Vibration suppression utilizing surface actuation

Abstract

A vibration suppression system for utilizing surface actuation of an aircraft includes an at least one aircraft control surface operably-coupled with an at least one flight control actuator, and a controller such that the controller is configured to determine a flight mode of the aircraft, calculate a predicted vibration in the aircraft based on the determined flight mode of the aircraft, and control the at least one flight control actuator connected to the at least one aircraft control surface of the aircraft such that the actuation of the at least one aircraft control surface counteracts the predicted vibration in the aircraft based on the determined flight mode of the aircraft.

Description

Attorney Docket No. 22-1339-WOVibration Suppression Utilizing Surface ActuationCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to provisional U.S. Application No. 63 / 471,875 filed June 8, 2023, the contents of which are hereby incorporated by reference in their entirety.BACKGROUND

[0002] An aircraft, such as a vertical takeoff and landing (VTOL) aircraft, a helicopter, a drone, a fixed-wing aircraft, or the like can be used to facilitate transportation of passengers and / or cargo. A person of ordinary skill in the art will realize that some aircraft, particularly passenger-sized aircraft, generate unwanted vibrations while in use. These vibrations can be noisy, may be uncomfortable or unpleasant to passengers of the aircraft or other people in proximity to the aircraft, and / or can cause a serious threat to components of the aircraft.

[0003] Accordingly, the present application seeks to reduce the vibrations to minimize the noise and potential discomfort to passengers, as well as to reduce fatigue due to the vibrations on the airframe and other aircraft components. Common solutions to vibration suppression is the practice of using damping, isolation, or other cancellation resolutions to reduce or eliminate vibrations acting on a system. A common approach to vibration suppression is adding damping, which dissipates some of the vibration energy by transforming it to heat. Isolation, on the other hand, is another means of vibration suppression when there is a limited path for transmission from a vibrating structure to a targeted component by isolating the targeted component from the source of the damaging vibrations. A vibration isolator takes mechanical energy out of the system to reduce its impact.Attorney Docket No. 22-1339-WOSUMMARY

[0004] Embodiments described herein relate to methods and systems of active vibration suppression utilizing control surface actuation for aircrafts, such as a VTOL aircraft, and, more particularly, to reducing known vibrations during a variety of modes of an aircraft in flight.

[0005] An example embodiment includes a method of suppressing vibrations on an aircraft, the method including sensing, by an at least one sensor, a vibration of the aircraft and controlling, by a controller, at least one flight control actuator connected to an at least one aircraft control surface of the aircraft to actuate the at least one aircraft control surface to counteract the vibration in the aircraft.

[0006] A further example embodiment includes a method of suppressing vibrations on an aircraft, the method including receiving, at a controller, a flight mode of the aircraft and estimating, by the controller, a predicted vibration in the aircraft based on the received flight mode of the aircraft. The method also includes sensing, by an at least one sensor, a sensed vibration of the aircraft. The method further includes calculating, at the controller, a total vibration comprising a sum of the predicted vibration and the sensed vibration of the aircraft. Additionally, the method includes controlling, by a controller, at least one flight control actuator connected to an at least one aircraft control surface of the aircraft to actuate the at least one aircraft control surface to counteract the total vibration in the aircraft.

[0007] In some embodiments, an aircraft system is disclosed, the system including an at least one aircraft control surface, an at least one flight control actuator connected to the at least one aircraft control surface, an at least one sensor on the aircraft, a controller having one or more processors, and a non-transitory computer readable medium. The non-transitory computer readable medium includes storage having program instructions that are executable by the one or more processors to control the at least one flight control actuator connected to the at least one aircraft control surface of the aircraft such that the actuation of the at least one aircraft control surface counteracts a vibration in the aircraft.

[0008] These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference, where appropriate, to the accompanying drawings.Attorney Docket No. 22-1339-WOBRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 depicts an aircraft configuration, according to exemplary embodiments of the present disclosure.

[0010] Figure 2 is a block diagram of an example aircraft system, according to exemplary embodiments of the present disclosure.

[0011] Figure 3 depicts a plurality of example actuators interacting with actuation surfaces on an aircraft, according to exemplary embodiments of the present disclosure.

[0012] Figure 4 is a flowchart illustrating a method of suppressing vibrations on an aircraft, according to exemplary embodiments of the present disclosure.

[0013] Figure 5 is a flowchart illustrating a method of suppressing vibrations on an aircraft, according to exemplary embodiments of the present disclosureAttorney Docket No. 22-1339-WODETAILED DESCRIPTION

[0014] Disclosed herein are examples of a vibration suppression system for an aircraft (e.g., an eVTOL aircraft), which may be utilized to reduce vibrations during an aircraft at any point during its operation, including but not limited to takeoff, landing, hovering, and cruising, without adding undue weight to the aircraft. As a person of ordinary skill in the art will recognize, the vibration suppression system according to the present invention may be used to reduce vibrations, as experienced by passengers nearby and / or onboard the aircraft, caused by operation of the aircraft, environmental influences on the aircraft, or other similar influences or forces. It is contemplated that the present invention may be operated as an active system, using sensor data monitoring the environment of the aircraft in real time, or as a passive system, based on a dataset of expected vibrations based on one or more flight conditions, or a combination of an active and passive system.

[0015] In some embodiments, and as noted above, the vehicle may be a VTOL, which may or may not use electric power to hover, takeoff, and / or land. It should be understood that in other embodiments, the vehicle may be any other type of vehicle that may be able to utilize the advantages of the present invention, such as a ground vehicle (i.e., an automobile), a sea vehicle (such as a boat), or a flying craft (such as an aerial, floating, soaring, hovering, airborne, aeronautical aircraft, airplane, plane, spacecraft, a helicopter, an airship, or an unmanned aerial vehicle, or a drone).

[0016] Figure 1 illustrates a craft 100 in a vertical take-off and landing configuration according to some embodiments of the present disclosure. As shown in Figure 1, craft 100 may include, among other things, one or more lift surfaces 102, one or more lift propellers 104, one or more tilting propellers 106 which may be mounted on respective hubs 108, a body 110, one or more booms 112, and a tail 114. Craft 100 may be manned or unmanned. It is envisioned that craft 100 may be used for any purpose known to those skilled in the art, including for example, as a taxi, a delivery vehicle, a personal vehicle, a cargo transport, a short or longdistance hauling aircraft, an emergency medical services (EMS) aircraft, and / or a video / photography craft.

[0017] In some embodiments, lift surface 102 may extend relatively horizontally, when the craft is at rest, from one end to another. Lift surface 102 may include an airfoil configured to generate lift when air flows past it. Lift surface 102 may be a single continuous surface, orAttorney Docket No. 22-1339-WO may include sections of lift surfaces, for example with one or more sections arranged inboard (e.g., towards body 110) of booms 112 (discussed below) and one or more sections arranged outboard (e.g., away from body 110) of booms 112. Lift surface 102 may incorporate portions of, or include shaped portions of, body 110, booms 112, and / or tilting propellers 106 to generate lift and / or reduce drag as air flows past. The lift surface 102, in some embodiments, may include a first partial lift surface at a first end of the lift surface 102 and a second partial lift surface at a second end of the lift surface 102. As will be understood by a person of ordinary skill in the art, the first and second partial lift surfaces may have any shape suitable to maximize lift and minimize drag, thereby reducing fuel consumption. For example, the partial lift surface may be rectangular, circular, triangular, or any combination thereof.

[0018] Lift propellers 104 may be located at any position on the craft, as will be understood by a person of ordinary skill in the art. In some embodiments, a first lift propeller 104 may be positioned forward of the lift surface 102 on a first side of the body, a second lift propeller 104 may be positioned aft of the lift surface on the first side of the body, a third lift propeller 104 may be positioned forward of the lift surface on a second side of the body, and a fourth lift propeller 104 may be positioned aft of the lift surface on the second side of the body. Lift propellers 104 may also be mounted on one or more booms 112. The one or more booms 112 may include a battery pack configured to supply electrical power to one or more electric motors or may be utilized for storage of goods, electrical or mechanical components of the craft, or any other items known to those skilled in the art. In some embodiments, two booms 112 are configured substantially perpendicular to the top or bottom surface of the lift surface 102, but a person of ordinary skill in the art will understand that more or less than two booms may be utilized, and they may be attached using known attachment techniques and / or arranged in any suitable configuration. The one or more booms 112 may include or connect to a tail 114 that comprises one or more control surfaces (e.g., one or more of an elevator, a rudder, a ruddervators, a spoiler, or similar). Control surfaces may be on relatively vertical portions of tail 114 or relatively horizontal portion of tail 114.

[0019] Any suitable number of lift propellers may be incorporated (for example, more or less than four lift propellers 104 may be utilized) on craft 100. Lift propellers may be configured to generate substantially vertical thrust. Lift propellers may operate at a fixed pitch and / or a fixed rpm. In some embodiments, lift propellers 104 may be positioned one either sideAttorney Docket No. 22-1339-WO of a lift surface and along booms 112. In some embodiments, lift propellers 104 may be positioned on lift surface 102. In some embodiments, lift propellers 104 may be driven by a gearbox, which in turn may be driven by an electric motor.

[0020] Tilting propellers 106 may be configured to rotate or move about an axis parallel with the ground along with partial lift surfaces, where the tilting propellers 106 and partial lift surfaces rotate outboard of booms 112. It should be understood that in other embodiments, the tilting propellers 106 may also be referred to as a tilting prop, a rotor, or a proprotor. In some embodiments, where lift surface 102 is a separate structure from booms 112, tilting propellers 106 may move or rotate with lift surface 102 aside from portions of lift surface 102 that include body 110. In some embodiments, tilting propellers 106 may move or rotate such that only a portion of a tilting propeller hub 108 and blades 106 move or rotate. In some embodiments, the tilting propeller hub 108 may move or rotate with the partial lift surface about an axis parallel to the ground. Based on the shape of lift surface 102, the lift surface not including body 110 may rotate with tilting propellers 106 to increase lift and decrease drag, thereby reducing fuel consumption. The lift surface 102 shape may also vary throughout the length of boom 112. For example, the lift surface 102 may be rectangular shaped to support the weight of body 110, and may be thinner out to tilting propeller 106 to reduce drag when tilting propeller 106 is configured for horizontal operation and wider when tilting propeller 106 is configured for vertical operation.

[0021] In some embodiments, tilting propellers 106 may be connected to lift surface 102 through a rotating linkage such as a rotating spar, and / or extending linkages. In some embodiments, the rotating spar may be actuated to rotate tilting propeller 106 relative to lift surface 102. Tilting propellers 106 may be positioned at any suitable location on the craft, including on the lift surface, on one or more sides of body 110, on a boom 112, or any other location. In some embodiments, extending linkages may be actuated to rotate tilting propeller 106 relative to lift surface 102. Actuators configured to actuate spars and / or rotating linkages may comprise one or more of a rotating actuator or a linear actuator. Tilting propellers 106 may be configured in one configuration to rotate around and / or relative to an axis substantially parallel with a ground surface and / or a lift surface, considered when the aircraft is at rest on the ground surface.

[0022] Both lift propellers 104 and / or tilting propellers 106 may be positioned aboveAttorney Docket No. 22-1339-WO or away from control surfaces and / or portions of body 110 such that a blade strike is unlikely or not possible. For example, tilting propellers 106 may be spaced above a tilting propeller hub 108 and / or lift propellers 104, when in a vertical take-off and landing configuration. Further, tilting propellers 106 may be spaced along lift surface 102 and substantially above body 110, and / or lift propellers 104 may be spaced along booms 112 and substantially above body 110. Tilting propellers 106 may be spaced along lift surface 102 away from tail 114 (e.g., outboard) to avoid a blade strike on tail 114. For example, each tilting propeller 106 may be positioned at more than half the distance of one wing from body 110 or, in some embodiments, more than two-thirds the distance of one wing from body 110. Tilting propellers, lift propellers 104, and / or controls may be operable by an onboard pilot, an onboard computer (e.g., autonomously), or from a control outside of the craft (e.g., remotely), or a mixture of one or more of an onboard pilot, an onboard computer, and / or a control outside of the aircraft. A tilting propeller may be configured to be controlled through a power control (e.g., throttle), a pitch control (e.g., collective) and / or an angle of attack control (e.g., cyclically), or any suitable combination of these controls. Each of these controls may comprise mechanical and electrical actuators, switches, or other controls known to one of ordinary skill in the art, in conjunction with one or more processors (e.g., within controllers, computers) to effect operation and management of each individual control or as a subset of controls or all controls altogether.

[0023] Both lift propellers 104 and tilting propellers 106 may be mechanically powered by one or more electric motors. It is contemplated that, in some embodiments, each lift propeller 104 and / or tilting propeller 106 may be powered by a dedicated motor, or one or more lift propellers 104 and / or tilting propellers 106 may be powered by a shared motor. As one example, two lift propellers 104 along one boom 112 may share a motor. It is contemplated that the motors discussed herein could be traditional fuel powered motors, electric motors, and / or hybrid motors. In some embodiments, a motor and rotor may be connected to a transmission that controls the use power generated by the motor. The transmission may be a continuously variable transmission (CVT), or an automatic transmission, or a manual or semimanual transmission to shift one or more gears to output differing amounts of power. Lift propellers and / or tilting propellers may be constant speed rotors or variable speed rotors. Lift propellers and / or tilting propellers may be at a constant angle of attack or have a changeable angle of attack (e.g., changeable through one or more actuators).Attorney Docket No. 22-1339-WO

[0024] Speed, position and / or angle of attack may be changed and / or gear may be shifted individually, as a set at the same time, or for all tilting propellers and / or all lift propellers simultaneously. For example, four lift propellers 104 may all change speed at once to initiate a takeoff sequence and / or landing sequence. As another example, tilting propellers 106 may be shifted from a take-off and landing configuration to a cruise condition simultaneously. As another example, two tilting propellers 106 and four lift propellers 104 may all change speed and / or angle of attack to affect a take-off and landing sequence simultaneously.

[0025] In some embodiments, the tilting propellers 106 may include a first tilting propeller attached to the first partial lift surface such that the first partial lift surface moves with tilting propellers during movement of the tilting propeller relative to and / or rotation about an axis parallel to the ground. A second tilting propeller may be attached to the second partial lift surface such that the second partial lift surface moves with tilting propellers during movement of the tilting propeller relative to and / or rotation about an axis parallel to the ground. The partial lift surfaces may include one or more control systems which may be operable by the pilot located in cabin 118. The partial lift surfaces may be operated via actuators, active inceptors, sidesticks, switches, and / or buttons and may be configured to generate lift for vertical take-off and / or landing craft in a horizontal thrust configuration. The partial lift surfaces may also be configured to generate lift in a vertical thrust configuration. The partial lift surfaces may comprise a wing portion with a similar cross-sectional area and / or airfoil shape to the rest of lift surface 102 (e.g., partial lift surfaces may comprise a continuation of lift surface 102). In some embodiments, the partial lift surfaces may comprise winglets, may consist of winglets, and in other embodiments, the partial lift surfaces may not have winglets. Whether the partial lift surfaces have winglets may depend on the type of cargo, travel time, and / or tilting propeller size. Partial lift surfaces may each comprise a winglet and a wing portion. Winglets may extend generally vertically from the end of the wing portions. Winglets may be configured to reduce drag, as will be understood by a person of ordinary skill in the art.

[0026] Body 110 may be any suitable shape, size, or configuration suitable for the purpose of the craft, as will be understood by a person of ordinary skill in the art. For example, body 110 may be oval, square, triangular, or otherwise any appropriate shape sufficient to hold cargo and / or passengers while remaining structurally sound. Moreover, body 110 may include gear 116 for landing on land and / or water, which may or may not be retractable. The gear 116Attorney Docket No. 22-1339-WO may be included at both the front and the back of the craft, and may include wheels, treads, pontoons, or other components that may aid the craft in landing in land and / or water. Body 110 may also include a cockpit 118 configured to hold a pilot, passenger(s), and / or cargo. In one example, the pilot may be located at the front of the aircraft and the passengers and / or cargo may be located behind the pilot. However, it is contemplated that the pilot could be located at any location within the body (or that the craft could be maneuvered without a pilot at least some of the time).

[0027] Body 110 may also include a windshield 120 of any suitable shape and size; one or more doors configured to open and / or close (e.g., by swinging, sliding, and / or raising / lowering) to allow ingress / egress of persons and / or cargo; one or more seats; and controls and / or a computer system configured to communicate and / or control craft systems for the craft, including for example, tilting propellers 106, lift propellers 104, and / or one or more control surfaces (e.g., elevator, rudder, ruddervator, actuator, spoiler, or other known control s / surf aces). Body 110 may include a fuselage configured to provide structure to connect and / or link a lift surface structure of lift surface 102. In some embodiments, the fuselage may be of truss, monocoque, or semi-monocoque construction. The fuselage may be constructed of aluminum of carbon fiber.

[0028] Further, in some embodiments, craft 100 may include one or more battery modules and one or more energy management systems (EMSs) that are in communication with the battery modules and that are configured as electronic regulators to monitor and control the charging and discharging of the battery modules.

[0029] Booms 112 may efficiently provide structure for tail structure 114, one or more electric motors for one or more lift propellers 104, and / or one or more batteries to power one or more lift propellers 104 and / or one or more tilting propellers 106. The lift propellers may also be connected to the craft's electrical and control systems. Booms 104 may be supported by lift surface 102 and the internal structure of the lift surface. Thus, the structure of lift surface 102 may efficiently provide lift to craft 100 to carry persons or cargo while incorporating structure to support booms 104, and / or additionally to support tilting propellers 106 in horizontal thrust and vertical take-off and landing configurations. Additionally, tilting propellers 106 can create stress on structure as it rotates, and it is thus advantageous to support tilting propellers 106 through the lift surface 102 that comprises internal structural components,Attorney Docket No. 22-1339-WO such as spars and ribs, that are capable of withstanding the stress from tilting propellers 106 as they operate to generate thrust and as they rotate between configurations. Efficient use of the structure in lift surface 102 can provide for a lighter craft, leading to less use of fuel and travel at greater speeds.

[0030] Tail 114 may be linked aft of booms 112. In some embodiments, tail 114 may be linked aft of lift surface 102. Tail 114 may comprise an elevator along the link between one boom 112 and another boom 112. Tail structure 114 may be aft of body 110. Tail structure 114 may comprise control surfaces such as rudders and / or ruddervators, where the control surfaces extend upwards and / or downwards from booms 112. In some embodiments, at least one control surface may be positioned at least partially above a rotation plane of the lift propellers. For example, a rudder, an elevator, or a ruddervators of tail 114 may extend partially above body 110 and / or lift propellers. Tail 114 may be configured to provide control to the craft through control surfaces that are positioned in a freestream (e.g., relatively undisrupted air) when the craft is in a horizontal thrust configuration.

[0031] A number of tail configurations are contemplated, including a T-tail, cruciform tail, dual tail, triple tail, V-tail, Bronco tail, low boom tail, or high boom tail. A Bronco tail may have relatively perpendicular vertical and horizontal surfaces. Tail 114 may have rounded edges between substantial vertical and horizontal surfaces to provide efficient support of substantially horizontal surfaces by the substantially vertical surfaces, considered when craft 100 is at rest on a ground surface. In some embodiments, a tail may extend from body 110 and booms 112 may be connected above the tail extending from the body, where the connection of booms 112 is separate from the tail extending from the body or connected to the tail extending from the body.

[0032] Figure 2 is a block diagram of an aircraft system, according to exemplary embodiments of the present disclosure. Operable on aircraft system 200 is any method described herein.

[0033] The aircraft system 200 may include one or more aircraft control surfaces 202 operatively-coupled with one or more flight control actuators 204. In some embodiments, the one or more aircraft control surfaces 202 includes any control surface or combination of control surfaces on a craft, including conventional aircraft control surfaces, one or more rotors on the craft, or the one or more flight control actuators 204 themselves, depending on the vibration toAttorney Docket No. 22-1339-WO be cancelled and / or minimized.

[0034] The flight control actuators 204 can comprise an electromechanical actuator, an electrohydraulic actuator, a hydraulic actuator, a self-contained hydraulic actuator, or any combination of the aforementioned. In some embodiments, a singular aircraft control surface of the one or more aircraft control surfaces 202 can be coupled with a singular flight control actuator 204. In other embodiments, a singular aircraft control surface of the one or more aircraft control surfaces 202 can be coupled with two or more flight control actuators 204. As such, each flight control actuator of the one or more flight control actuators 204 may actuate the aircraft control surface 202. However, if there are multiple flight control actuators 204 coupled with the aircraft control surface 202, each flight control actuator may not need to be actuated in order to effectively position the aircraft control surface 202. Each flight control actuator of the one or more flight control actuators 204 may be communicatively-coupled with the controller 206. In some embodiments, the one or more flight control actuators 204 can contact the aircraft control surface 202 at a singular point. In other embodiments, each flight control actuator of the one or more flight control actuators 204 can independently contact the aircraft control surface 202. By using the one or more flight control actuators 204 that are already needed to operate the aircraft system 200 for an additional purpose of dampening unwanted vibrations on the aircraft system 200, not only does the unwanted vibrations necessarily suppress, but also the aircraft system 200 is able to accomplish the vibration suppression without adding any additional weight which could be very detrimental to the aircraft system 200.

[0035] In some embodiments, the aircraft system 200 may be an eVTOL aircraft. As such, many eVTOL aircraft are likely to experience high levels of vibrations due to the multiple rotor systems associated with an eVTOL aircraft, in combination with eVTOL aircrafts often being used as transitioning aircrafts (e.g., multipurpose aircrafts) that are not optimized for one specific type of air travel but instead likely to convert between many different types of flying. Because of this, many eVTOL aircrafts are equipped with more aircraft control surfaces 202 than other types of aircraft (like a helicopter or a fixed-wing aircraft), the combination of which is able to be used to more accurately dampen unwanted vibrations on the aircraft by fine-tuning the series of aircraft control surfaces 202 via the flight control actuators 204.

[0036] In some embodiments, the flight control actuators 204 can be controllable by aAttorney Docket No. 22-1339-WO controller 206 such that the controller 206 can actuate the one or more flight control actuators 204 to change the position and / or orientation of the aircraft control surfaces 202.

[0037] The controller 206 can have a system 208 having one or more processors 210. The one or more processors 210 of the system 208 can include data storage 212, on which can be program instructions 214 that can be dictated by the one or more processors 210 of the system 208. As such, the instructions 214 can be given to the controller 206 to actuate the one or more flight control actuators 204 accordingly. In some embodiments, the system 208 with processor(s) 210 may further include a non-transitory computer readable medium such that the instructions 214 of data storage 212 are stored on the non-transitory computer readable medium. The instructions 214 may be executable by the one or more processors 210 to control the one or more flight control actuators 204 connected to the at least one aircraft control surface 202 of the aircraft such that the actuation of the at least one aircraft control surface 202 counteracts a vibration in the aircraft.

[0038] In some embodiments, the aircraft system 200 may also include one or more sensors 216. In some embodiments, the sensors 216 may comprise, for example, accelerometers, altimeters, airspeed indicators, position sensors, gyroscopes, attitude heading and reference systems, sideslip and / or angle of attack indicators, other vibration sensors, and the like. The one or more sensors 216 can be configured to obtain one or more environmental characteristics from an environment of the aircraft. In some embodiments, the environmental characteristics includes the velocity of the aircraft, the change in altitude of the aircraft over time, the acceleration of the aircraft, and the like.

[0039] In some embodiments, the non-transitory computer readable medium comprising data storage 212 having program instructions 214 that are executable by the one or more processors 210 further includes receiving, at the controller 206, a flight mode of the aircraft, estimating, by the controller 206, a predicted vibration in the aircraft based on the received flight mode of the aircraft, and determining, by the controller 206, the predicted vibration in the aircraft based on the received flight mode of the aircraft. In some embodiments, receiving the flight mode of the aircraft includes receiving an input, at the controller 206, indicative of a preprogramed setting. As such, determining the predicted vibration in the aircraft based on the determined flight mode of the aircraft comprises associating the input indicative of a preprogrammed setting with the predicted vibration in the aircraft based on aAttorney Docket No. 22-1339-WO predetermined calculation.

[0040] In other embodiments, the non-transitory computer readable medium comprising data storage 212 having program instructions that are executable by the one or more processors 210 further includes sensing, by the at least one sensor 216, the vibration of the aircraft. As such, the at least one sensor 216 may include an altimeter, an airspeed indicator, a position sensor, a gyroscope, an attitude heading and reference system, and a vibration sensor.

[0041] In some embodiments, the aircraft system 200 includes a plurality of aircraft control surfaces 202 such that each aircraft control surface of the plurality of aircraft control surfaces 202 is operably-coupled with one of a plurality of flight control actuators 204. As such, the program instructions 214 stored on the non-transitory computer readable medium and executable by the one or more processors 210 of the system 208 is further configured to control each aircraft control surface of the plurality of aircraft control surfaces 202 by actuating each of the plurality of flight control actuators 204 such that the actuation of each of the plurality of flight control actuators 204 counteracts a measured vibration in the aircraft at each aircraft control surface of the plurality of aircraft control surfaces 202. In some embodiments, each aircraft control surface of the one or more aircraft control surfaces 202 can be independently controlled by the respective flight control actuator 204 connected with the controller 206 of the aircraft system 200. In other embodiments, each of the flight control actuators 204 can be instructed by the controller 206 to actuate each of the aircraft control surfaces 202 in unison to suppress the vibrations in the aircraft.

[0042] Figure 3 illustrates a craft 300 in a forward flight configuration according to some embodiments of the present disclosure. Craft 300 may include any components described in Figures 1-2. As shown in Figure 3, craft 300 may include, among other things, one or more lift surfaces 302, one or more lift propellers 304, one or more tilting propellers 306 which may be mounted on respective hubs 308, a body 310, one or more booms 312, and a tail 314. Craft 300 may be manned or unmanned. It is envisioned that craft 300 may be used for any purpose known to those skilled in the art, including for example, as a taxi, a delivery vehicle, a personal vehicle, a cargo transport, a short or long-distance hauling aircraft, and / or a video / photography craft.

[0043] In some embodiments, craft 300 also includes a plurality of aircraft control surfaces configured to be controlled by one or more actuators suited for controlling the pluralityAttorney Docket No. 22-1339-WO of aircraft control surfaces. In some embodiments, craft 300 includes an inboard flap 316 between body 310 of craft 300 and a boom of the one or more booms 312. Inboard flap 316 may be controlled by flap actuator 318. As such, flap actuator 318 may aid inboard flap 316 in securing greater lift during the most critical part of take-off and landing, when the angle of the aircraft is high and the speed is relatively low. Further, flap actuator 318 may be configured to counteract and / or suppress unwanted vibrations on inboard flap 316 or elsewhere on the aircraft during operation of craft 300. Similarly, in some embodiments, craft 300 includes one or more flaperons, such as flaperon 320 and flaperon 324, on an aft portion of one or more lift surfaces 302. Flaperon 320 and flaperon 324 may be controlled by flaperon actuators 322 and 326, respectively. As such, flaperon actuators 322 and 326 may aid flaperons 320 and 324, respectively, to aid in the aileron functionality of craft 300, stabilizing craft 300 during low- speed flying during take-off and landing, creating lift or drag depending on the intended use, and preventing craft 300 from rolling over. Further, flaperon actuators 322 and 326 may be configured to counteract and / or suppress unwanted vibrations on flaperons 320 and 324 or elsewhere on the aircraft during operation of craft 300.

[0044] In some embodiments, craft 300 includes one or more conversion spindles, such as conversion spindle 328, to rotate one or more tilting propellers 306 of craft 300 between a hover mode about an axis. Conversion spindle 328 may be operated by conversion actuator 330. Conversion actuator 330 may also be configured to counteract and / or suppress unwanted vibrations on conversion spindle 328 or elsewhere on the aircraft during operation of craft 300. Similarly, in some embodiments, craft 300 includes one or more swashplates, such as swashplate 332, to transmit commands from the non-rotating components of craft 300 to the rotating rotor hub and blades of one or more tilting propellers 306. Swashplate 332 may be operated by swashplate actuators, such as swashplate actuators 334. Swashplate actuators 334 may also be configured to counteract and / or suppress unwanted vibrations on swashplate 332 or elsewhere on the aircraft during operation of craft 300.

[0045] Further, in some embodiments, tail 314 of craft 300 includes one or more ruddervator 336 and elevator 340, which may be connected to tail actuators 338 and 342, respectively. Tail actuator 338 may be configured to aid ruddervator 336 in yaw control of craft 300 and tail actuator 342 may be configured to aid elevator 340 in pitch control of craft 300. Tail actuators 338 and 342 may also be configured to counteract and / or suppress unwantedAttorney Docket No. 22-1339-WO vibrations on ruddervator 336 and elevator 340, respectively, or elsewhere on the aircraft during operation of craft 300. Other actuators on other components of craft 300 are also possible.

[0046] Figure 4 is a flowchart illustrating a method 400 of suppressing vibrations on an aircraft, according to exemplary embodiments of the present disclosure. As illustrated, the method 400 may include a step 402 of receiving, at the controller, one or more sensed conditions of the aircraft from an at least first sensor on the aircraft such that the one or more sensed conditions of the aircraft are indicative of a flight mode of the aircraft. In some embodiments, the one or more conditions may include airspeed and / or conversion angle of the aircraft. Other conditions are possible.

[0047] The method 400 may also include step 404 of determining, at the controller, the flight mode of the aircraft based on the one or more sensed conditions of the aircraft. In some embodiments, the available flight modes may include a preparation mode, which is a pretakeoff or post-landing mode where the aircraft is already powered on, a takeoff mode, a flying / cruise mode, a hover / helicopter mode, a landing mode, or a conversion / transition mode between any of the aforementioned flight modes. Each of these respective modes may be associated with an expected vibration in and around the aircraft.

[0048] The method 400 may also include step 406 of estimating, by the controller, a predicted vibration in the aircraft based on the received flight mode of the aircraft. Because an aircraft can have different vibration levels and frequencies based on the flight mode of an aircraft, by receiving an input indicative of which flight mode the aircraft is in, the controller can estimate the respective expected vibration levels and frequency levels. With this estimation, the controller is able to predict the vibrations occurring in and around the aircraft. In some embodiments, estimating the predicted vibration in the aircraft may include engaging with a known vibration profile for that particular flight condition on that particular aircraft. For example, the controller may utilize a look-up table based on the flight mode of the particular aircraft to obtain values for commanding the actuators or go into a specific subroutine for that flight mode based on the predicted vibrations in the aircraft. Further, the controller may be able to interpolate between two sets of data points on the look-up table if the exact data point is not included in the look-up table.

[0049] The method 400 may also include step 408 of controlling, by the controller, anAttorney Docket No. 22-1339-WO at least one flight control actuator connected to an at least one aircraft control surface of the aircraft such that the actuation of the at least one aircraft control surface counteracts the predicted vibration in the aircraft based on the received flight mode of the aircraft. After the controller has predicted the vibrations in the aircraft based on the determined flight mode of the aircraft, the controller can calculate the requisite algorithm for each flight control actuator to dampen and / or suppress those vibrations. As such, each flight control actuator can be controlled by the controller to execute the actuation of the relevant aircraft control surface to counteract the predicted vibration in the aircraft based on the determined flight mode of the aircraft.

[0050] In some embodiments, the method 400 may further include receiving, at the controller, a second flight mode of the aircraft, and, upon receipt of an input indicative of a change in flight mode of the aircraft to a second flight mode, the controller can calculate a second predicted vibration in the aircraft based on the determined second flight mode of the aircraft. As such, the controller can control the one or more flight control actuators connected to the aircraft control surface of the aircraft such that the actuation of the aircraft control surfaces counteracts the second predicted vibration in the aircraft based on the determined second flight mode of the aircraft.

[0051] In some passive systems, receiving the flight mode of the aircraft could include receiving an input at the controller an input that is indicative of a preprogramed setting of the flight mode. For instance, if an aircraft is manually switched from takeoff mode to flying mode, the controller may receive an input indicating the change from the first flight mode to the second flight mode. Based on that indication, the controller may calculate a predicted vibration in the aircraft based on the determined flight mode of the aircraft at the new flight mode.

[0052] In some embodiments, controlling the at least one flight control actuator connected to the at least one aircraft control surface of the aircraft includes superimposing, by the controller, a desired command of the at least one flight control actuator over an existing series of commands on the at least one flight control actuator such that the desired command of the at least one flight control actuator counteracts the predicted vibration in the aircraft based on the determined flight mode of the aircraft. For instance, in some embodiments, each flight control actuator can be preprogrammed to control an aircraft control surface throughout a flight of an aircraft based on a series of commands and / or instructions given to the flight controlAttorney Docket No. 22-1339-WO actuator by the controller. Based on the calculated vibrations, a desired position of the aircraft control surface can be calculated by the controller such that the vibrations on the aircraft control surface are suppressed. The controller can superimpose the instructions of the desired position of the aircraft control surface over the existing series of instructions already dictated to the flight control actuator from the controller. As such, a position of the aircraft control surface during the existing operative commands and a desired position of the aircraft control surface based on the calculated vibrations on the aircraft control surface can be summed such that the aircraft control surface is actuated to the desired position for aircraft vibration suppression.

[0053] In some embodiments, the controller may be integrated onto the aircraft. In other embodiments, the controller may be located remotely from the aircraft but is communicatively-coupled with the aircraft.

[0054] Figure 5 is a flowchart illustrating a method 500 of suppressing vibrations on an aircraft, according to exemplary embodiments of the present disclosure. As illustrated, the method 500 may include a step 502 of sensing, by an at least one sensor, a vibration of the aircraft. In some embodiments, the vibration of the aircraft may be sensed by specifically placed accelerometers on the aircraft located where the main areas of vibration are expected. Further, in some embodiments, the accelerations sensed by the aircraft’s inertial sensors used for the flight control system may be utilized to sense additional vibrations of the aircraft. As such, in some embodiments, the sensed accelerations may be fed into the flight control computer of the aircraft, which in turn may determine the input to the controller needed to control at least one flight control actuator to counteract the vibrations.

[0055] The method 500 may also include step 504 of controlling, by a controller, at least one flight control actuator connected to an at least one aircraft control surface of the aircraft to actuate the at least one aircraft control surface to counteract the vibration in the aircraft.

[0056] In some embodiments, the method 500 further includes continuously monitoring, by the at the at least one sensor, the vibrations on the aircraft and, upon sensing a second vibration of the aircraft, controlling, by the controller, the least one flight control actuator connected to the at least one aircraft control surface of the aircraft to actuate the at least one aircraft control surface to counteract the second vibration in the aircraft. As such, the controller can control the one or more flight control actuators connected to the aircraft controlAttorney Docket No. 22-1339-WO surface of the aircraft via instructions such that the actuation of the aircraft control surfaces counteracts the second vibration in the aircraft.

[0057] In some embodiments, determining the vibrations in the aircraft may comprise measuring, by an at least one sensor on the aircraft, an at least one condition of an environment of the aircraft such that the at least one condition of the environment is indicative of the vibrations. A condition of the environment of the aircraft might include the weather, including the wind speed and direction acting on the aircraft, the airspeed of the aircraft in relation to the environment, the pressure on the aircraft from the environment, the altitude in the environment, the climb rate of the aircraft, the descent rate of the aircraft, the angle of attack of the aircraft, the aircraft attitudes, or the like.

[0058] For instance, if the at least one sensor was configured to measure the velocity of an aircraft, if the velocity is determined to exceed a certain threshold, the relevant vibrations in the aircraft can be determined. In another example, if the at least one sensor was configured to detect an altitude change, if the altitude is detected to increase at a certain rate, then the vibrations in the aircraft can be determined. However, if the altitude is detected to decrease at a certain rate, then the aircraft can be determined to be landing, and the vibrations could be detected. In such embodiments, when calculating the vibration in the aircraft gathered by the at least one sensor on the aircraft, the controller can associate the at least one condition of the environment that was measured by the at least one sensor on the aircraft with the vibration in the aircraft based on a predetermined calculation. The predetermined calculation may include a lookup table such that the expected vibrations and the flight mode are mapped onto each other. Therefore, at a first measured sensed quality, a first expected value of the vibrations in the aircraft might be anticipated. However, a second expected value of the vibrations in the aircraft might be anticipated based on a change in the measured sense quality, such that the first expected value of the vibrations in the aircraft and the second expected value of the vibrations in the aircraft are different. However, in other embodiments, the controller may calculate the vibrations in real time based on a regression model of the vibrations in the aircraft.

[0059] In some embodiments, the controller may be integrated onto the aircraft. In other embodiments, the controller may be located remotely from the aircraft but is communicatively-coupled with the aircraft.

[0060] In some embodiments, a combination of an active and passive system forAttorney Docket No. 22-1339-WO suppressing unwanted vibrations on an aircraft system may exist. Further, any combination of steps in methods 400 and 500 may be incorporated into a single aircraft control system. For instance, an at least one sensor on the aircraft can retrieve sensed vibrations that are dependent on the specific flight conditions at the time of the sensing while at the same time, known vibrations based on the type of flight mode and other known structural details of the aircraft can be calculated at a controller. In some embodiments, both the sensed vibrations and known vibrations may be transmitted to the same actuator connected to an aircraft control surface such that the sensed vibrations and known vibrations are summed, and then the summed total is the input that the actuator acts on in order to alter the aircraft control surface and suppress the vibrations. In other embodiments, the known vibrations are sent to a first actuator and the sensed vibrations are sent to a second actuator such that the first actuator and the second actuator are connected to the same aircraft control surface. In such embodiments, both the first actuator and the second actuator may be used to control the aircraft control surface simultaneously, similarly resulting in the summed total effect on the aircraft control surface to suppress the vibrations. In other embodiments, the first actuator and the second actuator may be controlled in series- or an active / standby mode- such that when the first actuator is in operation, the second actuator is on standby and vice versa.

[0061] The above detailed description describes various features and functions of the disclosed systems, devices, and methods with reference to the accompanying figures. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The example embodiments described herein and in the figures are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

Claims

Attorney Docket No. 22-1339-WOCLAIMSWhat is claimed is:

1. A method of suppressing vibrations on an aircraft, the method comprising: sensing, by an at least one sensor, a vibration of the aircraft; and controlling, by a controller, at least one flight control actuator connected to an at least one aircraft control surface of the aircraft to actuate the at least one aircraft control surface to counteract the vibration in the aircraft.

2. The method of claim 1, further comprising: sensing, by the at least one sensor, a second vibration of the aircraft; controlling, by the controller, the least one flight control actuator connected to the at least one aircraft control surface of the aircraft to actuate the at least one aircraft control surface to counteract the second vibration in the aircraft.

3. The method of claim 1, wherein the at least one sensor comprises at least one of: an altimeter, an airspeed indicator, a position sensor, a gyroscope, an attitude heading and reference system, and a vibration sensor.

4. The method of claim 1, wherein the controller is integrated onto the aircraft.

5. The method of claim 1, wherein the controller is remote from the aircraft.

6. A method of suppressing vibrations on an aircraft, the method comprising: receiving, at a controller, a flight mode of the aircraft; estimating, by the controller, a predicted vibration in the aircraft based on the received flight mode of the aircraft; sensing, by an at least one sensor, a sensed vibration of the aircraft; calculating, at the controller, a total vibration comprising a sum of the predicted vibration and the sensed vibration of the aircraft;Attorney Docket No. 22-1339-WO controlling, by a controller, at least one flight control actuator connected to at least one aircraft control surface of the aircraft to actuate the at least one aircraft control surface to counteract the total vibration in the aircraft.

7. The method of claim 6, wherein controlling the at least one flight control actuator connected to the at least one aircraft control surface of the aircraft comprises superimposing, by the controller, a desired command of the at least one flight control actuator over an existing series of commands on the at least one flight control actuator, wherein the desired command of the at least one flight control actuator counteracts the total vibration in the aircraft.

8. The method of claim 6, further comprising: receiving, at the controller, a second flight mode of the aircraft; estimating, by the controller, a second predicted vibration in the aircraft based on the received second flight mode of the aircraft; calculating, at the controller, the total vibration comprising a sum of the second predicted vibration and the sensed vibration of the aircraft; and controlling, by the controller, the at least one flight control actuator connected to the at least one aircraft control surface of the aircraft such that the actuation of the at least one aircraft control surface counteracts the total vibration in the aircraft.

9. The method of claim 6, further comprising: sensing, by the at least one sensor, a second sensed vibration of the aircraft; calculating, at the controller, the total vibration comprising a sum of the predicted vibration and the second sensed vibration of the aircraft; controlling, by a controller, the at least one flight control actuator connected to the at least one aircraft control surface of the aircraft to actuate the at least one aircraft control surface to counteract the total vibration in the aircraft.

10. An aircraft system, the system comprising: an at least one aircraft control surface;Attorney Docket No. 22-1339-WO an at least one flight control actuator connected to the at least one aircraft control surface; an at least one sensor on the aircraft; a controller having one or more processors; and a non-transitory computer readable medium; wherein the non-transitory computer readable medium comprises storage having program instructions that are executable by the one or more processors to: control the at least one flight control actuator connected to the at least one aircraft control surface of the aircraft such that actuation of the at least one aircraft control surface counteracts a vibration in the aircraft.

11. The aircraft system of claim 10, wherein the non-transitory computer readable medium comprising storage having program instructions that are executable by the one or more processors further includes: sensing, by the at least one sensor, the vibration of the aircraft.

12. The aircraft system of claim 11, wherein the at least one sensor comprises at least one of: an altimeter, an airspeed indicator, a position sensor, a gyroscope, an attitude heading and reference system, and a vibration sensor.

13. The aircraft system of claim 10, wherein the at least one aircraft control surface is connected to a singular flight control actuator.

14. The aircraft system of claim 10, wherein the at least one aircraft control surface is operably-coupled with a plurality of flight control actuators, wherein each flight control actuator of the plurality of flight control actuators is communicatively-connected with the controller.

15. The aircraft system of claim 10, wherein the at least one flight control actuator comprises an electromechanical actuator.Attorney Docket No. 22-1339-WO16. The aircraft system of claim 10, further comprising: a plurality of aircraft control surfaces, wherein each aircraft control surface of the plurality of aircraft control surfaces is operably-coupled with one of a plurality of flight control actuators, and wherein the program instructions stored on the non-transitory computer readable medium and executable by the one or more processors is further configured to: control each aircraft control surface of the plurality of aircraft control surfaces by actuating each of the plurality of flight control actuators such that the actuation of each of the plurality of flight control actuators counteracts a measured vibration in each aircraft control surface of the plurality of aircraft control surfaces based on the measured vibration.

17. The aircraft system of claim 10, the system further comprising: a first aircraft control surface of the at least one aircraft control surface; a first actuator of the at least one flight control actuator connected to the first aircraft control surface, wherein the actuation of the first aircraft control surface by the first actuator counteracts a predicted vibration in the aircraft, and wherein the predicted vibration in the aircraft is based on at least a flight mode of the aircraft; and a second actuator of the at least one flight control actuator connected to the first aircraft control surface, wherein the actuation of first aircraft control surface by the second actuator counteracts a sensed vibration in the aircraft, and wherein the sensed vibration in the aircraft is based on at least a sensed vibration by the at least one sensor.

18. The aircraft system of claim 17, wherein the first actuator and the second actuator are configured to control the first aircraft control surface simultaneously.

19. The aircraft system of claim 17, wherein the first actuator is configured to control the first aircraft control surface first, and wherein the second actuator is configured to control the first aircraft control surface following the first actuator controlling the first aircraft control surface.Attorney Docket No. 22-1339-WO20. The aircraft system of claim 17, wherein the second actuator is configured to control the first aircraft control surface first, and wherein the first actuator is configured to control the first aircraft control surface following the second actuator controlling the first aircraft control surface.