U.S. patent application number 16/215011 was filed with the patent office on 2019-08-22 for method and apparatus for lifting a payload.
This patent application is currently assigned to PARALLEL FLIGHT TECHNOLOGIES, INC.. The applicant listed for this patent is JOSHUA ALAN RESNICK. Invention is credited to JOSHUA ALAN RESNICK.
Application Number | 20190256202 16/215011 |
Document ID | / |
Family ID | 67617214 |
Filed Date | 2019-08-22 |
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United States Patent
Application |
20190256202 |
Kind Code |
A1 |
RESNICK; JOSHUA ALAN |
August 22, 2019 |
METHOD AND APPARATUS FOR LIFTING A PAYLOAD
Abstract
A method and apparatus for lifting a payload wherein a first
mechanical-rotor is driven by an internal combustion engine. A
portion of the mechanical work developed by the internal combustion
engine is used to generate electrical power, which is either stored
in a battery or used to power an electric motor that drives a
second rotor. Thrust developed by the mechanical and electrical
rotors is directed downward to provide lift for the payload.
Inventors: |
RESNICK; JOSHUA ALAN; (BEN
LOMOND, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RESNICK; JOSHUA ALAN |
BEN LOMOND |
CA |
US |
|
|
Assignee: |
PARALLEL FLIGHT TECHNOLOGIES,
INC.
BEN LOMOND
CA
|
Family ID: |
67617214 |
Appl. No.: |
16/215011 |
Filed: |
December 10, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62632400 |
Feb 19, 2018 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64D 2027/026 20130101;
B64C 2201/044 20130101; B64D 1/00 20130101; B64C 27/08 20130101;
B64C 39/024 20130101; B64C 2201/042 20130101; B64C 2201/027
20130101; Y02T 50/60 20130101; B64C 2201/128 20130101; B64C
2201/024 20130101 |
International
Class: |
B64C 27/08 20060101
B64C027/08 |
Claims
1. A method for lifting a payload comprising: powering a first
mechanical-rotor using a first internal combustion engine;
generating electrical power using the first internal combustion
engine; storing the electrical power in an
electricity-storage-device; powering a first electrical-rotor using
electrical power stored in the electricity-storage-device; applying
to the payload in a substantially vertical direction a portion of a
thrust generated by the first mechanical-rotor; applying to the
payload in a substantially vertical direction a portion of a thrust
generated by the first electrical-rotor; sensing an attitude of the
payload; and adjusting the power to the first electrical-rotor
according to the sensed attitude.
2. The method of claim 1 further comprising: adjusting the power
applied to the first mechanical-rotor when the attitude cannot be
corrected by adjusting the power to the first electrical-rotor.
3. The method of claim 1 further comprising: converting electrical
power stored in the electricity-storage-device to mechanical work;
and applying the mechanical work to the first mechanical-rotor.
4. The method of claim 1 further comprising: adjusting a power
delivered by the first internal combustion engine to the first
mechanical-rotor in order to increase the vertical thrust applied
to the payload.
5. The method of claim 1 further comprising: directing an
additional portion of the thrust generated by the first
mechanical-rotor in a direction substantially opposite to a desired
path of flight; and generating lift using a lifting surface to
support the payload using airflow resulting from movement in the
desired path of flight.
6. The method of claim 5 further comprising removing power from the
first electrical-rotor.
7. The method of claim 1 further comprising: powering a second
mechanical-rotor using a second internal combustion engine; and
directing a substantial portion of a thrust developed by the second
mechanical-rotor in a direction substantially opposite to a desired
path of flight; and generating lift using a lifting surface to
support the payload using airflow resulting from movement in the
desired path of flight.
8. The method of claim 1 further comprising: directing an
additional portion of the thrust generated by the first
electrical-rotor in a direction opposite to a desired path of
flight; and generating lift using a lifting surface to support the
payload using airflow resulting from movement in the desired path
of flight.
9. The method of claim 8 further comprising: removing power from
the first mechanical-rotor; and continuing to operate the first
internal combustion engine in order to generate electrical
power.
10. The method of claim 1 wherein generating electrical power
comprises: receiving mechanical power from the first internal
combustion engine; altering a rotational speed of the mechanical
power; converting a portion of the speed-altered mechanical power
to electrical power; and conveying a substantially remaining
portion of the speed-altered mechanical power to the first
mechanical-rotor.
11. The method of claim 1 wherein generating electrical power
comprises: receiving mechanical power from the first internal
combustion engine; converting a portion of the mechanical power to
electrical power; and conveying a substantially remaining portion
of the mechanical power to the first mechanical-rotor.
12. The method of claim 10 further comprising: conveying a portion
of the electrical power to a first electrical-rotor; and conveying
an additional portion of the electrical power to a second
electrical-rotor.
13. The method of claim 10 further comprising: conveying a portion
of the electrical power to a first electrical-rotor; and storing an
additional portion of the electrical power for future use.
14. The method of claim 13 further wherein storing an additional
portion of the electrical power comprises: converting the
electrical power to a direct current; and charging a storage cell
according to the direct current.
15. A multi-rotor airframe comprising: energy storage device
capable of storing electrical power; first internal combustion
engine; first rotor capable of generating thrust according to
mechanical work applied thereto and disposed to direct a portion of
its thrust in a substantially downward direction; first
motor-generator mechanically coupled to the first rotor; first
mechanical coupler disposed to enable selective application of
mechanical power from the first internal combustion engine to the
first motor-generator; first motor controller capable of receiving
electrical power generated by the first motor-generator and
directing it to the energy storage device; second rotor capable of
generating thrust according to mechanical work applied thereto and
disposed to direct a portion of its thrust in a substantially
downward direction; second motor-generator coupled to the second
rotor; second motor controller capable of receiving electrical
power from the energy storage device and directing said electrical
power to the second motor-generator in accordance with a first
correction signal; attitude sensor that is capable of generating an
attitude signal according to an attitude exhibited by the airframe;
and flight controller that generates a first correction signal
according to the attitude signal and an intended attitude value and
wherein the first correction signal is directed to the second power
controller.
16. The multi-rotor airframe of claim 15 wherein first mechanical
coupler comprises a clutch.
17. The multi-rotor airframe of claim 15 wherein first mechanical
coupler comprises: clutch; and gear-box for adjusting the angular
speed of the mechanical power applied to the first
motor-generator.
18. The multi-rotor airframe of claim 15 wherein the first motor
controller is further capable of receiving electrical power from
the energy storage device and directing it to the first
motor-generator and wherein the first motor-generator is capable of
converting the electrical power to mechanical power and applying
said mechanical power to the first rotor.
19. The multi-rotor airframe of claim 15 wherein the flight
controller is capable of generating a second correction signal
according to an attitude exhibited by the airframe and according to
the first correction signal and wherein the first power controller
further includes a correction input and is capable of causing
electrical power to be applied to the first motor-generator
according to said second correction input when the attitude signal
indicates there is an attitude error and the first correction
signal indicates that it is at a control limit.
20. The multi-rotor airframe of claim 15 wherein the flight
controller is capable of generating a second correction signal
according to an attitude exhibited by the airframe and according to
the first correction signal and wherein the first internal
combustion engine further includes a throttle control input and is
capable of adjusting power to be applied to the first rotor
according to said second correction input when the attitude signal
indicates there is an attitude error and the first correction
signal indicates that it is at a control limit.
21. The multi-rotor airframe of claim 15 wherein the first internal
combustion engine further includes a throttle control input and the
flight controller is capable of generating a lift signal that, when
received by the throttle control input, causes the first internal
combustion engine to increase power applied to the first rotor.
22. The multi-rotor airframe of claim 15 further comprising a
lifting surface attached to the airframe and which is capable of
generating lift in a substantially vertical direction when subject
to an airflow and further comprising a tilt-mechanism that is
disposed to enable the first rotor to tilt about an axis
substantially parallel to a pitch-axis of the airframe and wherein
the flight controller is further capable of generating a tilt
signal and wherein the tilt-mechanism is capable of responding to
the tilt signal by tilting the first rotor so as to cause a portion
of its thrust to be directed in a direction opposite to a desired
direction of flight.
23. The multi-rotor airframe of claim 22 further comprising a speed
sensor capable of generating a speed signal according to a forward
path of the airframe and wherein the flight controller is further
capable of generating an power-down signal when the speed signal
indicates that the forward speed of the airframe will result in
sufficient lift generation by the lifting surface to support the
airframe and wherein the second power controller includes a
power-down input and is capable to discontinuing application of
electrical power to the second motor-generator when the power-down
is active.
24. The multi-rotor airframe of claim 15 further comprising a
forward thruster comprising at least one or more of an internal
combustion engine, a motor-generator and/or an electric motor
coupled to a rotor and wherein the thruster includes an enable
signal that is controlled by the flight controller.
25. The multi-rotor airframe of claim 15 further comprising a
payload bay for storing a secondary payload.
Description
RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Application Ser. No. 62/632,400, entitled "A METHOD AND APPARATUS
FOR LIFTING A PAYLOAD" by Resnick, which was filed on Feb. 19,
2017, the text and drawings of which are incorporated by reference
into this application in their entirety.
BACKGROUND
[0002] Hybrid power systems are not new. In fact, many
hybrid-powered vehicles are in service on our nation's roads and
highways. A hybrid power system relies on the conversion of
mechanical power to electrical power. The resulting electrical
power is used to power electric motors for propulsion. Any excess
electrical power is typically saved in a reservoir, e.g. a battery.
Hybrid-powered vehicles may also use regenerative braking so that
unwanted momentum can be converted back into electrical power and
saved in the reservoir.
[0003] Drones are also now using a form of hybrid-power. For
example, Phan describes (in published patent application
2016/0137304) a power system where an internal combustion engine
(ICE) uses fossil fuel in order to generate mechanical power. The
mechanical power is directed to a generator, which converts said
mechanical power into electrical power. A portion of the electrical
power is used to power electrical motors that are coupled to
propellers that affect flight for the droid. Any remaining power is
stored in a battery, or is used to power on-board payload
components.
[0004] The motivation for use of hybrid-power as described by Phan
is actually quite obvious. Electrical motors have long been
recognized as the best motor structure for use in powering droid
propellers. The reason for this is that an electrical motor is much
more responsive than an ICE. This higher degree of responsiveness
allows better flight control stability since the variation of power
applied to various propellers in a multi-rotor aerial vehicle
controls yaw, pitch and roll. Use of ICEs for direct drive of
propellers fails to support higher dynamics in flight control.
[0005] When considering the Phan reference as a whole, there is no
added advantage over traditional drone technology expect for the
fact that Phan introduces a generator that charges on-board
batteries during flight. Phan has increased loft time by providing
in-flight charging of batteries. Unfortunately, Phan has
compromised the amount of lift available for the payload. This is
because the electrical generator and the ICE are simply additional
loads that need to be carried by the electrically driven
propellers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Several alternative embodiments will hereinafter be
described in conjunction with the appended drawings and figures,
wherein like numerals denote like elements, and in which:
[0007] FIG. 1 is a flow diagram that depicts one example method for
lifting a payload;
[0008] FIG. 2 is a flow diagram that depicts one alternative
example method wherein attitude adjustment is further accomplished
by application of thrust generated by a mechanical-rotor;
[0009] FIG. 3 is a flow diagram that depicts one alternative
example method that further allows for ancillary power to be
applied to the first mechanical-rotor;
[0010] FIG. 4 is a flow diagram that depicts one alternative
example method for increasing the altitude of the payload;
[0011] FIG. 5 is a pictorial diagram that depicts the operation of
a dual-rotor embodiment of the present method;
[0012] FIG. 6 is a pictorial diagram that depicts operation of one
alternative example embodiment of the present method wherein
electrical power is used to augment the amount of mechanical work
applied to a mechanical-rotor;
[0013] FIG. 7 is a flow diagram that depicts one alternative
example method that provides for more efficient movement of a
payload from one location to another;
[0014] FIG. 8 is a flow diagram that depicts yet another variation
of the present method which provides for greater efficiency after
the payload has been transitioned into a forward-flight mode;
[0015] FIG. 9 is a flow diagram that depicts one alternative
variation of the present method where in forward-flight is achieved
using a fixed rotor;
[0016] FIG. 10 is a flow diagram that depicts one alternative
example variation of the present method where in forward-flight is
achieved by using the first electrical-rotor;
[0017] FIG. 11 is a flow diagram that depicts one alternative
example method wherein electrical power is generated by a first
internal combustion engine for use by an electrical-rotor as the
electrical-rotor is used to enable forward-flight;
[0018] FIG. 12A is a pictorial diagram that illustrates various
embodiments of the present method and variations thereof that
incorporate mechanical power engagement devices;
[0019] FIG. 12B is a flow diagram that depicts one alternative
example method wherein electrical power is generated based upon
consumption of a fossil fuel;
[0020] FIG. 12C is a pictorial diagram that illustrates one
alternative illustrative use case of the present method and
variations thereof that incorporate mechanical power engagement
devices and a speed-altering device;
[0021] FIG. 12D is a flow diagram that depicts one alternative
method where the efficiency of an ICE is accommodated at different
rotational speeds;
[0022] FIGS. 13 through 15 are flow diagrams that depict
alternative example methods for managing electrical power produced
by a machine that consumes a fuel;
[0023] FIG. 16A is a pictorial diagram that illustrates one example
embodiment of an internal combustion engine power unit;
[0024] FIGS. 16B and 16C are a pictorial diagrams that illustrates
other alternative example embodiments of an internal combustion
engine power unit that includes a second clutch;
[0025] FIG. 16C depicts an alternative embodiment that further
includes a gear-box 217, which is disposed to receive mechanical
power from the internal combustion engine 210;
[0026] FIG. 17A is a pictorial illustration that depicts one
example embodiment of a multi-rotor airframe;
[0027] FIG. 17B illustrates that the multi-rotor airframe of this
example embodiment also includes an energy storage device 270;
[0028] FIG. 17C is a block diagram that depicts one alternative
example embodiment of a flight controller 300;
[0029] FIG. 18 is a pictorial diagram that illustrates one
alternative example embodiment of an airframe that supports a
forward-flight mode;
[0030] FIGS. 19A through 19D are pictorial diagrams that illustrate
progression of an ICE power unit from vertical mode to
forward-flight mode;
[0031] FIGS. 20 through 22 are pictorial diagrams that depict the
relative placement of rotors in one alternative example embodiment
of a multi-rotor airframe; and
[0032] FIG. 23 is a pictorial diagram that depicts one alternative
embodiment of an airframe that includes a secondary payload
compartment.
DETAILED DESCRIPTION
[0033] In the interest of clarity, several example alternative
methods are described in plain language. Such plain language
descriptions of the various steps included in a particular method
allow for easier comprehension and a more fluid description of a
claimed method and its application. Accordingly, specific method
steps are identified by the term "step" followed by a numeric
reference to a flow diagram presented in the figures, e.g. (step
5). All such method "steps" are intended to be included in an
open-ended enumeration of steps included in a particular claimed
method. For example, the phrase "according to this example method,
the item is processed using A" is to be given the meaning of "the
present method includes step A, which is used to process the item".
All variations of such natural language descriptions of method
steps are to be afforded this same open-ended enumeration of a step
included in a particular claimed method.
[0034] Unless specifically taught to the contrary, method steps are
interchangeable and specific sequences may be varied according to
various alternatives contemplated. Accordingly, the claims are to
be construed within such structure. Further, unless specifically
taught to the contrary, method steps that include the phrase ". . .
comprises at least one or more of A, B, and/or C . . . " means that
the method step is to include every combination and permutation of
the enumerated elements such as "only A", "only B", "only C", "A
and B, but not C", "B and C, but not A", "A and C, but not B", and
"A and B and C". This same claim structure is also intended to be
open-ended and any such combination of the enumerated elements
together with a non-enumerated element, e.g. "A and D, but not B
and not C", is to fall within the scope of the claim. Given the
open-ended intent of this claim language, the addition of a second
element, including an additional of an enumerated element such as
"2 of A", is to be included in the scope of such claim. This same
intended claim structure is also applicable to apparatus and system
claims.
[0035] FIG. 1 is a flow diagram that depicts one example method for
lifting a payload. According to this example method, lifting a
payload comprises the steps of powering a first mechanical-rotor
using a first internal combustion engine (step 10); generating
electrical power using the first internal combustion engine (step
15); storing the electrical power in an electricity-storage-device
(step 20); powering a first electrical-rotor using electrical power
stored in the electrical-storage-device (step 25); applying a
portion of a thrust generated by the first mechanical-rotor, in a
substantially vertical direction, to the payload (step 30);
applying a portion of a thrust generated by the first
electrical-rotor, in a substantially vertical direction, to the
payload (step 35); sensing an attitude of the payload (step 40);
and adjusting the power to the first electrical-rotor according to
the sensed attitude (step 45).
[0036] It should be appreciated that, according to this example
method, a substantial portion of thrust generated by the first
mechanical-rotor is used to lift the payload. According to one
illustrative use case, the present example method is applied in a
situation where the first mechanical-rotor is affixed to an
airframe. In this illustrative use case, a thrust created by the
first mechanical-rotor is used to lift the payload, which in turn
lifts a payload. It should likewise be appreciated that, according
to yet another illustrative use case, there is no specific
secondary payload lifted according to this method, rather the
payload comprises the airframe itself. According to yet another
illustrative use case, the present method is applied in a situation
where the first electrical-rotor is attached to the airframe.
Accordingly, substantially vertical thrust from the first
mechanical-rotor and the first electrical-rotor are used in
conjunction to lift a payload. Again, it should be appreciated
that, according to various illustrative use cases, the payload
comprises at least one or more of an airframe and/or a secondary
payload.
[0037] It should likewise be appreciated that, according to this
example method, a first mechanical-rotor is a term that is used to
refer to a rotor that is driven by a mechanical work derived from a
machine that consumes a carbon-based fuel. In one alternative
example method, an included step provides for receiving mechanical
work from a power source comprising an internal combustion engine
("ICE"). It should likewise be appreciated that, according to one
alternative example use case, the first mechanical-rotor comprises
a propeller.
[0038] It should likewise be appreciated that, according to this
example method, a first electrical-rotor is a term used to refer to
a rotor that is driven by mechanical work derived from an
electrical machine. In one alternative example method, an included
step provides for receiving mechanical power from an electrical
machine comprising a motor-generator. In one alternative example
method, an included step provides for receiving mechanical power
from an electrical machine comprising at least one or more of an
induction motor-generator and/or a brushless direct current
motor-generator. It should also be appreciated that, according to
one alternative example use case, the first electrical-rotor
comprises a propeller.
[0039] It should likewise be appreciated that, according to one
alternative example method, mechanical power created by a machine
that consumes a carbon-based fuel is converted into thrust by an
included step for applying the mechanical power to a propeller.
[0040] According to one alternative example method, generating
electrical power is accomplished by an included step for receiving
mechanical work from a machine that consumes a carbon-based fuel
and converting the received mechanical work into electrical energy.
According to one illustrative use case, this is accomplished by
coupling mechanical work from an internal combustion engine to a
motor-generator. In yet another illustrative use case, this is
accomplished by coupling mechanical work from an internal
combustion engine to an induction motor-generator. In either of
these illustrative use cases, rotational work is then converted
into electrical energy by at least one or more of the
motor-generator and/or the induction motor-generator.
[0041] In yet another alternative example method, converting the
mechanical work into electrical energy comprises a step for
converting the mechanical work into an alternating current. In a
subsequent included step, the alternating current is conditioned in
order to create a direct current. And in yet another example
variation of the present method, a subsequent included step
provides for throttling the direct current in order to properly
charge an energy-storage-device. According to one illustrative use
case, the energy-storage-device comprises a battery. In yet another
illustrative use case, the present method is applied in a situation
where the energy-storage-device comprises a "super capacitor". It
should be appreciated that the present example method and
variations thereof are intended to be applied to a wide variety of
illustrative use cases and any particular example of an
energy-storage-device is presented herein solely to further enable
comprehension of this disclosure by those skilled in the art and is
not intended to limit the scope of the claims appended hereto.
[0042] Once electrical energy is stored in the
electrical-storage-device, one illustrative alternative method
comprises a step for drawing electrical energy from the
electrical-storage-device and a step for converting the electrical
energy into mechanical work. In a subsequent included step, this
mechanical work is then converted into thrust. According to yet
another alternative example method, converting the mechanical work
derived from the electrical energy into thrust is accomplished by
an included step for applying the mechanical work to a
propeller.
[0043] According to yet another alternative example method, sensing
an attitude of the payload comprises a step for sensing an attitude
of an airframe. It should be appreciated that, according to various
illustrative use cases, the airframe comprises the payload. It
should likewise be appreciated that, according to various
alternative example methods, sensing an attitude of the payload
comprises sensing the angular rotation of the payload in at least
one axis.
[0044] According to one alternative example method, sensing an
attitude of the payload comprises a step for sensing the angular
rotation of the payload about an axis of pitch, a further step for
sensing the angular rotation of the payload in about an axis of
yaw, and a further step for sensing the angular rotation about an
axis of roll, wherein the terms pitch, yaw and roll refer to
standard axis definitions in aeronautical engineering. It should be
appreciated that, according to one alternative example method,
sensing and angular rotation is accomplished by applying an
accelerometer to the airframe and receiving an acceleration signal
from the accelerometer. In yet another alternative example method,
thee such accelerometers are attached to the airframe. It should be
appreciated that, according this alternative example method, one
accelerometer is disposed to sense angular rotation about the axis
of pitch, one accelerometer is disposed to sense angular rotation
about the axis of yaw and another accelerometer is disposed to
sense angular rotation about the angle of role.
[0045] It should be appreciated that, according to various
illustrative use cases, the present method is applied in a manner
where angular acceleration signals for pitch, yaw and roll are
processed in order to ascertain changes in the attitude of the
payroll, for example the airframe itself. In one alternative
example method, an additional included step provides for using such
changes in attitude in order to return the airframe to an initial
attitude state. This, according to one alternative example method,
provides for an included step for engaging a control loop wherein
changes in attitude are used as feedback in a control system for
controlling thrust applied to the payload. According to this
example method and variations thereto, the control system adjusts
the power to the first electrical-rotor in order to maintain the
payload in a steady attitude state.
[0046] FIG. 2 is a flow diagram that depicts one alternative
example method wherein attitude adjustment is further accomplished
by application of thrust generated by a mechanical-rotor. It should
be appreciated that, according to the example method herein
described, adjustment of payload attitude in response to a sensed
changes thereto is accomplished by adjusting the power to the first
electrical-rotor. It should be appreciated that the
electrical-rotor is utilized for principal attitude adjustment
because of the response of nature of an electrical-rotor when
compared to a mechanical-rotor. The reason for this is that the
electrical-rotor is driven by a machine powered by electrical
power, whereas the mechanical-rotor is driven by a machine that
consumes fossil fuel. It should likewise be appreciated that the
angular velocity of the electrical-rotor may be changed at a much
greater rate when compared to the mechanical-rotor. Hence, one
exciting aspect of the present method is refined attitude
adjustment capability provided by the electrical-rotor.
[0047] There are, however, situations where the thrust provided by
the electrical-rotor is not sufficient to maintain steady-state
attitude. This, according to various illustrative use cases, occurs
when the payload is not evenly distributed among several rotors
operating in conjunction with each other to provide the lift
necessary to carry the payload. Accordingly, when the attitude of
the payload cannot be corrected by adjusting the power to the
electrical-rotor (step 60), then the power applied to the first
mechanical-rotor is also adjusted (step 65) in order to augment the
thrust necessary to maintain steady-state attitude of the
payload.
[0048] FIG. 3 is a flow diagram that depicts one alternative
example method that further allows for ancillary power to be
applied to the first mechanical-rotor. Referring briefly to FIG.
16B, a first mechanical rotor 225, according to one illustrative
embodiment of the present method, is driven by a first internal
combustion engine 210. It should be appreciated that, according to
this illustrative embodiment, the first internal combustion engine
210 also drives a first motor-generator 220. It should be
appreciated that, according to this alternative example method,
electrical power stored in the electricity-storage-device is
converted into mechanical work (step 50).
[0049] According to the illustrative embodiment of this alternative
method, this is accomplished by applying the electrical power to
the first motor-generator 220. Once the electrical power is
converted into mechanical work, the mechanical power is then
applied to the first mechanical-rotor (step 55), in conjunction
with any mechanical power developed by the first ICE 80. In this
manner, additional thrust is generated by mechanical power in order
to provide auxiliary lift capacity for a payload. This additional
thrust, according to other illustrative use cases, is applied in
situations where additional thrust is necessary to maintain the
attitude of the payload in a steady-state condition. This
additional thrust, according to yet other illustrative use cases,
is applied in situations where additional thrust is necessary to
maintain or change the altitude of the payload in a steady-state
condition.
[0050] FIG. 4 is a flow diagram that depicts one alternative
example method for increasing the altitude of the payload. It
should be appreciated that, according to the example method herein
described, the "heavy lifting" of a payload is accomplished by one
or more a mechanical-rotors. As heretofore described, the
mechanical-rotors are driven by machines that consume fossil fuel,
for example an ICE. Accordingly, one alternative example method
provides an included step for adjusting the power delivered by the
first internal combustion engine. By adjusting the power delivered
by the first internal combustion engine, the vertical thrust
applied to the payload is increased, thereby effecting increasing
the altitude of the payload.
[0051] FIG. 5 is a pictorial diagram that depicts the operation of
a dual-rotor embodiment of the present method. According to one
dual-rotor embodiment of the present method, a first
mechanical-rotor 75 is driven by a first internal combustion engine
80. It should be appreciated that, according to this illustrative
embodiment of the present method, the first internal combustion
engine 80 also drives a first motor-generator 85. In operation, the
first internal combustion engine 80 provides mechanical power to
the first mechanical-rotor 75, which in one alternative embodiment
comprises a propeller. An additional portion of mechanical power
generated by the internal combustion engine 80 is converted into
electrical power 87 by the first motor-generator 85. It should be
appreciated that a shaft included in the motor-generator 85 runs
through to the other end of the motor-generator 85.
[0052] This means that mechanical power is conveyed via this shaft
from the ICE 80 through to the mechanical-rotor 75.
[0053] As this example embodiment of the present method continues
to operate, a portion, if not all of the electrical power 87 is
then stored in an electricity-storage-device 95. Electric power 87
stored in the electricity-storage-device 95 is then used to power a
second motor-generator 90. The second motor-generator 90 then
operates a rotor, which according to one alternative embodiment
comprises a propeller. In the descriptions herein offered regarding
the present method and variations thereto, this second
motor-generator 90 drives the first electric-rotor referenced
herein with respect to the claims. Readers are cautioned not to
confuse this nomenclature with nomenclature used to describe
various apparatus that embody the present method and variations
thereof.
[0054] FIG. 6 is a pictorial diagram that depicts operation of one
alternative example embodiment of the present method wherein
electrical power is used to augment the amount of mechanical work
applied to a mechanical-rotor. Again referencing FIG. 21, the first
internal combustion engine 80 is coupled to the first
mechanical-rotor 75 and to the first motor-generator 85. Coupling
of the first internal combustion engine 82 both the first
mechanical-rotor 75 and to the first motor-generator 85 means that
the first motor-generator 85 is also coupled to the first
mechanical-rotor 75.
[0055] As this alternative example embodiment of the present method
continues to operate, electrical power 87, upon necessity for
additional thrust from the first mechanical-rotors 75, is directed
to the first motor-generator 85. The first motor-generator 85
converts the electrical power 87 into mechanical work 82, which is
also applied to the first mechanical-rotor 75.
[0056] FIG. 7 is a flow diagram that depicts one alternative
example method that provides for more efficient movement of a
payload from one location to another. It should be appreciated that
the use of vertical thrust to maintain lift necessary to move a
payload is a generally inefficient process. Accordingly, this
example variation of the present method provides for an included
step for directing an additional portion of the thrust generated by
the first mechanical-rotor in a direction opposite to that of a
desired flightpath (step 105). Accordingly, as a portion of the
thrust generated by the first mechanical-rotor is diverted from a
substantially vertical orientation toward a direction that is
substantially opposite to a direction of flight, lift is generated
as air flows across a lifting surface (step 110), which is an
additional included step of this variation of the present
method.
[0057] It should be appreciated that, according to various
illustrative use cases, this variation of the present method
provides for a transition from vertical suspension using
substantially vertical thrust to a forward-flight mode. As can be
appreciated, the first mechanical-rotor, in order to support this
variation of the present method, is adjusted so as to tilt the
orthogonal axis of the rotor from a substantially vertical
orientation toward a horizontal orientation. It should likewise be
appreciated that such reorientation of the first mechanical-rotor
is not intended to be accomplished instantaneously. Rather, a
gradual reorientation provides that forward-flight is initiated so
that lift is generated using a lifting surface, which according to
one illustrative use case comprises an airfoil. According to yet
another illustrative use case, the lifting surface comprises an
aeronautical wing.
[0058] It is important to appreciate that as the direction of
thrust generated by the first mechanical-rotor is adjusted in this
manner, the lift provided by the first mechanical-rotor is reduced
as the payload increases in speed so as to generate lift as air
flows across the lifting surface. At some point, a substantial
portion of the thrust generated by the first mechanical-rotor is
oriented in a direction opposite to that of a desired direction of
flight. Accordingly, lift to maintain elevation of the payload is
generated substantially by the lifting surface as heretofore
described.
[0059] FIG. 8 is a flow diagram that depicts yet another variation
of the present method which provides for greater efficiency after
the payload has been transitioned into a forward-flight mode. This
variation of the present method provides an included step for
removing power from the first electrical-rotor (step 115) once the
payload has achieved forward-flight. It should be appreciated that
once forward-flight is achieved, any rotor that continues to be
oriented such that is orthogonal axis is perpendicular to the
direction of forward-flight will cause instability and/or
additional resistance (e.g. drag) to forward-flight. By removing
power from the first electrical-rotor, the first electrical-rotor,
according to one illustrative use case, will naturally orient
itself in a manner that minimizes instability and additional
resistance to forward-flight. In yet another illustrative use case,
an electrical rotor (e.g. a propeller) may not orient itself in a
suitable position. Accordingly, one alternative variation of the
present method further includes a step for detecting the
orientation of the first-electrical rotor and applying electrical
power to the first electrical-rotor in order to maintain the
position of that rotor so as to minimize instability and resistance
to forward-flight.
[0060] FIG. 9 is a flow diagram that depicts one alternative
variation of the present method where in forward-flight is achieved
using a fixed rotor. It should likewise be appreciated that,
according to one variation of the present method, forward-flight is
achieved by applying thrust generated by a second mechanical-rotor
which is powered by a second internal combustion engine (step 120),
which is an included step in this variation of the present method.
According to another included step of this variation of the present
method, a substantial portion of the thrust generated by the second
mechanical-rotor is directed in a direction opposite to that of a
desired flightpath (step 125). It should be appreciated that, an
additional included step provides for generating lift using a
lifting surface as air flows across the lifting surface (step 130).
It should likewise be appreciated that as airflow across the
lifting service increases, so does the lift necessary for
maintaining altitude for a payload.
[0061] It should likewise be appreciated that, according to yet
another variation of the present method, forward-flight is achieved
by applying thrust generated by a second electrical-rotor.
According to one illustrative use case, this variation of the
present method is applied in a situation where a second
electrical-rotor is fixed in an orientation to enable thrust in a
direction opposite to that of a direction of desired flight.
Accordingly, as the second electrical-rotor operates, thrust
generated thereby is used to increase the speed of the payload so
as to generate lift by means of a lifting surface. It should
likewise be appreciated that, these variations of the present
method, according to various illustrative use cases, are applied to
a payload through an intermediary airframe. As heretofore
described, the intermediary airframe is included in one
illustrative use case. In yet another illustrative use case, the
intermediary airframe is used to carry a secondary payload. In all
such illustrative use cases, the present method and variations
thereof is intended to encompass all applications where
forward-flight is achieved through the use of a fixed rotor,
including at least one or more of a second mechanical-rotor and/or
a second electrical-rotor.
[0062] FIG. 10 is a flow diagram that depicts one alternative
example variation of the present method where in forward-flight is
achieved by using the first electrical-rotor. As heretofore
described, one alternative variation of the present method provides
for tilting the first mechanical-rotor in order to direct a portion
of its thrust in a direction opposite to that of a desired flight
path. This alternative variation of the present method includes a
step for directing a portion of the thrust generated by the first
electrical-rotor in a direction opposite to that of a desired
flightpath (step 135). Accordingly, lift is generated by a lifting
surface once airflow across that lifting surface increases
sufficiently as a result of forward-flight (step 135), which is
another included step in this example variation of the present
method.
[0063] It should be appreciated that, much akin to the alternative
method which relies upon tilting the first mechanical-rotor in
order to achieve forward-flight, this example variation of the
present method provides that the first electrical-rotor is tilted
in a gradual manner so that a portion of the thrust generated by
the first electrical-rotor continues to provide lift to maintain
altitude for the payload. As the first electrical-rotor is further
tilted, a greater portion of the thrust generated thereby is used
to move the payload forward in order to achieve fixed-wing flight.
It should likewise be appreciated that, according to one
illustrative use case, the lifting surface relied upon by this
example variation of the present method comprises at least one or
more of an aeronautical wing and/or an airfoil.
[0064] FIG. 11 is a flow diagram that depicts one alternative
example method wherein electrical power is generated by a first
internal combustion engine for use by an electrical-rotor as the
electrical-rotor is used to enable forward-flight. As heretofore
described, one alternative variation of the present method provides
for tilting the electrical-rotor in a manner so as to cause thrust
from the first electrical-rotor to be redirected from a
substantially vertical direction to a substantially horizontal
direction in order to achieve forward-flight. As also described, a
rotor that continues to operate and provide thrust in a vertical
direction when other rotors are used to maintain forward speed in
support of fixed-wing flight, such vertically operating rotors are
likely to induce instability in flight and create additional
resistance to forward motion.
[0065] This example variation of the present method provides an
included step for removing power from the first mechanical-rotor
(step 140). Again to the operation of an electrical-rotor that
would otherwise deliver thrust in a substantially vertical
direction, removing power from the first mechanical-rotor reduces
the likelihood that the first mechanical-rotor will induce flight
instability and reduces the likelihood that it will create
additional resistance to forward motion. However, it should be
appreciated that the first mechanical-rotor is operated by a first
internal combustion engine. In the various alternative methods
herein described, an internal combustion engine is used to generate
electrical energy necessary to operate the electrical-rotors.
Accordingly, this alternative example variation of the present
method includes a step for conferring mechanical work from the
first internal combustion engine into electrical energy (step 145).
Put plainly, the first internal combustion engine, according to
this alternative example variation of the present method, continues
to operate in order to generate said electrical power.
[0066] According to one illustrative use case, removing power from
the first mechanical-rotor is achieved by means of an apparatus
such as a clutch. By opening the clutch, mechanical power from the
first internal combustion engine is disengaged from the first
mechanical-rotor. However, the first internal combustion engine
continues to provide mechanical power to a first motor-generator,
which is coupled to the first internal combustion engine, at least
according to this illustrative use case.
[0067] FIG. 12A is a pictorial diagram that illustrates various
embodiments of the present method and variations thereof that
incorporate mechanical power engagement devices. It should be
appreciated that, as described above, there is at least one
situation where mechanical power is removed from a mechanical-rotor
75 so that a particular internal combustion engine 80 is allowed to
operate in order to provide mechanical work to a motor-generator
85. It should likewise be appreciated that there are other
situations where mechanical engagement/disengagement of mechanical
power from the internal combustion engine 80 provides for
alternative use scenarios, including recovery from various failure
scenarios. These will be discussed with reference to the table
presented immediately below.
TABLE-US-00001 Propeller M/G ICE OPERATING MODE CLUTCH 1 CLUTCH 2
RUN G ON (1) Thrust/Generating DIRECT DIRECT RUN G OFF Not
Applicable RUN M ON (2) Peak Thrust/Start ICE DIRECT DIRECT RUN M
OFF (3) Flame Out OPEN DIRECT STOP G ON (4) No Thrust/Generating
CLOSED OPEN STOP G OFF Not Applicable STOP M ON (5) Start ICE/No
Thrust CLOSED OPEN STOP M OFF Not Applicable
[0068] Referring to the table immediately above, the status of the
propeller is expressed in one of two states including "run" and
"stop". The state of the motor-generator ("M/G") is expressed in
one of two states including "motor" and "generate". The state of
the ICE is expressed in one of two states including "on" and "off".
The state of a particular clutch, if included in a particular
embodiment described herein, is expressed in two states including
"open" and "closed". The open state of a clutch corresponds to a
state where the clutch is disengaged and does not transmit
mechanical power from input to output of the clutch. The closed
state of the clutch corresponds to a state where the clutch is
engaged and transmits mechanical power from its input to its
output. The table above also defines that a particular clutch is
not provided in a particular embodiment of the example method and
variations thereof as described below.
[0069] It should likewise be appreciated that, as illustrated in
FIG. 12A, one particular embodiment of the present example method
and variations thereof does not include either a first clutch 83 or
a second clutch 88. In this embodiment, the internal combustion
engine 80 is directly coupled to the motor-generator 85 and
directly coupled to the mechanical-rotor 75. It should be
appreciated that, as defined in the table above, such direct
coupling of mechanical power from the internal combustion engine 80
to the motor-generator 85 and to the mechanical-rotor 75 supports
an illustrative use case (operating mode 1 in the table) wherein
propeller is spinning (i.e. it is in a "run" state) and the
motor-generator 85 is operating as a generator ("G").
[0070] This particular embodiment where the internal combustion
engine 80 is directly coupled to the motor-generator 85 and to the
mechanical-rotor 75 also supports an illustrative use case
(operating mode 2 in the table) where the motor-generator 85 is
operating as a motor ("M"). When the motor-generator 85 is
operating as a motor, this illustrative use case provides for a
situation where the motor is used to initially start the internal
combustion engine 80 and to provide additional mechanical power to
the mechanical-rotor 75.
[0071] According to yet another alternative example embodiment of
the present example method and variations thereof, a first clutch
83 is included and is disposed between the internal combustion
engine 80 and the motor-generator 85. In this alternative example
embodiment, the motor-generator 85 is directly coupled to the
mechanical-rotor 75. This particular embodiment supports an
illustrative use case (operating mode 3 in the table) wherein the
first clutch 83 is opened in the event of a flameout of the
internal combustion engine 80. In this state, the ICE is off and
the motor-generator operates as a motor ("M") in order to provide
mechanical power to the mechanical-rotor 75.
[0072] According to yet another alternative example embodiment of
the present example method and variations thereof, a first clutch
83 and a second clutch 88 are both included in the embodiment of an
ICE power unit ("ICE/PU"). It should be appreciated that an ICE/PU
includes the internal combustion engine 80 the motor-generator 85
and mechanical-rotor 75. Because this alternative example
embodiment includes both the first clutch 83 and the second clutch
88, this embodiment supports additional illustrative use cases,
which are identified as functions 4 and 5 in the table above.
[0073] According to the first additional illustrative use case
(operating mode 4), the internal combustion engine 80 is operated
in order to provide mechanical work to the motor-generator 85 when
the first clutch 83 is closed. In this illustrative use case, the
second clutch 88 is opened so that mechanical powers not delivered
to the mechanical-rotor 75, for example in those situations where
forward-flight has been achieved and the mechanical-rotor is
disengaged so that it does not impede such forward-flight.
[0074] According to the second additional illustrative use case
(operating mode 5), the first clutch 83 is closed and the second
clutch 88 is open. According to this illustrative use case, the
motor-generator 85 is used to start the internal combustion engine
80 without providing mechanical work to the mechanical-rotor 75. It
should be appreciated that this is an important feature because, in
some illustrative use cases, it is important to start the internal
combustion engine 80 without engaging the mechanical-rotor 75,
which would otherwise pose a hazard to personnel safety.
[0075] FIG. 12B is a flow diagram that depicts one alternative
example method wherein electrical power is generated based upon
consumption of a fossil fuel. According to this alternative example
method, generating electrical power comprises a step for receiving
mechanical power from the first internal combustion engine (step
150); converting a portion of the mechanical power to electrical
power (step 155); and conveying a substantially remaining portion
of the mechanical power to the first mechanical-rotor (step
160).
[0076] It should be appreciated that, according to one illustrative
use case, this alternative example method is embodied in a machine
that includes an internal combustion engine that is coupled to a
motor-generator and to a mechanical-rotor, as heretofore described.
Accordingly, mechanical work from the internal combustion engine is
delivered to the motor-generator, which converts the mechanical
work into electrical power. The remaining mechanical work from the
internal combustion engine is then directed to the
mechanical-rotor. Additional embodiments of apparatus that apply
this variation of the present method are described further,
below.
[0077] FIG. 12C is a pictorial diagram that illustrates one
alternative illustrative use case of the present method and
variations thereof that incorporate mechanical power engagement
devices and a speed-altering device. As described above with
support from FIG. 12A, an internal combustion engine 80 is used to
provide mechanical power to the mechanical-rotor 75. In this
alternative illustrative use case of the present method, the
mechanical power provided by the ICE 80 is first subject to a
speed-alteration, which is accomplished by means of a gear box
81.
[0078] In yet another alternative use case of the present method,
the gear box reduces the rotational speed of the mechanical power
received from the ICE 80. The power, at a reduced rotational speed,
is presented to the first clutch 83. The power from the first
clutch 83 then is directed to a motor-generator 85. The reduced
rotational-speed power from the motor-generator is then directed to
a second clutch 88, and from the second clutch 88 to the
mechanical-rotor 75.
[0079] FIG. 12D is a flow diagram that depicts one alternative
method where the efficiency of an ICE is accommodated at different
rotational speeds. It should be appreciated that different ICEs
exhibit varying efficiencies at varying rotational speeds. For
example, where one model of an ICE exhibits greater efficiency at a
higher rotational speed than a second ICEs model. In other
illustrative use cases, a motor-generator exhibits peak efficiency
at a different rotational rate than a particular ICEs. In order to
operate at maximum system efficiency, a conversion of rotational
speed is performed in order to match the efficiency of a particular
IECs to a particular motor generator.
[0080] Accordingly, one alternative example method provides
included steps for receiving mechanical power from an internal
combustion engine (step 152), altering the rotational rate of the
mechanical power (step 153), converting a portion of the
rotational-rate-adjusted mechanical power to electrical power (step
157) and then conveying the remaining rotational-rate-adjusted
mechanical power to a first mechanical-rotor (step 162).
[0081] It should be appreciated that different propellers exhibit
varying efficiencies at varying rotational speeds. In other
illustrative use cases, propellers exhibit peak efficiency at a
different rotational rate than a particular motor-generator. In
order to operate at maximum system efficiency, a conversion of
rotational speed is performed in order to match the efficiency of a
particular IKE to a particular motor generator.
[0082] Accordingly, one alternative example method provides
included steps for receiving mechanical power from an internal
combustion engine (step 152), altering the rotational rate of the
mechanical power (step 153), converting a portion of the
rotational-rate-adjusted mechanical power to electrical power (step
157) and then conveying the remaining rotational-rate-adjusted
mechanical power to a first mechanical-rotor (step 162).
[0083] FIGS. 13 through 15 are flow diagrams that depict
alternative example methods for managing electrical power produced
by a machine that consumes a fuel. According to one variation of
the present method, a portion of the electrical power generated by
a first internal combustion engine is directed to a first
electrical-rotor (step 165), which is an further included step in
this variation of the present method. This variation of the present
method further includes a step for conveying an additional portion
of the electrical power to a second electrical-rotor (step 170). It
should be appreciated that this variation of the present method
provides for operating additional electrical-rotors from electrical
power generated by a single internal combustion engine.
[0084] According to yet another example variation, the present
method further includes a step for conveying a portion of the
electrical power to a first electrical-rotor (175) and storing an
additional portion of the electrical power for future use (step
180). It should likewise be appreciated that, according to this
variation of the present method, electrical power is stored in
electrical storage device. According to one illustrative use case,
the present method is applied in conjunction with the use of a
battery for storing electrical power generated by the first
internal combustion engine.
[0085] And in yet another example variation of the present method,
an additional further step is included for converting the
electrical power to a direct current (step 185) and then charging a
storage cell according to the direct current (step 190). According
to some illustrative use cases, the various example methods herein
described are applied in conjunction with an induction machine,
which is used to generate electrical power. The output of the
induction machine, which produces an alternating current, is
converted to direct current and regulated in order to charge a
storage cell, which according to various illustrative use cases
comprises a battery.
[0086] FIG. 16A is a pictorial diagram that illustrates one example
embodiment of an internal combustion engine power unit. According
to this example embodiment, of internal combustion power unit 205
comprises an internal combustion engine 210, a clutch 215, a
motor-generator 220, and a mechanical-rotor 225. This particular
embodiment is referred to as a single-clutch embodiment. In such a
single-clutch embodiment, the clutch 215, as heretofore described,
selectively engages mechanical power from the internal combustion
engine 210 to the motor-generator 220. In this embodiment, the
motor-generator 220 is directly coupled to the mechanical-rotor
225. As also heretofore described, when a flameout of the internal
combustion engine occurs, the clutch 215 disengages the
motor-generator 220 and the mechanical-rotor 225 from the internal
combustion engine 210. Hence, in a flameout condition, the
motor-generator 220 operates as a motor in order to continue to
provide mechanical power to the mechanical-rotor 225.
[0087] FIGS. 16B and 16C are a pictorial diagrams that illustrates
other alternative example embodiments of an internal combustion
engine power unit that includes a second clutch. As heretofore
described, some example embodiments of a power unit include a
second clutch, which enables embodiments to operate according to
additional operating modes as heretofore described. As illustrated
in the FIG. 16B, one alternative example embodiment of an internal
combustion engine power unit 205 includes an internal combustion
engine 210, a first clutch 215, a motor-generator 220, and a second
clutch 230. FIG. 16C illustrates that, according to another
alternative example embodiment, an internal combustion engine power
unit 205 comprises an internal combustion engine 210, a gear-box
217, a first clutch 215, a motor-generator 220, and a second clutch
230.
[0088] In the alternative example embodiment depicted in FIG. 16B,
the motor-generator 220 is coupled to an included rotor 225 by the
second clutch 230. Accordingly, additional control is provided for
supporting operating modes wherein the propeller 225 is not
operated when the motor-generator 220 is driven by the internal
combustion engine 210 by closing the first clutch 215, but leaving
the second clutch 230 open. This allows the power unit to generate
electrical power from mechanical work derived from the internal
combustion engine 210 without providing thrust since the rotor 225
is not engaged in this operational mode, see operating mode 4 in
table above. This same clutch configuration also supports operating
mode 4, which provides for starting the internal combustion engine
210 by using the motor-generator 220 as a starter motor.
[0089] FIG. 16C depicts an alternative embodiment that further
includes a gear-box 217, which is disposed to receive mechanical
power from the internal combustion engine 210. The gear-box reduces
the rotational-speed of the mechanical power received from the
internal combustion engine 210. The reduced-speed mechanical power
is then directed from the gear-box 210 to the motor-generator
220.
[0090] In sharp contrast to prior-art hybrid-drive systems, the
present method and various alternative example embodiments thereof
use mechanical power from the internal combustion engine to drive a
propeller directly. Now, only a portion of the mechanical power
from the internal combustion engine is used to generate electrical
power. In the hybrid-drive system described by Phan, all the power
from the internal combustion engine is converted to electrical
energy, which is used to drive propellers driven by electric
motors.
[0091] FIG. 17A is a pictorial illustration that depicts one
example embodiment of a multi-rotor airframe. FIG. 17B is a block
diagram that depicts one example embodiment of a wiring structure
for connecting components in an airframe. In this example
embodiment, an airframe 400 includes a body portion 405 and one or
more internal combustion engine power units 205. It should be
appreciated that, according to one alternative example embodiment,
the airframe 405 includes three such internal combustion engine
power units 205. And in yet another alternative example embodiment,
the airframe 405 includes four such internal combustion engine
power units 205. It should likewise be appreciated that these
example embodiments are not intended to limit the scope of the
claims appended hereto and then various alternative embodiments are
contemplated that include various numbers of internal combustion
engine power units 205.
[0092] FIG. 17B illustrates that the multi-rotor airframe of this
example embodiment also includes an energy storage device 270. The
energy storage device 270, which according to alternative example
embodiments comprises at least one or more of a battery and/or a
super capacitor, is electrically coupled to a power control unit
265. Power control unit 265 operates to charge the energy storage
device 270 by receiving electrical power from a power bus 275 and
directing a charge current, derived from the power bus 275, to the
energy storage device 270.
[0093] FIG. 17A further illustrates that, according to this example
embodiment, the multi-rotor airframe includes a first rotor 215,
which is oriented to direct thrust in a substantially downward
direction. The first rotor 215 is mechanically coupled to a first
motor-generator 220 included in a first ICE power unit 205. The
first motor-generator 220 is coupled to the first internal
combustion engine 210 by means of a first clutch 215. The first
clutch 215 serves as a mechanical coupler that is capable of
selectively applying mechanical power generated by the first
internal combustion engine 210 to the first motor-generator 220. An
optional gear-box 217 is included in some alternative embodiments.
In these alternative embodiments, the gear-box changes the
rotational speed of mechanical power generated by the first
internal combustion engine 210.
[0094] FIG. 17B further illustrates that, according to this example
embodiment, the first motor-generator 220 is electrically connected
245 to a first motor control unit 235. The first motor control unit
235, in one operating mode, receives electrical power generated by
the motor-generator 220 and directed to a power bus 275, included
in this example embodiment. Accordingly, this path provides a means
whereby the first motor-generator 220 is capable of directing power
to the energy storage device 270.
[0095] FIG. 17A also illustrates that, according to this example
embodiment, the multi-rotor airframe 400 further includes a second
rotor 410. In this example embodiment, the second rotor 410 is
capable of generating thrust in a substantially downward direction
when mechanical work is applied thereto. A second motor-generator
415, included in this example embodiment, is coupled to the second
rotor 410.
[0096] FIG. 17B further illustrates that the second motor-generator
415 is controlled by a second motor control unit 280. The second
motor control unit 280 receives electrical power from the power bus
275 and directs the electrical power to the second motor-generator
415. It should be appreciated that the power bus 275 is depicted in
the figures in order to illustrate one alternative example
embodiment and is depicted in the figures for the sake of
convenience to allow better comprehension of how electrical power
is electrically coupled from the energy storage device 270 to any
other particular element in a multi-rotor airframe. Accordingly,
such limitation details of various alternative example embodiments
are not intended to limit the scope of the claims appended
hereto.
[0097] This example embodiment of a multi-rotor airframe also
includes a flight controller 300 and an attitude sensor 305. It
should be appreciated that, according to one alternative example
embodiment, the attitude sensor 305 comprises an inertial
measurement unit 305. The inertial measurement unit 305, according
to various alternative example embodiments, comprises at least one
or more of a mechanical gyroscope, an optical-energy gyroscope,
and/or a monolithic semiconductor device. In any of these
alternative example embodiments, the attitude sensor 305 generates
an attitude signal 350. The flight controller 300 receives the
attitude signal 350 and generates a first correction signal 260.
The first correction signal 260 is electrically coupled to the
second motor control unit 280.
[0098] In operation, the flight controller 300 of this example
embodiment adjusts the power to be applied to the second
motor-generator 415 in order to maintain attitude in accordance
with an intended attitude value 340 maintained in the flight
controller 300. As such, the second motor-generator 415 provides
varying amounts of mechanical power to the second rotor 410.
Because the motor-generator provides better power responsiveness,
it allows for agile control of attitude based on the first
correction signal 260, which is generated by the flight controller
300.
[0099] It should likewise be appreciated that, depending on the
magnitude and polarity of the first correction signal 260, the
second motor control unit 280 causes the second motor-generator 415
to apply additional power, to the limit of its power ability, or to
reduce power to the limit of his minimum power ability. It should
be noted that, according to various alternative embodiments, the
minimum power ability of a particular motor-generator 415 includes
an off state, wherein no mechanical work is generated by the second
motor-generator 415.
[0100] In certain situations, attitude of the multi-rotor airframe
cannot be maintained by using the mechanical power provided by the
second motor-generator 415. Accordingly, the flight controller 300
of one alternative example embodiment generates a second correction
signal, which is directed to an internal combustion engine control
unit 240. It should be appreciated that, according to one
alternative example embodiment, the internal combustion engine
control unit 240 is communicatively coupled 347 to the flight
controller 300 by means of a bidirectional data channel. In this
embodiment, a message is sent from the flight controller 300 to the
ICE control unit 240 in order to direct the ICE 242 either apply
additional power, or reduce the power applied to the first rotor
215. This is accomplished by increasing or decreasing fuel
consumption by the first internal combustion engine 210. Fuel
consumption by the first internal combustion engine 210 is
controlled by a throttle signal 250. The ICE control unit 240
adjusts the throttle signal in order to increase or decrease the
amount of mechanical work applied by the first internal combustion
engine 210 the first rotor 215.
[0101] According to yet another alternative example embodiment, the
flight controller 300, using an included control signal 342,
directs the first motor control unit 235 to cause the first
motor-generator 220 to receive electrical power from the power bus
275 in order to generate additional mechanical work for application
to the first rotor 215. This functionality is provided to enable
additional attitude control. It should likewise be appreciated
that, according to various alternative example embodiments,
additional attitude control is provided either by adjusting the
amount of power delivered by the first internal combustion engine
210. In another alternative example embodiment, additional attitude
control is provided by adjusting the amount of power delivered by
the first motor-generator 220. It should likewise be appreciated
that, according to various alternative example embodiments, the
power bus 275 receives electrical power, by way of the power
control unit 265, from the energy storage device 270.
[0102] In certain operational modes, for example when additional
lifting capacity is required, the first motor control unit 235 is
capable of receiving electrical power from the power bus 275 and
directing the electrical power to the first motor-generator 220. In
this manner, the amount of mechanical work applied to the first
rotor 215 includes mechanical work generated by the first internal
combustion engine 210 and mechanical work generated by the first
motor-generator 220. This provides greater thrust capability the
first rotor 215, which is useful for increasing the altitude with a
heavy payload. According to this alternative example embodiment,
the first motor control unit 235 receives a control signal 342 from
the flight controller 300. The flight controller 300 directs the
first motor control unit 235 to enable additional mechanical work
to be generated by the first motor-generator 220 when additional
lift is necessary in order to maintain, or increase altitude of the
airframe.
[0103] FIG. 17B also illustrates that, according to one alternative
example embodiment, the ICE control unit provides a starting
function, which is initiated by a message received from the flight
controller 300. Again, such message is received by the ICE control
unit 240 by means of a bidirectional data communications path 347.
Starting function provided by the ICE control 240 includes a choke
control signal 255. In operation, the ICE control unit 240 receives
engine rotations per minute ("RPM") indications by means of an RPM
feedback signal 260. Based on this alternative example embodiment,
the ICE control unit 240 manipulates the throttle signal 250 in
conjunction with the choke control signal 255 in order to start the
internal combustion engine 210.
[0104] It should also be appreciated that, according to one
alternative example embodiment, the throttle control input included
in the first internal combustion engine 210 is responsive to a lift
signal received from the flight controller 300. As heretofore
described, the flight controller directs a lift message to the ICE
control unit 240 by way of a bidirectional communications path 347.
Accordingly, the ICE control unit 240 will increase the amount of
work to be delivered by the first internal combustion engine 210 in
order to increase altitude of the payload. This is accomplished by
increasing the amount of fuel consumed by the internal combustion
engine, which is affected by manipulating the throttle signal
250.
[0105] FIG. 17C is a block diagram that depicts one alternative
example embodiment of a flight controller 300. According to one
alternative example embodiment, the flight controller 300 includes
an intended attitude indicator 340. The intended attitude indicator
340 is compared, by means of a first included differencing
amplifier 342, against the attitude signal 350 generated by the
attitude sensor 305. The differencing amplifier 342 included in
this alternative example embodiment then generates the first
correction signal 260.
[0106] In yet another alternative example embodiment, the flight
controller 300 includes a second differencing amplifier 347.
According to one alternative example embodiment, the second
differencing amplifier 347 generates a second correction signal
342, which the second differencing amplifier 347 communicates to
the ICE control unit 240 by way of a digital message 34. In
operation, when the first correction signal 260 reaches a control
limit, the second differencing amplifier 347 generates the second
correction signal (i.e. either 342 or 347) to cause at least one or
more of the first motor-generator 220 and/or the first internal
combustion engine 210 to provide additional power to the first
rotor 215. This is done to add additional attitude control
capability when the second rotor 410, which is driven by the second
motor-generator 415, is unable to maintain the attitude correction
according to the first correction signal 260.
[0107] FIG. 18 is a pictorial diagram that illustrates one
alternative example embodiment of an airframe that supports a
forward-flight mode. According to this alternative example
embodiment, the airframe 400 further includes a lifting surface
435. The lifting surface 435 of this alternative example embodiment
is disposed so as to generate lift in a substantially vertical
direction when it is subject to airflow. This alternative example
embodiment of the airframe 400 further comprises a tilt mechanism
430. The tilt mechanism 430, when engaged, causes the first ICE
power unit 205 to tilt from a vertical thrust orientation to a
forward-flight thrust orientation.
[0108] FIGS. 19A through 19D are pictorial diagrams that illustrate
progression of an ICE power unit from vertical mode to
forward-flight mode. It should be appreciated that, according to
this alternative example embodiment of an airframe 400, the first
ICE power unit 205 begins operation in a substantially vertical
flight mode where in thrust 440 is directed in a substantially
downward direction. As the tilt mechanism 430 is engaged, the first
ICE power unit 205 begins to rotate 445 forward. As the progression
begins and then continues, the thrust generated by the first rotor
225 is used to maintain lift of the airframe and also begin moving
the airframe and a forward direction. At some point, there is
sufficient lift generated by the lifting surface 435 to maintain
forward-flight. The progression of tilting completes, as shown in
FIG. 19D, and the first ICE power control unit 205 is disposed in a
manner so as to direct a substantial portion of its thrust in a
direction opposite to that of an intended forward-flight direction.
In this example embodiment, the tilt mechanism 430 is responsive to
a tilt signal 262, which is generated by the flight controller 300
when transitioning from vertical flight mode to forward-flight
mode.
[0109] As the airframe begins moving forward, as more thrust is
directed in a direction opposite of an intended forward-flight
direction, lift is generated by the lifting surface. According to
one alternative example embodiment, the airframe 400 further
includes a speed sensor 312. A speed sensor 312 generates a speed
signal 357, which is directed to the flight controller 300. When
forward-flight is achieved, the flight controller 300, upon sensing
sufficient forward-flight speed, commands the second
motor-generator 415 to power off. This is accomplished by
manipulating the first correction signal 260. This is further
illustrated in FIG. 17C where in the speed signal 357 causes the
first difference amplifier 342 to drive the first correction signal
260 to a state that causes the second motor-generator to shut off.
In some alternative example embodiments, the second motor control
unit 280 includes a second input for shutting down the second
motor-generator 415 according to a shutdown signal 261 generated by
the flight controller 300.
[0110] FIG. 17C also illustrates that, according to one alternative
example embodiment, the flight controller 300 also receives an
altitude signal 355. In this alternative example embodiment, the
airframe 400 includes an altitude sensor 310. In various
alternative example embodiments, the altitude sensor comprises a
satellite navigation receiver 310. A third differencing amplifier
349 included in this alternative example embodiment of a flight
controller 300 compares an intended altitude indicator 345,
maintained in the flight controller 300, to the altitude signal 355
received from the altitude sensor 310. An adjustment to altitude is
affected by means of a correction signal, which is communicated to
the ICE control unit 240 by means of a digital message 347. The ICE
control unit 240, in turn, adjusts the amount of power generated by
the internal combustion engine 210 through manipulation of the
throttle signal 250.
[0111] FIG. 18 also illustrates one alternative example embodiment
of an airframe 400 that includes a forward thruster 430. It should
be appreciated that, according to this alternative example
embodiment, the forward thruster 430 includes a forward-thrust
rotor 432 mechanically coupled to at least at least one or more of
an internal combustion engine 433, a motor-generator 431 and/or an
electric motor 431. In this alternative example embodiment, the
first ICE power unit 205 is not tilted in a forward manner in order
to achieve forward-flight. Forward-flight, according to this
alternative embodiment, is affected by thrust provided by thruster
430. When forward-flight is achieved, the flight controller 300 of
this alternative example embodiment shuts down the first ICE power
unit 205 and the second motor-generator 415 in order to help
achieve stable flight.
[0112] FIGS. 20 through 22 are pictorial diagrams that depict the
relative placement of rotors in one alternative example embodiment
of a multi-rotor airframe. It should be appreciated that, according
to various alternative example embodiments, the first rotor and the
second rotor are substantially coaxial when the airframe is in a
vertical flight mode. This is apparent from the figures herein
presented. FIG. 21 further clarifies that the first rotor 215 and
the second rotor 410 are substantially coaxial in an axis 299
substantially orthogonal to a vertical flight attitude. FIG. 21
also illustrates that the vertical separation 298 between the first
rotor 215 and the second rotor 410 is maintained at a minimum
distance so as to minimize turbulence in various flight modes,
including when transitioning from a vertical flight mode to a
forward-flight mode by tilting the first rotor 215 in a forward
direction.
[0113] FIG. 23 is a pictorial diagram that depicts one alternative
embodiment of an airframe that includes a secondary payload
compartment. In one alternative embodiment, the airframe further
includes a secondary payload compartment 480. In yet another
alternative embodiment, the airframe further includes a door
structure 475 that is automatically engaged to enclose a secondary
payload 485 in the payload compartment 480.
[0114] While the present method and apparatus has been described in
terms of several alternative and exemplary embodiments, it is
contemplated that alternatives, modifications, permutations, and
equivalents thereof will become apparent to those skilled in the
art upon a reading of the specification and study of the drawings.
It is therefore intended that the true spirit and scope of the
claims appended hereto include all such alternatives,
modifications, permutations, and equivalents.
* * * * *