DUAL-MODE DUCTED FAN UNMANNED AIR VEHICLE

VEHICULE AERIEN SANS PILOTE A VENTILATEUR A CONDUIT DOUBLE MODE

English Abstract

This invention of dual-mode ducted fan unmanned air vehicle has two flight
modes which
consist of hovering flight and horizontal flight. That means it could not only
hover in the air
as a helicopter but also fly horizontally in high speed mode as an airplane.
By using digital
signal system and electronic devices, this unmanned air vehicle can be
controlled remotely
or can autonomously complete variable missions, such as reconnaissance for
natural
disasters, suspect monitoring and aerial mapping. This innovative unmanned air
vehicle
consists of several components including duct, coaxial propellers, vanes,
fuselage, and
wings. The duct is the main part of ensuring the propeller slipstream to fully
pass through
vanes which are submerged in the propeller slipstream to achieve attitude
control of vehicle
even in low-speed flight and hovering. Two wings with fuselage attached to
duct is the
guarantee for providing sufficient lift during the horizontal flight.

Claims

The Embodiments Of The Invention
In Which An Exclusive Property Or Privilege Is Claimed Are
Defined As Follows:
1. This dual-mode ducted fan unmanned air vehicle consists of a duct, two
coaxial
propellers, four vanes (control surfaces), an upper cross stator frame, a
lower cross
stator frame, four landing gears, two traditional rectangular wings and a
fuselage.
Combination of ducted fan (two coaxial propellers in the duct) and two wings
mounted
to fuselage is a hybrid innovation for this ducted fan unmanned aerial vehicle
which
is designed not only for vertical take-off or landing (VTOL) and hovering, but
also for
horizontal flight in high speed. In contrast to other ducted fan UAVs, the
maneuver
transition from hovering to horizontal flight is also the core technique of
this invention.
2. The combination defined in claim 1 wherein the ducted fan including a duct,
two
coaxial propellers, four vanes, an upper cross stator frame, a lower cross
stator frame
and four landing gears could be an isolated device which can realize vertical
take-off
or landing and hovering flight without two wings and fuselage.
3. The combination defined in claim 1 wherein the two wings fixed with
fuselage is able
to be disassembled from ducted fan unmanned air vehicle.
4. The ducted fan unmanned air vehicle defined in claim 1 wherein the vane
comprises
three pieces of parallel rudders which improve the efficiency of aerodynamic
force
used for attitude control.
5. The ducted fan unmanned air vehicle defined in claim 1 wherein the duct is
made of
carbon fiber.
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6. The ducted fan unmanned air vehicle defined in claim 1 wherein the upper
cross stator
frame is fabricated from composite material.
7. The ducted fan unmanned air vehicle defined in claim 1 wherein the lower
cross stator
frame is fabricated from composite material.
8. The ducted fan unmanned air vehicle defined in claim 4 wherein said rudder
is made
of foam.
9. The maneuver transition defined in claim 1 wherein the process of
transition is
completed automatically by artificial intelligent control system.
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Description

CA 02902931 2015-09-03
Description Of The Invention
Dual-mode Ducted Fan Unmanned Air Vehicle
This invention of unmanned air vehicle could not only hover relied on ducted
fan in the air as
a helicopter but also fly horizontally as an airplane. Therefore it is named
as Dual-mode
ducted fan unmanned air vehicle.
Background Of The Invention
As we know, aircraft has two big branches which are fixed-wing aircraft and
rotary-wing
aircraft. Airplane represents the first branch and it could fly horizontally
in high speed, but it
needs runway to take off and land. That means airplane can't hover in the
fixed point of air
and can't take off or land vertically. Meanwhile, Helicopter represents the
second branch.
Although it could take off or land vertically and is capable to hover in the
air, the limitation of
horizontal flight speed becomes its real weakness for remote missions compared
with
airplane. Therefore, how to combine both advantages of fixed-wing aircraft and
rotary-wing
aircraft has been being a hot point of research among the aeronautical
scientists all over the
world since several years ago.
The coaxial counter-rotating propellers in the duct combined with two wings
attached to both
sides of the fuselage is a hybrid innovation for this ducted fan unmanned
aerial vehicle (UAV)
which is designed not only for vertical take-off or landing (VTOL) and
hovering, but also for
horizontal flight in high speed. Compared with other ducted fan UAVs, the
maneuver
transition from vertical climb to horizontal flight is the unique technique of
this invention.
Ensuring vanes (control surfaces) to be fully submerged in the propeller
slipstream from
ducted fan is critical technology to achieve longitudinal transition (from
hovering to horizontal
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CA 02902931 2015-09-03
flight). The conventional aircraft can't achieve this transition when climbing
vertically at low
speed due to lack of sufficient forces acting on their elevators which play
the main role in the
pitch-control.
This invention thus represents an advantageous solution to any applications
involving
helicopters and airplanes, particularly emergency preparedness missions and
complicated
missions, such as reconnaissance for natural disasters, suspect monitoring and
aerial
mapping.
Description Of Prior Art
It is known in the prior act to provide an aircraft attached with two ducted
rotors at the wing
tips and with a horizontal fan in the fuselage, Canada Patent Number CA
2894465 which is
applied by Bermond Gerome on December 9, 2013, discloses a convertible
aircraft. This
prior invention achieves the transition (from vertical take-off to horizontal
flight) by pivoting
its two ducted rotors.
Moreover, Canada Patent Number CA 2138656, which issued to Cycon, James P.
etc.
on April 18, 2000, discloses an unmanned aerial vehicle (UAV). It has a
composite toroidal
fuselage structure that surrounds a rotor assembly and includes pair of
coaxial, multi-bladed,
counter-rotating rotors. It shows a similar arrangement as ducted fan.
Another similar prior art is Canada Patent CA 2448679 which issued to Urban
Aeronautics
Ltd. On November 23, 2010. It has two ducted fans to realize the hovering and
attitude
control but not horizontal flight.
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CA 02902931 2015-09-03
Finally, United Technologies Corporation Sikorsky Aircraft Division owns the
Patent CA
2189854 which discloses an unmanned aerial vehicle (UAV) who has a toroidal
fuselage and
a rotor assembly having a pair of counter-rotating rotors se-cured in fixed
coaxial
combination with the toroidal fuselage to provide a vertical take-off and
landing (VTOL)
capability for the UAV.
It is apparent from the foregoing that the prior arts fail to combine the
advantages between
fixed-wing aircraft and rotary-wing aircraft in the way of appropriate design.
For example,
although the Patent CA 2894465 realizes the combination of vertical take-off
and horizontal
flight, the mechanical structures of this convertible aircraft is really
complicated and it's not
convenient to maintain.
Summary Of The Invention
This invention of unmanned air vehicle consists of two main devices. The first
device is called
Hover-Flight (HF) system which includes duct, coaxial propeller, four vanes
(control
surfaces), one upper cross stator frame, one lower cross stator frame and four
landing gears.
The Hover-Flight system is the core system of providing sufficient power for
flight and
generating the propeller slipstream, meanwhile it also plays the key role in
ensuring propeller
slipstream to pass through the vanes which are submerged in the propeller
slipstream in
order to achieve attitude control of vehicle even in low-speed flight and
hovering as helicopter.
The second device is called Cruise-Flight (CF) system that contains two
traditional
rectangular wings and one fuselage. These two rectangular wings are
symmetrically fixed at
each side of the fuselage for generating sufficient lift when flying
horizontally as airplane.
Connecting these two devices together is the terminal goal to realize the
flight transition
between two modes from HF to CF or from CF to HF. In a word, compared with
other existing
similar inventions, the dual-mode ducted fan unmanned air vehicle own
advantages of both
helicopter and airplane and it also has the simpler structure which is
expected for fabrication.
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CA 02902931 2015-09-03
Brief Description Of The Drawings
Fig. 1 is an isometric view of two rectangular wings fixed with a fuselage;
Fig. 2 is an isometric view of upper cross stator frame;
Fig. 3 is an isometric view of lower cross stator frame;
Fig. 4 is an isometric view of four vanes (control surfaces);
Fig. 5 is an isometric view of duct attached with four landing gears;
Fig. 6 is a bottom view of dual-mode ducted fan unmanned air vehicle;
Fig. 7 is an isometric view of dual-mode ducted fan unmanned air vehicle;
Fig. 8 is a diagram of transition process (from hovering to horizontal flight)
of dual-mode
ducted fan unmanned air vehicle.
Detailed Description Of The Invention
In the drawings embodiment of the invention illustrated, ducted fan UAV
comprises two
rectangular wings 2 fixed on two side of fuselage 1 as seen in Fig.1, one duct
3 as shown in
Fig.5 and a couple of coaxial propellers 8, four vanes as seen in Fig.4, one
upper cross stator
frame 4 shown in Fig.2, one lower cross stator frame 7 shown in Fig.3 and four
landing gears
6.
One propeller connects with upper cross stator frame 4 and the other propeller
fixed in the
center of the lower cross stator frame 7. The upper propeller rotates in the
direction of
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CA 02902931 2015-09-03
clockwise, whereas the lower one rotates in the direction of counter-
clockwise. That means
the torque is counteracted by these two counter rotating propellers.
The upper cross stator frame connects with upper hollows 9 of duct by using
screws. In the
same way, the lower cross stator frame could be mounted with lower hollows 10
of duct. As
seen in Fig.4, the four vanes, which pivot along with axis X and axis Y are
attached under
the lower cross stator frame. Every vane comprises three pieces of parallel
rudders 5. As
long as the rotating propellers generates the slipstreams that flow over the
vanes, the forces
to control the attitude is created based on the Bernoulli Theory.
As shown in Fig.1 the two wings 2 are assembled symmetrically at two sides of
fuselage 1
for generating sufficient lift when flying horizontally. The materials of
wings should be low
density, such as carbon fiber, ABS or composite materials. Meanwhile, there is
a hollow in
the middle of fuselage where the electronic devices could be installed. To
connect fuselage
1 with upper cross stator frame 4 the screws are recommended to use. For the
reason of
convenient assembly and disassembly, joints of any two components are proposed
to apply
screws rather than rivets.
The Fig.8 shows the whole process of transition of ducted fan UAV. Firstly it
takes off
vertically, then hovers in the air as a helicopter. Moreover, it pitches to
horizontal flight in
high speed as an airplane. The flight transition is the main innovation of
this invention which
is an advantaged combination of rotary-wing aircraft and fixed-wing aircraft.
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Representative Drawing