WO2022237995A1

WO2022237995A1 - Aerial platform lighter than air equipped with trajectory control systems and inflatable antennas for data and power transmission

Info

Publication number: WO2022237995A1
Application number: PCT/EP2021/066922
Authority: WO
Inventors: Victor MIHEREA; Gabriele SARTOR
Original assignee: Stratobotic S.R.L.
Priority date: 2021-05-10
Filing date: 2021-06-22
Publication date: 2022-11-17
Also published as: IT202100011987A1

Abstract

A lighter-than-air aerial platform is consisting of two or more inflatable elements (100), balloons or dirigibles, a propulsion system (400), aerodynamic lifting and flight surfaces (500) which are optionally inflatable, an on-board electronic system (303) and a release actuator that separates or deflates at least one of the inflatable elements or balloons or airships; wherein the release actuator is located at the apex of the platform, and allows the rest of the system to descend in a controlled manner to be then recovered on land or at sea; wherein at least two of the inflatable elements, balloons or dirigibles that compose it are connected together by one or more cables (200) which place them at two different flight altitudes and wherein at least one of the inflatable elements, balloons or dirigibles that generates its own vertical force due to the Archimedes effect is an antenna (600) for receiving or sending radio, light or radiation signals through the use of specific sensors or cameras.

Description

AERIAL PLATFORM LIGHTER THAN AIR EQUIPPED WITH TRAJECTORY CONTROL SYSTEMS AND INFLATABLE ANTENNAS FOR DATA AND POWER

TRANSMISSION

The present invention relates to an aerial platform lighter than air which includes one or more additional inflatable chambers, which integrate sensors or cameras or antennas that are capable of being aimed at specific objects on the ground or in flight to interact with radio signals, electromagnetic waves, light rays or lasers coming from external sources or directed to them. Some lighter-than-air aerial platforms currently proposed are composed of several inflatable chambers or balloons connected to each other, and can be stationed on a precise area of the ground, but none of the current solutions integrates inside inflatable antennas capable of being pointed, mechanically or electronically, towards external signals or objectives and at the same time participate in the control of the flight of the platform itself, developing static vertical forces (due to the Archimedes effect) or aerodynamic forces (lift and drag), all under the control of

1 on-board processing units or of any operators on the ground.

Furthermore, there is no reference to the fact that a system of this kind can receive energy from other objects, present in flight or on the ground, through the reception of radio signals or light rays or lasers transmitted by them, to use it in the control of a flight and possibly accumulate it on board. For example, patent "Systems and applications of lighter-than-air (LTA) platforms" (US9678193B2, GM Knoblach) and other similar ones propose a network of small aerial platforms lighter than air for the transmission of radio signals, making use of low directivity and low gain antennas; therefore, no swiveling antennas or inflatable antennas of any kind are proposed and the flight control systems are related only to the variation of the flight altitude since the platforms do not have propellers and aerodynamic surfaces. The "Multibody aircrane" patent (US8157205B2, BK McWhirk) and others similar ones, instead, propose a lighter-than-air platform composed of two or more inflatable elements connected by a variable length cable and possibly equipped with a propulsion system and aerodynamic surfaces capable of generating lift and possibly maintaining a fixed position with respect to the ground, but there is no hint of the possibility that one of the balloons or inflatable chambers that make up the system and that support the flight could be oriented so as to point towards a specific target on the ground or in flight, even that these may include inflatable antennas. Patent

2 "Information processing apparatus and information processing method" (US10267949B2, T. Narabu) and others similar ones, propose flying platforms that are lighter than air, but do not have inflatable antennas inside them. Patents "Ground based inflatable antenna" (US20060071872A1, P. Gierow),

"Automatically Deployable Communications System"

(US20140266970A1, WR Clayton) and others similar ones, propose inflatable antennas of various types and complexity for applications on the ground possibly composed of several chambers nested inflatables: however, there is no reference to solutions for their use in flight. Patent "Spherical reflector antenna for terrestrial and stratospheric applications" (US20180198214A1, CK Walker) and others similar ones, describe typically spherical antennas equipped with a single inflatable chamber and devices for electronic pointing to be used in space aboard satellites or in the stratosphere: there is no reference to joint methods of mechanical and electronic pointing of the antenna, simultaneous installation on the same aircraft of several antennas capable of operating as radio repeaters and not even references to the possibility that the antenna is an integral part of the flight system, contributing to control its trajectory.

The present invention, on the other hand, as claimed in Claim 1, has the objective of making an aircraft lighter than air, composed of two or more inflatable elements (such as

3 balloons, airships or flexible containers filled with gas), connected to each other by cables or other mobile or extendable elements, of which at least one is able to deviate a variable distance from at least one of the others and of which at least one is made up of an inflatable antenna which can be mechanically oriented towards specific directions or objectives, on the ground or in flight, fixed or mobile. The inflatable antenna contributes to the sustenance and control of the flight of the aircraft by generating its own upward force (due to the Archimedes effect) which, if the inflatable antenna can be moved away from or brought closer to one or more carrier balloons by means of extensible cables or other similar solutions as described in precedence, can be modulated and modified during the flight to allow a change in altitude of the entire system. Furthermore, since the distance of at least one of the inflatable elements with respect to the rest of the body of the aircraft is variable, this element will fly at a different altitude compared to that of the rest of the aircraft and can generate a static lifting force (ie Archimedes force) and/or aerodynamic forces (i.e. lift and drag) predetermined due to the different atmospheric conditions present at the two different altitudes. These forces can be modulated, by varying the distance between the inflatable elements, so as to make changes in the trajectory of the aircraft, possibly including maintaining its position with respect to the ground. In addition, the inflatable

4 antenna can be mechanically oriented or electronically pointed towards a predetermined target, ensuring the reception or transmission of high-performance radio signals. The inflatable antenna will also be able to accommodate solar panels that can be pointed towards the sun or cameras or other types of sensors, widening the range of applications of the system and improving its general performance. In addition, the platform may include a propulsion system and a parachute that allow flight control and recovery, on land or at sea, for subsequent reuse. Finally, the suspension cable present between the balloons or dirigibles that make up the aircraft of the present invention, will be able to house lighting systems, LEDs or other types of lamps capable of generating a light signal within certain predetermined directions. Figure 1 describes a simple implementation of the proposed system, consisting of a carrier balloon (100) under which a cable (200) is suspended at the end of which a glider or small airplane (300) equipped with a propulsion apparatus (400) is attached and aerodynamic surfaces (500). Under the glider there is an inflatable sphere (600) filled with helium or other gas, which makes up the inflatable antenna. The antenna can be equipped with systems for electronic pointing, but also with mechanical actuators for its mechanical pointing (700) which allow it to move on one or more rotation axes (800). The wings and aerodynamic surfaces (500) can also be made using

5 inflatable systems and therefore develop a static lifting force, as well as an aerodynamic force.

Figure 2 shows the system proposed by the invention in a more complex embodiment which includes four inflatable spherical antennas (600). In addition, the glider (300) suspended from the main carrier balloon (100) consists of aerodynamic surfaces (500), propulsion system (400) and an additional central inflatable element that makes up the fuselage (301). Figure 3 describes a different version of the system of the present invention, which does not have mechanical elements for mechanical pointing of the inflatable antennas (600) since the antennas are only equipped with electronic pointing systems. Furthermore, the system is here equipped with a more complex propulsion system in which the motors can be rotated in order to generate a thrust not only in the direction of flight but also upwards or downwards (401). The system is now also equipped here with solar panels in the central part of the glider fuselage (900). In addition, the glider is also equipped with a parachute or parafoil (302) which, after separation from the carrier balloon, facilitates its safe and controlled recovery on land or at sea.

Figure 4 describes some possible implementations of the inflatable antennas. The shape mainly considered is spherical, but it is possible to make inflatable antennas having other

6 shapes such as cylindrical or elliptical. The antenna typically includes one or more reflective surfaces (601) which can line the outer walls of the inflatable (as described in

Figure 4-B) or one or more internal inflatable chambers (607) as described in Figure 4-A. This reflecting surface allows concentrating the light or the electromagnetic waves (602), which make up the radio signal to be received or transmitted, towards a transceiver or feed (603) placed inside the inflatable antenna or in its immediate vicinity. Alternatively, the inflatable antenna can be equipped with sensors or solar panels (604) placed on a part of its external wall (as in figure 4-C) so as to be able to receive sunlight or other types of radiation (605). The inflatable antenna will then be equipped with one or more valves or ducts (606) for its appropriate inflation, on the ground before flight or during flight, and for the inflation of any multiple and internal chambers of which it can be composed (607).

Figure 5 describes one of the methods of use of the aircraft object of the present invention. The radio signal (602) is received by one of the inflatable antennas and retransmitted by a second antenna creating a real high- performance, real-time data-relay system. It should be noted that both the transceiver apparatus and the propulsion system, as well as all the on-board actuators and sensors not shown in the figure, are connected to an electronic flight control

7 system (303). It should also be noted that the radio signal received by the first inflatable antenna can be reprocessed before its retransmission, for example by changing the frequency or phase of the signal or by amplification or by processing its information content, or it can be retransmitted without any modification, allowing the system object of the present invention to function as a real passive radio link.

Figure 6 describes a way of implementing and using the aircraft object of the present invention in which a part of the energy necessary for its operation is extracted from the received radio signal. The figure in question describes more precisely the electronic flight control system (303) already indicated in the previous figure. The radio signal (602) in this case is transmitted from the external source at a high intensity and, after being received by the first transceiver (603) and sent to a signal sorter (304), it is sent to an electronic management system of the on-board energy, power management (306), which powers the propulsion system (400) and possibly other on-board systems, not shown in the figure, including a rechargeable battery for accumulating excess energy. In the event that the received signal also contains an information content to be retransmitted to another external receiver, the signal sorter (304) will also feed an electronic system for managing the signal, data management (305), which will send it to the transmitter of the second inflatable

8 antenna (603), suitably reworked if necessary. The figure also shows the deployment system (307) of the suspension cable (200) present between the carrier balloon and the glider. The deployment system (307) is here composed of an electric motor equipped with a pulley capable of winding the cable under the control of an electronic unit not shown in the figure. However, it is possible to use alternative systems.

Finally, Figure 7 describes the flight control method and an optional lighting system and generation of light signals that the aircraft of the present invention is capable of building. Figure 7-A shows the carrier balloon (100) and the glider or airplane (300) suspended from it by a suspension cable (200). By appropriately varying the length of the cable (200), the carrier balloon (100) and the glider (300) are at two different flight altitudes which are subject to two different weather conditions, air density and above all winds. The carrier balloon will be subject to winds (201) other than those to which the glider is subject (202). The carrier balloon therefore generates an upward force (101) and a force of friction with the air (102). The glider below, on the other hand, will eventually be subject to a horizontal traction force (301), generated by the horizontal air flow (305) produced by the thrusters (400), but also by a vertical force that can be directed upwards (303) or downwards (304). The intensity of the traction force (301), of the total vertical

9 force (which is the result of the sum of the forces 303 or 304 and 101) and therefore of the altitude and flight path of the complete system, will be regulated by the on-board electronic systems or by a remote control system on the ground (present but not represented in the figures) by performing at least part of the following actions: the variation in length of the cable (200), the variation in intensity and direction (as already described in Figure 3) of the air flow generated by the propulsion system (305), the movement of moving surfaces on the wings or other aerodynamic surfaces (500) (so as to generate lift or downforce or other horizontal or lateral aerodynamic forces) or by varying (on the ground before the launch or in flight) the gas filling level of at least one of the inflatable elements of which our aircraft is composed. Figure 7 also shows the possible arrangement of lamps,

LEDs or other lighting systems (203) along the suspension cable (200). As shown in Figure 7-B, a certain number of aircraft object of the present invention can be placed in coordinated flight so as to constitute a fixed formation in the sky and, by acting to turn on a part of the lamps (204) and turn off the remaining part (205), one or more remote observers on the ground or in flight will be able to see and identify a certain symbol or writing, possibly moving or flashing.

10 Figure 8 shows a different embodiment in which the antenna

(600) is placed between the carrier balloon (100) and the glider (300). The antenna is now moved or pointed by cables or tie rods (200) to which actuators or motors (700) can be connected.

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Claims

1. Lighter-than-air aerial platform consisting of two or more inflatable elements (100), balloons or airships, a propulsion system (400), aerodynamic surfaces (500) optionally inflatable support and flight control and an on-board electronic system (303), in which at least two of the inflatable elements, balloons or dirigibles that compose it are connected together by one or more cables (200) which place them at two different flight altitudes; said platform also comprising: a release actuator that separates or deflates at least one of the inflatable modules or balloons or airships located at the apex of the platform and which allows the rest of the system to descend in a controlled manner to be then recovered on land or at sea; and characterized in that it also comprises: at least one of the inflatable elements that generates its own vertical force due to the Archimedes effect which is an antenna (600) for receiving or sending radio, light or radiation signals through the use of specific sensors or cameras.

2. Aerial platform according to claim 1, in which one or more of said connection cables can be lengthened or shortened in real time during the flight by means of actuators or motors

12 which act under the control of on-board electronic devices equipped with position sensors (604) or measuring the reciprocal distance between some of the elements that make up the flight platform.

3. Aerial platform according to one of the preceding claims, in which said inflatable antenna is provided with pointing systems, with the antenna itself or with the signal or radiation that it receives or transmits, towards a desired direction or towards a fixed object or towards an object in movement, said aiming being of the electronic or mechanical type provided with one or more actuators or motors (700) and said aiming taking place under the control of the on-board electronic system and under the monitoring and control of a remote electronic or manual system located on the ground.

4. Aerial platform according to one of the preceding claims, in which a part of the internal or external fabric of said inflatable antenna is covered with material reflecting electromagnetic radiation, or material reflecting visible light, or photovoltaic panels or mirrors.

5. Aerial platform according to one of the preceding claims, in which the system receives electrical power from photovoltaic solar panels or internal batteries or from one or more antennas that absorb electromagnetic radiation or radio signals or wireless communication lines from external sources located on the ground either in flight or in orbit.

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6. Aerial platform according to one of the preceding claims, in which at least one of the inflatable elements, balloons or airships that compose it can be deflated or inflated during flight under the automatic control of an on-board electronic system or under the remote monitoring and control of an automatic or manual electronic system placed on the ground.

7. Aerial platform according to one of the preceding claims, in which the propulsion system (400) has thrusters equipped with systems for orienting or directing the thrust in a horizontal, vertical or diagonal direction, under the control of an on-board automatic electronic system or a remote control system or manual monitoring placed on the ground.

8. Aerial platform according to one of the preceding claims, in which, along said one or more suspension cables, one or more parachutes (302) are housed, optionally provided with cables and actuators for controlling their gliding trajectory, which inflate following the separation command or the bursting of at least one of the balloons that make up the system and where said parachutes subsequently allow a reduction in the descent speed of the system or the control of its descent trajectory.

9. Aerial platform according to one of the preceding claims, in which, along said one or more suspension cables, one or more lamps or lighting systems or LEDs (203) are housed, which generate a visible light at a great distance and which are

14 adjustable by a special electronic system on board to switch off or on or vary its intensity or color or the direction of propagation of the light emitted.

10. Aerial platform according to one of the preceding claims, which is controlled in flight to operate in swarm with one or more similar platforms, so as to maintain their mutual distance within a certain limit, so as to ensure observation of the same area on the ground or the reception of signals or radiations coming from the same antenna placed on the ground or the sending of signals or radiations to the same antenna placed on the ground or its visibility according to a predetermined geometry or shape by an observer placed on the ground.

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