mean the thunder season).

Known among devices for protecting antennas from lightning strikes, in particular, a lightning rod, which is a radio-transparent dielectric tube, which is closed and grounded from below. Pressure reduction inside the pipe is created by the oncoming wind. The developing lightning creates a gas discharge gradient in the pipe. A lightning discharge is discharged into the ground by plasma inside the pipe (US Pat. RF No. 19992, 1994).

There is a universal method of protecting an object from linear, clear and ball lightning, which solves the problem of protecting any object from direct damage by all types of lightning, as well as from the penetration of ball lightning into it, and with the same and high degree of reliability. To this end, the method introduced an additional operation of creating a zone near the protected object with a magnetic field strength exceeding the Earth's geomagnetic field strength by installing a metal magnetic dipole on a known lightning rod, which attracts ball lightning that appears in its vicinity and destroys them ( Pat. of the Russian Federation No. 2152695, 2000).

A lightning rod is known, comprising a central lightning rod, a central grounding rod, side rods, a dielectric housing with a metal cover into which a central lightning rod and side rods are inserted, as well as a lower opening into which a central grounding rod is inserted. Capacitor plates in the form of metal plates and two successive chains of resistors are placed in the housing. The upper plate of the upper capacitor is connected to the housing cover. The lower plate of the lower capacitor is connected to the central ground rod. The arresters are located on adjacent plates of adjacent capacitors. The first findings of the resistors of the first circuit are connected to the upper plates of the capacitors. The first findings of the resistors of the second circuit are connected to the lower plates of the capacitors. The number and ratings of resistors in both circuits are the same. The housing is filled with a dielectric, which is capable of self-healing of the initial properties after the device is triggered. The technical result consists in increasing the service life and increasing the efficiency of the device (US Pat. RF No. 2208887, 2003).

A device for protecting underground cables from thunderstorms is known, in which protection against direct lightning strikes into the ground is made by applying an electrical circuit, the specific properties of which arise in the electromagnetic field of a thunderstorm and are used to divert and drain the lightning trunk into the plane of the circuit. A lightning protection circuit containing a rectangular frame made of a metal cable is closed to an electric capacitor, laid on the basis of weak conductivity, and has the properties of a receiving antenna (RF application No. 95103385, 1996).

The closest analogue is the method of forming regional wireless networks for the transmission of information, implemented in a telecommunication air platform (patent for pol. Mod. Of the Russian Federation No. 52296, publ. In bulletin No. 7, 2006). The peculiarity of the method of forming regional wireless information transmission networks, including placing airborne telecommunication platforms at specified heights by creating lift to hold them at predetermined points in the regional network of a geographical region and stabilizing the position of platforms at these points, is that the lifting force for each platform is created using a remotely and / or autonomously piloted aircraft due to the vertical component of its thrust vector, and holding it aircraft and platform at a given point regional geographic area network is performed by associating them with a given point of the surface geographic region flexible rod, which is used as supply energy supply path for creating thrust vector of the aircraft. Stabilization of the position of the platform is ensured by inertial navigation of the aircraft at a given point in the regional network of the geographical region.

Telecommunication air platform is characterized in that the lifting force generating unit is made in the form of a fuselage with an instrument compartment connected to a screw propulsion device in the form of at least one nacelle, in which an electric motor with a gearbox and a traction screw are installed, while the fuselage is connected via a biaxial a gimbal with a cable, the second end of which is fixed with the possibility of changing the length of the cable at a given point on the surface of the geographical region and is connected electrically to the source th energy at this point.

The disadvantage of these technical solutions is the fact that the cable cable connecting the aircraft with a ground source of electrical energy is a natural lightning rod, because the aircraft should be located above natural or artificial structures that worsen the conditions for receiving and transmitting a telecommunication information network, which leads to a decrease in its reliability.

The technical result of the proposed inventions is to increase the reliability of navigation of air platforms of a telecommunication information network by providing increased lightning protection of the power supply channel for power supply of electric motors of screws and devices of air platforms.

The specified technical result is achieved in a method of forming regional wireless information transmission networks, including placing airborne telecommunication platforms at predetermined heights by creating a lifting force to hold them at predetermined points in the regional network of a geographical region using a remotely and / or autonomously piloted aircraft, the retention of which and the platform at a given point, they are carried out by linking them to a given point on the surface of the geographical region with flexible traction, using used as a channel for supplying electric energy to the aircraft to ensure the creation of a thrust vector for the aircraft, in that an electric wire with the possibility of its connector in the middle part is used as a channel for supplying electric energy to this flexible thrust, and the ends of the electric wire connector are bred to provide lightning protection for the information transmission network the distance is not less than the value of L _CR , which is calculated by the formula

where Egr is the average electric field in thunderclouds, Epr is the electric breakdown air,

Nysv - the height of the aircraft.

The indicated technical result for a high-altitude rotorcraft platform containing a signal receiving and transmitting station in a given geographical region, mounted on an aircraft having an instrument compartment and a propeller in the form of an electric motor with a gearbox and a traction screw and connected by a biaxial cardan suspension with a cable cable, the second end of which is fixed with the possibility of changing the length of the cable at a given point on the surface of the geographical region, is connected with a source of electric energy at this point and has at least one electrically insulated conductive conductor for supplying electrical energy to the electric motor of the screw propulsion device, is achieved by the fact that the conductive conductors are made with a connector in the middle part of the cable length with the ability to move at least one of the ends of the connector along the cable and fixing them at a given distance from each other.

In addition, the coaxial cable cable may contain at least two electrically insulating elements movable relative to each other, one of which is rigidly connected to the first end of the cable conductor connector, and the other to the second end of the cable conductor connector.

In addition, the insulating elements can be placed inside the coaxial cable under the layer of external climatic and mechanical protection and / or under the insulating layer with the ability to move at least one of the insulating elements along these layers.

In addition, the layer of external climatic and mechanical protection may contain at least one lightning conduit, grounded at a given point on the surface of the geographical region.

The invention is illustrated by drawings.

Figure 1 - shows a General diagram illustrating the invention.

Figure 2 - presents a structural diagram of a platform with a single-screw propulsion.

Figure 3 - presents a structural diagram of a detachable part of a coaxial cable-cable connecting the aircraft with a source of electrical energy at a given point on the surface of the geographical region.

The high-altitude rotorcraft platform 1 (Fig. 1) contains a node for generating lift (aircraft) 2, a station 3 for receiving and transmitting signals in a given geographical region, which serves information consumers 34a, 34b, 34 s, 34d, 34e, 34f . The node forming the lifting force 2 is made, for example, in the form of a fuselage 4 (figure 2) with the instrument compartment 5 and is connected with a screw propulsion 6 in the form of at least one nacelle 7, in which an electric motor 8 with a gearbox and a traction screw is installed 9. The fuselage is connected via a biaxial gimbal 10 with a cable 11, the second end of which is fixed with the possibility of changing the length of the cable, for example, on a cable reel 12 at a given point on the surface of a geographical region and is connected to an electric energy source 13 this point.

An autonomous control system is placed in the instrument compartment, consisting of a microprocessor 14 and a strapdown inertial block 15, an altimeter 16, a magnetometer 17, a GPS receiver 18, and steering machines 19 for turning rotation axes of electric motors and screws connected to its inputs gondola or fuselage on a gimbal.

A station 3 for receiving and transmitting signals in a given geographical region is made in the form of a base station of a wireless broadband access system 20 and is located in the instrument compartment, which also contains a battery 21, voltage converters 22, secondary power sources 23. The instrument compartment also contains a surveillance camera 24.

The cable cable 11 is made coaxial with the support rod 25 sequentially located from the center to the periphery, the qivlar carrier layer 26, the information fiber-optic layer 27, the insulation layer 28 and the layer of external climatic and mechanical protection 29. In the insulation layer along the entire length of the cable at least two electrically insulated conductive conductors 30 are arranged for supplying electric energy from the surface of a geographical region to the electric motors of the lifting force generating unit.

At least two electrically insulating elements 31 movable relative to each other are placed in a coaxial cable cable, one of which is rigidly connected to the first end of the cable conductor connector 30 of the cable cable, and the other to the second end of the cable conductor connector 30.

These electrical insulating elements 31 are placed inside a coaxial cable under a layer of external climatic and mechanical protection 29 and / or under the insulating layer 30 with the possibility of moving at least one of the electrical insulating elements 31 along these layers.

The layer of external climatic and mechanical protection may contain at least one lightning discharge channel 32, grounded at a given point on the surface of the geographical region and placed in the guide element 33.

The operation of a high-altitude rotorcraft platform is as follows.

The lifting force is created by a propeller driven by an electric motor, the power of which is electric power supplied through the cable conductors from the surface of a geographical region or a battery. To create a horizontal component of the thrust of the screw, an electric motor mounted in a gimbal is tilted in the desired direction with the help of two steering machines 19.

One of the main advantages of the proposed technical solution is the ability to use a well-developed technology for the transmission of electrical energy and information flows using a cable cable. The presence of copper wires in the cable ensures reliable power supply to the platform electric motors and their operation for a long time without lowering the platform to the ground (at least one year); the optical fiber in the cable allows you to transfer large amounts of information from board to ground and from land to board at high speed (100 Mbps).

In addition, these platforms can provide video surveillance functions and a number of other functions that have been described previously.

The initial data in the event of a thunderstorm situation and the necessary parameters of a telecommunication switching system using an air platform with flexible traction, providing the necessary lightning protection, are given below.

When lightning hits the conductor, a high current energy in a split second heats the wiring to such a temperature that it simply burns out. This phenomenon applies to all conductors whose diameter is less than 16 mm of copper. For these reasons, the grounding of the antennas in accordance with international IEC standards is required to be performed with a diameter of at least 16 mm of copper, which corresponds to the cross-section of the wire

The following are the minimum weight and size requirements that a high altitude rotorcraft must satisfy:

- the mass of radio equipment placed on the platform is not less than 30 kg;

- platform hover height up to 200 meters;

- weight of cable cable 12 kg;

- power consumption of radio equipment 600 W;

- supply voltage of radio equipment 5 V and 12 V DC;

- time of continuous operation of the equipment without maintenance, at least a year;

- the performance of the device in all climatic zones of the region;

- operating temperature range of radio equipment -55 ° С - + 55 ° С;

- wind speed up to 20 m / s.

To meet the above requirements, it is necessary to choose a rational scheme for building a telecommunications platform that has the best overall dimensions.

With the required propeller thrust of 500 n, the mass of the electric motor is Mq = 10 kg, respectively, and the power consumption is 10 kW.

According to the reference data [Reference engineering. In three volumes. Volume 1. Ed. Acad. E.A. Chudakov M., GINTI "Mechanical Engineering", 1951, 1036 pp.] The average efficiency of the helicopter's lifting force is approximately E = 0.2 hp (horsepower) per 1 kg of lifting force. Given that:

1 hp. = 75 kgm / s; 1 kW = 102 kgm / s; then 1 hp = 0.736 kW.

Find the lift coefficient for the helicopter:

To determine the parameters of the electric cable, you must know the permissible current density. For an approximate calculation we use reference data.

So for non-insulated aluminum wire (the lightest of the widely used conductors) outdoors without insulation with heating up to 70 ° C permissible current density

For the convenience of comparisons of options, the calculation will be carried out at a power of P = 1 kW. Then:

For an approximate calculation (in order of magnitude), we will accept the permissible current density somewhat lower due to the inevitable presence of insulation (even the most elementary). We take a current density with a certain margin in relation to the permissible -

We also neglect the voltage drop in the cable, as it can be compensated on Earth.

Let us take the voltage drop at the payload (on the electric motor and aircraft devices) equal to U = 100 V. Then the wire cross section will be:

Since the current (J) flows in two directions, we have at least two wires in the cable cable, i.e. S ₂ = 4 mm ² ;

Then the mass of 1 m of aluminum wire with a transmitted electric power of 1 kW will be

For 10 kW, we get about 108 g / m.

However, in order to ensure navigation and operability of the telecommunication switching system using an air platform with flexible traction after lightning strikes the conductor (so that it does not burn out completely), in accordance with the requirements of international IEC standards (S = 201 mm ² ), the wire cross section must be increased not less than fifty times, which, accordingly, proportionally increases the weight of the cable.

In addition, it must be borne in mind that with increasing operating voltage, the proportion of insulation in the weight of the cable will increase. In turn, an increase in insulation will positively affect resistance to atmospheric electricity.

Regarding atmospheric electricity, the following data are available [I. Imyanitov, D. Tikhiy. Beyond the bounds of the law of L., Gidrometeoizdat, 1967,143 p.]:

- the average electric field strength (E) in thunderclouds is 1000-2000 V / cm,

- in individual clouds, the intensity can reach values of 4000-5000 V / cm,

- vertical lightnings are 10-12 km long,

- horizontal reach a length of 50 km and even 150 km,

- the electric breakdown intensity of dry air at 1 atm is E = 30 kV / cm.

Based on these data, voltage can occur at a length (height) of 200 m at E = 2 kV / cm

U = 2 [kV / cm] · 20,000 [cm] = 40,000 [kV] = 4 · 10 ⁷ V.

If you break the wire using the plug connector and part the ends to a distance (L _CR ), then with E _breakdown = 30 kV / cm, we get:

Thus, spreading the wire to a distance L> L _CR , breakdown can be prevented without increasing the cross-section of the wires and, accordingly, the mass of the cable.

In this case, an automatic mode of operation of the platform using the energy of the onboard battery is provided.

However, several circumstances need to be considered.

Firstly, humid air has a lower dielectric strength, like an insulator.

Secondly, since lightning discharges nevertheless occur at the average average electric field strength (E) of 1000-2000 V / cm indicated above, there are certain initiators of breakdown. They are various sources of primary ionization. They can be showers of cosmic rays, and air pollution. Therefore, here we can only talk about the probabilities of reducing the risk of breakdown. The requirement that when the cable is torn through (SHR) there should be no bare (uninsulated) wires with sharp ends on it, is not superfluous. From the sharp ends of the conductors there is a "drain" of charges (Elm lights), which can also initiate a breakdown. The option is also not excluded when in parallel with the cable you will have to lift the uninsulated lightning conductor wire upward. At the top, it should be above the platform.

Thus, the application of the proposed inventions ensured a technical result consisting in increasing the reliability of navigation of high-altitude platforms of a telecommunication information network by providing increased lightning protection of a power supply channel.

Claims (5)

1. A method of forming a wireless information transmission network, including placing airborne telecommunication platforms at predetermined heights by creating a lifting force to hold them at predetermined points in a regional network of a geographical region using a remotely and / or autonomously piloted aircraft, the retention of which and the platform at a given point is carried out by linking them to a given point on the surface of the geographic region by flexible traction, used as a channel for supplying electric energy to power for creating a vector of the aircraft thrust, characterized in that the channel quality of electric power supply of this flexible rod is used electrically, with its connector in the middle part, and to provide lightning protection information transmission network diluted ends of the electric wire connector by a distance not less than the magnitude L _ave, which is calculated by the formula

where Yegr is the average electric field strength in thunderclouds, EPR - the electric breakdown of air, Nysv - the height of the aircraft. 2. A high-altitude rotorcraft platform containing a signal receiving and transmitting station in a given geographical region, mounted on an aircraft having an instrument compartment and a propeller in the form of an electric motor with a gearbox and a traction screw and connected by a biaxial cardan suspension with a cable, the second end which is fixed with the possibility of changing the length of the cable at a given point on the surface of a geographical region, is connected with a source of electrical energy at this point and has at least one electrically insulated conductive conductor for supplying electric energy to the electric motor of the screw propulsion device, characterized in that the conductive conductors are made with a connector in the middle part of the length of the cable cable with the possibility of moving at least one of the ends of the connector along the cable cable and fixing them on given distance from each other. 3. The platform according to claim 2, characterized in that the coaxial cable-cable contains at least two electrically insulating elements movable relative to each other, one of which is rigidly connected to the first end of the connector of the conductive conductor of the cable-cable, and the other to the second the end of the conductor connector. 4. The platform according to claim 3, characterized in that the insulating elements are placed inside the coaxial cable cable under a layer of external climatic and mechanical protection and / or under the insulating layer with the ability to move at least one of the insulating elements along these layers. 5. The platform according to claim 4, characterized in that the layer of external climatic and mechanical protection contains at least one lightning conduit, grounded at a given point on the surface of the geographical region.

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