Tethered aerial system and tether cable

Abstract

A tethered aerial system includes an on-board fuel cell for powering on-board electronics and a tether cable which is less conductive than air. The tether cable includes a pipe for carrying a flow of gas to the fuel cell and/or maintain the gas level in a lighter-than-air platform, so that the tethered aerial system can remain operational for an extended period of time. The system is particularly applicable for maintaining communication links in remote areas, agriculture and applications in the IoT (Internet of Things), event coverage, interactive marketing, for post-disaster situations in rural areas and at mining sites or construction sites in remote environments. The system also is immune to rays.

Claims

1. A tethered aerial system comprising: an aerostat; a payload configured to be carried by the aerostat; an on-board electrical energy generator for powering on-board electronics and the payload, wherein the on-board electrical energy generator comprises a fuel cell configured to run on hydrogen gas; and a tethering cable connecting the aerostat to a hydrogen gas source on a ground, wherein the tethering cable comprises material that is electrically non-conductive and less conductive than air to prevent atmospheric discharge attraction and wherein the tethering cable includes a tube for supplying the hydrogen gas to the aerostat for inflating the aerostat and for supplying the fuel cell for the on-board electrical energy generator, wherein maintenance of a flight is ensured by delivery of the gas by the tube contained within the tethering cable; wherein the tethering cable has a first end that is configured to connect to the aerostat of the tethered aerial system and a second end configured to be fixed to the gas source on the ground; and wherein the tethering cable is configured to provide the flow of hydrogen gas through the tube for maintaining flight capacity of the aerostat and to act as a fuel feed for the fuel cell to generate electrical energy for the on-board electronics and the payload of the tethered aerial system.

2. The system according to claim 1, wherein the payload comprises circuits responsible for performing telecommunications and visual monitoring.

3. The system according to claim 1, wherein the tube for carrying hydrogen is made of nylon or polytetrafluoroethylene.

4. The system according to claim 1, wherein the material includes a mechanical support synthetic fiber surrounding the tube and a coating of electrical insulating material covering the mechanical support synthetic fiber and wherein the coating of electrical insulating material is formed of polytetrafluoroethylene or a thermoplastic elastomer.

5. The system according to claim 1, wherein the tethering cable is configured for control of the aerostat on the ground, and wherein the tethering cable is configured to permit the aerostat to rotate around its vertical and horizontal axes, allowing the winding of a safety cable.

6. The system according to claim 1, wherein the material includes a mechanical support synthetic fiber surrounding the tube and a coating of electrical insulating material covering the mechanical support synthetic fiber and wherein the synthetic fiber for mechanical support is made of a polyester fiber, with a mechanical strength functionality.

7. The system according to claim 6, further including fiber optics passing through the synthetic fiber, which are coated with an electrical insulating material.

8. The system according to claim 1, wherein the aerostat includes rotary wings, fixed wings, or a combination thereof.

9. The system according to claim 8, wherein the aerostat includes on-board electronics, stabilizing empennages, a deflation device, and a light indicating device.

10. The system according to claim 9, wherein the aerostat has one or more of the following features: an oblong elliptical shape; comprising an inner envelope of thermoplastic polyurethane (TPU) and an outer envelope of nylon; up to 26 meters in length; up to 480 cubic meters in volume; and flying to a height of up to 1000 meters.

11. The system according to claim 9, wherein the deflation device, and the light indicating device are configured as safety devices.

12. The system according to claim 9, wherein the on-board electronics comprise drive circuits for the deflation device and the light indication safety device, the on-board electrical energy generator, and the payload.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For the full and complete visualization of the object of this invention, there follow figures to which reference is made, as follows:

(2) FIG. 1 is a graphical representation of the present invention, with details of the tethered air system and the tethering cable (3) disclosed herein.

(3) FIG. 2 is a detailed graphical representation of the tethered air system of the present invention with the aerial vehicle (2) being a lighter-than-air platform.

(4) FIG. 3 is a detailed graphical representation of the tethering cable (3) of the present invention.

(5) FIG. 4 is a detailed graphical representation of the aerial vehicle (2) of the lighter-than-air platform type, emphasizing the visualization of the on-board electronics.

DETAILED DESCRIPTION OF THE INVENTION

(6) The present invention relates to a tethered aerial system comprising electrical energy self-generating means by fuel cell (10) for powering its on-board electronics, comprising an aerial vehicle (2) and payload (9), wherein said aerial vehicle (2) is connected to a gas source (8) on the ground by a tethering cable (3) which is an atmospheric discharge attraction preventer.

(7) The aerial vehicle (2) may be selected from a group of options comprising: a lighter-than-air platform, a rotary wing aerial vehicle, a fixed wing aerial vehicle or a combination thereof.

(8) When the option is made to use the lighter-than-air platform type aerial vehicle (2), which is the preferred option of the present invention, as illustrated in the examples of FIGS. 1 to 4, it is necessary to use the following additional elements with the system: a gondola (4), stabilizing empennages (5), a deflation device (6), and a light indicating device (7).

(9) In this preferred option of the aerial vehicle (2), said lighter-than-air platform preferably comprises an aerostat, in a preferred cigar shape and aerodynamically designed to withstand winds of more than 100 kilometers per hour, preferably made of a composite material of polyurethane thermoplastic (TPU) for the inner envelope and nylon for the outer envelope, further presenting preferred dimensions of up to 26 meters in length, up to 480 cubic meters in volume and flying at a height of up to 1000 meters. Such a lighter-than-air platform has the aforementioned stabilizing empennage (5) and the following safety actuators: the deflation device (6) and the light indicating device (7).

(10) In the gas source (8), the gas preferably is hydrogen. However, when the gas is used only for maintaining the aerostat inflated, it may be the helium gas.

(11) With respect to the electrical energy self-generating means for powering the on-board electronics of an aerial vehicle (2), four different options are preferably provided: Wind: Energy generated by aerogenerators, which are devices with wind turbines adjusted to be built in aerostats. This type of technology is more flexible than traditional towers and its generation has the advantage that at balloon operating altitude, the winds are stronger and more consistent than those achieved by traditional tower mounted turbines. Fiber optics (Power over Fiber—PoF): In case the tethered aerostat has fiber optics in its cable, the same can carry optical power through a laser transmitted by it, which is used as an energy source, instead of, or as well as carrying data. This enables remote power supply while providing electrical insulation between the on-board system and the power supply. Solar: Solar panels that generate electricity can be installed in the envelope of the aerostats and produce energy for the payload that is in the aerostat. Fuel cell (10): The fuel cell is a component that converts the chemical energy of a fuel (in this case hydrogen gas) into electrical energy by means of a chemical reaction of positively charged hydrogen ions with oxygen or another oxidant. Fuel cells are different from batteries. The fuel cell needs a continuous source of fuel and oxygen or air to maintain the chemical reaction, whereas in a battery the chemicals present in the battery are fixed to react with one another and generate an electromotive force (EMF). Fuel cells can produce electricity continuously during the time fuel and oxygen inputs are fed.

(12) When using the fuel cell (10), which is the preferred embodiment of the present invention, the generation of energy depends on hydrogen gas for the production of electrical energy, and therefore, in this branching of the product, the hydrogen gas may be used for maintaining the lighter-than-air platform inflated, allowing the flight for long periods, in addition to being the fuel to generate electrical energy supplying the on-board electronics.

(13) In the wind, solar and laser power generation options, no chemical reaction with hydrogen gas is used; so, in the case of the use of lighter-than-air platforms in the present invention, they may be inflated or maintained with helium gas and/or hydrogen gas, and the maintenance of the flight is ensured by carrying this gas through the tube (12) contained in the tethering cable (3), which will be detailed below.

(14) In the preferred embodiment of the present invention, that is, the use of lighter-than-air platform, a gondola (4) is attached to such a platform and contains its electronic devices. In the gondola (4), the fuel cell (10) and the payload (9) are installed, wherein, in addition, circuits are inserted in said payload (9) that are responsible for telecommunications and/or visual monitoring and applying of the safety devices of deflation (6) and light indication (7).

(15) In the present invention, the fuel cell (10) is responsible for the generation of continuous electrical energy for the payload (9), whereas if energy sources such as solar and wind are used, the generation depends on environmental factors (cloudiness, wind speed, day length and solar incidence), and to cover the time length without generation there are two options: to arrange a cable with an electrical conductor for the energy to be carried from the base on the ground, or to place batteries and energy converters on board the aerostat causing an extra weight that is not ideal for the system. Neither case is desirable for the present invention because if electrical conductors are used, the system loses the ability to be lightning-free; in addition, batteries and converters are generally very heavy and the purpose of the present invention is to be as lightest as possible.

(16) Another plausible conclusion is that the system with energy generation by the fuel cell has a lower cost in relation to the platform than other self-powered electrical technologies for the payload, since the aerial vehicle (2), especially lighter-than-air platform type, can be of a smaller size.

(17) In addition, the present invention further discloses a tethering cable (3) preferably comprising a tube for transporting hydrogen or helium gas (12) made of nylon or Teflon™ polytetrafluoroethylene (PTFE), encased with a synthetic fiber for mechanical support (13), preferably of Vectran™ polyester fiber, with mechanical strength functionality, wherein externally it is possible to have a coating of electrical insulating material (14), preferably PTFE or Hytrel™ thermoplastic elastomer. Additionally, it is further possible to have or not a fiber optics (11) within the tethering cable and passing through the synthetic fiber (13).

(18) The tethering cable (3), which has one end connected to the lighter-than-air platform, is attached to the ground by means of a tethering device (1) directly connected to a gas source (8), which preferably operates by hydrogen gas cylinders, hydrocarbon and alcohol reforming or, further, by electrolysis of the water. The tethering device (1) must necessarily be responsible for the tethering of the platform and its control on the ground, and must preferably be able to rotate about its vertical and horizontal axes and favoring the winding of the tethering cable (3) with little or no friction. Preferably, this device should be of small size with good portability.

(19) Accordingly, the tethering cable (3) provides the flow of hydrogen or helium gas through the tube (12), which may be responsible for maintaining the flight potential of the aerial vehicle (2) of the lighter-than-air platform type, and specifically in case the gas is hydrogen, to generate electrical energy for the platform payload. It is only possible to pass one gas at a time through the tethering cable (3). The aerial vehicle (2) is inflated with helium or hydrogen by a specific hose to inflate the platform, starting entirely empty. After the same vehicle (2) is ready to fly, the tube (12) from the tethering cable (3) is installed and the hydrogen can then be delivered by this tube (12), which will supply the aerial vehicle (2) of lighter-than-air platform and the fuel cell (10). Or else, if in some special case there is no fuel cell (10), the gas passing through the tube (12) of the tethering cable (3) may be helium, also being delivered by the same tube (12) to maintain the platform inflated.

(20) Fiber optics (11) is optional for the cable, as it has the utility of transferring data at rates of more than 1 Giga Byte per second. However, if the fiber is not used, wireless linking means for data transfer are further provided in the present invention. Vectran synthetic fiber (13), which provides mechanical strength of more than 1 ton, supports tension on the cable due to the balloon. Finally, the outer cover of electrical insulation material (14) causes the cable to not be conductive primarily on its surface, where the cable is vulnerable to moisture and impurities of the atmosphere.

(21) The present invention enables the establishment of point-to-point and multipoint telecommunication links as well as for real-time video and data transmission.

(22) The content disclosed herein especially addresses to communication links in remote areas, agriculture and IoT (Internet of Things) applications, coverage of events, interactive marketing and post-tragedy solutions, for example, wherein it is common a lack of access to traffic data, voice or internet, in rural areas, mining or construction sites in remote environments.

(23) By placing itself in a privileged height, providing for mobility and height flexibility, the aerostat herein is capable of providing communication links in remote areas. In this situation the present invention functions as an ERB (Base Radio Station) and acts either as a transmitting station or as a relay station, according to the operator's need.

(24) In urban events, which concentrate a large number of people, for example, where overhead of cellular lines is ordinary, the use of the present invention makes it possible to expand the telephone or internet network with existing operators.

(25) Those skilled in the art will appreciate the knowledge presented herein and can reproduce the invention in the embodiments presented and in other variants within the scope of the appended claims.