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Title:
DRONE
Document Type and Number:
WIPO Patent Application WO/2021/044330
Kind Code:
A1
Abstract:
This invention relates to a drone, and more particularly but not exclusively to a waterproof drone. The drone includes a chamber having an internal volume, an opening extending through a wall of the chamber and configured to bring the internal volume in flow communication with ambient conditions outside the chamber; and a sealing member for sealing off the opening. The sealing member is flexible and water impermeable, and is adapted to be resiliently deformed when a pressure differential develops between the internal volume of the chamber and the ambient conditions outside the chamber, in order to aid in equalizing the pressure differential between the internal volume and ambient conditions outside of the drone.

Inventors:
VENTER JACQUES (ZA)
Application Number:
PCT/IB2020/058199
Publication Date:
March 11, 2021
Filing Date:
September 03, 2020
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
VENTER JACQUES (ZA)
International Classes:
B64C27/04
Foreign References:
US20170233073A12017-08-17
US20150102159A12015-04-16
US20170327220A12017-11-16
US20180362157A12018-12-20
Attorney, Agent or Firm:
SPOOR & FISHER et al. (ZA)
Download PDF:
Claims:
CLAIMS:

1 . A drone having a body and a plurality of arms, suitable for carrying rotors, extending from the body, the drone including: a chamber having an internal volume; an opening extending through a wall of the chamber and configured to bring the internal volume in flow communication with ambient conditions outside the chamber; and a sealing member for sealing off the opening; wherein the sealing member is flexible and water impermeable; and wherein the sealing member is adapted to be resiliently deformed when a pressure differential develops between the internal volume of the chamber and the ambient conditions outside the chamber, in order to aid in equalizing the pressure differential between the internal volume and ambient conditions outside of the drone.

2. The drone according to claim 1 wherein the flexible sealing member is in the form a resilient membrane configured to seal the opening.

3. The drone according to claim 2 wherein the membrane is made from an elastic material selected from the group including rubber, latex, polychloroprene and nylon, or a combination thereof.

4. The drone according to claim 2 wherein the membrane is in the form of a balloon or bladder.

5. The drone according to any one of claims 2 wherein the membrane is in the form of a balloon or bladder having a neck and an expandable body, wherein the neck of the balloon terminates in a mouth that fits over the opening, or over a tubular spigot or conduit extending from the opening. 6. The drone according to claim 4 wherein a volumetric expansion element is located inside the balloon or bladder.

7. The drone according to claim 6 wherein the volumetric expansion element is in the form of a compressible sponge-like or lattice-like structure which is positioned inside the balloon or bladder in order to keep the balloon or bladder in an at least partially expanded position, thus allowing the balloon or bladder to be compressed when the pressure in the internal volume is larger than the ambient pressure, or inflated when the ambient pressure is larger than the pressure inside the internal volume.

8. The drone according to claim 1 wherein the body of the drone is hollow, and wherein the chamber is defined as the hollow interior of the body, with the ventilation opening accordingly located in the drone body.

9. The drone according to any one of claims 1 wherein the body of the drone is hollow, and wherein the chamber is a separate chamber located inside the hollow interior of the body, with the opening located in a wall of the chamber in order to link the interior of the chamber with the interior of the hollow body of the drone.

10. The drone according to claim 9 wherein the body of the drone includes further ventilation openings for allowing the pressure inside the body of the drone to be the same as the ambient pressure.

11 . The drone according to claim 1 including an equalization valve for selectively opening and closing an equalization passage in a wall of the chamber, in order to equalize the pressure in the internal volume of the chamber and the environment during setup of the drone.

12. The drone according to claim 1 substantially as herein described with reference to the accompanying figures.

Description:
DRONE

BACKGROUND TO THE INVENTION

THIS invention relates to a drone, and more particularly but not exclusively to a waterproof drone.

A drone is an unmanned aerial vehicle that is controlled by a remote human operator. Many different drones are available in the trade, and are used for a variety of purposes including, to name but a few, military, cinematographic and recreational uses.

In some applications it is beneficial for drones to be waterproof, for example drones used for fishing, which accordingly operate over an expanse of water and in a high-humidity environment. Although non -waterproof drones also work in these environments, it is beneficial to use a waterproof drone, as such a drone will not be damaged by the high humidity conditions that it will encounter, and will furthermore be able to fall / land in the water without any adverse implications.

Various waterproof drones are available in the marketplace, and are used with limited success. It should be noted that one should distguish between waterproof drones, and water resistant drones. A water resistant drone is a lower level, partially waterproof drone that it is not sealed completely and which therefore cannot be even partially submerged below the water. Water resistant drones can probably be more accurately described as splash proof drones. The invention disclosed in this specification finds particular application in fully waterproof drones.

The navigation and control system of a drone includes, as one of the control components, a barometric pressure sensor. The barometric pressure sensor is used in order to control the drone, and more particularly to control the height of the drone. It is therefore important for the barometric pressure sensor to be exposed to ambient conditions, failing which it will not give an accurate reading. The barometric pressure sensor is located inside the body of the drone, and it is accordingly important for the pressure in the internal volume of the drone (or at least the internal volume where the sensor is located) to correspond to the ambient pressure, or at the very least to change proportionally to a change in ambient pressure, even if the pressures are not identical. This is not problematic with non -waterproof drones, as their bodies are not sealed, and the internal volume is therefore at the same pressure as the ambient pressure as the pressure constantly equalizes.

The optimal functioning of the barometric pressure sensor is, however, more problematic when waterproof drones are concerned, as the internal volumes of these drones (by their very nature) have to be enclosed and sealed from the environment. If the drone body is fully sealed, it will mean that the pressure inside the drone body will remain constant, and the pressure sensor will therefore not sense a change in pressure, and the control system will assume that the drone is staying at the same height.

To counter this problem, waterproof drones typically include some sort of partially sealed ventilation system that allows flow of air into and out of the drone body. For example, in some cases a ventilation hole is provided in the body, which hole is then covered by a mesh or sponge-like material that allows air ingress, but which reduces water ingress. However, these systems are still not optimal. For example, when the sponge or mesh like cover gets wet, it tends to prevent the movement of air as well, thus preventing optimal functioning of the barometric pressure sensor. They also tend to allow at least some water into the drone body, which is not ideal.

It is accordingly an object of the invention to provide a drone that will, at least partially, alleviate the above shortcomings.

It is also an object of the invention to provide a drone that will be a useful alternative to existing drones.

SUMMARY OF THE INVENTION

According to the invention there is provided a drone having a body and a plurality of arms, suitable for carrying rotors, extending from the body, the drone including: a chamber having an internal volume; an opening extending through a wall of the chamber and configured to bring the internal volume in flow communication with ambient conditions outside the chamber; and a sealing member for sealing off the opening; wherein the sealing member is flexible and water impermeable; and wherein the sealing member is adapted to be resiliently deformed when a pressure differential develops between the internal volume of the chamber and the ambient conditions outside the chamber, in order to aid in equalizing the pressure differential between the internal volume and ambient conditions outside of the drone. In one embodiment of the drone the flexible sealing member is in the form a resilient membrane configured to seal the opening.

There is provided for the membrane to be made from an elastic material selected from the group including rubber, latex, polychloroprene and nylon, or a combination thereof.

The membrane may be in the form of a balloon or bladder.

The membrane may be in the form of a balloon having a neck and an expandable body, wherein the neck of the balloon terminates in a mouth that fits over the opening, or over a tubular spigot or conduit extending from the opening.

The balloon or bladder may be sufficiently rigid in order not to collapse when the pressure inside the balloon or bladder and outside the balloon or bladder is the same.

There is also provided for a volumetric expansion element to be located inside the balloon or bladder in order to prevent the balloon or bladder to collapse.

The volumetric expansion element may be in the form of a compressible sponge-like or lattice-like structure which is positioned inside the balloon or bladder in order to keep the balloon or bladder in an at least partially expanded position, thus allowing the balloon or bladder to be compressed when the pressure in the internal volume is larger than the ambient pressure, or inflated when the ambient pressure is larger than the pressure inside the internal volume.

In one embodiment of the invention there is provided for the body of the drone to be hollow, and for the chamber to be defined as the hollow interior of the body, with the ventilation opening accordingly located in the drone body.

In another embodiment of the invention there is provided for the body of the drone to be hollow, and for the chamber to be a separate chamber located inside the hollow interior of the body, with the opening located in a wall of the chamber in order to link the interior of the chamber with the interior of the hollow body of the drone.

There is provided for the drone to include further ventilation openings for allowing the pressure inside the body of the drone to be the same as the ambient pressure.

There is also provided for the drone to include an equalization valve for selectively opening and closing an equalization passage in a wall of the chamber, in order to equalize the pressure in the internal volume of the chamber and the environment during setup of the drone.

There is provided for the equalization valve to be in the form of an air permeable membrane that is located in a battery compartment of the drone, which will cause equalization automatically to take place when a closure of the battery compartment is opened.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention is described by way of a non limiting example, and with reference to the accompanying drawings in which:

Figure 1 is a cross-sectional side view of a drone in accordance with the invention; Figure 2 is a cross-sectional top plan view of the drone of Figure 1 ;

Figure 3 is a top plan view of the drone of Figure 1 ; Figure 4 is a cross-sectional side view of a pressure equalization device of the drone;

Figure 5 is a top plan view of the pressure equalization device of Figure 4; and

Figure 6 is a cross-sectional side view of another embodiment of the drone in accordance with the invention.

DETAILED DESCRIPTION OF INVENTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. It is noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the," and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

Referring to the drawings, in which like numerals indicate like features, a non-limiting and simplified example of a drone in accordance with the invention is generally indicated by reference numeral 10.

With reference now to Figures 1 to 5, the drone 10 includes a body 11 and four arms 12 extending outwardly from the body 11 . Each arm terminates in an end suitable for receiving a rotor 13, as is well known in the art. The body 11 is hollow, so as to define an interior or internal volume 14 inside which some of the drone components, for example all the electronic control components 15, are housed. It should be noted that the specific depiction of the electronic control components 15 in the drawings is purely illustrative to show that the circuitry is housed inside the internal volume 14 of the body 11. One of the components located inside the drone 10, although not specifically shown in the drawings, is a barometric pressure sensor, which forms part of the electronic control components 15, and which is therefore also located inside the internal volume 14 of the body 11 of the drone 10.

Although not required in this embodiment of the invention, the electronic control components 15 are shown housed in its own housing or chamber 45. This chamber is in open flow communication with the interior volume 14 of the body 11 , for example by way of a ventilation opening 40. The ventilation opening 40 may be covered by an air permeable membrane (not shown) to allow for pressure equalization while still providing some additional waterproofing of the chamber 45. The pressure inside the chamber 45 and the interior volume of the body 11 will therefore be the same. In this embodiment, the electronic control components 15 need not be located in a separate housing or chamber, but this is convenient from a manufacturing and design perspective, while providing additional waterproofing integrity. In order for the drone 10 operate properly, it is imperative for the barometric pressure sensor (not specifically shown, but forming part of the electronic control components 15), and hence the internal volume 14 of the drone, to be exposed to the environmental or ambient pressure outside the drone. Although this is easily achievable in drones that are not waterproof, in this application it is not that simple, as the drone 10 is a waterproof drone and the body is therefore a hermetically sealed unit. In order for the pressure inside the sealed body 11 , and more particularly the pressure of the internal volume 14, to correspond to the pressure outside the drone, a pressure equalization device 20 is provided. The pressure equalization device is in the form of a flexible membrane that is impervious to water, but which can be displaced when pressure is exerted thereon. Although the membrane might be somewhat air permeable, this cannot be relied on for equalization purposes, as this will happen too slowly if the air permeability is such that the membrane remains water impermeable.

In this example, the pressure equalization device takes the form of a bladder 21 , and more particularly a balloon. In this embodiment the bladder or balloon 21 is made from a suitably flexible material, for example a resilient material such as plastic, latex or rubber. The bladder or balloon is also water impermeable. The bladder or balloon may also in addition be air impermeable, but the important requirements are for it to be water impermeable and flexible. The bladder or balloon 21 includes an inflatable body 21.1 which terminates in an elongated neck section 21.2. The neck section 21.2 is in turn connected to a connector 22, which connects the bladder or balloon 21 to a tube or conduit 23. A ventilation opening 16 is provided in the body 11 of the drone (and in particular in the wall defining the body), with the tube or conduit 23 being in flow communication with the ventilation opening. A volumetric expansion element in the form of a resiliency compressible medium, for example a sponge structure (shown in broken lines in Figure 4) is provided inside the inflatable body 21.1 of the bladder or balloon 21 , and ensures that the bladder or balloon 21 is at least partially expanded or open when no pressure is exerted thereon, in so doing facilitating both potential compression or inflation of the bladder or balloon, dependent on the prevailing conditions. Functionally, the balloon or bladder defines a partially displaceable sidewall of the body 11 of the drone, with the effective surface in this embodiment having been increased by using the configuration of a balloon or bladder instead of a flat diaphragm.

In this embodiment the volumetric expansion device 100 is in the form of a plurality of resilient sponge sections 102 skewered onto a central shaft 101 (with adjacent sections being 90 degrees offset relative to one another), but it will be appreciated that many embodiments can be utilized, provided the volumetric expansion device resiliency retains the bladder or balloon in an erect or ‘uncollapsed’ state. It should also be understood that the bladder or balloon 21 can in itself be designed to be sufficiently rigid (for example by increasing the wall thickness or by adding resilient structural ribs) to remain open (i.e. not collapsed) when there is no pressure differential present, in which case no additional volumetric expansion device will be required.

A pressure equalization valve 30 is provided in the body 11 of the drone 10, and can be opened to equalize the pressure inside the body relative to the ambient pressure when the drone is initially set up for use at a particular elevation. In another embodiment, not shown in the drawings, the equalization valve functionality can be provided by the removable closure of a battery compartment (not shown) of the drone. In such a design, the battery compartment may also be a separate compartment, in which case a ventilation aperture will be provided between the battery compartment and the internal volume of the drone. Such a ventilation aperture may be covered by an air permeable membrane, with equalization automatically taking place when the removable closure of the battery compartment is removed. In use, the pressure inside the internal volume 14 will first be equalized to the ambient pressure of the specific location where the drone is to be used by opening the equalization valve 30. Once the pressure has been equalized, the valve is closed and the drone is ready for use. As the drone rises and the ambient pressure reduces, the pressure inside the drone body will initially stay the same. In a completely sealed drone, the internal pressure will remain the same, and the barometer will therefore not sense the change in pressure, and hence the change in height. However, in the drone in accordance with this invention, a pressure differential will start to develop across the bladder 21 , thus resulting in the higher air pressure in the internal volume 14 of the drone 10 compressing the partially pre opened (by the volumetric expansion element or its own structural rigidity) balloon towards a collapsed condition. The effective volume of the internal volume 14 will therefore increase, thus resulting in a reduction of pressure inside the internal volume until the pressure has been equalized. The inverse will happen when the drone descends. The drone therefore maintains its height control functionality, as the barometric pressure sensor will still give accurate readings. This, however, happens in a sealed environment where no moisture can enter the internal volume of the drone.

It will be appreciated that the entire interior volume of the drone body does not necessarily have to be sealed, but it could potentially only be an electronics chamber inside the body of the drone that may be located in a sealed compartment. In this case, the pressure equalization device will be configured to equalize the pressure inside the chamber and the environment, as is shown in the embodiment of Figure 6.

In this embodiment the electronic control components 15 are located inside an internal chamber 45 inside the main body 11. In this embodiment the chamber 45 is defined by a continuous chamber wall 46 inside the interior volume 14 of the body 11 . The chamber 45 is therefore located inside the interior volume 14 of the main body 11 , but is hermetically sealed from the interior volume 14, save for the provision of a ventilation opening 40 that brings the interior of the chamber 45 in flow communication with the interior of the body 11. In this embodiment additional apertures 41 are provided in the wall of the body 11 of the drone, so as to ensure that the interior volume 14 of the main body 11 remains at the same pressure as the ambient pressure. In order for the barometer to function, there will therefore be a need to equalize the pressure differential that will develop between the interior volume 14 of the body 11 , and the interior volume of the chamber 45. This is still achieved by using a bladder or balloon 21 as in the previous embodiment, but in this case the inside of the balloon is in flow communication with the interior volume of the chamber 45, to which it is linked via the ventilation aperture 40. When the drone ascends, the pressure in the interior volume 14 will decrease. The pressure differential between the chamber and the interior volume of the drone will result in the balloon or bladder expanding or inflating, resulting in pressure equalization. When the drone descends, the balloon or bladder will be collapsed again, resulting in the inverse pressure equalization.

In this embodiment, the equalization valve 30 will move to a position on the body where it is in flow communication with the chamber 45, rather than the interior volume 14 of the body 11 .

It should be noted that in all embodiments of the invention, the balloon or bladder can take many different shapes, and could for example also be a diaphragm that is affixed across a larger ventilation opening. What is essentially needed is a flexible element that is at least water impermeable (preferably also air impermeable to improve the seal), and which seals of a ventilation opening between two volumes to be equalized. These two volumes can be the external environment and the interior volume of the drone or the interior volume of the body and a chamber located inside the body, both of which is described above. It should be noted that even if the flexible element has an air impermeability sufficiently low still to render it water impermeable, the element will still have to be flexible as the rate of air permeation will be too low for sufficiently speedy pressure equalization. It will be appreciated that the above is only one embodiment of the invention and that there may be many variations without departing from the spirit and/or the scope of the invention. It is easily understood from the present application that the particular features of the present invention, as generally described and illustrated in the figures, can be arranged and designed according to a wide variety of different configurations. In this way, the description of the present invention and the related figures are not provided to limit the scope of the invention but simply represent selected embodiments.

The skilled person will understand that the technical characteristics of a given embodiment can in fact be combined with characteristics of another embodiment, unless otherwise expressed or it is evident that these characteristics are incompatible. Also, the technical characteristics described in a given embodiment can be isolated from the other characteristics of this embodiment unless otherwise expressed.