WO2018144544A1

WO2018144544A1 - Daisy-chain cross-flow fan aerial vehicle configuration

Info

Publication number: WO2018144544A1
Application number: PCT/US2018/016150
Authority: WO
Inventors: Joseph Kummer; Rick SAGA; Mark MIYAOKA
Original assignee: Propulsive Wing, LLC; Drone Propulsion Matrix, Llc
Priority date: 2017-02-01
Filing date: 2018-01-31
Publication date: 2018-08-09

Abstract

A daisy-chain aerial vehicle includes at least two component aerial vehicles. Each component aerial vehicle includes at least one wing having a wing body, a trailing edge, and a wingtip, the wing body shaped like an airfoil. At least one cross-flow fan propulsor is located at the trailing edge, and at least one connection element on the wing is configured to connect and disconnect the aerial vehicles during flight.

Description

DAISY-CHAIN CROSS-FLOW FAN AERIAL VEHICLE CONFIGURATION

BACKGROUND OF THE INVENTION

REFERENCE TO RELATED APPLICATIONS

This application claims one or more inventions disclosed in Provisional Application Number 62/453,183, entitled "DAISY-CHAIN CROSS-FLOW FAN VEHICLE

CONFIGURATION", filed February 1, 2017. The benefit under 35 USC § 119(e) of the United States provisional application is hereby claimed, and the aforementioned application is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to unmanned aerial vehicles, and in particular to daisy-chained cross-flow fan-propelled UAVs.

DESCRIPTION OF RELATED ART

Individual small unmanned aerial vehicles (UAVs) have great utility for many missions. Unfortunately, due to their low aspect ratio, endurance and range (i.e. flight time and distance traveled) are often limited. In addition, multirotor vehicles have disadvantages in terms of cruise efficiency because they require exponentially increasing power to fly faster.

SUMMARY OF THE INVENTION

In an embodiment, a daisy-chain aerial vehicle includes at least two component aerial vehicles. Each component aerial vehicle includes at least one wing having a wing body, a trailing edge, and a wingtip, the wing body shaped like an airfoil. At least one cross-flow fan propulsor is located at the trailing edge, and at least one connection element on the wing is configured to connect and disconnect the aerial vehicles during flight.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a 4- vehicle daisy-chain aerial vehicle, according to an embodiment of the invention. FIG. IB shows an alternate view of the 4-vehicle daisy-chain aerial vehicle of FIG. 1A.

FIG. 2A shows a 6- vehicle daisy-chain aerial vehicle, according to an embodiment of the invention.

FIG. 2B shows an alternate view of the 6-vehicle daisy-chain aerial vehicle of FIG. 2A.

FIG. 3 shows the daisy-chain aerial vehicle of FIG. 1 separatable into component vehicles.

FIG. 4 shows a daisy-chain aerial vehicle consisting of two hybrid axial/cross-flow fan- propelled multirotor UAVs, according to an embodiment of the invention.

FIG. 5 shows a daisy-chain aerial vehicle consisting of four hybrid axial/cross-flow fan- propelled multirotor UAVs, according to an embodiment of the invention.

FIG. 6 shows a daisy-chain aerial vehicle consisting of six hybrid axial/cross-flow fan- propelled multirotor UAVs, according to an embodiment of the invention.

FIG. 7 shows an example of a cross-flow fan that may be used in the vehicles described herein, according to an embodiment of the invention.

FIG. 8 shows a daisy-chain consisting of three cross-flow fan propelled UAVs and four hybrid axial/cross-flow fan propelled multirotor UAVs, according to an embodiment of the invention.

FIG. 9 shows a hybrid cross-flow fan/axial fan UAV with fully closed covers on the bottom side of the vehicle, according to an embodiment of the invention.

FIG. 10 shows a daisy-chain consisting of two hybrid cross-flow fan/axial fan UAVs, each with fully closed covers on the bottom sides of the vehicles, according to an embodiment of the invention.

FIG. 11 shows a hybrid cross-flow fan/axial fan UAV with partially closed covers on the bottom side of the vehicle, according to an embodiment of the invention. FIG. 12 shows a daisy-chain consisting of two hybrid cross-flow fan/axial fan UAVs, each with partially closed covers on the bottom sides of the vehicles, according to an embodiment of the invention.

FIG. 13 shows a hybrid cross-flow fan/axial fan UAV with fully closed covers on the top side of the vehicle, according to an embodiment of the invention.

FIG. 14 shows a daisy-chain consisting of two hybrid cross-flow fan/axial fan UAVs, each with fully closed covers on the top sides of the vehicles, according to an embodiment of the invention.

FIG. 15 shows a hybrid cross-flow fan/axial fan UAV with partially closed covers on the top side of the vehicle, according to an embodiment of the invention.

FIG. 16 shows a daisy-chain consisting of two hybrid cross-flow fan/axial fan UAVs, each with partially closed covers on the top sides of the vehicles, according to an embodiment of the invention.

FIG. 17 shows a daisy-chain consisting of two hybrid cross-flow fan/axial fan UAVs, each with fully closed iris-type covers on the top sides of the vehicles, according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Individual small unmanned aerial vehicles (UAVs) have great utility for many missions. As discussed above, though, due to their low aspect ratio, endurance and range (i.e. flight time and distance traveled) are often limited. In addition, multirotor vehicles have clear disadvantages in terms of cruise efficiency, since they require exponentially increasing power to fly faster. A daisy-chain aerial vehicle is described herein that improves upon these limitations. The daisy-chain aerial vehicle combines the benefits of embedded cross-flow fan propulsion with a daisy-chain vehicle configuration, increasing the aspect ratio and cruise efficiency over conventional individual small UAVs. In an embodiment, a daisy-chain aerial vehicle configuration includes a combination of cross-flow fans and axial fans for efficient takeoff, landing, hover, and forward flight performance. Individual vehicles can combine during flight to increase the effective aspect ratio, thus improving efficiency in forward flight, but break away either one at a time or all at once to perform specifics tasks. The individual vehicles can be capable of vertical takeoff and landing (VTOL) or combined with VTOL vehicles to provide vertical flight capability for the entire daisy-chain. This approach substantially improves the flight range and endurance of cross-flow fan propelled vehicles. Figures 1A and IB show a daisy-chain aerial vehicle 10 including four cross-flow fan propelled component vehicles 11. Figures 2A and 2B show an alternative daisy-chain aerial vehicle 20 including six cross-flow fan-propelled component vehicles 11. Each component vehicle 11 has at least one wing body 1 and at least one wingtip 12, and at least one connection element 14 on the wing body 1 or the wingtip 12. Each connection element 14 is configured to connect and disconnect the component vehicles 11 during flight. Although daisy-chain aerial vehicle 10 and daisy-chain aerial vehicle 20 have four and six component vehicles, respectively, any number of component vehicles could be connected in this manner wingtip 12 to wingtip 12 by connection elements 14. Because cruise efficiency is directly related to aspect ratio (defined as the wing span squared divided by the wing area), as more vehicles are daisy-chained together, the wing span increases, thus increasing the overall aspect ratio of the daisy-chain aerial vehicle 10, 20. As a result, forward flight efficiency improves dramatically (i.e. the power required for forward flight reduces).

Figure 3 shows that the 4-vehicle configuration 10 separates into the component vehicles 11. The vehicle 10 can be set aflight with the component vehicles 11 connected, either launched from a ground launch unit (not shown) or dropped from an aircraft (not shown) in flight. One or more component vehicles 11 can separate from the vehicle 10 mid- flight, and can recombine with vehicle 10 mid- flight. The component vehicles 11 can also be launched separately and combined mid- flight to form vehicle 10. A benefit of the ability for the component vehicles 11 to combine or recombine mid- flight is that one or more of the component vehicles 11 can be utilized for specific missions while the remainder of the connected component vehicles 11 forming the vehicle 10 act as a "mothership". The 6- vehicle configuration 20, or a configuration with any other plurality of component vehicles 11, can also separate into component vehicles 11.

This configuration can be extended to include multirotor vehicles, and in particular, hybrid axial/cross-flow fan-propelled propulsive wings (PWYs). U.S. Patent No. 9,783,291, which is incorporated herein by reference, describes PWYs. PWY have vertical takeoff and landing capability. Figure 4 shows a daisy-chain 40 of two PWY component vehicles 51 , while Figure 5 shows a daisy-chain 55 of four PWY component vehicles 51 and Figure 6 shows a daisy-chain 60 of six PWY component vehicles 51. As with the component vehicles 11, the PWY component vehicles 51 can include connection elements 14 (as illustrated in Figures IB and 2B) to connect or disconnect the component vehicles 51 during flight. By utilizing the PWY configuration, launch and recovery become significantly easier, because the PWY component vehicles 51 can takeoff separately, hover, combine, and then transition to forward flight. The entire daisy-chain 40, 55, 60 of PWY component vehicles 51 can also easily takeoff and land as a combined unit.

In some embodiments, a cross-flow fan propulsor includes at least one cross-flow fan at least partially embedded into the airfoil shaped wing body, a motor, a rotor including a plurality of fan blades, and a cover or housing surrounding the rotor and having an inlet and an outlet. Figure 7 shows a cross-section of a cross-flow fan propulsor 400 located at a trailing edge 16 (see Fig. 1A, IB, 2A, and 2B) of a wing body 1, with a cross-flow fan 41 and a housing. The cross-flow fan 41 is embedded within the wing body 1, which is shaped like an airfoil. The cross-flow fan 41 has fourteen or more individual fan blades 42, a lower housing wall 43, and an upper housing wall 44. Air flows radially into the cross-flow fan 41 at the inlet 45 and exhausts at the outlet 46. Figure 8 shows a daisy-chain aerial vehicle 80 comprising four PWY component vehicles 51 and three component vehicles 11 without vertical lift fans 53. The four PWY component vehicles 51 include two on each end of the daisy chain aerial vehicle 80, separated by the three component vehicles 11 in the middle. The daisy-chain aerial vehicle 80 has the ability to take-off and land vertically, as well as hover, which allows the vehicle to both fly as fast and as efficiently as a fixed-wing aircraft, and break apart into the component vehicles 11, 51. The component vehicles 11, 51 can be coated with a ceramic fire retardant coating for applications such as firefighting. The component vehicles 11 , which are in the center of the daisy-chain, can be utilized for equipment, fuel cells, graphene batteries, lithium ion batteries, solar, other power sources, electronics components, and as a communications hub for switching packets of information between vehicles. Alternatively, each component vehicle 11, 51 in the daisy-chain can have a different piece of equipment, such that when they are connected they form a complete system.

The component vehicles 11, 51 can comprise one or more cross-flow fans 41, as well as three or more axial fans 53 in the case of the PWY component vehicles 51. In the PWY component vehicles 51, the axial fans 53 can be canted at an angle such that in forward flight they contribute to the overall thrust of the vehicle.

The connection element 14 to connect the component vehicles 11, 51 together in a daisy-chain configuration can include magnets. By incorporating variable magnetism wing tips the magnets can be altered between an attractive and repulsive state. Once locked in by magnetic forces, a universal serial bus ("USB") interface between the wing tips can be automatically established for communications and power distribution.

Figure 9 shows a PWY, or Y-Copter, component vehicle 90 including covers 91 or shutters which can be opened and closed, covering the axial fans 53. Figure 9 shows fully closed covers 91 on the bottom side of the vehicle, and Figure 10 shows a daisy-chain aerial vehicle 101 comprising two of these PWY 90 vehicles. In this configuration, the daisy-chain aerial vehicle 101 can take off with the covers 91 fully opened, thus allowing full airflow through the axial fans 53. In cruise, however, the covers 91 can be partially or even fully closed to cover the axial fans 53, thus reducing drag and improving cruise performance. Figures 11 and 12 show the covers 91 partially closed on the bottom sides of the PWY component vehicles 90. Likewise, covers 92 can be placed on the top side of the PWY component vehicles 90, as shown in Figures 13-16, or could even be placed on both the bottom and top surfaces simultaneously. An option for the covers 91, 92 is an iris-type mechanical shutter 95, as shown in Figure 17. Here, the iris 95 opens and closes as necessary to regulate the airflow through the axial fans 53, and can be placed on the top, bottom, or both top and bottom surfaces of the component vehicles 90.

Specific applications for cross-flow fan propelled daisy-chain vehicles include:

pipeline, utility line, and infrastructure reconnaissance; production operation reconnaissance; small parts delivery on offshore platforms; animal safari surveillance and monitoring;

firefighting reconnaissance and assistance; police reconnaissance and enforcement; military reconnaissance and combat; crop reconnaissance and dusting; sport photography and video capture; real estate appraisal, aerial reconnaissance, and surveying.

It is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.

Claims

What is claimed is:

1. A daisy-chain aerial vehicle comprising: at least two component aerial vehicles, each component aerial vehicle including: at least one wing having a wing body, a trailing edge, and a wingtip, the wing body shaped like an airfoil; at least one cross-flow fan propulsor located at the trailing edge; and at least one connection element on the wing configured to connect and disconnect the aerial vehicles during flight.

2. The daisy-chain aerial vehicle of claim 1 , wherein each of the at least two component aerial vehicles is connected to another of the at least two component aerial vehicles by a respective connection element.

3. The aerial vehicle of claim 1, wherein the cross-flow fan propulsor comprises a lower housing wall, an upper housing wall, and at least one cross-flow fan at least partially embedded into the airfoil shaped wing body and comprising at least fourteen fan blades.

4. The daisy-chain aerial vehicle of claim 1, wherein at least one of the component aerial vehicles comprises at least three axial fans spaced around the center of mass of the wing body.

5. The daisy-chain aerial vehicle of claim 4, further comprising a control system allowing transition from hover to forward flight by increasing power transmitted to the cross-flow fan propulsor and decreasing power transmitted to the axial fans.

6. The daisy-chain aerial vehicle of claim 4, wherein the axial fans produce primarily vertical thrust and the cross-flow fan propulsor produces primarily horizontal thrust.

7. The daisy-chain aerial vehicle of claim 4, further comprising covers configured to open and close during flight.

8. The daisy-chain aerial vehicle of claim 7, wherein the covers are comprised of iris-type mechanical shutters.

9. The daisy-chain aerial vehicle of claim 1 : wherein at least one of the component aerial vehicles comprises at least six axial fans spaced around a center of mass of the wing body; wherein half of the axial fans rotate in the clockwise direction and half of the axial fans rotate in the counter-clockwise direction.

10. The daisy-chain aerial vehicle of claim 9, further comprising a control system allowing transition from hover to forward flight by increasing power transmitted to the cross-flow fan propulsor and decreasing power transmitted to the axial fans.

11. The daisy-chain aerial vehicle of claim 10, wherein the axial fans produce primarily vertical thrust and the cross-flow fan propulsor produces primarily horizontal thrust.

12. The daisy-chain aerial vehicle of claim 9, further comprising covers capable of opening and closing during flight.

13. The daisy-chain aerial vehicle of claim 12, wherein the covers are comprised of iris- type mechanical shutters.

14. The daisy-chain aerial vehicle of claim 1, wherein the connection element comprises a set of magnets embedded within the wings.

15. The daisy-chain aerial vehicle of claim 1, wherein the component aerial vehicles are coated with a ceramic fire retardant coating.

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