DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This is in response to the correspondence filed on 8/13/2026 and interviews conducted via telephone on 8/25/2026 and 8/28/2026.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 4/9/2026 has been entered.
Election/Restrictions
Applicant elected with traverse Species D (Figs. 18-22), Sub-Species 1 (Fig. 11) and Sub-Sub-Species C1 (Fig. 25) in the reply filed on 6/12/2025. The traversal is on the ground(s) that the Office fails to demonstrate why each Species, Sub-Species and Sub-Sub-Species are distinct and/or independent. This is not found persuasive because The Restriction/Election dated 4/14/2025 identifies characteristics of each of the Species, Sub-Species and Sub-Sub-Species in a manner that one of ordinary skill would recognize each mutually exclusive characteristics, and the species are not obvious variants of each other, as discussed in previous office action.
Figures 8-10, 16, 17 and 24 are non-elected species.
Figures 12-14 are non-elected species.
Figure 26 is non-elected species.
Election by Original Presentation:
The amended claims filed on 12/05/2025 included new claims 9-18 directed to inventions that are independent or distinct from the invention originally claimed.
Since applicant has received an action on the merits for the originally presented invention, this invention was constructively elected by original presentation for prosecution on the merits. Accordingly, claims 9-19 were withdrawn from consideration as being directed to a non-elected invention. See 37 CFR 1.142(b) and MPEP § 821.03 on the office action dated 1/9/2026.
On Correspondence received on 8/13/2026, applicant argues the Office has not established how the search and examination of the claims would impose a serous burden on the office, the independent claims of each alleged separate invention are nearly identical.
Examiner’s response:
Applicant’s arguments were considered and upon further consideration, the Examiner partially agrees with Applicant regarding claims 9-12 filed on 12/5/2025; independent apparatus claim 1 does appear to include all the limitations of the then new apparatus claim 9 (in the claim set of 12/5/2026). Therefore the restriction of claims 9-12 is withdrawn.
Regarding the restriction of the independent method claim 13, the, the election by original presentation is proper as discussed in the previous office actions. Inventions I and II, and Invention III, are related as process and apparatus for its practice. The inventions are distinct if it can be shown that either: (1) the process as claimed can be practiced by another and materially different apparatus or by hand, or (2) the apparatus as claimed can be used to practice another and materially different process. (MPEP § 806.05(e)). In this case Inventions I and II can be used to practice a method that does not require "receiving" sensor information, or "determining a thrust", “determining a moment”, “controlling the first propeller pair based on the determined thrust and moment” as required by Invention III. Search burden is also established where the inventions require a different field of search (for example, searching different classes/subclasses or electronic resources, or employing different search queries), and/or where the prior art applicable to one invention would not likely be applicable to another invention. Note, the number of references in each class/subclass continually increases over time such that searches of entire classes/subclasses is often not achievable in the given amount of time for each case. As such, modern search strategies involve extensive text limiting and subclass cross-limited/combination searching, which are specific to the features of each invention. For these reasons, search results addressing the apparatus claims may not be sufficient to address the process claims.
The requirement is still deemed proper and is therefore made FINAL.
In the claims filed on 8/13/2026:
Claims 3-4, 14, 18, 22 are cancelled.
Claims 13, 16-17, 19 are withdrawn.
Claims 27-30 are new claims
Claims 1-2, 5-12, 20-21, 23-30 are examined.
Claim Rejections - 35 USC § 101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
Claim 1, and dependent claims, are rejected under 35 U.S.C. 101 because the claimed invention is directed to an abstract idea without significantly more. The claim(s) recite(s) “determine a thrust signal to be transmitted to the pair of propellers based on the vehicle dynamics of the aircraft using a first set of one or more control laws, the thrust signal indicating a thrust to be provided by the pair of propellers; [[and]] determine a moment signal to be transmitted to the pair of propellers based on the vehicle dynamics of the aircraft using a second set of one or more control laws, the moment signal indicating a moment to be provided by the pair of propellers ” This judicial exception is not integrated into a practical application because Claim 1 is directed to a machine (an aircraft) comprising a processor configured to determine a thrust signal and a moment signal (i.e., calculating a signal based on sensor information), a Mathematical Concept MPEP 2106.04(a)(2)(I)) and a Mental process MEPE 2106.04(a)(2)(III), in form of comparing data (i.e., comparing data and concluding that higher or lower signal values are needed). The claim(s) does/do not include additional elements that are sufficient to amount to significantly more than the judicial exception, because they were well known and conventional at the time of filing, said structural recitations being:
“An aircraft comprising: a pair of propellers; and a flight control system comprising a processor configured to: receive sensor information indicative of vehicle dynamics of the aircraft; […] wherein the aircraft is an electric vertical takeoff and landing aircraft, the aircraft is configured to be operated by an onboard pilot, and the aircraft is capable of carrying a payload of at least 400 pounds”.
These limitations are known and taught by Baity 20190329882 “Aircraft systems are known to have certain characteristics. Example systems include the following: [0003] 1) Unmanned Small Multi-Rotor Quad-Copters (“drones”) [0004] 2) Unmanned Fixed-Wing Electric [0005] 3) Unmanned Internal Combustion (IC) Engine Fixed-Wing/Rotor Craft [0006] 4) Unmanned Separated Lift/Thrust Fixed wing aircraft (Hybrid-Quad) Rotor [0007] 5) Tail-Sitters [0008] 6) Manned Single Engine Fixed-Wing Aircraft [0009] 7) Manned Rotorcraft Aircraft”. And the "processor" (computer) was known for performing mathematical operations, receiving data inputs, processing data, and outputting data. At issue are the limitations reciting "control unit" that do not necessarily result in a physical change to the aircraft, the limitation “transmit the thrust signal and the moment signal to the pair of propellers” does not necessarily indicate a physical change (the signal being transmitted is not the same as the propellers reacting and changing speed, pitch, etc). This lack of physical manifestation and the use of conventional structures to perform conventional functions renders the claim(s) an abstract idea lacking "significantly more". Consequently, Claims 1 and its dependent claims are rejected under 35 USC101.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 21, and dependent claims, are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 21: the limitation “wherein the moment signal comprises indicates at least one of a rotation speed of at least one of the first propeller or the second propeller or collective pitch of at least one of the first propeller or the second propeller, the rotation speed or collective pitch being determined to achieve a desired moment aircraft flight condition” appears to be new matter. Applicant indicates that support may be found in paragraph [0085] but this paragraph does not appear to discuss moment.
Claim 21: in “the moment signal comprises indicates at least one of a rotation speed of at least one of the first propeller or the second propeller or collective pitch of at least one of the first propeller or the second propeller, the rotation speed or collective pitch being determined to achieve a desired moment aircraft flight condition”, it is unclear how the moment signal comprises a collective pitch and how that achieves a desired moment. Collective pitch appears to be discussed in paragraph [0085] but it does not provide additional explanation of how moment and collective pitch are correlated.
Claims 1, 9, 21, 25, 28, and their dependent claims, are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Claims 1, 9, 21, 25, 28: the limitation “moment” is present in claims 1, 9, 21, 25, 28, but it is not clear what it refers to and how it is generated and how it affects the system. As understood, as defined by Merriam-Webster dictionary, is “a: tendency or measure of tendency to produce motion especially about a point or axis; b: the product of quantity (such as a force) and the distance to a particular axis or point”, but no points or axis are defined in the claims. It is further unclear how the moment is produced in the system, it is not clear if changes in speed of the propellers are involved, or changes in pitch of a group of propeller blades or individual propeller blades, or by movement of the motors with respect to the fuselage, or other possible changes in the system, and how the aircraft is expected to react in response to the application of the “moment” (it is not clear if an expected response to a moment would be a change in “nose attitude”, roll about a longitudinal axis, yaw, or anything else).
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1, 9, 21, 25, 28, and their dependent claims, are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 1, 9, 21, 25, 28: the limitation “moment” is present in claims 1, 9, 21, 25, 28, but it is not clear what it refers to. As understood, as defined by Merriam-Webster dictionary, is “a: tendency or measure of tendency to produce motion especially about a point or axis; b: the product of quantity (such as a force) and the distance to a particular axis or point”, but no points or axis are defined in the claims.
Claim 21: it is unclear if the limitation “collective pitch” in “the rotation speed or collective pitch being determined” (line 4 in claim 21) is related “collective pitch” in line 3, or if it refers to a separate collective pitch.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-2, 5-12, 20-21, 23-30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Elshafei 20160023755 in view of Olson 3181810.
The rejections below are based on the beset attempt to interpret the claimed invention, see 112(a) and 112(b) discussions above.
Regarding claim 1, Elshafei teaches:
An aircraft (quadrotor air vehicles (QRAV) (abstract); QRAV may perform vertical takeoff and landing (VTOL) [0009]) comprising:
a pair of propellers (inter alia, 1 and 3; “A first pair of rotors of the four rotors may rotate in a first direction while a second pair of the four rotors may rotate in a second direction, opposite of the first direction. The angular speed of each of the rotors may be controlled independently. Separately, the thrust of each rotor may be independently tilted in any direction within a hemisphere. Therefore, the air vehicle may include a total of twelve independent control parameters to enable full and precise control” [0022]; regarding a pair of propellers, Elshafei teaches multiple propellers that can be controlled independently, as discussed above, and the grouping of two propellers forms a pair of propellers under a broadest reasonable interpretations BRI),
a flight control system (inter alia, Fig. 3) comprising a processor (flight computer [0024], computer [0094-0095], Figs. 3, 7) configured to:
receive sensor information indicative of vehicle dynamics of the aircraft (a central processing core may be provided to communicate with sensors, [0024]; sensors 723 Fig. 7, sensors [0098, 0100]);
determine a thrust signal to be transmitted to the pair of propellers (“the pilot control panel 400 may, in response to the pilot's action, generate a command signal proportional to the pilot's action” [0007], hover elevation [0023], “the thrust of each rotor may be independently tilted in any direction within a hemisphere” [0022] (where grouping two rotors creates a pair), elevation/ascending speed z, ż […] roll control φ [0061]; as discussed above, the propellers can be controlled independently, and two propellers form a pair of propellers, as discussed above, and the thrust signal transmitted to one of propellers and the thrust signal transmitted to the other propeller in the pair under consideration read on the thrust signal to be transmitted to the pair of propellers, as claimed) based on the vehicle dynamics of the aircraft ( as shown in FIG. 6, the dynamics of the quadrotor 601 is measured by the on-board flight instruments 602, the measurement vector X 610 is then compared with the desired values in 605. The error, that is the difference between the desired and measured states of the air vehicle, is then used by the one of the control methods to produce the control vector U 609 [0083]) using a first set of one or more control laws (elevation/ascending speed z, ż […] roll control φ [0061]), the thrust signal indicating a thrust to be provided by the pair of propellers (The angular speed of each of the rotors may be controlled independently. Separately, the thrust of each rotor may be independently tilted in any direction within a hemisphere. Therefore, the air vehicle may include a total of twelve independent control parameters to enable full and precise control [0022]); [[and]]
determine (“a control panel may be provided in order for a pilot or operator of a QRAV to access and manipulate a plurality of control parameters” [0023]) a moment signal (“a plurality of control parameters for each of the four rotors […] The inputs may control parameters of the air vehicle such as rotational movement of the air vehicle, pitch, pitch rate, roll, roll rate, yaw angular velocity, yaw angle, hover elevation, lateral motion acceleration and/or ascending speed” [0023], where at least pitch, pitch rate, roll, roll rate, yaw angular velocity, yaw angle read on a moment signal) to be transmitted to the pair of propellers based on the vehicle dynamics of the aircraft (“A QRAV's motion states of interest to pilot control of the aircraft may include: {{dot over (x)},{umlaut over (x)},{dot over (y)},ÿ,z,ż,θ,{dot over (θ)},φ,{dot over (φ)},{dot over (ψ)},{umlaut over (ψ)}}, which correspond to: forward speed, forward acceleration, lateral speed, lateral acceleration, elevation, ascending speed, pitch angle, rate of change of pitch angle, roll angle, rate of change of roll angle, yaw angular velocity, and yaw angular acceleration” [0102], where pitch, roll yah etc are controlled based on moment) using a second set of one or more control laws (pitch control θ; yaw control {dot over (ψ)}; and/or roll control φ” [0061]; “In one embodiment, the twelve control parameters enable the pilot to have independent control over each of the above QRAV motion states” [0102], teaching multiple control laws to independently control each motion state), the moment signal indicating a moment to be provided by the pair of propellers (The angular speed of each of the rotors may be controlled independently. Separately, the thrust of each rotor may be independently tilted in any direction within a hemisphere. Therefore, the air vehicle may include a total of twelve independent control parameters to enable full and precise control [0022]; it is noted that moment can be a result of different control parameters discussed above);_and
transmit the thrust signal and the moment signal to the pair of propellers (“a plurality of digital to analog channels 707 which may be used to send control commands to various on board actuators and servo systems, including the four main rotors, and eight servo actuators, which may align the rotors to desired tilt angles” [0100]; as discussed above, the propellers can be controlled individually, and the signals sent to the two propellers in the pair, can be combined as a pair as well and read on the limitation as claimed), wherein the aircraft is an electric vertical takeoff and landing aircraft (“The quadrotor air vehicle, also known as a quadrotor, quadrotor helicopter, quadrocoptor, or quadcopter, is a multi-rotor air vehicle that is lifted and propelled by four rotors” [0002], “QRAV may perform vertical takeoff and landing (VTOL)” [0009]), the aircraft is configured to be operated by an onboard pilot (“QRAV may also be employed in manned aerial vehicles” [0008]), and the aircraft is capable of carrying a payload of at least 400 pounds (“manned operations for effective transport and for military deployment operations in hostile environments where VTOL is a requirement.” [0009] and “in related art […] This design was eventually realized in Boeing's Bell V-22 Osprey aircraft which began operating in 1989 [0011] The Bell Boeing team disclosed a Quad TiltRotor design in 1999 as an improvement over the previous V-22 twin rotor design. The original design goal was to have a maximum takeoff weight of 45,000 kg with a payload of up to 11,000 kg in hover. However, the design goal was revised and downsized in 2000 to be more V-22 based and was to have a payload of only 8,200 to 9,100 kg in hover” [0011-0012]; Elshafei teaches payloads above 400 pounds were known and scaling the size of Elshafei’s invention can be accomplished by one of ordinary skill in the art. Elshafei Art is recognized as suitable for the intended purpose. See MPEP 2144.07).
Elshafei teaches a vehicle with 2 pairs of propellers (Fig. 1), which can be grouped in pairs, but is silent about:
the pair of propellers including a first propeller and a second propeller positioned on opposite sides of an aircraft center of gravity along a line that is oblique to a longitudinal axis of the aircraft;
However, Olson teaches “an attitude control system for "VTOL aircraft" of a kind having a plurality of thrust producing devices such as propellers, rotors, ducted fans or jet engines which selectively sustain or propel the aircraft in flight, and which are so situated that moments about one or more of the control axes of pitch, roll and yaw may be created by selectively adjusting thrust of the thrust producing units” (Col 1, ll. 15-60), also teachings many of the limitations already discussed above, teaching pairs of propellers and their operation to control moment (rolling and yaw, for example), inter alia, “means for changing thrusts of two thrust producing devices on one side of the aircraft while also changing the thrusts of the other two thrust producing devices on the other side of the aircraft to produce a rolling moment for control of the aircraft, said means including mechanism for proportioning said thrust changes to prevent the creation of yaw moments on the aircraft” Claim 2, and “The propellers in such configuration would be rotated in opposite directions from that shown in the drawings to take advantage of the torque changes occurring when the blade angles of the propellers are adjusted in the manner described for the purpose of yawing the vehicle. It is also possible to have the axes of rotation of all four propellers vertical in hover, and to yaw the vehicle with only the yawing moments due to the torque changes produced by increasing the blade angles of one pair of diagonally opposite propellers and decreasing blade angles of the other propellers”, Col 6 ll. 40-50), and:
the pair of propellers including a first propeller (1, Fig. 1, Col 4 ll. 63-66) and a second propeller (3, Fig. 1, Col 4 ll. 63-66) positioned on opposite sides of an aircraft center of gravity (26, Fig. 1, Col 4 ll. 45-49) along a line (a line connecting the center of 1 and the center of 3 in Fig. 1, solid line in Image below) that is oblique to a longitudinal axis of the aircraft (dashed line in Image below);
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Elshafei with Olson's teachings discussed above in order to provide the appropriate arrangement so the “aircraft ascends and descends vertically, and hovers with the propellers in their nearly vertical positions, whereas sustained horizontal flight is achieved with the propeller axes in their nearly horizontal positions. The propeller axes are gradually tilted between these extreme positions to accomplish a transition between the horizontal and other modes of flight” (Col 1 ll. 47-56), and to control roll and yaw moments, as taught by Olson and discussed above.
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Regarding claim 2, Elshafei in view of Olson teaches the invention as discussed for claim 1.
Elshafei in view of Olson, as discussed so far, is silent about:
The VTOL aircraft of claim 1 additionally comprising a second pair of propellers (2 and 4).
However, Olson teaches:
The VTOL aircraft of claim 1 additionally comprising a second pair of propellers (2 and 4, Fig. 1).
Regarding claim 5, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1 wherein a dynamics error value (The error, that is the difference between the desired and measured states of the air vehicle, is then used by the one of the control methods to produce the control vector U 609 [0083]) is translated into a coordinate frame of the pair of propellers (inter alia, the earth inertia frame [0059], and coordinate frame about the aircraft center of gravity [0053-0061]) by the electronic flight control system (inter alia, Fig. 6, 7).
Regarding claim 6, Elshafei in view of Olson teaches the invention as discussed for claim 5. Elshafei further teaches:
The aircraft of claim 5 wherein the electronic flight control system computes a vehicle dynamics control signal (609 [0083]) using the translated error value (The error, that is the difference between the desired and measured states of the air vehicle, is then used by the one of the control methods to produce the control vector U 609 [0083]).
Regarding claim 7, Elshafei in view of Olson teaches the invention as discussed for claim 6. Elshafei further teaches:
The aircraft of claim 6 wherein the flight control system commands an electric motor (rotors 1, 2, 3, 4 may be driven by brushless DC motors [0043]) using the vehicle dynamics control system (“The output from the flight control filters may include set-points for the vehicle control systems which determine the thrust of each motor and the tilting angles of each rotor” [0073]).
Regarding claim 9, Elshafei teaches::
A flight control system for an aircraft (inter alia, Fig. 3),
comprising at least one processor (flight computer [0024], computer [0094-0095], Figs. 3, 7) configured to:
receive sensor information indicative of vehicle dynamics of the aircraft (a central processing core may be provided to communicate with sensors, [0024]; sensors 723 Fig. 7, sensors [0098, 0100]);
determine a thrust signal to be transmitted to a pair of propellers (“the pilot control panel 400 may, in response to the pilot's action, generate a command signal proportional to the pilot's action” [0007], hover elevation [0023], “the thrust of each rotor may be independently tilted in any direction within a hemisphere” [0022] (where grouping two rotors creates a pair), elevation/ascending speed z, ż […] roll control φ [0061]; regarding a pair of propellers, Elshafei teaches multiple propellers that can be controlled independently, as discussed above, and the grouping of two propellers forms a pair of propellers under a broadest reasonable interpretations BRI; and the thrust signal transmitted to one of propellers and the thrust signal transmitted to the other propeller in the pair under consideration read on the thrust signal to be transmitted to the pair of propellers, as claimed) based on the vehicle dynamics of the aircraft ( as shown in FIG. 6, the dynamics of the quadrotor 601 is measured by the on-board flight instruments 602, the measurement vector X 610 is then compared with the desired values in 605. The error, that is the difference between the desired and measured states of the air vehicle, is then used by the one of the control methods to produce the control vector U 609 [0083]) using a first set of one or more control laws (elevation/ascending speed z, ż […] roll control φ [0061]),
determine (“a control panel may be provided in order for a pilot or operator of a QRAV to access and manipulate a plurality of control parameters” [0023]) a moment signal (“a plurality of control parameters for each of the four rotors […] The inputs may control parameters of the air vehicle such as rotational movement of the air vehicle, pitch, pitch rate, roll, roll rate, yaw angular velocity, yaw angle, hover elevation, lateral motion acceleration and/or ascending speed” [0023], where at least pitch, pitch rate, roll, roll rate, yaw angular velocity, yaw angle read on a moment signal) to be transmitted to [[a]] the pair of propellers based on the vehicle dynamics of the aircraft (“A QRAV's motion states of interest to pilot control of the aircraft may include: {{dot over (x)},{umlaut over (x)},{dot over (y)},ÿ,z,ż,θ,{dot over (θ)},φ,{dot over (φ)},{dot over (ψ)},{umlaut over (ψ)}}, which correspond to: forward speed, forward acceleration, lateral speed, lateral acceleration, elevation, ascending speed, pitch angle, rate of change of pitch angle, roll angle, rate of change of roll angle, yaw angular velocity, and yaw angular acceleration” [0102], where pitch, roll yah etc are controlled based on moment) using a second set of one or more control laws (pitch control θ; yaw control {dot over (ψ)}; and/or roll control φ” [0061]; “In one embodiment, the twelve control parameters enable the pilot to have independent control over each of the above QRAV motion states” [0102], teaching multiple control laws to independently control each motion state); and
transmit the thrust signal and the moment signal to the pair of propellers (“a plurality of digital to analog channels 707 which may be used to send control commands to various on board actuators and servo systems, including the four main rotors, and eight servo actuators, which may align the rotors to desired tilt angles” [0100] as discussed above, the propellers can be controlled individually, and the signals sent to the two propellers in the pair, can be combined as a pair as well and read on the limitation as claimed), wherein the thrust signal indicates a thrust to be provided by the pair of propellers (The angular speed of each of the rotors may be controlled independently. Separately, the thrust of each rotor may be independently tilted in any direction within a hemisphere. Therefore, the air vehicle may include a total of twelve independent control parameters to enable full and precise control [0022]), the moment signal indicates a moment to be provided by the pair of propellers (The angular speed of each of the rotors may be controlled independently. Separately, the thrust of each rotor may be independently tilted in any direction within a hemisphere. Therefore, the air vehicle may include a total of twelve independent control parameters to enable full and precise control [0022]; it is noted that moment can be a result of different control parameters discussed above),
the aircraft is an electric vertical takeoff and landing aircraft (“The quadrotor air vehicle, also known as a quadrotor, quadrotor helicopter, quadrocoptor, or quadcopter, is a multi-rotor air vehicle that is lifted and propelled by four rotors” [0002], “QRAV may perform vertical takeoff and landing (VTOL)” [0009]),
the aircraft is configured to be operated by an onboard pilot (“QRAV may also be employed in manned aerial vehicles” [0008]), and
the aircraft is capable of carrying a payload of at least 400 pounds (“manned operations for effective transport and for military deployment operations in hostile environments where VTOL is a requirement.” [0009] and “in related art […] This design was eventually realized in Boeing's Bell V-22 Osprey aircraft which began operating in 1989 [0011] The Bell Boeing team disclosed a Quad TiltRotor design in 1999 as an improvement over the previous V-22 twin rotor design. The original design goal was to have a maximum takeoff weight of 45,000 kg with a payload of up to 11,000 kg in hover. However, the design goal was revised and downsized in 2000 to be more V-22 based and was to have a payload of only 8,200 to 9,100 kg in hover” [0011-0012]; Elshafei teaches payloads above 400 pounds were known and scaling the size of Elshafei’s invention can be accomplished by one of ordinary skill in the art. Elshafei Art is recognized as suitable for the intended purpose. See MPEP 2144.07).
Elshafei teaches a vehicle with 2 pairs of propellers, which can be grouped in pairs, but is silent about:
the pair of propellers including a first propeller and a second propeller positioned on opposite sides of an aircraft center of gravity along a line that is oblique to a longitudinal axis of the aircraft;
However, Olson teaches “an attitude control system for "VTOL aircraft" of a kind having a plurality of thrust producing devices such as propellers, rotors, ducted fans or jet engines which selectively sustain or propel the aircraft in flight, and which are so situated that moments about one or more of the control axes of pitch, roll and yaw may be created by selectively adjusting thrust of the thrust producing units” (Col 1, ll. 15-60), also teachings many of the limitations already discussed above, teaching pairs of propellers and their operation to control moment (rolling and yaw, for example), inter alia, “means for changing thrusts of two thrust producing devices on one side of the aircraft while also changing the thrusts of the other two thrust producing devices on the other side of the aircraft to produce a rolling moment for control of the aircraft, said means including mechanism for proportioning said thrust changes to prevent the creation of yaw moments on the aircraft” Claim 2, and “The propellers in such configuration would be rotated in opposite directions from that shown in the drawings to take advantage of the torque changes occurring when the blade angles of the propellers are adjusted in the manner described for the purpose of yawing the vehicle. It is also possible to have the axes of rotation of all four propellers vertical in hover, and to yaw the vehicle with only the yawing moments due to the torque changes produced by increasing the blade angles of one pair of diagonally opposite propellers and decreasing blade angles of the other propellers”, Col 6 ll. 40-50), and:
the pair of propellers including a first propeller (1, Fig. 1, Col 4 ll. 63-66) and a second propeller (3, Fig. 1, Col 4 ll. 63-66) positioned on opposite sides of an aircraft center of gravity (26, Fig. 1, Col 4 ll. 45-49) along a line (a line connecting the center of 1 and the center of 3 in Fig. 1, solid line in Image below) that is oblique to a longitudinal axis of the aircraft (dashed line in Image below);
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Elshafei with Olson's teachings discussed above in order to provide the appropriate arrangement so the “aircraft ascends and descends vertically, and hovers with the propellers in their nearly vertical positions, whereas sustained horizontal flight is achieved with the propeller axes in their nearly horizontal positions. The propeller axes are gradually tilted between these extreme positions to accomplish a transition between the horizontal and other modes of flight” (Col 1 ll. 47-56), and to control roll and yaw moments, as taught by Olson and discussed above.
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Regarding claim 10, Elshafei in view of Olson teaches the invention as discussed for claim 9. Elshafei further teaches:
The flight control system of claim 9, wherein a dynamics error value (The error, that is the difference between the desired and measured states of the air vehicle, is then used by the one of the control methods to produce the control vector U 609 [0083]) is translated into a coordinate frame of the pair of propellers (inter alia, the earth inertia frame [0059], and coordinate frame about the aircraft center of gravity [0053-0061]) by the flight control system (inter alia, Fig. 6, 7).
Regarding claim 11, Elshafei in view of Olson teaches the invention as discussed for claim 10. Elshafei further teaches:
The flight control system of claim 10, wherein the flight control system is configured to compute a vehicle dynamics control signal (609 [0083]) using the dynamics error value (The error, that is the difference between the desired and measured states of the air vehicle, is then used by the one of the control methods to produce the control vector U 609 [0083]).
Regarding claim 12, Elshafei in view of Olson teaches the invention as discussed for claim 11. Elshafei further teaches:
The flight control system of claim 11, wherein the flight control system is configured to command an electric motor (rotors 1, 2, 3, 4 may be driven by brushless DC motors [0043]) using the vehicle dynamics control signal (“The output from the flight control filters may include set-points for the vehicle control systems which determine the thrust of each motor and the tilting angles of each rotor” [0073]).
Regarding claim 19, Elshafei in view of Olson teaches the invention as discussed for claim 6. Elshafei further teaches:
The aircraft of claim 7, wherein the electric motor is coupled to a propeller of a pair of propellers (rotors 1, 2, 3, 4 may be driven by brushless DC motors [0043])
Regarding claim 20, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1, wherein the thrust signal comprises at least one of a rotation speed or collective pitch to achieve a desired thrust (“the control of QRAV is achieved by varying the rotational speed of one or more rotors, thereby changing a torque load, thrust” [0004]).
Furthermore, Olson teaches “For longitudinal balance in hover, it is obvious that the moment of the thrusts of the front propellers about the center of gravity of the aircraft in the hover condition must be equal and opposite to the moment of the thrusts of the rear propellers. If the center of gravity is midway between the propellers, the thrusts of the front propellers would be the same as Those of the rear. It will also be readily apparent that the angle which the axis of the front propellers male with the vertical would be the same as that of the rear propellers and that for yaw, pitch or roll moment above, the magnitude of the blade angle change would be the same for all four propellers.
If the center of gravity is not midway between the front and rear propellers in hover position, the thrusts-and hence the blade angles of the propellers nearer the center of gravity must be greater than those of the more remote propellers and the angle which the axes of the nearer propellers makes with the vertical must be less than That of the rear propeller axes. In this case, for yaw moment without any resulting roll_ moment and for roll moment without any resulting yaw~ moment. the blade angle changes for forward and rear propellers must differ in magnitude.” Col 7. ll. 47-75
Regarding claim 21, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1, wherein the moment signal comprises at least one of a rotation speed or collective pitch to achieve a desired moment (“angular speed of each of the rotors may be controlled independently. Separately, the thrust of each rotor may be independently tilted in any direction within a hemisphere. Therefore, the air vehicle may include a total of twelve independent control parameters to enable full and precise control to allow for superior maneuverability” [0022]).
Furthermore, Olson teaches “For longitudinal balance in hover, it is obvious that the moment of the thrusts of the front propellers about the center of gravity of the aircraft in the hover condition must be equal and opposite to the moment of the thrusts of the rear propellers. If the center of gravity is midway between the propellers, the thrusts of the front propellers would be the same as Those of the rear. It will also be readily apparent that the angle which the axis of the front propellers male with the vertical would be the same as that of the rear propellers and that for yaw, pitch or roll moment above, the magnitude of the blade angle change would be the same for all four propellers.
If the center of gravity is not midway between the front and rear propellers in hover position, the thrusts-and hence the blade angles of the propellers nearer the center of gravity must be greater than those of the more remote propellers and the angle which the axes of the nearer propellers makes with the vertical must be less than That of the rear propeller axes. In this case, for yaw moment without any resulting roll_ moment and for roll moment without any resulting yaw~ moment. the blade angle changes for forward and rear propellers must differ in magnitude.” Col 7. ll. 47-75
Regarding claim 23, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1, wherein the sensor information comprises information from at least one of: GPS, a magnetometer, or an inertial measurement unit (IMU) (“The IMU unit 732 provides the flight measurement vector X at a specified sampling rate. The IMU includes various flight sensors as accelerometers, gyros, GPS, compass, and elevation radar” [0098]).
Regarding claim 24, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1, wherein the first set of one or more control laws is independent of the second set of one or more control laws (inter alia, [0041-0061], especially the equations and [0060-0061], “elevation/ascending speed z, ż; pitch control θ; yaw control {dot over (ψ)}; and/or roll control φ” [0061].; the table on page 7, “Activated Control Parameter” depicts the different control laws for, inter alia, vertical motion, roll and others; “With respect to fault tolerance, the control method for a QRAV with up to twelve total control inputs may be operated using different modes. A QRAV's motion states of interest to pilot control of the aircraft may include: {{dot over (x)},{umlaut over (x)},{dot over (y)},ÿ,z,ż,θ,{dot over (θ)},φ,{dot over (φ)},{dot over (ψ)},{umlaut over (ψ)}}, which correspond to: forward speed, forward acceleration, lateral speed, lateral acceleration, elevation, ascending speed, pitch angle, rate of change of pitch angle, roll angle, rate of change of roll angle, yaw angular velocity, and yaw angular acceleration. In one embodiment, the twelve control parameters enable the pilot to have independent control over each of the above QRAV motion states” [0102]”; furthermore, “can fully function with two rotors, can fully function if one or more tilting servos fail, provide safe flight even if all servos fail, and provide emergency landing with a single rotor.” [0020] would require different control laws that operate based on different parameters and availability of different rotors. The independent control of each propeller indicates independent control laws, and pairing of propellers teaches pairs of propellers operating under separate control laws, independent of the others.
Furthermore, Olson teaches “For longitudinal balance in hover, it is obvious that the moment of the thrusts of the front propellers about the center of gravity of the aircraft in the hover condition must be equal and opposite to the moment of the thrusts of the rear propellers. If the center of gravity is midway between the propellers, the thrusts of the front propellers would be the same as Those of the rear. It will also be readily apparent that the angle which the axis of the front propellers male with the vertical would be the same as that of the rear propellers and that for yaw, pitch or roll moment above, the magnitude of the blade angle change would be the same for all four propellers.
If the center of gravity is not midway between the front and rear propellers in hover position, the thrusts-and hence the blade angles of the propellers nearer the center of gravity must be greater than those of the more remote propellers and the angle which the axes of the nearer propellers makes with the vertical must be less than That of the rear propeller axes. In this case, for yaw moment without any resulting roll_ moment and for roll moment without any resulting yaw~ moment. the blade angle changes for forward and rear propellers must differ in magnitude.” Col 7. ll. 47-75
Regarding claim 25, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1, wherein the processor is further configured to determine a second moment signal to be provided to a second pair of propellers (“the twelve control parameters enable the pilot to have independent control over each of the above QRAV motion states” [0102]; Elshafei teaches independent control to each rotor, therefore different pairs of propellers would have a different combination of inputs provided to the different rotors; furthermore, “can fully function with two rotors, can fully function if one or more tilting servos fail, provide safe flight even if all servos fail, and provide emergency landing with a single rotor” [0020])
Regarding claim 26, Elshafei in view of Olson teaches the invention as discussed for claim 25. Elshafei in view of Olson, as discussed so far, is silent about:
The aircraft of claim 25, wherein the second pair of propellers mirrors a layout of the pair of propellers across an axis of the aircraft.
However, Olson teaches:
the second pair of propellers (2 and 4) mirrors a layout of the pair of propellers across an axis of the aircraft (Fig. 1, image below).
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Regarding claim 27, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1, wherein the thrust signal commands the net thrust of the pair of propellers (regarding the pair of propellers, as already discussed, the multiple propellers that can be controlled independently and the grouping of two propellers forms a pair of propellers under a broadest reasonable interpretations BRI; the thrust signal to the propellers command the thrust of the propellers, and the sum of the thrust of the pair of propellers is the net thrust of the pair of propellers).
Furthermore, Olson teaches “For longitudinal balance in hover, it is obvious that the moment of the thrusts of the front propellers about the center of gravity of the aircraft in the hover condition must be equal and opposite to the moment of the thrusts of the rear propellers. If the center of gravity is midway between the propellers, the thrusts of the front propellers would be the same as Those of the rear. It will also be readily apparent that the angle which the axis of the front propellers male with the vertical would be the same as that of the rear propellers and that for yaw, pitch or roll moment above, the magnitude of the blade angle change would be the same for all four propellers.
If the center of gravity is not midway between the front and rear propellers in hover position, the thrusts-and hence the blade angles of the propellers nearer the center of gravity must be greater than those of the more remote propellers and the angle which the axes of the nearer propellers makes with the vertical must be less than That of the rear propeller axes. In this case, for yaw moment without any resulting roll_ moment and for roll moment without any resulting yaw~ moment. the blade angle changes for forward and rear propellers must differ in magnitude.” Col 7. ll. 47-75
Regarding claim 28, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1, wherein the pair of propellers is configured to control at least one of altitude or attitude of the aircraft in response to the thrust signal and the moment signal (“The control of QRAV is achieved by varying the rotational speed of one or more rotors, thereby changing a torque load, thrust, and lift characteristics of the QRAV.” [0005])
Regarding claim 29, Elshafei in view of Olson teaches the invention as discussed for claim 1. Elshafei further teaches:
The aircraft of claim 1, wherein the aircraft consists of four propellers (Fig. 1). Furthermore, also see Olson Fig. 1.
Regarding claim 30, Elshafei in view of Olson teaches the invention as discussed for claim 1. As already shown in claim 1, Elshafei in view of Olson teaches:
wherein the pair of propellers are positioned diagonally across a fuselage of the aircraft (taught by Olson, see image below)
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Response to Arguments/Remarks
Applicant’s arguments have been considered, but they are not persuasive because they do not apply to the new combination of references, i.e., adding a new reference to the old combination of references, that was necessitated by applicant’s amendment. However, to the extent possible, applicant’s arguments have been addressed in the body of the rejections above, at the appropriate location.
Applicant argues on page 9:
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Examiner’s response: The arguments above were fully considered but they it does not appear the amendment overcomes the rejection under 35 U.S.C. 101. Transmitting the signals to the pair of propellers do not amount to significantly more, the transmission of a signal does not necessarily guarantee that the system will change, it does not necessarily indicate that the pair or propellers change their status based on the signals being transmitted.
Applicant argues on page 11:
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Examiner’s response: Applicant’s arguments were fully considered but are not persuasive. See 112 rejections and 103 rejections above. To further clarify, the broadest reasonable interpretation of a pair of propellers is a group of two propellers, which is discussed in the rejections. The control of aircrafts such as the ones taught by the prior art requires a balance of forces between all operating propellers in order to maintain balanced flight. Olson, as discussed in the rejections, teaches “longitudinal balance in hover, it is obvious that the moment of the thrusts of the front propellers about the center of gravity of the aircraft in the hover condition must be equal and opposite to the moment of the thrusts of the rear propellers”, so a thrust signal or a moment signal transmitted to a propeller would have to take into account the signals sent to other propellers, in order to maintain the required combination of forces, torque, etc. Therefore the combination of propellers in pairs, as discussed, can be done as discussed in the rejection. During interview with Applicant representative on 28 August 2026, the representative clarified that the present invention does not require both propellers in the pair to provide the exact same amount of torque or moment as each other, as previously indicated in the interview on 4 August 2026; the pair of propellers provide a net thrust. Examiner notes that independent signals sent to each propeller, in view of the explanation presented above, can be taken into account together and therefore read on the limitations discussed above.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Roberto T. Igue whose telephone number is (303)297-4389. The examiner can normally be reached Monday-Friday 7:30-4:30 PT.
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/ROBERTO TOSHIHARU IGUE/Examiner, Art Unit 3741
/PHUTTHIWAT WONGWIAN/Supervisory Patent Examiner, Art Unit 3741
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