Estimating and displaying remaining control margin in an over-actuated flight control system

Abstract

A method for providing to a user a remaining control margin in an over-actuated flight control system of an aircraft includes determining, by a processor, a current state of the aircraft. The method also includes determining, by the processor, a current position of an effector. The method further includes selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector. The method additionally includes determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft. The method also includes displaying, on a display, a representation of the determined amount of remaining moment generating capability.

Description

ESTIMATING AND DISPLAYING REMAINING CONTROL MARGIN IN AN OVER-ACTUATED FLIGHT CONTROL SYSTEMCROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to U.S. Provisional Application No. 63 / 578,127, filed on August 22, 2023, the entire contents of which are herein incorporated by reference as if fully set forth in this description.BACKGROUND

[0002] Control systems are used in many applications including the operation of land, water, and aerial vehicles. Control systems may control the vehicle by taking input on a control device and translating it to output on a control surface.

[0003] Conventional control systems, such as mechanical and hydromechanical systems, include a series of mechanical linkages (e.g., pushrods, cables, and pulleys) directly connecting the control device and control surface. The series of mechanical linkages move in response to the control device input to actuate the control surface.

[0004] In fly-by-wire control systems inputs from the control device may generate digital signals. A flight control computer (FCC) may receive the digital signals and translate them to a corresponding movement of the control surface. Because fly-by-wire systems lack a direct mechanical linkage between an inceptor and the control surface, one difficulty posed by fly-by-wire systems is accurately providing tactile control margin feedback between the inceptor displacement and the position of the control surface.

[0005] Control surfaces on vehicles such as aircraft are often isolated per axis such that a single control surface may orient the aircraft about the respective axis. In an over actuated system multiple control surfaces may orient the vehicle about a single axis and / or a single control surface may orient the vehicle about multiple axes.

[0006] It is with respect to these and other considerations that the disclosure made herein is presented.SUMMARY

[0007] The present disclosure describes implementations that relate to providing pilot awareness of control margin in an over-actuated, highly augmented, fly-by- wire flight control system.

[0008] In a first example embodiment, a method for providing to a user a remaining control margin in an over-actuated flight control system of an aircraft is provided. The method includes determining, by a processor, a cunent state of the aircraft. The method also includes determining, by the processor, a current position of an effector. The method additionally includes selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector. The method further includes determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft. The method also includes displaying, on a display, a representation of the determined amount of remaining moment generating capability.

[0009] In some embodiments, the current state of the aircraft includes at least one of an airspeed, an altitude, an attitude, an angle of attack, and a sideslip.

[0010] In some embodiments, the method further includes determining a software enforced limit of the aircraft, where the determined amount of remaining moment generating capability is based at least partially on the determined software enforced limit.

[0011] In some embodiments, the software enforced limit is a stall velocity.

[0012] In some embodiments, determining the amount of remaining moment for each control axis is further based on the current position of the effector and the selected model.

[0013] In some embodiments, the method further includes scaling the determined amount of remaining moment generating capability such that the determined amount of remaining moment generating capability is represented as a value between a standardized maximum range and a standardized minimum range.

[0014] In some embodiments, the standardized maximum range is 1 and the standardized minimum range is -1 .

[0015] In some embodiments, for the effector. 1 represents a maximum allowable effector deflection in a first direction and -1 represents a maximum allowable effector deflection in a second direction which is different than the first direction.

[0016] In some embodiments, the displayed representation of the determined amount of remaining moment generating capability is between the standardized maximum range and the standardized minimum range.

[0017] In some embodiments, the method further includes providing a haptic or an audible indication to a user when the determined amount of remaining moment generating capability is within 10 percent of the standardized maximum range and the standardized minimum range.

[0018] In some embodiments, determining the amount of remaining moment generating capability further includes determining an amount of currently utilized moment for each control axis.

[0019] In some embodiments, the method further includes displaying, on the display, a representation of the amount of currently utilized moment.

[0020] In some embodiments, where each of the determined amount of remaining moment generating capability is assigned a value, the method further includes assigning a first color to values within a first range and a second color to values within asecond range which is different than the first range, such that the representation of the determined amount of remaining moment generating capability is color coded based on the assigned value.

[0021] In some embodiments, the control axis includes a pitch axis, a yaw axis, and a roll axis, and the determined amount of remaining moment is separately displayed for each of the pitch axis, the yaw axis, and the roll axis.

[0022] In some embodiments, the effector is a first effector and the method further includes determining a current position of a second effector, and the determined amount of remaining moment displayed in at least one of the pitch axis, the yaw axis, and the roll axis is based on the first and second effectors.

[0023] In some embodiments, the determined amount of remaining moment displayed in at least two of the pitch axis, the yaw axis, and the roll axis is based on the effector.

[0024] In some embodiments, the effector is a first effector and the method further includes: determining a current position of a second effector; and selecting a model from a database of models of the moment generating capability for the second effector.

[0025] In some embodiments, determining the amount of remaining moment for each control axis is based at least partially on the moment generating capability for the first and second effector.

[0026] In some embodiments, the method further includes determining an amount of remaining power generating capability, where the determination is based on the current state of the aircraft; and displaying, on a display, a representation of the determined amount of remaining power generating capability.

[0027] In a second example embodiment, a non-transitory computer-readable medium having stored thereon program instructions executable by a processor of a device to cause the device to carry out operations is provided. The operations include determining, by a processor, a current state of the aircraft. The operations also include determining, by the processor, a current position of an effector. The operations additionally include selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector. The operations further include determining an amount of remaining moment generating capability for each control axis, where the determination is based on the current state of the aircraft. The operations also include displaying, on a display, a representation of the determined amount of remaining moment generating capability.

[0028] In a third example embodiment, a system is provided. The system includes a processor; and a non-transitory data storage storing program instructions executable by the processor to carry out operations. The operations include determining, by a processor, a current state of the aircraft. The operations also include determining, by the processor, a current position of an effector. The operations additionally include selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector. The operations further include determining an amount of remaining moment generating capability for each control axis, where the determination is based on the current state of the aircraft. The operations also include displaying, on a display, a representation of the determined amount of remaining moment generating capability.

[0029] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, implementations, and features described above, further aspects, implementations, and features will become apparent by reference to the following detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate multiple embodiments of the presently disclosed subject matter and, together with the description, serve to explain the principles of the presently- disclosed subject matter; and, furthermore, are not intended in any manner to limit the scope of the presently disclosed subject matter

[0031] Figure 1 illustrates a craft in a vertical take-off and landing configuration, according to exemplary embodiments of the present invention.

[0032] Figure 2 illustrates a block diagram of a process 200 for determining an amount of moment and thrust generating capability remaining for each control axis, according to exemplary embodiments of the present invention.

[0033] Figure 3A illustrates a display of standardized control and moment margins, according to exemplary embodiments of the present invention.

[0034] Figure 3B illustrates a display of standardized control and moment margins, according to exemplary embodiments of the present invention.

[0035] Figure 3C illustrates a display of standardized power margins, according to exemplary- embodiments of the present invention.

[0036] Figure 4 is a block diagram showing some of the components of an example computing device, according to exemplary embodiments of the present invention.

[0037] Figure 5 is a block diagram showing an aircraft system including the computing device of Figure 4, according to exemplary embodiments of the present invention.

[0038] Figure 6 illustrates a flowchart of a method for providing to a user a remaining control margin in an over-actuated flight control system of an aircraft, according to example embodiments of the present invention.DETAILED DESCRIPTION

[0039] Disclosed herein are examples of devices, processes, and methods for providing pilot awareness of control margin in a craft. More specifically, for providing pilot awareness of control margin in an over-actuated, highly augmented, fly-by -wire flight control system. In some examples, the disclosed devices, processes, and / or methods may be implemented on a vehicle. In some examples, the vehicle may be a VTOL, which may or may not use propellers 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, soanng, hovering, airborne, aeronautical aircraft, airplane, plane, spacecraft, a helicopter, an airship, or an unmanned aerial vehicle, or a drone).

[0040] In a conventionally controlled aircraft, the position of a pilot’s controls provides an indication of the remaining control authority available to the pilot in each axis. Maximum stick deflection results in maximum control surface (e.g., effector) deflection. The pilot’s knowledge of control margin may be an important part of the pilot’s decision-making process when maneuvering the aircraft.

[0041] In some examples, a fly-by-wire aircraft with highly augmented stick response types in which the sticks command the trajectory of the aircraft may no longer have a direct mapping of stick displacement to control surface deflection. In examples where one effector is used to control each axis, the remaining margin maybe trivial to calculate in each axis.

[0042] However, in examples where an over actuated aircraft includes more effectors than axes of control, displaying the remaining margin using the control surfacedeflections may become too difficult for the pilot to quickly interpret. Examples discussed herein address displaying the remaining margin in an over actuated aircraft.

[0043] In some examples, the aircraft state, control surface positions, stick positions, and / or information about the vehicle dynamics may be used to calculate a metric for an easy to interpret control margin in each axis. The examples discussed herein may provide the pilot with the situational awareness necessary to maintain control of the aircraft.

[0044] For conventionally controlled aircraft, the control margin may be indicated directly by the position of the stick.

[0045] For fly-by-wire fixed wing aircraft, even if the stick deflection does not map directly to a control surface deflection, a single effector may be used per axis. Thus, control margin may be simply determined by directly using the remaining range for each effector.

[0046] For fly-by-wire rotorcraft, even if the stick deflection does not map directly to cyclic and tail rotor commands there is only one control effector per axis, such that a relatively simple method of using effector range applies for determining control margin.

[0047] When the pilot’s inceptor input does not map directly to a control surface deflection, the pilot may lose awareness about a maximum amount of control that may be achieved in each axis. If the pilot is not aware of the remaining control margins, the vehicle response could become unpredictable leading to a pilot’s loss of situational awareness.

[0048] The examples discussed herein may provide an intuitive indication to the pilot of a remaining control margin, such as a remaining control margin in the pitch, roll, yaw, and thrust axes. For example, while hovering in winds one or more swashplate actuators may be used to control all axes. In such examples, if a yaw control authority is saturated bythe aerodynamic forces on the vehicle, the vehicle may experience a yaw acceleration response that is not commanded by the pilot. Providing indication of saturated yaw authority may give the pilot the awareness to know that turning into the wind may alleviate the yaw control margin issue.

[0049] In some examples, determining the remaining control margin for each axis may include information such as: 1) Current state of the aircraft, including airspeed, altitude, attitude, angle of attack or sideslip, 2) Current effector positions, 3) A model of the moment generating capability for each of those effectors as a function of the required variables, and / or 4) Limits imposed on the aircraft through software limits in the control system.

[0050] In some examples, an algorithm may compute an amount of moment and / or thrust generating capability remaining for each axis. The algorithm may scale that dimensional value to something that may be easily interpreted by the pilot. In such examples, the dimensional thrust and / or moment generating capability' of the aircraft may vary' greatly throughout a flight envelope, especially for transitioning aircraft. Thus, scaling the remaining margin in each axis to a unit that is consistent across the flight envelope may be advantageous. The flow chart shown in Figure 2 illustrates high-level details of an example algorithm.

[0051] Figure 1 illustrates a craft 100 in a vertical take-off and landing configuration, according to exemplary embodiments of the present invention. As shown in Figure 1. the craft 100 may include, among other things, a body 110, one or more lift rotors 104, one or more proprotors 106 which may be mounted on respective hubs 107. one or more boom assemblies 150, one or more lift surfaces 102, and a tail 114. In some examples, the craft 100 may be manned or unmanned. It is envisioned that the craft 100 may be used for any purpose known to those skilled in the art, including for example, as ataxi, a delivery vehicle, a personal vehicle, a cargo transport, a short or long-distance hauling aircraft, and / or a video / photography craft. Thus, in some examples, the craft 100 may be a manned and / or unmanned aerial vehicle (e.g., aircraft).

[0052] The body 110 may be any suitable shape, size, or configuration suitable for the purpose of the craft. For example, the body 110 may be oval, square, triangular, or otherwise any appropriate shape sufficient to hold cargo and / or passengers while remaining structurally sound. Moreover, the body 110 may include gear 116 for landing on land and / or water, which may or may not be retractable. The gear 116 may be included at both the front and the back of the craft 100, and may include wheels, treads, pontoons, or other components that may aid the craft in landing in land and / or water. The 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, in other examples, 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).

[0053] The body 1 10 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 (e.g., a computing device) configured to communicate and / or control craft systems for the craft, including for example, the proprotors 106, the lift rotors 104. and / or one or more control surfaces (e.g., elevator, rudder, ruddervator. actuator, spoiler, rotor, or other known controls / surfaces). The body 110 may include a fuselage configured to provide structure to connect and / or link a lift surface structure of the lift surface 102. In some examples, the fuselage may be of truss, monocoque, or semi- monocoque construction. The fuselage may be constructed of any suitable material, suchas metal and / or a composite laminate. In some examples, the fuselage may include aluminum, while in other examples the fuselage may include a carbon fiber composite laminate. In further examples, the fuselage may include a combination of metal and composite laminate.

[0054] The proprotors 106 and / or the lift rotors 104 may be positioned above or away from control surfaces and / or portions of the body 110 such that a blade strike is unlikely or not possible. For example, the proprotors 106 may be spaced above a proprotor hub 107 and / or the lift rotors 104, when in a vertical take-off and landing configuration. The proprotors 106 may be spaced along the lift surface 102 and substantially above the body 110, and / or the lift rotors 104 may be spaced along the boom assemblies 150 and substantially above the body 110. The proprotors 106 may be spaced along the lift surface 102 away from the tail 114 (e.g., outboard) to avoid a blade strike on the tail 114. For example, each proprotor 106 may be positioned at more than half the distance of one wing from the body 110 or, in some examples, more than two-thirds the distance of one wing from body 110.

[0055] The proprotors 106, the lift rotors 104, and / or controls may be operable by an onboard pilot, an onboard computer (e.g., autonomously), 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. The proprotor 106 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.

[0056] The lift surface 102 may extend relatively horizontally, when the craft is at rest, from one end to another. The lift surface 102 may include an airfoil configured to generate lift when air flows past it. The lift surface 102 may be a single continuous surface, or may include sections of lift surfaces, for example with one or more sections arranged inboard (e.g., towards the body 110) of the boom assemblies 150 (discussed below) and one or more sections arranged outboard (e.g., away from the body 110) of the boom assemblies 150. The lift surface 102 may incorporate portions of, or include shaped portions of, the body 110, the boom assemblies 150, and / or the proprotors 106 to generate lift and / or reduce drag as air flows past. In some examples, the lift surface 102 may be a wing.

[0057] The boom assemblies 150 may provide a structure for the tail structure 114, one or more electric motors for the one or more lift rotors 104, and / or one or more batteries to power the one or more lift rotors 104, and / or the one or more proprotors 106. The lift rotors 104 may also be connected to the craft's electrical and control systems. The boom assemblies 150 may be supported by the lift surface 102 and the internal structure of the lift surface. Thus, the structure of the lift surface 102 may efficiently provide lift to the craft 100 to cany7persons or cargo while incorporating structure to support the boom assemblies 150, and / or additionally to support the proprotors 106 in horizontal thrust and vertical take-off and landing configurations. Additionally, the proprotors 106 can create stress on structure as it rotates, and it is thus advantageous to support the proprotors 106 through the lift surface 102 that comprises internal structural components, such as spars and ribs, that are capable of withstanding the stress from the proprotors 106 as they operate to generate thrust and as they rotate between configurations. Efficient use of the structure in the lift surface 102 can provide for a lighter craft, leading to less use of fuel and travel at greater speeds.

[0058] While Figure 1 illustrates four lift rotors 104, any suitable number of lift rotors 104 may be incorporated in a craft (for example, the craft may utilize more or less than four lift rotors 104). Lift rotors 104 may be configured to generate substantially vertical thrust. Lift rotors 104 may operate at a fixed pitch and / or a fixed revolutions per minute (RPM). In some examples, the lift rotors 104 may be positioned on either side of a lift surface and along the boom assemblies 150. In some examples, the lift rotors 104 may be positioned on the lift surface 102.

[0059] The lift rotors 104 and the proprotors 106 may be mechanically powered by one or more electric motors. In some examples, each lift rotor 104 and / or proprotor 106 may be powered by a dedicated motor, or one or more lift rotors 104 and / or proprotors 106 may be powered by a shared motor. As one example, two lift rotors 104 along one boom assembly 150 may share a motor. The motors discussed herein may be traditional fuel powered motors, electric motors, and / or hybrid motors. In some examples, a motor and rotor may be connected to a transmission that controls the use of power generated by the motor. The transmission may be a continuously variable transmission (CVT), or an automatic transmission, or a manual or semi-manual transmission to shift one or more gears to output differing amounts of power.

[0060] The lift rotors 104 and / or the proprotors 106 may be constant speed rotors or variable speed rotors. The lift rotors and / or the proprotors may be at a constant angle of attack or have a changeable angle of attack (e.g., changeable through one or more actuators).

[0061] Speed, position, and / or angle of attack may be changed and / or gears may be shifted individually, as a set at the same time, or for all proprotors 106 and / or all lift rotors 104 simultaneously. For example, four lift rotors 104 may all change speed at once to initiate a takeoff sequence and / or landing sequence. As another example, the proprotors106 may be shifted from a take-off and landing configuration to a cruise condition simultaneously. As another example, two proprotors 106 and four lift rotors 104 may all change speed and / or angle of attack to affect a take-off and landing sequence simultaneously.

[0062] In some examples, the proprotors 106 may be puller rotors or pusher rotors. The proprotors 106 may include a thrust rotor (e.g., a propeller). In some examples, the proprotors 106 may be configured to move between a horizontal thrust configuration, a vertical thrust configuration, and / or any position in between. In such examples, the vertical thrust configuration may allow for slow flight (e.g., hovering and / or sub-horizontal stall velocity flight) and / or take-off and / or landing (e.g., vertical / short take-off and landing (V / STOL)). In some examples, one or more actuators may engage the proprotors 106 to control movement between the horizontal and vertical thrust configuration.

[0063] The lift rotors 104 may be located at any position on the craft 100. As illustrated in Figure 1, a first lift rotor 104 may be positioned forward of the lift surface 102 on a first side of the body, a second lift rotor 104 may be positioned aft of the lift surface on the first side of the body, a third lift rotor 104 may be positioned forward of the lift surface on a second side of the body, and a fourth lift rotor 104 may be positioned aft of the lift surface on the second side of the body. The lift rotors 104 may also be mounted on the one or more boom assemblies 150. The one or more boom assemblies 150 may include a battery pack configured to supply electrical power to one or more electric motors or may be utilized for storage of goods, electncal or mechanical components of the craft, or any other items known to those skilled in the art. While Figure 1 illustrates two boom assemblies 150 configured substantially perpendicular to the top or bottom surface of the lift surface 102, in other examples 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 oneor more boom assemblies 150 may include or connect to the 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).

[0064] Control surfaces may be on relatively vertical portions of the tail 114 or relatively horizontal portions 126 of the tail 114. The tail 114 may be linked aft of the boom assemblies 150. In some examples, the tail 114 may be linked aft of the lift surface 102. The tail 114 may comprise an elevator along the link between one boom assembly 150 and another boom assembly 150. The tail structure 114 may be aft of the body 110. The tail structure 114 may comprise control surfaces such as rudders and / or ruddervators, where the control surfaces extend upwards and / or downwards from the boom assemblies 150. In some examples, at least one control surface may be positioned at least partially above a rotation plane of the lift rotors. For example, a rudder, an elevator, or a ruddervators of the tail 114 may extend partially above the body 110 and / or the lift rotors 104. The tail 114 may be configured to provide control to the craft 100 through control surfaces that are positioned in a freestream (e.g., relatively undisrupted air) when the craft is in a horizontal thrust configuration.

[0065] In some examples one or more of the control surfaces (e.g., elevator, rudder, ruddervator, spoiler, rotor, or other known controls / surfaces) may be referred to as an effector. One or more of the control surfaces may be coupled to an actuator or other suitable structure for adjusting a position of the control surface throughout one or more positions. For example, the one or more control surfaces may be operated via actuators, active inceptors, sidesticks, switches, and / or buttons and may be configured to adjust the position of the control surface throughout the one or more positions. The one or more control surfaces may be coupled (e.g.. communicatively coupled) to a computing device, such as a flight control computer of a flight control system, which may further be coupledto at least one inceptor (e.g., an inceptor located in the cockpit 118). The flight control system may communicate with the actuator to adjust a position of the one or more control surfaces. The flight control system may facilitate communication between the at least one inceptor and the one or more control surfaces. For example, the flight control system mayreceive position and / or state information about the one or more control surfaces and / or the at least one inceptor, such as via one or more coupled sensors. The flight control system may thus facilitate communication between the at least one inceptor and the one or more control surfaces by translating inputs from the at least one inceptor into outputs to control position information of the one or more control surfaces, while also providing position information feedback of the one or more control surfaces to the at least one inceptor and / or a user device.

[0066] In some examples, the craft 100 may include one or more over-actuated control axis. For example, at least one of a yaw axis, a pitch axis, and / or a roll axis may be over-actuated. Certain control surfaces may control movement of the craft 100 in one or more control axis. For example, adjusting a position of a single control surface may produce a movement of the craft 100 in both the yaw axis and the pitch axis, in both the yaw axis and the roll axis, or in both the pitch axis and the roll axis. In other examples, one or more control axis may be effected through a plurality of control surfaces, such as two or more control surfaces producing a movement of the craft 100 about a single control axis. For example, a first control surface and a second control surface may both produce a movement of the craft 100 in the yaw axis, the pitch axis, and / or the roll axis. In further examples, certain control surfaces may produce a movement of the craft 100 in one or more control axis as well as adjusting a direction of thrust, such as actuation of a swashplate coupled to a rotor.

[0067] 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. The 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 the craft 100 is at rest on a ground surface. In some examples, the tail 114 may extend from the body 110 and the boom assemblies 150 may be connected above the tail 114 extending from the body 110, where the connection of the boom assemblies 150 is separate from the tail 114 extending from the body 110 or connected to the tail 114 extending from the body 110.

[0068] The proprotors 106 may be connected to the lift surface 102 through a rotating linkage such as a rotating spar, and / or extending linkages. In some examples, the rotating spar may be actuated to rotate the proprotor 106 relative to the lift surface 102. The proprotors 106 may be positioned at any suitable location on the craft, including on the lift surface, on one or more sides of the body 110, on the boom assembly 150, or any other location. In some examples, extending linkages may be actuated to rotate the proprotor 106 relative to the 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.

[0069] The proprotors 106 may be configured in one configuration to rotate around and / or relative to an axis 108 substantially parallel with a ground surface and / or a lift surface, considered when the aircraft is at rest on the ground surface. As shown in Figure 1. the axis 108 may extend along or within the lift surface 102 from one end of the lift surface 102 to another end of the lift surface 102. The lift surface may include a first partial lift surface 122 at a first end of the lift surface 102 and a second partial lift surface 122 at a second end of the lift surface 102. The first and second partial lift surfaces mayhave any shape suitable to maximize lift and minimize drag, thereby reducing fuel consumption. For example, the partial lift surface may be rectangular, elliptical, circular, triangular, or any combination thereof.

[0070] In some examples, a first proprotor 106 may be attached to the first partial lift surface such that the first partial lift surface moves with the proprotors 106 during movement of the proprotor 106 relative to and / or rotation about axis 108. A second proprotor 106 may be attached to the second partial lift surface such that the second partial lift surface moves with the proprotors 106 during movement of the proprotor 106 relative to and / or rotation about axis 108. The partial lift surfaces 122 may include one or more control systems which may be operable by the pilot located in the cabin 118. The partial lift surfaces 122 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.

[0071] In some examples, the partial lift surfaces 122 may be configured to generate lift in a vertical thrust configuration. In some examples, the partial lift surfaces 122 may comprise a wing portion with a similar cross-sectional area and / or airfoil shape to the rest of the lift surface 102 (e.g., partial lift surfaces 122 may comprise a continuation of the lift surface 102). In some examples, the partial lift surfaces 122 may comprise winglets, may consist of winglets, and in other examples, the partial lift surfaces 122 may not have winglets. Whether the partial lift surfaces 122 have winglets may depend on the type of cargo, travel time, and / or proprotor size. The partial lift surfaces 122 may each comprise a winglet 124 and a wing portion, as shown in Figure 1. The winglets 124 may extend generally vertically from the end of the wing portions. In some examples, the winglets 124 may be configured to reduce drag.

[0072] In some examples, the proprotors 106 may be configured to rotate or move about the axis 108 along with the partial lift surfaces 122, where the proprotors 106 and the partial lift surfaces 122, 124 rotate outboard of the boom assemblies 150. In some examples, where the lift surface 102 is a separate structure from the boom assemblies 150, the proprotors 106 may move or rotate with the lift surface 102 aside from portions of the lift surface 102 that include the body 110. In some examples, the proprotors 106 may move or rotate such that only a portion of the proprotor hub 107 and the blades 106 move or rotate. In some examples, the proprotor hub 107 may move or rotate with the partial lift surface 122 about axis 108. Based on the shape of the lift surface 102, the lift surface not including the body 110 may rotate with the proprotors 106 to increase lift and decrease drag, thereby reducing fuel consumption. The lift surface 102 shape may also vary throughout a root to tip length. For example, the lift surface 102 may be rectangular shaped to support the weight of the body 110, and may be thinner out to the proprotor 106 to reduce drag when the proprotor 106 is configured for horizontal operation and wider when the proprotor 106 is configured for vertical operation. One or more components of the craft 1 0 may be communicatively coupled to a control system that controls at least one operation of the one or more components of the craft 100. The control system may include a computing device that, based on received inputs, determines a command for the control system to execute on the one or more components.

[0073] Figure 2 illustrates a block diagram of a process 200 for determining an amount of moment and thrust generating capability remaining for each control axis, according to exemplary embodiments of the present invention. The process 200 includes a sensed aircraft state 202, an effector state 204. a control system limit 206, and a dynamic model database 208.

[0074] Together, one or more of the sensed aircraft state 202, the effector state204, the control system limit 206, and / or the dynamic model database 208 may each serve as inputs into block 210. Block 210 may utilize the one or more inputs to determine an amount of remaining moment, force, and / or thrust generating capability7of one or more effectors. For example, the sensed aircraft state 202 and / or the effector state 204 may be used to determine the control system limit 206 and / or select a dynamic model from the dynamic model database. Based on one or more of the dynamic model from the dynamic model database 208, the control system limit 206, the effector state 204, and the sensed aircraft state 202, block 210 may determine the remaining thrust, moment, and / or force generating capability7of the aircraft. The determined result from block 210 may be output to block 212. Block 212 may scale the output from block 210 into a standardized format for outputting to a display 214, such as displaying to a user on a display device located within the cockpit 118.

[0075] In some examples, the sensed aircraft state 202 may include an airspeed of the aircraft, an altitude of the aircraft, an attitude of the aircraft, an angle of attack of the aircraft, an orientation of the aircraft, and / or a sideslip of the aircraft. The type of airspeed of the aircraft may be an indicated airspeed (IAS), a calibrated airspeed (CAS), a true airspeed (TAS), and / or an equivalent airspeed (EAS). Airspeed may be measured in knots in some examples, while in other examples the airspeed may be measured using another unit, such as meters per second, kilometers per hour, feet per second, and / or miles per hour.

[0076] As an example, true airspeed may be the speed of the aircraft relative to the surrounding air mass, which may7include correcting indicated airspeed for air density and / or temperature. In examples where the sensed aircraft state 202 includes the true airspeed, the true airspeed may serve as an input in determining an amount of remaining thrust generating capability and / or an amount of remaining moment and / or force generating capability for each control axis. For example, the true airspeed of the aircraft may be used,in part, to reference a dynamic model from the dynamic model database 208 and / or the control system limit 206. In some examples, the dynamic model from the dynamic model database 208 and / or the control system limit 206 referenced may vary based on the true airspeed of the aircraft. For example, the true airspeed of the aircraft may be compared to the control system limit 206 selected, such as the stall velocity7, to determine a remaining amount of margin available before the control system limit 206 is reached. In another example, effector displacement may be related to true airspeed of the aircraft. For example, at higher velocities less effector deflection may be needed to produce a desired result whereas at lower velocities a larger effector deflection may be needed to produce the desired result. Thus, true airspeed of the aircraft may be used to reference a dynamic model from the dynamic model database 208 to determine the amount of remaining moment and / or force generating capability7for each control axis.

[0077] As another example, sideslip of the aircraft may serve as an input for block 210. The sideslip of the aircraft may be a current sideslip. The current sideslip may be measured in degrees or radians relative to a longitudinal axis, such as a longitudinal axis running from the nose to the tail of the aircraft. The current sideslip may indicate a cunent heading of the aircraft in relation to relative wind, such as indicating the orientation of the aircraft relative to a wind direction. In some examples, maintaining an angle of the current sideslip may require deflection of one or more effectors, such as deflection of an effector contributing to moment and / or force about a yaw axis of control, which may reduce an amount of remaining moment and / or force generating capability in yaw. Further, in overactuated aircraft the effector that contributes to moment and / or force about the yaw axis may also contribute to moment and / or force about another axis of control, such as a pitch axis. In such examples, the current sideslip may serve as an input when referencing a dynamic model from the dynamic model database 208 to determine an amount of remaining moment and / or 1force generating capability for each control axis. Knowing the amount of remaining moment and / or force generating capability for each control axis may aid the pilot in making informed decisions when operating the aircraft.

[0078] In some examples, the effector state 204 may include position information, such as surface position information, of one or more effectors of the aircraft. For example, the effector state 204 may include a current position or displacement of each of the one or more effectors. The current position of the effector may be measured in degrees or radians based on a reference axis. In some examples, the effector state 204 may be a current position of a control surface, such as a ruddervator, aileron, stabilizer, rotor, and / or elevator. In such examples, each of the control surfaces may include a reference axis having zero degrees correspond to an un-deflected position of the control surface. Deflection of each of the control surfaces may be measured relative to the respective reference axis. For example, deflection may be measured in positive angles of deflection and negative angles of deflection, where positive angles correspond to deflection of the control surface in a first direction from the reference axis and negative angles correspond to deflection of the control surface in a second direction from the reference axis opposite the first direction.

[0079] In some examples, the control system limit 206 may be a software enforced limit. For example, the software enforced limit may include at least one flight envelope limit, such as a stall condition of the aircraft, a structural load limit of one or more components of the aircraft, and / or a dynamic load limit of one or more components of the aircraft. The structural load limit may include a physical limit of an actuator coupled to an effector (e.g., a control surface). In some examples, the software enforced limit may also include a performance limit, such as a rate limit of conversion for an actuator, a flying quality limit, such as an attitude limit, and / or an acoustic limit, such as a rotor angle of attack limit to reduce vibratory noise from the rotor. The software enforced limits, such as the stallcondition and / or the structural load limit, may be based on the configuration of the aircraft, such as whether the aircraft is in the vertical take / off landing configuration, the horizontal flight configuration, or transitioning between configurations. The configuration of the aircraft may correspond to a position of one or more components of the aircraft. For example, the rotor tilt angle and / or a control surface orientation may vary based on the configuration of the aircraft such that the software enforced limit (e.g., the stall condition and / or the structural load limit) may be different depending on the rotor tilt angle and / or the control surface orientation. The software enforced limit may also be based on a sensed aircraft state, such as a velocity of the aircraft, an attitude of the aircraft, or a weight (e.g., gross weight) of the aircraft.

[0080] In some examples, an upper and lower bounds of the position of the effector may be set by the control system limit 206 based on the software enforced limit (e.g., the stall condition limit, the structural load limit, the performance limit, the flying quality limit, and / or the acoustic limit). For example, in the given configuration and / or sensed aircraft state (e.g., attitude and / or airspeed), the control system limit 206 may impose a maximum and / or a minimum effector position. Imposing a maximum and / or a minimum effector position may affect an amount of moment and / or thrust generating capability of the effector. Thus, in some examples, the amount of remaining moment, force, and / or thrust generating capability for a particular control axis may be based on the control system limit 206.

[0081] In some examples, the dynamic model database 208 may include one or more dynamic models of the aircraft. The one or more dynamic models of the aircraft may include information and / or aspects of the aircraft as the aircraft executes maneuvers while flying throughout a flight envelope. Throughout the flight envelope of the aircraft the state (e.g.. deflection) of an effector may vary. For example, while executing a port side roll theeffector may be displaced to a first position but while executing a starboard side roll the effector may be displaced to a second position different than the first position. Thus, in some examples dynamic model may mean that the model varies based on the state of the effector.

[0082] The one or more dynamic models may include information about a component of the aircraft and how actuation of that component affects flight dynamics, such as how actuation of that component affects movement of the aircraft about a control axis. For example, the one or more dynamic models may include information about how actuation of an effector contributes to movement of the aircraft about the control axis. The one or more dynamic models may include information about structural loads, aerodynamic loads, and / or control surface deflections of the aircraft while operating throughout the flight envelope. In some examples, the dynamic model database 208 may be one or more lookup tables that contain information about the aircraft. The lookup tables may include the same and / or similar information as the one or more dynamic models. For example, the lookup tables may be a table version of information obtained from the one or more dynamic models.

[0083] The one or more dynamic models in the dynamic model database 208 may be referenced by the computing device when executing block 210 to determine an amount of remaining moment, force, and / or thrust generating capability of the one or more effectors. In some examples, the sensed aircraft state 202 and / or the effector state 204 may serve as inputs when referencing the dynamic model database 208. For example, the sensed aircraft state 202 and / or the effector state 204 may be used to reference a particular dynamic model and / or lookup table from the dynamic model database 208 to determine the amount of remaining moment, force, and / or thrust generating capability of the effector.

[0084] Aircraft maneuverability about a control axis may vary based on the sensed aircraft state 202 and / or the effector state 204. As a non-limiting example, aircraft maneuverability may vary based on a velocity of the aircraft, such that at lower velocities agreater effector deflection may be needed to effect a particular maneuver than at a higher velocity; Further, at lower velocities (e.g., hovering and / or low speed flight) a particular effector, such as a rotor, may contribute a greater input to maneuverability about a control axis than at higher velocities (e.g., steady level flight). In such examples, an effector deflection at the lower velocity' may not produce the same moment generating capability' about a control axis than at the higher velocity7. The current velocity' and the displacement of the effector may be useful in referencing the dynamic model database 208 to select an appropriate dynamic model and / or lookup table to determine a current remaining maneuverability' of the aircraft about the control axes. Thus, the sensed aircraft state 202 and / or the effector state 204 may be used to reference the particular dynamic model and / or lookup table such that remaining moment, force, and / or thrust generating capability' of the aircraft may be determined.

[0085] For example, block 210 may use the sensed aircraft state 202 and / or the effector state 204 as inputs when referencing the dynamic model database 208 to determine the remaining thrust, moment, and / or force generating capability. In some examples, block 210 may also reference the control system limit 206 to determine the upper and / or lower bounds of effector deflection. The determined result from block 210 may be output to block 212. Block 212 may scale the output from block 210 into a standardized format for outputting to a display 214. In some examples, the display 214 may receive the output from block 212 for display. For example, the display 214 may receive and display the scaled remaining moment and / or force generating capability' for the aircraft performed in block 212.

[0086] Aircraft typically express movement along three principal control axis: a yaw axis, a pitch axis, and a roll axis. In over-actuated aircraft systems, such as a VTOL aircraft, multiple control surfaces may contribute to at least one control axis (e.g., yaw, pitch, and / or roll). Having multiple control surfaces contributing to at least one control axis mayresult in difficulty for the pilot in determining an amount of remaining maneuvering capability' in the particular control axis and / or determining which control surface to engage to effect a desired maneuver of the aircraft. Thus, displaying total aircraft moment capabilities in relation to each of the control axes may provide a more intuitive representation to the pilot in over-actuated aircraft systems which may allow the pilot to better determine which control surfaces to engage to effect the desired maneuver. For example, a saturated yaw authority due to aerodynamic forces (e.g., crosswinds) while in a hover may indicate to the pilot that turning the aircraft into the crosswinds may improve yaw control margins by reducing an amount of yaw moment used by the aircraft.

[0087] Figure 3 Aillustrates a display 300A of standardized control and moment margins, according to exemplary embodiments of the present invention. The display 300A may include a thrust display 310, a pitch display 320, a yaw display 330, and a roll display 340. In some examples, the pitch display 320 may display a representation of the pitch capabilities of the aircraft, the yaw display 310 may display a representation of the yaw capabilities of the aircraft, and the roll display 340 may display a representation of yaw capabilities of the aircraft. Similarly, the thrust display 310 may display the thrust capabilities of the aircraft.

[0088] Each of the thrust display 310, the pitch display 320, the yaw display 330 and / or the roll display 340 may include an axis 302 having an upper limit 302A and a lower limit 302B. In some examples of the pitch display 320, the yaw display 330 and / or the roll display 340, the upper limit 302A may correspond to a standardized maximum value in a first direction and the lower limit 302B may correspond to a standardized maximum value in a second direction opposite the first direction. The standardized maximum values may represent a total amount of moment and / or force generating capability for each of the pitch display 320, the yaw display 330 and / or the roll display 340 in the first and second directions,respectively. Thus, the upper limit 302A and the lower limit 302B may be a standardized representation of the maximum amount of moment and / or force generating capability for each control axis (e.g., yaw, pitch, and roll) in the first and second directions.

[0089] For example, on the pitch display 320, the first direction may be upwards and the second direction may be downwards such that the upper limit 302A may correspond to the maximum amount of pitch moment generating capability in the upwards direction and the lower limit 302B may correspond to the maximum amount of pitch moment generating capability in the downwards direction. On the yaw display 330, the first direction may be right and the second direction may be left such that the upper and lower limits 302A and 302B respectively correspond to the maximum amount of yaw moment generating capability in the right and left directions. Similarly, on the roll display 340, the first direction may be a right-hand roll and the second direction may be a left-hand roll such that the upper and lower limits 302A and 302B respectively correspond to the maximum amount of roll moment generating capability in the right-hand and left-hand directions.

[0090] In some examples, the upper limit 302A may correspond to a standardized maximum value of 1 and the lower limit 302B may correspond to a standardized maximum value of-1, with 0 corresponding to a neutral value (e.g., no moment, force, and / or thrust). In such examples, the standardized maximum value of 1 and -1 may represent a total percentage, such as representing 100 percent, of the amount of moment, force, and / or thrust generating capability in the first and second directions for each of the thrust, pitch, yaw, and roll. The total percentage for moment and / or force generating capability may include a combination of all control surfaces that contribute to moment and / or force about a particular control axis. For example, the total percentage for pitch moment and / or force generating capability may include a combination of the one or more control surfaces that contribute to pitch moment and / or force in either the first and / or second directions. Similarly, the totalpercentage for yaw moment and roll moment generating capabilities may include a combination of the one or more control surfaces that contribute to yaw moment and roll moment in either the first and / or second directions, respectively. Similar functionality maybe included for force determinations in the yaw and roll control axis. The total percentage for thrust generating capability7may include a combination of one or more components that contribute to thrust in either the first and / or second directions, such as the contribution to thrust from one or more proprotors and one or more lift rotors. In other examples, the upper limit 302A may correspond to a standardized maximum value of 1 and the lower limit 302B may correspond to a standardized minimum value of 0, where 0 corresponds to a zero value (e.g., no moment, force, and / or thrust). In such examples, the 0 value may indicate an “off” state, such as no thrust, power, and / or torque is being produced.

[0091] In some examples, the upper limit 302A and / or the lower limit 302B may include one or more control system limits, such as the control system limit 206. For example, a maximum thrust, moment, and / or force generating capability of the aircraft may exceed a control system limit of the aircraft which may pose a safety concern, such as placing the aircraft in a stall. In such examples, the upper limit 302A and / or the lower limit 302B may be bounded by the one or more control system limits such that control surface deflections may not exceed the one or more control system limits. Thus, in some examples, the standardized maximum value of 1 and -1 may include the one or more control system limits.

[0092] In some examples, at least one control surface may contribute to moment about one or more control axis and / or thrust. For example the at least one control surface may contribute to moment about the pitch axis and the roll axis; about the pitch axis and the yaw axis; about the yaw axis and the roll axis; or about the pitch axis, the yaw axis, and the roll axis. In examples where the at least one control surface contributes to thrust, the at least one control surface may also contribute to the moment about one or more of the control axis.In examples where the at least one control surface contributes to moment about one or more control axis and / or thrust, the moment and / or thrust contribution of the control surface may be separated by the contribution for each of thrust, pitch, yaw, and / or roll. In some examples, force may be included in place of or in addition to moment.

[0093] As a non-limiting example, a first control surface may contribute to 20 percent of total pitch moment generating capabilities as well as 50 percent of total roll moment generating capabilities of the aircraft. In such examples, the pitch display 320 may include a currently utilized amount of pitch moment from the first control surface and the roll display 340 may include a currently utilized amount of roll moment from the first control surface. The currently utilized amount of pitch moment and / or roll moment may be based on a position of the control surface, such as an amount of deflection, where when fully deflected the control surface contributes to all 20 percent of total pitch moment generating capabilities and 50 percent of total roll moment capabilities. Thus, in some examples, the currently utilized amount of pitch moment and / or yaw moment may be expressed as a proportion of the total amount the first control surface contributes.

[0094] In another non-limiting example, a first control surface, a second control surface, and a third control surface may each respectively contribute to 20 percent, 30 percent, and 50 percent of the total yaw moment generating capabilities of the aircraft. At current deflection positions the first control surface may be at 50 percent of maximum contribution, the second control surface may be at 50 percent of maximum contribution, and the third control surface may be at 20 percent of maximum contribution to the total yaw moment generating capabilities in the first direction, such as each respectively contributing 10 percent (50 percent of 20 percent), 15 percent (50 percent of 30 percent), and 10 percent (20 percent of 50 percent) to total yaw moment generating capabilities in the first direction. Thus, the yaw display 330 may indicate that 35 percent (e.g., 10+15+10 percent) of total yawmoment generating capabilities in the first direction are currently being utilized, which may indicate to the pilot a remaining control margin of yaw moment generating capabilities to be 65 percent in the first direction.

[0095] In some examples, each of the thrust display 310, the pitch display 320, the yaw display 330, and / or the roll display 340 may include an indicator 306. The indicator 306 may indicate a currently utilized amount of thrust, moment, and / or force generating capability of the aircraft. For example, the indicator 306 on the thrust display 310 may indicate an amount of currently utilized thrust generating capability, the indicator 306 on the pitch display 320 may indicate an amount of currently utilized pitch moment generating capability, the indicator 306 on the yaw display 330 may indicate an amount of currently utilized yaw moment generating capability, and / or the indicator 306 on the roll display 340 may indicate an amount of currently utilized roll moment generating capability. In some examples, the indicator 306 may be dynamically adjustable based on the amount of currently utilized thrust, moment, and / or force generating capabilities of the aircraft.

[0096] In some examples, one or more of the thrust display 310, the pitch display 320, the yaw display 330, and / or the roll display 340 may include a color bar, such as a first color bar 308A or a second color bar 308B. The first color bar 308A may be a first color and the second color bar 308B may be a second color different than the first color. For example, the first color may be green and the second color may be yellow, however any color may be used for either the first or second colors. While only the first and second color bars 308A and 308B are show n in Figure 3A, in other examples any number of color bars may be used, where each color bar is assigned a different color. For example, one or more of the thrust display 310, the pitch display 320, the yaw display 330, and / or the roll display 340 may include a third color bar having a third color, such as red.

[0097] The first and / or second color bars 308 A and / or 308B may be dynamically adjustable based on a currently utilized amount of thrust, moment, and / or force generating capability. For example, the first color bar 308A may be assigned to a first range of currently utilized amount of thrust, moment, and / or force generating capability and the second color bar 308B may be assigned to a second range of currently utilized amount of thrust, moment, and / or force generating capability7. The first range may be different and / or non-overlapping than the second range. The first color bar 308A may be displayed when the currently utilized amount of thrust, moment, and / or force generating capability is within the first range. The second color bar 308B may be displayed when the currently utilized amount of thrust, moment, and / or force generating capability is within the second range. For example, for the thrust display 310 the first range may be between 0 and 50 percent of total thrust, moment, and / or force generating capabilities and the second range may be between 50 and 100 percent of total thrust, moment, and / or force generating capabilities.

[0098] In such examples, when the currently utilized amount of thrust generating capability is between 0 and 50 percent, such as currently at 30 percent, the first color bar 308 A may show the area between the indicator 306 and the neutral value 0 as the first color (e.g., green). When the currently utilized amount of thrust generating capability is between 50 and 100 percent, such as currently at 80 percent, the second color bar 308B may be displayed on the thrust display 310 to color the area between the indicator 306 and neutral value 0 the second color (e.g., yellow). In other examples, another percentage ranges and / or number of color bars may be used. Using multiple color bars, where each color bar is assigned a different color, may quickly visually indicate to the pilot the amount of currently utilized, and remaining, thrust, moment, and / or force generating capability for each of the control axes. For example, the color green may indicate to the pilot that a healthy margin (e.g., greater than a 50 percent margin remaining) may exist for the respective control axis,while the color yellow may indicate to the pilot that the control axis is approaching saturation(e.g., less than a 50 percent margin remaining). Thus, color coding one or more components of the display 300Amay provide an intuitive way for the pilot maintain situational awareness of remaining control margins in an over-actuated aircraft and / or to quickly determine an aircraft maneuver to improve the control margins.

[0099] In some examples, a warning indication may be triggered when one or more of the remaining thrust and / or moment generating capability is below a threshold value. For example, the warning indication may occur when one or more of the remaining thrust and / or moment generating capability is below a threshold value of 30 percent, below a threshold value of 20 percent, or below a threshold value of 10 percent. The warning indication may provide an indication to the pilot that one or more of the thrust and / or moment generating capability is approaching the limit (e.g., maximum). In some examples, upon satisfying the threshold value the warning indication may be a haptic indication, a visual indication, and / or an audible indication. For example, the haptic indication may include vibrations through one or more inceptors (e.g.. pedals and / or sticks), the visual indication may include flashing lights on the display 300A or in the cockpit, and the audible indication may include one or more noise alerts (e.g., beeping, sirens, and / or verbal warnings of approaching the maximum).

[0100] In the example shown, the pitch display 320 is oriented in a vertical position while the yaw display 330 and the roll display 340 are oriented in a horizontal position. Aircraft pitch movements are typically vertical while aircraft yaw and roll movements are typically horizontal. Positioning the pitch display 320 vertically while positioning the yaw display 330 and the roll display 340 horizontally may provide a more intuitive display for the pilot to allow the pilot to more efficiently discern indications on the display 300A with physical positioning of the aircraft.

[0101] Figure 3B illustrates a display 300B of standardized control and moment margins, according to exemplary' embodiments of the present invention. The display 300B may include a pitch display 350, a roll display 360, and a yaw display 370. As shoyvn on the display 300B, the pitch display 350 and the roll display 360 may intersect in a cross-like pattern and the yaw display 370 may be displayed separately, such as above or below the pitch display 350 and the roll display 360. However, in other examples the pitch display 350 and the yaw display 370 may intersect in a cross-like pattern on the display 300B and the roll display 360 may be displayed separately. In some examples, the pitch display 350, the roll display 360, and the yaw display 370 may be the same as and / or similar to the pitch display 320, the yaw display 310, and the roll display 340 discussed in Figure 3 A. Thus, the display 300B may include one or more features and / or functions as the display 300A described in Figure 3A. In some examples, the display 300B may include standardized force margins in place of or in addition to moment margins.

[0102] The pitch display 350 may include a lower limit 352 and an upper limit 354. In some examples of the pitch display 350. the upper limit 354 may correspond to a standardized maximum value in a first direction and the lower limit 352 may correspond to a standardized maximum value in a second direction opposite the first direction. For example, the first direction may be a pitch up direction and the second direction may be a pitch down direction for the aircraft. The standardized maximum values may represent a total amount of moment and / or force generating capability for each of the pitch display 350 in the first and second directions, respectively.

[0103] Similarly, the roll display 360 may include a lower limit 362 and an upper limit 364. In some examples of the roll display 360, the upper limit 364 may correspond to a standardized maximum value in a first direction and the lower limit 362 may correspond to a standardized maximum value in a second direction opposite the firstdirection. For example, the first direction may be a starboard side roll direction (e.g., righthand roll) and the second direction may be a port side roll direction (e.g., left-hand roll) for the aircraft.

[0104] The yaw display 370 may include a lower limit 372 and an upper limit 374. In some examples of the yaw display 370, the upper limit 374 may correspond to a standardized maximum value in a first direction and the lower limit 372 may correspond to a standardized maximum value in a second direction opposite the first direction. For example, the first direction may be a starboard side yaw direction (e.g., right-hand yaw) and the second direction may be a port side yaw direction (e.g., left-hand yaw) for the aircraft. Thus, for each of the pitch display 350, the roll display 360, and the yaw display 370 the respective upper and lower limits may be a standardized representation of the maximum amount of moment and / or force generating capability for each control axis (e.g., yaw, pitch, and roll) in the respective first and second directions.

[0105] In some examples, one or more of the pitch display 350, the roll display 360, and / or the yaw display 370 may include a color bar, such as a first color bar 382 and / or a second color bar 384. The first color bar 382 may be a first color and the second color bar 384 may be a second color different than the first color. For example, the first color may be green and the second color may be white, however any color may be used for either the first or second colors. The first and / or second color bars 382 and / or 384 may be dynamically adjustable based on a currently utilized amount of moment and / or force generating capability. For example, the first color bar 382 may be assigned to an amount of remaining moment and / or force generating capability for a particular control axis and the second color bar 384 may be assigned to an amount of currently utilized moment and / or force generating capability for the particular control axis. The first and / or second color bars 382 and / or 384 may dynamically adjust along the particular control axis based on the determined amount ofcurrently utilized and / or currently remaining moment and / or force about the particular control axis. Thus, in some examples, the amount of the first color 382 displayed on the particular control axis may decrease while the amount of the second color 384 displayed on the particular control axis may increase indicating the currently remaining moment and / or force is decreasing. Similarly, in other examples, the amount of the first color 382 displayed on the particular control axis may increase while the amount of the second color 384 displayed on the particular control axis may decrease indicating the currently remaining moment and / or force that may be utilized by the aircraft is increasing.

[0106] As a non-limiting example, the display 300B indicates that the aircraft is currently using approximately 50 percent of the pitch up moment generating capability, approximate 33 percent of the right-hand roll moment generating capability, and approximately 66 percent of the yaw moment generating capability in both the left-hand and right-hand yaw directions. With respect to the yaw display 370. this indicates an available remaining yaw moment generating capability’ of 33 percent in either the left-hand and / or right-hand yaw directions. In such examples, the reduced yaw margin in both the left-hand and right-hand yaw directions is due to an over-actuated effector, such as a shared effector that contributes to both yaw and pitch moment generating capabilities. In such examples, pitch may be assigned a higher priority’ than yaw for control purposes, which may reduce an amount of displayed remaining margin for yayv. Thus, in some examples, remaining control margin about a particular axis may further be based on a level of priority' assigned to the particular effector and / or control axis.

[0107] Figure 3C illustrates a display 300C of standardized power margins, according to exemplary embodiments of the present invention. The display 300C includes a poyver display (P) 390. In some examples, the power display 390 may be similar to the thrust display 310 discussed in Figure 3A. Thus, the display 300C may include one or more featuresand / or functions as the display 300A described in Figure 3A. Further, features and / or functions described with respect to thrust throughout the specification may be equally applicable to power as used herein.

[0108] In some examples, the power display 390 may include a minimum power output 392 and a maximum power output 394. In some examples of the power display 390, the maximum power output 394 may correspond to a standardized maximum power currently being utilized by the aircraft and the minimum power output 392 may correspond to a standardized minimum power currently being used by the aircraft. Thus, in some examples, the maximum power output 394 may represent the aircraft operating at a maximum power output and the minimum power output 392 may represent the aircraft operating at a minimum power output.

[0109] As illustrated, the display 300C may include a power indicator 396A. The power indicator 396Amay indicate a currently utilized amount of power by the aircraft. In some examples, the power indicator 396A may be dynamically adjustable based on the amount of currently utilized power by the aircraft. For example, as the aircraft consumes more power the power indicator 396A may dynamically adjust towards the maximum power output 394, indicating a decreasing margin of remaining power for utilization. Similarly, as the aircraft consumes less power the power indicator 396A may dynamically adjust towards the minimum power output 392, indicating an increasing margin of remaining power for utilization. The power indicator 396A may further display the currently utilized amount of power as a numerical representation 396B. For example, the numerical representation 396B displayed on the display 300C indicates that the currently utilized amount of power by the aircraft is 1210 kilowatts. The numerical representation 396B may aid the user in quickly determining a unit based amount of power currently being utilized.

[0110] The power display 390 may include a color bar, such as a first color bar398A, a second color bar 398B, and a third color bar 398C. The first color bar 398A may be a first color, the second color bar 398B may be a second color different than the first color, and the third color bar 398C may be a third color different than the first and second colors. For example, the first color may be green, the second color may be yellow, and the third color may be red; however, any color combination may be used for the first, second, and third colors.

[0111] In some examples, the first color bar 398A may be assigned to a first range of power output of the aircraft, the second color bar 398B may be assigned to a second range of power output of the aircraft, and the third color bar 398C may be assigned the a third range of power output of the aircraft. Each of the first, second, and third ranges may be different and / or non-overlapping than the others. For example, the first range may be between 0 and 60 percent of total power output, the second range may be between 60 and 80 percent of total power output, and the third range may be between 80 and 100 percent of total power output. However, in other examples another series of ranges may be used, such as 0 and 70 percent, 70 and 85 percent, and 85 and 100 percent for the first, second and third ranges, respectively. Using multiple color bars, where each color bar is assigned a different color, may quickly visually indicate to the pilot the amount of currently utilized, and remaining, power output for the aircraft.

[0112] In some embodiments, additional features such as temperature (T) and energy (E) (e.g., an aircraft state of charge (SOC) or a fuel gauge) may be included on the display 300C in a similar manner as the power display 390.

[0113] Figure 4 is a block diagram showing some of the components of an example computing device 400. according to exemplary embodiments of the present invention. In some examples, a control system and / or a controller (e.g., a flight controlsystem of an aircraft) may include the computing device 400. The computing device 400 may correspond to a computing device configured to perfonn additional functions (e.g., in communication with one or more other computing devices using a web browser and / or an application). In various examples, the computing device 400 may be an onboard aircraft computing device, a mobile computing device (e.g., a smartphone), a desktop computing device, a laptop computing device, a tablet computing device, or a wearable computing device (e.g., a smartwatch or a smart wristband). In some examples, the computing device 400 may be remote from the aircraft, such as ground based computing device communicably coupled to the aircraft. As illustrated in Figure 4, the computing device 400 may include a network interface 402, a user interface 404, a processor 406, and data storage 408. The network interface 402, the user interface 404, the processor 406, and / or the data storage 408 may be communicatively linked together by a bus 410 (e.g., an electrical interconnect defined on one or more printed circuit boards).

[0114] The network interface 402 may be used by the computing device 400 to communicate with other computing devices over one or more networks (e.g., the public Internet). In some examples, the network interface 402 may include a wired interface (e.g., Ethernet). Additionally or alternatively, the network interface 402 may include a wireless interface, such as WIFI. Other interfaces may be included in the network interface 402 and are contemplated herein.

[0115] The user interface 404 may function to allow computing device 400 to receive input from and / or provide output to a user. As such, the user interface 404 may include inputs (e.g., an inceptor, a joystick, a thumbwheel, a pedal, a knob / dial, a keypad, a keyboard, a touch-screen, a computer mouse, a microphone, a microphone jack, etc.) and / or outputs (e.g., a cathode-ray tube (CRT) display, a liquid-crystal display (LCD), a lightemitting diode (LED) display, a speaker, a speaker jack, headphones, a headphone jack, etc.).

[0116] The processor 406 may include one or more general purpose processors(e.g., microprocessors) and / or one or more special-purpose processors (e.g., graphics processing units (GPUs) or application-specific integrated circuits (ASICs)).

[0117] The data storage 408 may include one or more volatile and / or nonvolatile memories. For example, the data storage may include a RAM, a ROM, a hard drive, a solid state drive, etc. In some examples, the data storage 408 may be partially or wholly integrated with the processor 406 (e.g., a level 1 (LI) cache or a level 2 (L2) cache within a central processing unit). The data storage 408 may include removable components (e.g., a flash drive) and / or non-removable components (e.g., a ROM integrated with a motherboard).

[0118] The processor 406 may be configured to execute instructions 418 (e.g., compiled or non-compiled program logic and / or machine code) stored in the data storage 408 to carry out the methods described herein. Hence, the data storage 408 may include a non- transitory computer-readable medium, having stored thereon program instructions that, when executed by the processor 406, cause the processor 406 to carry out any of the methods, processes, or operations disclosed in this specification and / or the accompanying drawings. In some examples, the processor 406 may use the application data 412 while executing the instructions 418.

[0119] In some examples, the instructions 418 may include an operating system 422 (e.g., an operating system kernel, device driver(s), and / or other modules) and one or more applications 420 (e.g., mobile applications, sometimes referred to as ”apps"). As described above, the processor 406 may access the application data 412 when executing the applications 420.

[0120] The applications 420 may communicate with the operating system 422 through one or more application programming interfaces (APIs). These APIs may facilitate,for instance, the applications 420 reading and / or writing the application data 412, transmitting or receiving information via the network interface 402, receiving and / or displaying information on the user interface 404, etc.

[0121] Additionally, the applications 420 may be downloadable to the computing device 400 through one or more online application stores or application markets (e.g., using the network interface 402). However, application programs can also be installed on the computing device 400 in other ways, such as via a web browser or through a physical interface (e.g., a universal serial bus (USB) port) on the computing device 400. In some examples, the applications 420 may include a plurality of control system limits and / or a dynamic model database that may be referenced when determining a remaining amount of moment generating capability for each control axis, a remaining amount of force generating capability for each control axis, a remaining amount of thrust generating capability, and / or a remaining amount of power output of the aircraft.

[0122] While many of the techniques and functions described herein may be performed by the processor 406 executing one of the applications 420, other ways for the computing device 400 to perform such techniques and functions are also possible and are contemplated herein. For example, some or all of the calculations may be performed remotely (e.g., on a server computing device). Such examples may be referred to as a “browser-based app” when the computing device 400 provides data (e.g., application data 412) to a different computing device for analysis using a web browser. Additionally or alternatively, such an interaction between the computing device 400 and another computing device may be performed using an API or a browser-based language (e.g., JavaScript).

[0123] Figure 5 is a block diagram showing an aircraft system 500 including the computing device 400 of Figure 4, according to exemplary embodiments of the present invention. The aircraft system 500 may include at least one effector 532 operatively-coupledwith at least one actuator 534. The actuators 534 may include an electromechanical actuator, an electrohydraulic actuator, a hydraulic actuator, a self-contained hydraulic actuator, or any combination of the aforementioned. In some examples, a singular effector of the at least one effector 532 may be coupled with a singular actuator 534. In other examples, a singular effector may be coupled with more than one actuator 534. In further examples, a plurality7of effectors may be coupled with a singular actuator 534. The actuator 534 may actuate the effector 532 to adjust a position of the effector 532 from a first position to a second position different than the first position, such as from a current effector position to a desired effector position. Position information about the effector 532 may serve as a dynamic input into the computing device 400.

[0124] For example, information about the effector 532, such as position information and / or type information, may be used by computing device 400 to determine which dynamic model to reference in the dynamic model database 208. In some examples, effector position and / or type information may be used by the computing device 400 to detennine, at least in part, an amount of remaining moment and / or force for one or more control axis.

[0125] Each actuator 534 may be communicatively-coupled with the computing device 400, described in Figure 4. In some examples, the at least one actuator 534 may be controllable by the computing device 400 such that the computing device 400 may command the at least one actuator 534 to change the position and / or orientation of the at least one effector 532. For example, the computing device 400 may send a command signal to the actuator 534 to command the actuator 534 to adjust the effector 532 from the current effector position to the desired effector position. In examples where the desired effector position may exceed control system limits, the computing device 400 may output an alert to the user, such as outputting a visual alert, an audio alert, and / or a haptic alert on the user interface 404 orto one or more components in communication with the user. In some examples, the user interface 404 may include the display 300A.

[0126] For example, the computing device 400 may output the alert to the user that the desired maneuver exceeds a control system limit. Further, in some examples commands from the computing device 400 to the actuator 534 may be set to operate within the control system limits such that the actuator 534 may engage the effector 532 to move the position of the effector 532 up to but not exceeding the control system limit. Thus, in such examples the control system limit may be a maximum and / or a minimum position of the effector 532 that the computing device 400 may command the actuator 534 to engage the effector 532.

[0127] In some examples, the position of one or more control surfaces, such as the effector 534, may be based on an input received from an inceptor 550. The inceptor 550 may include sidesticks / joy sticks, pedals, thumbwheels, tillers, knobs, dials, levers, and the like. Thus, the inceptor 550 may be communicatively-coupled with the computing device 400. In some examples, the inceptor 550 may be an active inceptor. In other examples, the inceptor 550 may be a passive inceptor.

[0128] In some examples, the inceptor 550 may be movable by a pilot of the aircraft. At least one action, such as a movement, of the inceptor 550 may serve as a dynamic input into the computing device 400. For example, inputs from the inceptor 550 may adjust a position of the effector 532. Adjusting the position of the effector 532 may produce a change in the amount of remaining moment, force, and / or thrust generation capability of the aircraft. When the pilot moves the inceptor 550 (e.g., provides a physical user input), the longitudinal position, lateral position, and / or twist of the inceptor 550 may be displaced. As such, the inceptor 550 may be configured to receive physical user input from the user (e.g.,the pilot). The inceptor 550 may transform the physical user input into digital signals that are representative of the physical user input.

[0129] In some examples, the inceptor 550 may include one or more sensors to determine a displacement of the inceptor 550. The sensors of the inceptor 550 may generate corresponding signals (e.g., alternating current signals) indicative of the respective displacement. The signals may be processed and converted into digital signals that are indicative of the respective displacement. For example, the computing device 400 may process signals received from the inceptor 550 to determine the dynamic input from the inceptor 550. In some examples, the signals may be received as the dynamic input by the computing device 400 which may be used to control one or more operations of the aircraft, such as determining an actuator command for the effector 532 based on the dynamic input received from the inceptor 550.

[0130] As shown, the aircraft system 500 may include at least one sensor 540. In some examples, the sensor 540 may include accelerometers, altimeters, airspeed indicators, position sensors, effector sensors, inceptor sensors, gy roscopes, attitude heading and reference systems, sideslip and / or angle of attack indicators, and the like. The at least one sensor 540 may be configured to obtain information about a current state of the aircraft, such as a sensed aircraft state and / or one or more environmental characteristics from an environment of the aircraft. For example, the sensor 540 may obtain an airspeed of the aircraft, an altitude of the aircraft, position and / or orientation information of the aircraft (e.g., attitude information), acceleration of the aircraft, a weight of the aircraft (e.g., gross weight), a sideslip of the aircraft, an angle of attack of a control surface, and / or the current state of the at least one effector 532. The sensor 540 may transmit the obtained information to the computing device 400.

[0131] In some examples, information obtained by the sensor 540 may be used as a dynamic input to determine a particular dynamic model from the dynamic model database, the control system limit, and / or the remaining moment, force, and / or thrust generating capability of the aircraft. Thus, the dynamic inputs may include information obtained by the sensor 540. In some examples the computing device 400 may use information obtained by the sensor 540 to determine, in part, the remaining moment, force, and / or thrust generating capability of the aircraft and scale the remaining moment, force, and / or thrust generating capability into a standardized format for outputting to a display, such as outputting to the display, such as the display 300A, 300B, or 300C.

[0132] Thus, in some examples the aircraft system 500 may determine, by the computing device 400, a current state of the aircraft and / or a current position of the effector 532. The current state of the aircraft and / or the current position of the effector 532 may serve as dynamic inputs to determine remaining moment and / or force generating capabilities of the aircraft. For example, based on the dynamic input from the effector 532, the aircraft system 500 may select, by the computing device 400, a model from a database of models of the moment and / or force generating capability for the effector 532. Based on the dynamic input of the current state of the aircraft, the aircraft system 500 may further determine, by the computing device 400, an amount of remaining moment and / or force generating capability for each control axis of the aircraft. In some examples, the amount of remaining moment and / or force generating capability for each control axis of the aircraft may further be determined based on the current position of the effector 532. The aircraft system 500 may additionally scale, by the computing device 400, the determined amount of remaining moment and / or force generating capability such that the determined amount of remaining moment and / or force generating capability is represented as a value between a standardized maximum and minimum range, such as a standardized maximum and minimum range of 1and -1. The aircraft system 500 may additionally display, by the computing device 400, a representation (e.g., scaled values) of the determined amount of remaining moment and / or force generating capability on a display device.

[0133] Figure 6 illustrates a flowchart of a method 600 for providing to a user a remaining control margin in an over-actuated flight control system of an aircraft, according to example embodiments of the present invention. The method 600 may include one or more operations, or actions as illustrated by one or more steps 602-610. Although the steps are illustrated in a sequential order, these steps may in some instances be performed in parallel, and / or in a different order than those described herein. Also, the various blocks may be combined into fewer steps, divided into additional steps, and / or removed based upon the desired implementation.

[0134] As illustrated, at step 602, the method 600 may include determining, by a processor, a current state of the aircraft.

[0135] At step 604, the method 600 may also include determining, by the processor, a current position of an effector.

[0136] At step 606, the method 600 may also include selecting, based on the current position of the effector, a model from a database of models of a moment generating capability' for the effector.

[0137] At step 608, the method 600 may also include determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft.

[0138] At step 610, the method 600 may also include displaying, on a display, a representation of the determined amount of remaining moment generating capability.

[0139] In some examples of the method 600, the current state of the aircraft comprises at least one of an airspeed, an altitude, an attitude, an angle of attack, and a sideslip.

[0140] In some examples, the method 600 may further include determining a software enforced limit of the aircraft, wherein the determined amount of remaining moment generating capability is based at least partially on the determined software enforced limit.

[0141] In some examples of the method 600, the software enforced limit is a stall velocity.

[0142] In some examples of the method 600, determining the amount of remaining moment for each control axis is further based on the current position of the effector and the selected model.

[0143] In some examples, the method 600 may further include scaling the determined amount of remaining moment generating capability such that the determined amount of remaining moment generating capability is represented as a value between a standardized maximum range and a standardized minimum range.

[0144] In some examples of the method 600, the standardized maximum range is 1 and the standardized minimum range is -1.

[0145] In some examples of the method 600, for the effector. 1 represents a maximum allowable effector deflection in a first direction and -1 represents a maximum allowable effector deflection in a second direction which is different than the first direction.

[0146] In some examples of the method 600, the displayed representation of the determined amount of remaining moment generating capability is between the standardized maximum range and the standardized minimum range.

[0147] In some examples, the method 600 may further include providing a haptic or an audible indication to a user when the determined amount of remaining momentgenerating capability is within 10 percent of the standardized maximum range and / or the standardized minimum range.

[0148] In some examples of the method 600, determining the amount of remaining moment generating capability further includes determining an amount of currently utilized moment for each control axis.

[0149] In some examples, the method 600 may further include displaying, on the display, a representation of the amount of currently utilized moment.

[0150] In some examples of the method 600, each of the determined amount of remaining moment generating capability is assigned a value, and the method 600 further includes assigning a first color to values within a first range and a second color to values within a second range which is different than the first range, such that the representation of the determined amount of remaining moment generating capability' is color coded based on the assigned value.

[0151] In some examples of the method 600, the control axis includes a pitch axis, a yaw axis, and a roll axis, and wherein the determined amount of remaining moment is separately displayed for each of the pitch axis, the yaw axis, and the roll axis.

[0152] In some examples of the method 600, the effector is a first effector and the method 600 further includes determining a current position of a second effector, wherein the determined amount of remaining moment displayed in at least one of the pitch axis, the yaw axis, and the roll axis is based on the first and second effectors.

[0153] In some examples of the method 600, the determined amount of remaining moment displayed in at least two of the pitch axis, the yaw axis, and the roll axis is based on the effector.

[0154] In some examples of the method 600, the effector is a first effector and the method 600 further includes determining a current position of a second effector; and selecting a model from a database of models of the moment generating capability for the second effector.

[0155] In some examples of the method 600, determining the amount of remaining moment for each control axis is based at least partially on the moment generating capability for the first and second effector.

[0156] In some examples, the method 600 further includes determining an amount of remaining power generating capability, wherein the determination is based on the current state of the aircraft; and displaying, on a display, a representation of the determined amount of remaining power generating capability.

[0157] Implementations of the present disclosure can thus relate to one of the example embodiments listed below.

[0158] Embodiment 1 is a method for providing to a user a remaining control margin in an over-actuated flight control system of an aircraft, the method comprising: determining, by a processor, a current state of the aircraft; determining, by the processor, a current position of an effector; selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector; determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft; and displaying, on a display, a representation of the determined amount of remaining moment generating capability.

[0159] Embodiment 2 is the method according to embodiment 1 , wherein the current state of the aircraft comprises at least one of an airspeed, an altitude, an attitude, an angle of attack, and a sideslip.

[0160] Embodiment 3 is the method according to embodiment 1 or embodiment2, further comprising determining a software enforced limit of the aircraft, wherein the determined amount of remaining moment generating capability is based at least partially on the determined software enforced limit.

[0161] Embodiment 4 is the method according to embodiment 3, wherein the software enforced limit is a stall velocity.

[0162] Embodiment 5 is the method according to any of embodiments 1 to 4, wherein determining the amount of remaining moment for each control axis is further based on the current position of the effector and the selected model.

[0163] Embodiment 6 is the method according to any of embodiments 1 to 5, further comprising scaling the determined amount of remaining moment generating capability such that the determined amount of remaining moment generating capability is represented as a value between a standardized maximum range and a standardized minimum range.

[0164] Embodiment 7 is the method according to embodiment 6, wherein the standardized maximum range is 1 and the standardized minimum range is -1.

[0165] Embodiment 8 is the method according to embodiment 7, wherein for the effector, 1 represents a maximum allowable effector deflection in a first direction and -1 represents a maximum allowable effector deflection in a second direction which is different than the first direction.

[0166] Embodiment 9 is the method according to embodiment 7, wherein the displayed representation of the determined amount of remaining moment generating capability’ is between the standardized maximum range and the standardized minimum range.

[0167] Embodiment 10 is the method according to embodiment 9, further comprising providing a haptic or an audible indication to a user when the determined amount of remaining moment generating capability is within 10 percent of the standardized maximum range and the standardized minimum range.

[0168] Embodiment 11 is the method according to any of embodiments 1 to 10, wherein determining the amount of remaining moment generating capability further comprises determining an amount of currently utilized moment for each control axis.

[0169] Embodiment 12 is the method according to embodiment 11, further comprising displaying, on the display, a representation of the amount of currently utilized moment.

[0170] Embodiment 13 is the method according to any of embodiments 1 to 12, wherein each of the determined amount of remaining moment generating capability is assigned a value, the method further comprising: assigning a first color to values within a first range and a second color to values within a second range which is different than the first range, such that the representation of the determined amount of remaining moment generating capability is color coded based on the assigned value.

[0171] Embodiment 14 is the method according to any of embodiments 1 to 13, wherein the control axis comprises a pitch axis, a yaw axis, and a roll axis, and wherein the determined amount of remaining moment is separately displayed for each of the pitch axis, the yaw axis, and the roll axis.

[0172] Embodiment 15 is the method according to embodiment 14, wherein the effector is a first effector and the method further comprises determining a current position of a second effector, and wherein the determined amount of remaining moment displayed in atleast one of the pitch axis, the yaw axis, and the roll axis is based on the first and second effectors.

[0173] Embodiment 16 is the method according to embodiment 14, wherein the determined amount of remaining moment displayed in at least two of the pitch axis, the yaw axis, and the roll axis is based on the effector.

[0174] Embodiment 17 is the method of any of embodiments 1 to 16, wherein the effector is a first effector and the method further comprises: determining a current position of a second effector; and selecting a model from a database of models of the moment generating capability for the second effector.

[0175] Embodiment 18 is the method according to embodiment 16, wherein determining the amount of remaining moment for each control axis is based at least partially on the moment generating capability for the first and second effector.

[0176] Embodiment 19 is the method according to any of embodiments 1 to 18, further comprising: determining an amount of remaining power generating capability, wherein the determination is based on the current state of the aircraft; and displaying, on a display, a representation of the determined amount of remaining power generating capability.

[0177] Embodiment 20 is a non-transitory computer-readable medium having stored thereon program instructions executable by a processor of a device to cause the device to earn out operations comprising: determining, by a processor, a current state of the aircraft; determining, by the processor, a current position of an effector; selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector; determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft; anddisplaying, on a display, a representation of the determined amount of remaining moment generating capability.

[0178] Embodiment 21 is the non-transitory computer-readable medium of embodiment 20, wherein the processor is arranged to carry out the method according to any of embodiments 1 to 19.

[0179] Embodiment 22 is a system comprising: a processor; and a non- transitory data storage storing program instructions executable by the processor to carry out operations comprising: determining, by a processor, a current state of the aircraft; determining, by the processor, a current position of an effector; selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector; determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft; and displaying, on a display, a representation of the determined amount of remaining moment generating capability7.

[0180] Embodiment 23 is the system according to embodiment 22, wherein the processor is arranged to carry out the method according to any of embodiments 1 to 19.

[0181] The present disclosure describes various features and operations of the disclosed systems. The illustrative implementations described herein are not meant to be limiting. Certain aspects of the disclosed systems can be arranged and combined in a wide variety of different configurations, all of which are contemplated herein.

[0182] Further, unless context suggests otherwise, the features illustrated in each of the figures may be used in combination with one another. Thus, the figures should be generally viewed as component aspects of one or more overall implementations, with the understanding that not all illustrated features are necessary for each implementation.

[0183] Additionally, any enumeration of elements, blocks, or steps in this disclosure is for purposes of clarity. Thus, such enumeration should not be interpreted to require or imply that these elements, blocks, or steps adhere to a particular arrangement or are carried out in a particular order.

[0184] Further, devices or systems may be used or configured to perform functions presented in the figures. In some instances, components of the devices and / or systems may be configured to perform the functions such that the components are actually configured and structured (with hardware and / or software) to enable such performance. In other examples, components of the devices and / or systems may be arranged to be adapted to. capable of. or suited for performing the functions, such as when operated in a specific manner.

[0185] The arrangements described herein are for purposes of example only. As such, those skilled in the art will appreciate that other arrangements and other elements (e.g., machines, interfaces, operations, orders, and groupings of operations, etc.) can be used instead, and some elements may be omitted altogether according to the desired results. Further, many of the elements that are described are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location.

[0186] While various aspects and implementations have been disclosed herein, other aspects and implementations will be apparent to those skilled in the art. The various aspects and implementations disclosed herein are for purposes of illustration and are not intended to be limiting. Also, the terminology used herein is for the purpose of describing particular implementations only, and is not intended to be limiting.

Claims

CLAIMS1. A method for providing to a user a remaining control margin in an over-actuated flight control system of an aircraft, the method comprising: determining, by a processor, a cunent state of the aircraft; determining, by the processor, a current position of an effector; selecting, based on the cunent position of the effector, a model from a database of models of a moment generating capability for the effector; determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft; and displaying, on a display, a representation of the determined amount of remaining moment generating capability.

2. The method of claim 1 , wherein the current state of the aircraft comprises at least one of an airspeed, an altitude, an attitude, an angle of attack, and a sideslip.

3. The method of claim 1, further comprising: determining a software enforced limit of the aircraft, wherein the determined amount of remaining moment generating capability is based at least partially on the determined software enforced limit.

4. The method of claim 3, wherein the software enforced limit is a stall velocity.

5. The method of claim 1, wherein determining the amount of remaining moment for each control axis is further based on the current position of the effector and the selected model.

6. The method of claim 1 , further comprising: scaling the determined amount of remaining moment generating capability such that the determined amount of remaining moment generating capability is represented as a value between a standardized maximum range and a standardized minimum range.

7. The method of claim 6, wherein the standardized maximum range is 1 and the standardized minimum range is -1.

8. The method of claim 7, wherein for the effector. 1 represents a maximum allowable effector deflection in a first direction and -1 represents a maximum allowable effector deflection in a second direction which is different than the first direction.

9. The method of claim 7, wherein the displayed representation of the determined amount of remaining moment generating capability is between the standardized maximum range and the standardized minimum range.

10. The method of claim 9, further comprising:providing a haptic or an audible indication to a user when the determined amount of remaining moment generating capability is within 10 percent of the standardized maximum range and the standardized minimum range.

11. The method of claim 1, wherein determining the amount of remaining moment generating capability further comprises: determining an amount of currently utilized moment for each control axis.

12. The method of claim 11, further comprising: displaying, on the display, a representation of the amount of currently utilized moment.

13. The method of claim 1, wherein each of the determined amount of remaining moment generating capability' is assigned a value, the method further comprising: assigning a first color to values within a first range and a second color to values within a second range which is different than the first range, such that the representation of the determined amount of remaining moment generating capability is color coded based on the assigned value.

14. The method of claim 1, wherein the control axis comprises a pitch axis, a yaw axis, and a roll axis, and wherein the determined amount of remaining moment is separately displayed for each of the pitch axis, the yaw axis, and the roll axis.

15. The method of claim 14, wherein the effector is a first effector and the method further comprises determining a current position of a second effector, and wherein the determined amount of remaining moment displayed in at least one of the pitch axis, the yaw axis, and the roll axis is based on the first and second effectors.

16. The method of claim 14, wherein the determined amount of remaining moment displayed in at least two of the pitch axis, the yaw axis, and the roll axis is based on the effector.

17. The method of claim 1, wherein the effector is a first effector and the method further comprises: determining a current position of a second effector; and selecting a model from a database of models of the moment generating capability for the second effector.

18. The method of claim 1 , wherein determining the amount of remaining moment for each control axis is based at least partially on the moment generating capability for the first and second effector.

19. The method of claim 1, further comprising: determining an amount of remaining power generating capability, wherein the determination is based on the current state of the aircraft; anddisplaying, on a display, a representation of the determined amount of remaining power generating capability.

20. A non-transitory computer-readable medium having stored thereon program instructions executable by a processor of a device to cause the device to carry’ out operations comprising: determining, by a processor, a current state of the aircraft; determining, by the processor, a current position of an effector; selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector; determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft; and displaying, on a display, a representation of the determined amount of remaining moment generating capability.

21. A system comprising: a processor; and a non-transitory data storage storing program instructions executable by the processor to carry out operations comprising: determining, by a processor, a current state of the aircraft; determining, by the processor, a current position of an effector;selecting, based on the current position of the effector, a model from a database of models of a moment generating capability for the effector; determining an amount of remaining moment generating capability for each control axis, wherein the determination is based on the current state of the aircraft; and displaying, on a display, a representation of the determined amount of remaining moment generating capability.

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