Damping unit as a secondary load path for a movable element equipped with an actuator

Abstract

The embodiment provides a damping unit connected to a movable element. An actuator configured to drive the movable element provides a primary load path, and the damping unit provides a secondary load path that slows down the uncontrolled motion of the movable element in the event of a failure in the primary load path. To test the operation of the damping unit, the load on the actuator can be measured when the actuator drives the movable element. If the load is greater than a predetermined threshold, it can be determined that the damping unit is providing a damping force to the actuator, i.e., the damping unit is operational.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 468,500, filed May 23, 2023, entitled "METHOD OF DETECTING SECONDARY LOAD PATH PERFORMANCE CAPABILITY," under 35 U.S.C. § 119(e), and the entire disclosure thereof is incorporated herein by reference for all purposes.

Background Art

[0002] A primary load path may be damaged, broken, severed, or otherwise fail, causing the moving element to enter an uncontrolled and unsupported state. To manage the failure mode, a secondary load path can be provided for the moving element. However, since the secondary load path is usually not loaded or utilized until the primary load path fails, it is typically difficult to determine whether the secondary load path is in an operating state and ready to support the moving element in case the primary load path suddenly fails. In the context of an aircraft, it may be considered important or required to verify that the secondary load path is in an operating state. However, current solutions for detecting proper operation of the secondary load path require costly and time-consuming removal and inspection processes, or expensive active sensors intended to identify the operation of the secondary load path.

[0003] Embodiments address these problems and other problems, either individually or collectively.

Summary of the Invention

[0004] The techniques disclosed herein generally relate to damping units that provide a secondary load path in the event of failure of the primary load path. More specifically, the techniques disclosed herein can be applied to aircraft including a tiltable propulsion system. An actuator configured to drive the tiltable propulsion system provides a primary load path, and a damping unit provides a secondary load path that slows down the uncontrolled motion of the tiltable propulsion system in the event of actuator failure.

[0005] The embodiments further provide a method for testing the operational state of a damping unit. While the aircraft is stationary, the actuator can tilt the tiltable propulsion system, and the load on the actuator can be determined. For example, the amount of energy used by the tiltable propulsion system can be measured and used to determine the amount of force used by the actuator to move the tiltable propulsion system. With the damping unit configuration described herein, a functioning damping unit resists the movement of the propulsion system, thereby increasing the load on the actuator. If the load is greater than a predetermined threshold, it can be determined that the damping unit is providing a damping force to the actuator, i.e., the damping unit is operational. Various embodiments of the invention, including methods, processes, systems, devices, etc., are described herein.

[0006] The embodiment provides a system comprising a movable element configured to move between a first position and a second position, a fixed element, an actuator configured to operate between an extended position and a retracted position, a primary load path located between the movable element and the fixed element and including an actuator configured to move the movable element between a first position and a second position, a damping unit configured to passively extend or retract to provide the movable element with a damping force to counteract the motion of the movable element, and a secondary load path located between the movable element and the fixed element and including a damping unit configured to move parallel to the actuator and dampen the motion of the movable element.

[0007] In a further embodiment, the system further includes a first coupler providing a first connection between an actuator and a movable element such that the operation of the actuator between an extended position and a retracted position causes the movable element to move between a first position and a second position; a second coupler providing a second connection between the actuator and a fixed element; a third coupler providing a third connection between a damping unit and a movable element such that the movement of the movable element causes the damping unit to extend or retract; and a fourth coupler providing a fourth connection between the damping unit and a fixed element.

[0008] In a further embodiment, the movable element includes a truss structure, the truss structure includes a first coupler and a third coupler, the third coupler being located above the first coupler.

[0009] In a further embodiment, the secondary load path is configured to oppose the primary load path during the operation of the actuator.

[0010] In a further embodiment, the motion of the movable element is the first motion of the movable element, and the secondary load path is configured to decelerate the second motion of the movable element in the event of a failure of the primary load path.

[0011] In a further embodiment, the actuator is a linear actuator that extends or retracts linearly, and the damping unit is configured to passively extend or retract linearly.

[0012] In a further embodiment, the system further comprises an aircraft, and the movable element is a tiltable propulsion system for the aircraft.

[0013] According to a further embodiment, the aircraft further comprises a support structure, the movable element being a tiltable propulsion system and the fixed element being an aircraft, the system being an aircraft, the fuselage, a pair of wings connected to both sides of the fuselage, a support structure, the support structure being connected to one of the pair of wings, and a tiltable propulsion system, the tiltable propulsion system being connected to the support structure.

[0014] In a further embodiment, the first position is a vertical flight configuration, and the second position is a forward flight configuration.

[0015] In a further embodiment, the system further comprises a load measuring device configured to measure the load on an actuator, and a control system configured to control the actuator, and further configured to determine the state of a damping unit based on the load on the actuator, so as to receive information from the load measuring device regarding the load on the actuator in order to control the actuator to actuate.

[0016] In addition, the embodiment provides a method comprising: controlling a control system to operate an actuator in order to move a movable element, wherein the actuator is connected to the movable element, and a damping unit is also connected to the movable element, and the damping unit is configured to provide a damping force to counteract the motion of the movable element; determining the load applied to the actuator during the motion of the movable element using the control system; comparing the load applied to the actuator with a predetermined threshold using the control system; and determining that the damping unit is operating when the load applied to the actuator exceeds the predetermined threshold using the control system.

[0017] According to a further embodiment, determining the load on an actuator during the motion of a movable element includes receiving measurement parameters from a load measuring device and calculating the load on the actuator based on the measurement parameters.

[0018] In a further embodiment, the load measuring device is an ammeter, and the measuring parameter is the amount of current drawn (drawn in) by the actuator.

[0019] In further embodiments, the magnitude of the damping force is based on the speed of motion of the movable element, with higher speeds resulting in a greater magnitude.

[0020] In further embodiments, when the load applied to the actuator exceeds a predetermined threshold, it indicates that the damping unit is applying a damping force to the movable element and the actuator.

[0021] In a further embodiment, a predetermined threshold is based on the previous load applied to the actuator during the previous motion of the movable element when the damping unit is disengaged.

[0022] In a further embodiment, the actuator operates linearly between an extended position and a retracted position, the damping unit is configured to passively extend or retract linearly, the damping unit is configured to resist extension or retraction, and the movement of the movable element causes the damping unit to extend or retract.

[0023] In a further embodiment, the actuator provides a primary load path between the movable and fixed elements, the damping unit provides a secondary load path between the movable and fixed elements, the secondary load path opposes the primary load path, and determining that the damping unit is operating includes determining that the secondary load path is functioning.

[0024] In a further embodiment, the motion of the movable element is the first motion of the movable element, and in the event of a failure in the primary load path, the secondary load path slows down the second motion of the movable element.

[0025] In a further embodiment, the movable element is a tiltable propulsion system coupled to the aircraft, the motion is tilting motion, and the control to activate the actuator is performed while the aircraft is stationary on a surface, and the flight process is initiated after determining that the damping unit is operational.

[0026] Further details regarding embodiments of the present invention are described in the detailed description of the invention and the drawings.

[0027] Various embodiments of the present invention are disclosed in the following detailed description of the invention and the accompanying drawings. In the accompanying drawings, similar components or features may have the same reference label. Further, by continuing a dash after the reference label and continuing a second label to distinguish between similar components, various components of the same or similar type can be distinguished.

Brief Description of the Drawings

[0028] [Figure 1A] It is a plan view showing an exemplary aircraft having a tilting fan in a forward configuration according to an embodiment. [Figure 1B] It is a plan view showing an exemplary aircraft having a tilting fan in a vertical configuration according to an embodiment. [Figure 2A] It is an example diagram showing an example of a tilting propulsion system in a vertical flight configuration according to an embodiment. [Figure 2B] It is an example diagram showing an example of a tilting propulsion system in a first intermediate tilt configuration according to an embodiment. [Figure 2C] It is an example diagram showing an example of a tilting propulsion system in a second intermediate tilt configuration according to an embodiment. [Figure 2D] It is an example diagram showing an example of a tilting propulsion system in a forward flight configuration according to an embodiment. [Figure 3] It is a diagram of a method for testing the state of a damping unit according to various embodiments.

Detailed Description of the Invention

[0029] The techniques disclosed herein generally relate to damping units that provide a secondary load path in the event of failure of the primary load path. More specifically, the techniques disclosed herein can be applied to aircraft including a tiltable propulsion system. An actuator configured to drive the tiltable propulsion system provides a primary load path, and a damping unit provides a secondary load path that slows down the uncontrolled motion of the tiltable propulsion system in the event of actuator failure.

[0030] The embodiments further provide a method for testing the operational state of a damping unit. While the aircraft is stationary, the actuator can tilt the tiltable propulsion system, and the load on the actuator can be determined. For example, the amount of energy used by the tiltable propulsion system can be measured and used to determine the amount of force used by the actuator to move the tiltable propulsion system. With the damping unit configuration described herein, a functioning damping unit resists the movement of the propulsion system, thereby increasing the load on the actuator. If the load is greater than a predetermined threshold, it can be determined that the damping unit is providing a damping force to the actuator, i.e., the damping unit is operational. Various embodiments of the invention, including methods, processes, systems, devices, etc., are described herein.

[0031] Next, several exemplary embodiments are described with reference to the accompanying drawings that form part of this specification. The following description is merely to provide examples and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the following description of embodiments provides to those skilled in the art a possible explanation for implementing one or more embodiments. It should be understood that various modifications may be made to the function and arrangement of elements without departing from the spirit and scope of this disclosure. In the following description, specific details are given for illustrative purposes to give a full understanding of a particular embodiment of the invention. However, it will be apparent that various embodiments can be practiced without these specific details. The drawings and description are not intended to be restrictive. In this specification, the words “example” or “exemplary” are used to mean “to serve as an example, case, or illustration.” Any embodiment or design described herein as “exemplary” or “exemplary” is not necessarily construed as being preferable or advantageous to other embodiments or designs.

[0032] Figures 1A and 1B show plan views of an exemplary aircraft 100 according to an embodiment. The aircraft 100 can be any suitable type of aircraft, such as an airplane, helicopter, drone, or hybrid aircraft. In some embodiments, the aircraft 100 may be capable of vertical take-off and landing (VTOL). The aircraft 100 can be configured for human piloting, remote piloting, and / or autonomous flight.

[0033] In the illustrated examples, the aircraft 100 includes a fuselage 104 which may include a cabin section (for example, facing the nose) for carrying passengers and / or cargo. A pair of wings, including a first wing 102 and a second wing 103, may be mounted on the fuselage 104 or otherwise attached. The pair of wings can be connected to both sides of the fuselage and can take any suitable shape and configuration. For example, the pair of wings can be a rectangular straight wing, a tapered straight wing, a rounded or elliptical straight wing, a swept wing, a delta wing, or any other suitable type of wing. In some embodiments, the first wing 102 and the second wing 103 can be connected to the fuselage 104 in a high-wing configuration. That is, as shown in Figures 1A and 1B, the first wing 102 and the second wing 103 can be mounted on top of the fuselage 104.

[0034] The aircraft 100 may also include support structures 106(A) to (F) that can be connected to the wings 102, 103. As shown in Figures 1A to 1B, each of the support structures 106(A) to (F) may take the form of a boom, but embodiments may include any other suitable structures. Six support structures 106(A) to (F) are shown in Figures 1A to 1B, with three support structures 106(A) to (F) provided beneath each of the pair of wings 102, 103. The support structures 106(A) to (F) may be connected to the underside of the pair of wings and may include a forward portion extending forward of the wings and a rearward portion extending backward of the wings.

[0035] In some embodiments, each of the support structures 106(A) to (F) is identical, and therefore, the support structures 106(A) to (F) can be interchangeable in terms of their positions on the wing. For example, the first support structure 106(A) closer to the fuselage may be interchangeable with the adjacent second support structure 106(B) (e.g., the central boom on the wing) or a further third support structure 106(C) (e.g., the boom furthest from the fuselage).

[0036] Propulsion system The aircraft 100 may also include propulsion systems 101(A) to (L). Twelve propulsion systems 101(A) to (L) are shown in Figures 1A to 1B, but any appropriate number of propulsion systems 101(A) to (L) may be included. The propulsion systems 101(A) to (L) may be connected to a pair of wings 102, 103, or they may be evenly distributed among the wings. In some embodiments, one or more of the propulsion systems 101(A) to (L) may be installed on support structures 106(A) to (F), as shown in Figures 1A to 1B. For example, a pair of propulsion systems 101(A) to (L) may be installed at both ends of each support structure 106(A) to (F), in which case one propulsion system may be installed in front of the wing and the other propulsion system may be installed behind the wing. In other embodiments, one or more of the propulsion systems 101(A) to (L) may be directly connected to the wings. The number of booms and / or propulsion systems may vary depending on the flight needs and requirements of the aircraft 100.

[0037] In various embodiments, each of the propulsion systems 101(A) to (L) may be configured to provide thrust to the aircraft 100. The thrust from one or more of the propulsion systems 101(A) to (L) can be used to move, control, and / or stabilize the aircraft 100. The propulsion systems 101(A) to (L) can take the form of any suitable mechanism for providing thrust. In one example, the propulsion system may include a rotor (e.g., a fan). The propulsion system may also include a drive mechanism for the rotor, such as a dedicated electric motor (e.g., in the case of an electric vehicle).

[0038] The rotor may have any suitable number of rotor blades (e.g., 2, 3, 4, 5, 6, 7, or 8 blades). The rotor blades may be evenly spaced or unevenly spaced. The rotor may further have a hub. The rotor blades may be mounted on the hub. In some embodiments, the rotor blades and the integrated hub may be manufactured as a single piece. The hub provides a central structure to which the rotor blades connect, and in some embodiments, it is made in a shape that encloses the motor.

[0039] The rotor blades may have a predetermined pitch or a predetermined angle of attack. In some embodiments, all rotor blades may have the same pitch or the same angle of attack. In other embodiments, at least two rotor blades may have different pitches or angles of attack from each other.

[0040] In some embodiments, one or more rotor blades of a propulsion system may have an adjustable pitch setting (also referred to as a variable pitch position). Such a propulsion system is sometimes referred to as a variable-pitch propeller. In a variable-pitch propeller, the blade pitch of one or more rotor blades may be adjusted during flight. Thus, the blade pitch may be adjusted to optimize thrust and / or efficiency based on the phase of flight, such as takeoff, climb, or cruising. For example, a fine-pitch setting may be used to provide greater thrust during takeoff, acceleration, altitude gain, and / or landing. A coarse-pitch setting may be used for high-speed cruising flight, which may provide better efficiency. An example of a low pitch used during takeoff is about 15 degrees. An example of a high pitch used during cruising flight is about 40 degrees.

[0041] The amount of thrust generated by the rotor blades depends on the rotor blade speed and angle of attack. The effective angle of attack of the rotor blades may decrease as the airspeed increases. The blade pitch may be increased to maintain a constant effective angle of attack, or an otherwise optimal effective angle of attack.

[0042] In some embodiments, the motor components are thin enough so that the entire motor fits within the rotor hub, resulting in less resistance to airflow during forward flight. The rotor can be mounted on the rotating parts of the motor. The stationary parts of the motor can be mounted on a support structure. In some embodiments, the motor can be a permanent magnet motor and can be controlled by an electronic motor controller. The electronic motor controller can supply current to the motor in a precise sequence, allowing the rotor to rotate at a desired speed or torque.

[0043] In various embodiments, the aircraft 100 may be an electric aircraft or a hybrid electric aircraft. One or more battery units may be contained within the aircraft 100 (e.g., within the fuselage 104) and configured to power various aircraft components such as one or more electric motors and / or onboard computer systems. The propulsion systems 101(A) to (L) may be driven by electric motors powered by a power system including one or more battery units. In some embodiments, each of the propulsion systems 101(A) to (L) may be coupled to a dedicated battery unit. Alternatively, there may be a one-to-many relationship between one or more battery units and the propulsion systems 101(A) to (L). In some cases, one or more battery units may be the sole power source for the aircraft 100. Each battery unit may contain one or more battery cells.

[0044] Orientation of the propulsion system - vertical According to various embodiments, one or more of the propulsion systems 101(A) to (L) may be positioned, directed, and / or otherwise configured to impart thrust and / or motion to the aircraft 100 in a predetermined direction. For example, one or more of the propulsion systems 101(A) to (L) may be configured to provide vertical upward thrust. As shown in Figure 1A, these may include propulsion systems 101(D), 101(E), 101(F), 101(J), 101(K), and / or 101(L). A propulsion system configured to provide vertical thrust may also be referred to as a vertical fan or lift fan, or a propulsion system having a lift direction or a hovering direction. A vertical fan may be used to generate vertical thrust (e.g., lift) for takeoff, landing, hovering, stabilization, and / or control of the aircraft 100.

[0045] The vertical direction may be defined relative to the body of the aircraft 100. For example, the vertical direction may be the aircraft's vertical axis or z-axis (e.g., a vertical line intersecting the zenith and perpendicular to the ground when the aircraft 100 is stationary on the ground or hovering directly above the ground). In some embodiments, the vertical direction may be perpendicular to the ground when the aircraft 100 is stationary on the ground and / or in a stable hovering state directly above the ground in a flat orientation. If the aircraft 100 is tilted, the aircraft's z-axis (and vertical direction) may no longer be perpendicular to the ground. Vertical thrust may be vertical thrust (e.g., up or down).

[0046] Vertical thrust can be achieved by mounting the vertical fans and / or their corresponding support structures 106(A)-(F) such that the rotation axis of each vertical fan is parallel to the vertical direction and / or perpendicular to the direction of forward flight. In other words, the vertical fans can be oriented so that their rotor blades rotate in a horizontal plane (e.g., a plane horizontal to the fuselage, or a plane defined by the x and y axes of the aircraft 100) and around a vertical axis (e.g., the z axis of the aircraft 100). In some embodiments, the vertical fans can be configured so that each set of rotor blades rotates in the same plane. In other embodiments, the vertical fans can be configured so that one or more sets of rotor blades rotate in different planes (e.g., parallel planes).

[0047] In other embodiments, some or all of the vertical fans are oriented at an angle such that, at an individual level, one or more vertical fans have rotor blades that do not rotate in the horizontal plane, and do not provide perfectly vertical thrust, but instead provide thrust in a direction angled to the vertical. However, in combination, a set of angled vertical fans together can provide net thrust in the vertical direction. For example, the non-vertical thrust component provided by the angled vertical fan on the first wing 102 can be canceled out by an equal and opposite non-vertical thrust component provided by the oppositely angled vertical fan on the second wing 103.

[0048] In some embodiments, two adjacent vertical fans may have their blades positioned at opposite angles of attack such that their rotor blades spin in opposite directions. Adjacent vertical fans may refer to two vertical fans connected at both ends of the same support structure 106(A) (e.g., 101A and 101D), or two vertical fans on different support structures (e.g., 101A and 101B), or two vertical fans on different blades (e.g., 101A and 101G).

[0049] According to various embodiments, a first subset of the vertical fans may spin in a first direction, and a second subset of the vertical fans (e.g., the remaining vertical fans) may spin in a second direction opposite to the first direction. Configuring the vertical fans so that some spin in the first direction and others spin in the opposite second direction can favorably cancel out any angular momentum produced by the spinning blades, thereby allowing the aircraft 100 to hover in a stable manner without rotation.

[0050] Furthermore, rotational motion of the aircraft 100 around its vertical axis (e.g., yaw) can be performed at any time by temporarily reducing the spin rate of some or all of the first subset of vertical fans spinning in a first direction, and / or temporarily increasing the spin rate of the second subset of vertical fans spinning in a second direction, so as not to cancel out the total angular momentum produced by the spinning blades. Thus, the aircraft 100 can rotate using the vertical fans without requiring another thrust source directed in a different direction.

[0051] Orientation of the propulsion system - horizontal According to various embodiments, one or more of the propulsion systems 101(A) to (L) may be configured to provide horizontal forward thrust. As shown in Figure 1A, these may include propulsion systems 101(A), 101(B), 101(C), 101(G), 101(H), and / or 101(I). A propulsion system configured to provide horizontal thrust may also be referred to as a horizontal fan or propeller, or as a propulsion system having a forward flight orientation. A horizontal fan can be used to provide horizontal thrust for forward flight, ascent, descent, and / or cruising. As shown in Figures 1A to 1B, two propulsion systems of the same type (e.g., two vertical fans) or different types (e.g., one vertical fan and one horizontal fan) may be installed in each of the support structures 106(A) to (F).

[0052] The horizontal direction may be defined relative to the body of the aircraft 100. For example, the horizontal direction may be the forward axis or x-axis of the aircraft. In some embodiments, the horizontal direction may be parallel to the ground when the aircraft 100 is stationary on the ground, when it is in a stable hovering state directly above the ground in a flat orientation, and / or when it is in forward flight. If the aircraft 100 is tilted, the x-axis (and horizontal direction) of the aircraft may no longer be parallel to the ground. Horizontal thrust may be thrust in the horizontal direction (e.g., forward or backward).

[0053] Horizontal thrust (e.g., forward thrust) can be achieved by mounting the horizontal fans and / or their corresponding support structures 106(A)-(F) such that the rotation axis of each horizontal fan is parallel to the horizontal direction and / or parallel to the direction of forward flight. In other words, the horizontal fans can be oriented so that their rotor blades rotate in a vertical plane (e.g., the plane defined by the z and y axes of the aircraft 100) and around a forward axis (e.g., the x axis of the aircraft 100). In some embodiments, the horizontal fans can be configured so that each set of rotor blades rotates in the same plane. In other embodiments, the horizontal fans can be configured so that one or more sets of rotor blades rotate in different parallel planes.

[0054] In some embodiments, the horizontal fan may be configured to have the ability to spin in either direction. As a result, the horizontal fan can provide reverse thrust. Reverse thrust may be useful for moving the aircraft 100 backward (for example, moving it back from a hovering position out of the hangar area). In addition, reverse thrust may be used to reduce forward flight speed. For example, reverse thrust from the horizontal fan can be used instead of or in addition to flaps to decelerate the aircraft 100 and / or to keep the aircraft 100 in a stationary hover.

[0055] In some embodiments, the horizontal and vertical directions may be orthogonal to each other. Thus, the vertical and horizontal fans can provide thrust in substantially orthogonal directions. In other embodiments, the vertical and horizontal fans can provide thrust that is nearly orthogonal, or nearly orthogonal, but not exactly orthogonal. Separating directional thrust into two distinct types of components is beneficial for simplifying the control and design of the aircraft 100. In some embodiments, the horizontal and vertical fans can be operated, powered on, and otherwise controlled independently of each other, thereby allowing thrust to be applied independently in orthogonal directions (e.g., thrust can be applied in different directions simultaneously and at different times).

[0056] The combination of horizontal fans and wings 102, 103 can achieve both forward motion and lift. In some embodiments, it may be more efficient to use horizontal fans and wings 102, 103 instead of vertical fans to achieve vertical lift. Once the aircraft 100 reaches a speed (e.g., a predetermined speed, or cruising speed) sufficient for the wings to provide sufficient lift to the aircraft 100, the vertical fans no longer need to provide lift and may temporarily deactivate. For example, the vertical fans are initially active and can generate vertical thrust to lift the aircraft 100. As the aircraft 100 leaves the ground and / or reaches a certain altitude, the horizontal fans can activate and / or increase horizontal thrust so that the aircraft 100 gains horizontal speed. Since the wings 102, 103 cannot provide sufficient vertical lift until a predetermined speed (e.g., cruising speed) is achieved, the vertical fans can continue to provide vertical lift while the horizontal speed increases. The vertical fans can eventually (or gradually) reduce their contribution to vertical thrust as the wings 102, 103 gradually provide further (e.g., an increasing amount) of vertical lift during an increase in horizontal speed. Then, as the aircraft 100 decelerates or returns to a hovering position, the vertical fans can reactivate and / or increase vertical thrust.

[0057] Propulsion system orientation - fixed According to various embodiments, one or more of the propulsion systems 101(A) to (L) may have a fixed orientation. For example, one or more of the propulsion systems 101(A) to (L) may be installed in a fixed orientation relative to each wing 102 or 103, each support structure 106(A) to (F), and / or the aircraft 100. The rotor blades of a fixed propulsion system may be able to rotate when activated, but the orientation of the propulsion system housing and structure may not be rotatable relative to the aircraft 100. As a result, a fixed propulsion system can be configured to provide thrust to the aircraft 100 in a fixed direction. According to embodiments, the thrust direction and orientation of a fixed propulsion system relative to the aircraft 100 (e.g., fuselage, wings, and / or support structure) may remain unchanged or immovable regardless of the current activity and / or direction of movement of the aircraft 100 (e.g., both forward and vertical flight).

[0058] In some embodiments, one or more vertical fans may have a fixed orientation. For example, one or more of the propulsion systems 101(D), 101(E), 101(F), 101(J), 101(K), and / or 101(L) may have a fixed vertical orientation. These may also be referred to as fixed vertical fans.

[0059] Furthermore, according to some embodiments, one or more horizontal fans may have a fixed orientation. For example, propulsion systems 101(A), 101(B), 101(C), 101(G), 101(H), and / or 101(I) may have a fixed horizontal orientation. These may also be referred to as fixed horizontal fans.

[0060] In some embodiments, all of the propulsion systems 101(A) to (L) may have a fixed orientation. As a result, the vertical and horizontal fans may be permanently configured to provide thrust in orthogonal (or substantially orthogonal) directions.

[0061] Propulsion system orientation - tiltable In other embodiments, one or more of the propulsion systems 101(A) to (L) may be configured to change direction. For example, one or more of the propulsion systems 101(A) to (L) may be configured and / or installed in such a way that their angle and direction are tiltable relative to each wing 102 or 103, each support structure 106(A) to (F), and / or the aircraft 100. As a result, a tiltable propulsion system, which may also be called a tiltable propulsion system or tiltable fan, can be configured to provide thrust to the aircraft 100 in multiple directions.

[0062] As described above, the propulsion systems 101(A), 101(B), 101(C), 101(G), 101(H), and / or 101(I) can take the form of fixed horizontal fans. However, in other embodiments, one or more of the propulsion systems 101(A), 101(B), 101(C), 101(G), 101(H), and / or 101(I) can instead take the form of tilting fans. Such tilting fans can be configured to switch between horizontal and vertical orientations (e.g., rotate or tilt). The horizontal orientation may also be referred to as the horizontal direction, forward flight configuration, second tilt configuration, second position, and / or second tilt angle. The vertical orientation may also be referred to as the vertical direction, vertical flight configuration, first tilt configuration, first position, and / or first tilt angle. Figure 1A shows the tilt fan currently set up in the forward flight configuration (also referred to as the second tilt configuration or second tilt angle). Figure 1B shows the tilt fan currently set up in the vertical flight configuration (also referred to as the first tilt configuration or first tilt angle).

[0063] As shown in Figure 1B, all of the propulsion systems 101(A) to (L) can have a vertical orientation. Some of these may be vertical fans with a fixed vertical orientation (e.g., the propulsion systems in the rear row locations of 101(D), 101(E), 101(F), 101(J), 101(K), and / or 101(L)), while others may be tilting fans that currently and temporarily have a vertical orientation or are set up in a vertical flight configuration (e.g., the propulsion systems in the front row locations of 101(A), 101(B), 101(C), 101(G), 101(H), and / or 101(I)). The tilting fans may have the same orientation as the vertical fans, or a similar orientation. Figure 1A shows the tilting fan in the forward flight configuration (e.g., the forward-positioned propulsion system in 101(A), 101(B), 101(C), 101(G), 101(H), and / or 101(I)).

[0064] The embodiment allows the aircraft 100 to include any suitable combination and number of tilting fans, fixed horizontal fans, and / or fixed vertical fans. Furthermore, each type of fan can be positioned at any suitable location along the wings 102, 103 and / or any suitable support structure 106(A)~(F). The type of propulsion system at each location can be selected to enhance any number of flight characteristics, including forward thrust, vertical thrust, maneuverability, drag, and / or suitable flight characteristics.

[0065] While tilting fans can provide the ability to increase thrust in a specific direction as desired, it may be beneficial to incorporate one or more propulsion systems in a fixed orientation to reduce weight, reduce moving parts, reduce potential failure points, and / or reduce maintenance concerns.

[0066] Figures 2A to 2D show examples of propulsion systems 201 configured to tilt. One or more of the propulsion systems 101(A) to (L) in Figures 1A to 1B can take the form of propulsion system 201 shown in Figures 2A to 2D. The propulsion system 201 (also referred to as a tilting fan) may be configured to tilt over a range of predefined tilt configurations. The tilt configurations may include any other suitable intermediate tilt configurations between the vertical flight configuration and the forward flight configuration, such as the vertical flight configuration shown in Figure 2A (e.g., 90 degrees, or about 90 degrees), the forward flight configuration shown in Figure 2D (e.g., 0 degrees, or about 0 degrees), and / or the first intermediate tilt configuration shown in Figure 2B and the second intermediate tilt configuration shown in Figure 2C.

[0067] The propulsion system 201 can be controlled to switch its inclination configuration to provide additional thrust in any appropriate direction, depending on the needs of the aircraft's current movement. For example, during takeoff, landing, and / or hovering, the propulsion system 201 may be set to a vertical flight configuration to provide additional vertical thrust. During forward cruising flight, the propulsion system 201 may be set to a forward flight configuration to provide horizontal thrust. During forward acceleration, deceleration, altitude gain, and / or altitude loss phases, the propulsion system 201 may be set to an intermediate inclination angle and configuration to provide both horizontal and vertical thrust components.

[0068] According to the embodiment, the propulsion system 201 may be tilted gradually, repeatedly, or otherwise through a plurality of different intermediate tilt angles, based on the flight phase and / or the needs of the aircraft. For example, during the forward acceleration and / or altitude gain phase of flight, the propulsion system 201 may be tilted gradually from vertical to horizontal (e.g., 0.5 degrees at a time, 1 degree at a time, etc.) as speed and / or altitude are gained.

[0069] In some embodiments, the vertical flight configuration may be at the maximum inclination, and the forward flight configuration may be at the minimum inclination of the propulsion system 201. In other embodiments, the propulsion system 201 may have inclination angles and configurations that exceed those of the vertical flight configuration (e.g., angled above vertical such that an inverse horizontal component exists), and / or lower inclination angles and configurations than those of the forward flight configuration (e.g., angled below horizontal such that a downward component exists).

[0070] tilting mechanism The tilting mechanism can be configured to tilt the propulsion system 201. The tilting mechanism may include one or more controllable components connected to the propulsion system 201 and / or the support structure 206, which, according to embodiments, can thereby allow changes in relative position and angle between the propulsion system 201 and the support structure 206. The support structure 206 may also be referred to as a fixed element. The propulsion system 201 may be referred to as a movable element because it can move relative to the fixed element. According to embodiments, the motion can be a tilting motion. As shown in Figures 2A to 2D, the tilting mechanism may include an actuator 230, a rotary joint 260, and / or any other suitable components. The tilting mechanism 220 shown in Figures 2A to 2D is for illustrative purposes only, and embodiments allow for any other suitable components and configurations of the tilting mechanism.

[0071] The rotary joint 260 may include a rotatable connection between the propulsion system 201 and the support structure 206. Also referred to as a hinge or pin joint, the rotary joint 260 may include pins, bolts, rotary bearings, and / or other suitable components.

[0072] The actuator 230 can be any suitable device configured to produce motion. According to the embodiment, any suitable type of actuator 230 can be used in the propulsion system 201 to produce motion (e.g., tilting motion). For example, the actuator 230 can take the form of a linear actuator. A linear actuator may include any suitable device configured to produce linear motion. A linear actuator can be configured to convert rotational motion (e.g., from a rotating rotor and / or gear) into linear motion (e.g., of a rod or shaft). A linear actuator can be a two-force member actuator that applies force in either direction along one axis. Examples of linear actuators include ball screws, cam actuators, wheel and handle actuators, and the like.

[0073] The actuator 230 can be connected to the propulsion system 201. For example, the propulsion system 201 includes a truss structure 235, and the actuator 230 can be connected to the truss structure 235. In some embodiments, the truss structure 235 may include a rigid skeleton. For example, the truss structure 235 includes an assembly of members (e.g., beams or other structural components) connected by nodes (e.g., joints) to form a rigid skeleton. The members may be two-force members, and the members can be organized so that the assembly behaves as a single object.

[0074] The embodiments include any suitable coupling between the actuator 230 and the propulsion system 201. In some embodiments, the first coupling 233 can connect the actuator 230 to the truss structure 235 of the propulsion system 201. The first coupling 233 may include one or more of the following: pins, bolts, spherical joints, trunnion joints, fixing brackets, pivot brackets, shackles, gimbals, and / or any other suitable structural coupling and / or mounting mechanisms. In some embodiments, the first coupling 233 can be incorporated into the truss structure 235 and / or otherwise become part of the truss structure 235.

[0075] The actuator 230 can also be connected to the support structure 206. According to the embodiment, a second connector 234 can connect the actuator 230 to the support structure 206. The second connector 234 may include one or more of the following: pins, bolts, spherical joints, trunnion joints, fixing brackets, pivot brackets, shackles, gimbals, and / or any other suitable structural connecting and / or mounting mechanisms.

[0076] In one embodiment, the support structure 206 can surround the actuator 230. The support structure 206 can be a hollow structure that partially surrounds the actuator 230. In the illustrations of Figures 2A to 2D, a portion of the support structure 206 is not shown in order to reveal the internal components (e.g., the actuator 230 and the damping unit 250) located within the support structure 206.

[0077] In some embodiments, the actuator 230 may include a translation component 232 and an actuation component 231.

[0078] The actuation component 231 can take the form of a motor, one or more gears (e.g., a gearbox), and / or an engagement component, according to some embodiments. The motor is an electric motor and may include a stator and a rotor. The rotor may be coupled to one or more gears to cause its rotation. One or more gears may be coupled to an engagement component, which may include a drive nut, a slide block, a ball nut, a lead nut, and the like. The engagement component engages with the translation component 232 and can move the translation component 232. In some embodiments, the engagement component may include a ball bearing circulating in an internal raceway. Embodiments allow the actuator 230 to include a local power source (e.g., a battery) and / or be connected to a separate aircraft power source (e.g., a battery). In addition, embodiments allow the actuation component 231 to instead include other suitable power sources and / or kinetic sources, such as a hydraulic system.

[0079] The translational component 232 may be configured to move (e.g., to extend or retract linearly) when actuated by the actuation component 231. The translational component 232 may take the form of a rod, shaft, lead screw, or any other suitable elongated object. The translational component 232 may be screw-in or may include a ball groove. The translational component 232 may be extendable (e.g., a “slider” configured for extension and retraction), thereby providing an extendable, retractable, and / or otherwise dynamic and adjustable connection between the propulsion system 201 and the support structure 206. As the translational component 232 extends toward the extended position and retracts toward the retracted position, the propulsion system 201 may rotate around the rotary joint 260. This causes the propulsion system 201 to enter motion and changes the tilt configuration of the propulsion system 201. For example, the extension of the translational component 232 toward the extended position may move the propulsion system 201 upward toward the vertical flight configuration (e.g., tilt it). The contraction of the translational component 232 toward the contracted position can cause the propulsion system 201 to tilt downward toward the forward flight configuration. Thus, the actuator 230 can be configured to provide linear motion in the propulsion system 201 that is converted into rotational motion or otherwise causes rotational motion.

[0080] As described above, the actuator 230 (for example, the translational component 232 of the actuator 230) can be configured to act linearly with respect to its own structure. Furthermore, by being coupled to the propulsion system 201, the actuator 230 may experience pivoting or rotational motion as a result of its linear operation. As shown in Figures 2A to 2D, when the propulsion system 201 tilts, the first coupler 233 moves with the propulsion system 201, and the actuator 230 may be pivoted as the first coupler 233 moves while the second coupler 234 maintains a fixed position on the support structure 206. The actuator 230 can pivot around an axis located at the second coupler 234 (referred to as the first axis).

[0081] Damping unit As shown in Figures 2A to 2D, the damping unit 250 can also be included as part of the tilting mechanism or in addition to the tilting mechanism. As previously mentioned, Figure 2A shows an example of the propulsion system 201 in a vertical flight configuration. Figure 2B shows an example of the propulsion system 201 in a first intermediate tilting configuration. Figure 2C shows an example of the propulsion system 201 in a second intermediate tilting configuration. Figure 2D shows an example of the propulsion system 201 in a forward flight configuration. In each of these drawings, the damping unit 250 can be connected to the propulsion system 201, and the damping unit 250 may be in a corresponding extended or retracted state depending on the tilting configuration of the propulsion system 201.

[0082] The damping unit 250 can be a device configured to provide a damping force. The damping unit 250 can absorb and dissipate kinetic energy. The damping unit 250 can be a mechanical device, a hydraulic device, a pneumatic device, an electromagnetic device, and / or any other suitable device configured to resist motion. As an example, the damping unit 250 can enclose one or more springs, cushions, pneumatic shock absorbers, hydraulic shock absorbers, dashpots, etc.

[0083] In some embodiments, the damping unit 250 can take the form of a dashpot. The dashpot can resist motion by utilizing viscous friction. For example, the dashpot may include a cylinder with a piston immersed in a viscous fluid. An external force acting on the piston moves the piston in the viscous fluid. The viscous fluid resists the movement of the piston, thereby causing the piston to experience a resistive force opposite to the direction of the external force.

[0084] According to the embodiment, the damping unit 250 can resist motion in one or two directions. The second direction may be opposite to the first direction. In some embodiments, the damping unit 250 can provide relatively large resistance to motion in the first direction and relatively small resistance to motion in the second direction. The damping unit 250 may include an elongated cylinder, rod, and / or piston. One or more directions of resistance may be along the axis of the elongated cylinder, rod, and / or piston.

[0085] As shown in Figures 2A to 2D, the damping unit 250 can be connected to the propulsion system 201. For example, the damping unit 250 can be connected to the truss structure 235 of the propulsion system 201.

[0086] The embodiments include any suitable coupling between the damping unit 250 and the propulsion system 201. In some embodiments, a third coupling 251 can connect the damping unit 250 to the truss structure 235 of the propulsion system 201. The third coupling 251 may include one or more of the following: pins, bolts, spherical joints, trunnion joints, fixing brackets, pivot brackets, shackles, gimbals, and / or any other suitable structural coupling and / or mounting mechanisms. In some embodiments, the third coupling 251 may be incorporated into the truss structure 235 and / or otherwise become part of the truss structure 235.

[0087] According to the embodiment, the damping unit 250 can be connected to the truss structure 235 of the propulsion system 201 at a higher position than the connection between the actuator 230 and the truss structure 235 of the propulsion system 201. For example, the third coupler 251 can be positioned vertically above the first coupler 233. The horizontal position of the third coupler 251 relative to the first coupler 233 may vary depending on the inclination configuration of the propulsion system 201, but the third coupler 251 can be positioned above the first coupler 233 for almost all inclination configurations.

[0088] The damping unit 250 can also be connected to the support structure 206. For example, the frame element 255 can be provided within the support structure 206, and the damping unit 250 can be connected to the frame element 255. The frame element 255 can take the form of an intermediate component, such as a bracket, or any other suitable structure for fixing a first component (e.g., the damping unit 250) to a second component (e.g., the support structure 206). In some embodiments, the frame element 255 can have a circular shape. The frame element 255 can be mounted on the inner surface of the support structure 206 and can surround the internal space within the support structure 206. The frame element 255 can be positioned at a predetermined distance from the first end of the support structure 206 (e.g., to the left from the illustrated viewpoint).

[0089] The embodiments include any suitable connection between the damping unit 250 and the support structure 206. In some embodiments, a fourth connector 252 can connect the damping unit 250 to a frame element 255 of the support structure 206. The fourth connector 252 may include one or more of the following: pins, bolts, spherical joints, trunnion joints, fixing brackets, pivot brackets, shackles, gimbals, and / or any other suitable structural connecting and / or mounting mechanisms.

[0090] In one embodiment, the support structure 206 can surround the damping unit 250. The support structure 206 can be a hollow structure that partially surrounds the damping unit 250. In the illustrations of Figures 2A to 2D, a portion of the support structure 206 is not shown in order to reveal the internal components (e.g., the actuator 230 and the damping unit 250) located within the support structure 206. Both the actuator 230 and the damping unit 250 can be housed in the same housing between the first end of the support structure 206 and the frame element 255. Although a single damping unit 250 is shown, additional damping units connected to the propulsion system 201 and the support structure 206 may be further included.

[0091] The damping unit 250 can be configured to change length by extension and / or compression (also referred to as contraction). Because both the propulsion system 201 and the support structure 206 (for example, at both ends of the damping unit 250) are connected, when the propulsion system 201 enters motion (e.g., tilting motion), the dynamic position of the third coupler 251 can move closer to or further away from the fixed position of the fourth coupler 252, so that the damping unit 250 can passively extend and / or contract. For example, when the propulsion system 201 tilts vertically upward, tension may be generated in the damping unit 250, which causes the length of the damping unit 250 to extend. When the propulsion system 201 tilts horizontally downward, the damping unit 250 may be subjected to a compressive force, which causes the length of the damping unit 250 to contract or compress.

[0092] The damping unit 250 can be configured to extend and / or contract linearly relative to its structure. Furthermore, by being coupled to the propulsion system 201, the damping unit 250 may experience pivoting or rotational motion. As shown in Figures 2A to 2D, when the propulsion system 201 tilts, the third coupler 251 moves with the propulsion system 201, and the damping unit 250 may be pivoted as the third coupler 251 moves, while the fourth coupler 252 maintains a fixed position on the frame element 255 of the support structure 206. The damping unit 250 can pivot around an axis located at the fourth coupler 252 (referred to as the second axis).

[0093] The damping unit 250 may be configured to resist or counteract either or both extension and / or compression. In addition, the damping unit 250 may be configured to provide a damping force whose degree varies in response to the speed or rate of extension and / or compression. For example, the damping force may be proportional or exponential to the speed of motion of the damping unit 250 (e.g., change in length). Generally, faster speeds or quicker movements of the damping unit 250 (e.g., extension or compression) will produce a larger (e.g., greater degree) damping force. As a result, relatively slow tilting motion of the propulsion system 201 may produce a relatively small damping force, while relatively fast tilting motion of the propulsion system 201 may produce a relatively large damping force.

[0094] As shown in Figures 2A to 2D, the third coupler 251 and the fourth coupler 252 may be located in different positions than the first coupler 233 and the second coupler 234. In other words, the damping unit 250 and the actuator 230 can be connected to the propulsion system 201 and the support structure 206 at different locations. Nevertheless, the damping unit 250 and the actuator 230 can each provide a structural connection and / or load path between the propulsion system 201 and the support structure 206.

[0095] The actuator 230 may be configured to provide a primary load path between the propulsion system 201 and the support structure 206. The actuator 230 may be configured to provide sufficient support force to change, set, and maintain the tilt direction of the propulsion system 201 even under large loads (e.g., tension and / or compression) caused by air resistance, gravity, thrust generated by the propulsion system 201, etc.

[0096] The damping unit 250 may be configured to provide a secondary load path (also referred to as a preliminary or redundant load path) between the propulsion system 201 and the support structure 206. The damping unit 250 may be configured to provide sufficient damping force to resist abrupt and / or sudden tilting movements of the propulsion system 201, which may include large loads in the form of tension and / or compression. The damping unit 250 may have any appropriate size (e.g., length, circumference, width), material and / or other configuration to provide sufficient force under given conditions (e.g., a specific speed of tilting movement).

[0097] In one embodiment, the damping unit 250 may be configured to apply a damping force (e.g., tension or compression) between the propulsion system 201 and the support structure 206 only when relative movement occurs between the propulsion system 201 and the support structure 206, thereby causing the damping unit 250 to passively extend or contract. For example, if the tilt configuration (also referred to as the tilt position) of the propulsion system 201 is set and is not currently changing, the damping unit 250 may not experience extension or contraction and therefore may not apply any damping force. In contrast, the actuator 230 may provide structural support with a force sufficient to maintain the set tilt configuration of the propulsion system 201.

[0098] When actuator 230 is activated and causes a change in the tilt configuration of the propulsion system 201, the damping unit 250 experiences extension or contraction and can therefore provide a damping force. The damping unit 250 can provide a force that counteracts the movement of the propulsion system 201, which can provide an extra force that overcomes the damping force and thus cause an extra load on actuator 230. In other words, actuator 230 in the primary load path may be driven against damping unit 250 in the secondary load path. Thus, the primary and secondary load paths can apply tilt forces to the propulsion system 201 simultaneously and / or in opposite directions. However, according to the embodiment, actuator 230 can be controlled to change the tilt configuration slowly and stepwise. As a result, activation can be controlled to produce only a relatively small damping force that is not difficult to overcome and / or smaller than other external forces (such as those caused by air resistance, gravity, and / or thrust).

[0099] The primary and secondary load paths can be considered as parallel load paths. Parallel load paths can operate in parallel with each other. Operating in parallel may include providing two separate paths or branches that support the load, and / or applying forces between two components (e.g., the propulsion system 201 and the support structure 206). The primary and secondary load paths can operate in parallel even if the actuator 230 and the damping unit 250 are not geometrically parallel (e.g., they are not aligned with each other in three-dimensional space or are at different heights).

[0100] According to the embodiment, the secondary load path may be configured to fully activate and support some or all of the load between the propulsion system 201 and the support structure 206 in the event of a failure of the primary load path. If the actuator 230 fails and no longer provides support force between the propulsion system 201 and the support structure 206, the propulsion system 201 may undergo a sudden movement. This sudden movement can cause a corresponding sudden extension and / or contraction of the damping unit 250, as a result of the damping unit 250 generating a large resistive force. The damping unit 250 thus provides a secondary load path that has sufficient force to decelerate the tilting motion of the propulsion system 201 even in the absence of the primary load path.

[0101] If actuator 230 mechanically fails, one or more of its components may break. For example, failure in any of the actuation components 231, translational components 232, and / or the first coupling 233 may render the primary load path impossible. If the primary load path does not provide structural stability and support to the propulsion system 201, many movements of the propulsion system 201 that depend on multiple variables are possible. For example, if the aircraft is in a forward flight configuration at cruising speed and the propulsion system 201 is providing forward thrust, the propulsion system 201 can exert a large force to propel the aircraft forward. Actuator 230 can support this load by transmitting force to the support structure 206 (and other parts of the aircraft). Actuator 230 provides a strong stabilizing tension between the propulsion system 201 and the support structure 206, and this force effectively pulls the support structure 206 (and the rest of the aircraft) forward in space together with the propulsion system 201. If actuator 230 fails, the tension provided by the primary load path may no longer be available. As a result, the propulsion system 201 can propel itself forward by the forward thrust it generates. With the rotary joint 260 in place and the propulsion system 201 connected to the support structure 206, the propulsion system 201 can be propelled by a sudden and / or powerful upward tilting motion around the rotary joint 260. This motion may be fast and / or powerful enough to damage and / or break the rotary joint 260, potentially causing the propulsion system 201 to detach from the aircraft. Due to the high-speed nature of such events, it may not be possible to shut off the power to the propulsion system 201 and stop thrust generation before the movement and possible damage occur.

[0102] In another example, if the actuator 230 fails when the power to the propulsion system 201 is cut off, the propulsion system 201 may suddenly descend from a vertical tilt configuration to a forward flight configuration. This could potentially damage the rotary joint 260, components of the propulsion system 201, and / or components of the support structure 206. Other uncontrolled movements of the propulsion system 201 are also possible in the event of actuator 230 failure.

[0103] The damping unit 250 can be configured to slow down any other uncontrolled movement of the propulsion system 201 in the event of a failure of the actuator 230. The damping unit 250 can be a constantly engaged passive mechanism and therefore does not require control commands from the control system, and responds automatically and immediately to sudden movements of the propulsion system 201. The control system can deactivate the propulsion system 201 immediately after a failure event.

[0104] The damping unit 250 may not completely stop the movement of the propulsion system 201 (e.g., upward tilting due to thrust, or downward tilting due to gravity). However, the damping unit 250 may be configured to extract energy from the movement of the propulsion system 201 so as to prevent the rotary joint 260, the components of the propulsion system 201, and / or the components of the support structure 206 from detaching or otherwise being damaged. As described above, the damping unit 250 can cause greater extension or compression of the damping unit 250, so that it can provide a greater damping force in response to faster tilting movements of the propulsion system 201. Thus, the damping unit 250 can provide a variable and sufficient force to resist sudden and variable tilting forces so that the tilting of the propulsion system 201 occurs below a threshold speed or at other acceptable levels.

[0105] This specification primarily describes embodiments relating to tilting propulsion systems equipped with actuators configured to tilt the tilting propulsion system. The embodiments are also applicable to any other suitable type of moving element and / or actuator used in any other suitable context. For example, the embodiments are applicable to other moving elements and corresponding actuators on aircraft, and / or actuators in other types of vehicles, and other suitable mechanical applications. Examples of other moving elements on aircraft that utilize actuators, and examples to which embodiments can be applied, include ailerons, elevators, rudders, spoilers, flaps, slats, air brakes, and / or any other suitable control elements or lift surfaces used to maneuver and control the movement, speed, and / or altitude of an aircraft. Such moving elements are similarly driven by actuators that operate between an extended position and a retracted position, thereby causing the motion of the moving element. In addition, damping units may be coupled to such moving elements as a secondary load path that supports the moving element in the event of failure of the actuator or other primary load path.

[0106] A system for testing damping units As discussed above, the actuator 230 may be configured to provide a primary load path between the propulsion system 201 and the support structure 206. If the actuator 230 fails, the damping unit 250 may be configured to provide a secondary load path through a damping force that mitigates the tilting motion of the propulsion system 201. A further concern is the integrity and reliability of the damping unit 250 itself. If the damping unit 250 fails, further redundancy to prevent damage to the rotary joint 260, the propulsion system 201, and / or the support structure 206 may be lost.

[0107] The damping unit 250 may be a passive component that is not controlled or actuated by the control system. Therefore, without manual inspection, it can be difficult to determine the condition of the damping unit 250, such as whether it is undamaged and functioning correctly. In the absence of periodic inspection, the only way to naturally discover whether the damping unit 250 is operational may be through a failure event of the actuator 230. If the damping unit 250 is operational, the secondary load path can function normally. If the damping unit 250 is not operational, the secondary load path may also be faulty and prone to damage. If the damping unit 250 is not operational, it may have failed earlier and remained in an undetectable fault state until the moment it was needed. This may be referred to as a latent failure. In aircraft applications, not knowing the condition of the damping unit 250 until the moment it is needed may be considered an unacceptable risk.

[0108] One method for achieving greater reliability in the damping unit 250 is manual inspection of the damping unit 250 by a human operator before flight. However, inspecting the damping unit 250 may involve removing, disassembling, and / or manually testing parts, and an aircraft may contain multiple (e.g., 6 or 12) damping units, each of which may require inspection. As a result, periodic manual inspection of the damping unit 250 can be costly in terms of the time, work, and flight delays required. Therefore, in the case of high-throughput airport operations where a large number of aircraft operate frequently, it may not be practical to periodically (e.g., before each flight, every 5 flights, or every 10 flights) manually inspect the damping units.

[0109] The embodiment provides a system for testing the operating condition of a damping unit 250. Compared to manual inspection, the embodiment allows for testing of the damping unit 250 in a simpler, faster, quicker, and / or integrated and automated manner, without requiring disassembly of the damping unit 250, physical access to the damping unit 250, or visual inspection of the damping unit 250. The damping unit 250 can be tested using one or more of the actuator 230, control system 207, load measuring device 295, and / or power supply 280.

[0110] A control system 207, such as a flight control system, may be configured to control an aircraft. The control system 207 may be configured to control the aircraft automatically and / or remotely (e.g., via control signals received from a remote entity such as a remote controller, remote pilot, or remote control tower). In various embodiments, the control system 207 may include one or more computers having one or more non-temporary computer-readable media for storing instructions and one or more processors configured to execute instructions to perform the processing and control functions described herein. A corresponding control system 107 is also shown in Figures 1A and 1B and will be discussed in more detail below.

[0111] Referring back to Figures 2A to 2D, the power supply 280 can be configured to supply power to the propulsion system 201 and / or the actuator 230. According to the embodiment, the power supply 280 may include one or more battery units and / or any other suitable power supply. The power supply 280 may represent a power supply dedicated to the propulsion system 201 and / or the actuator 230, or a shared power supply for multiple components of the aircraft or for the entire aircraft.

[0112] The load measuring device 295 can be configured to measure one or more parameters associated with the load on the actuator 230. In some embodiments, the load measuring device 295 cannot directly measure the load on the actuator 230, but the load on the actuator 230 can be determined based on one or more parameters measured by the load measuring device 295. For example, in order to actuate and cause a tilting motion, the actuator 230 can draw power from the power supply 280 via the power distribution line 290. The load measuring device 295 can be configured to determine the amount and / or rate of power being drawn from the power supply 280 by the actuator 230. The amount of power can then be used to calculate the load on the actuator 230.

[0113] As an example, the load measuring device 295 can take the form of an ammeter. The ammeter can determine the amount of current drawn from the power supply 280 by measuring the current in the power distribution line 290 or any other suitable location. Using the measured amount of current (e.g., in amperes), the amount of power drawn from the power supply 280 and / or the amount of force acted by the actuator 230 (e.g., in Newtons) can be determined. For example, the control system 207 can store information about a known ratio of the force acted by the actuator 230 per unit of power drawn from the power supply 280 (e.g., based on a known gear ratio and torque constant of the actuator 230).

[0114] The embodiment includes other types of load measuring devices. For example, the load measuring device 295 can alternatively take the form of a load sensor, pressure sensor, strain gauge, or other force sensor in the actuator 230, a residual energy meter in the power supply (e.g., to determine the total amount of energy used during the complete tilting motion), a voltmeter, etc. The load measuring device 295 may be located in any suitable place and / or integrated into any suitable component. For example, the embodiment allows the load measuring device 295 to be integrated into the actuator 230, the power supply 280, and / or the control system 207.

[0115] As shown by the connection communication lines in Figures 2A to 2D, the control system 207 is operably able to communicate with one or more of the power supply 280, load measuring device 295, actuator 230, and / or other suitable components. Although these elements are shown as being located within the support structure 206, one or more of the control system 207, power supply 280, and / or load measuring device 295 may be located elsewhere on the aircraft.

[0116] According to the embodiment, the control system 207 can test the damping unit 250 by intentionally driving the actuator 230. For example, when the aircraft is stationary on the ground, such as at an airport, the control system 207 can control and operate the actuator 230 to tilt the propulsion system 201. When the damping unit 250 is functioning correctly, it provides a certain amount of resistance to the tilt and the actuator 230 based on the speed of the tilt. Therefore, if the actuator 230 outputs at least a certain amount of force, it can be determined that the damping unit 250 is functioning correctly and is not malfunctioning.

[0117] Method for testing damping units With respect to Figure 3, a method 300 for testing the condition of the damping unit can be described.

[0118] In step 1, the actuator can be controlled to act. In practice, a control system or a human operator can control the actuator to act. The actuation of the actuator can cause the movement of the movable element connected to the actuator to occur. For example, the actuation of the actuator can cause the propulsion system to perform a tilting motion. The tilting motion can include an upward tilting motion (e.g., toward a vertical flight configuration) and / or a downward tilting motion (e.g., toward a forward flight configuration).

[0119] The actuator can be controlled to act for any appropriate length of time and / or distance. For example, the actuator can be controlled to act over the entire stroke range so that the propulsion system tilts from a forward flight configuration to a vertical flight configuration, or from a vertical flight configuration to a forward flight configuration. Alternatively, in some embodiments, the actuator can be controlled to act over a portion of the entire stroke range that is less than the entire stroke range, such as half of the entire stroke range from the forward flight configuration to the vertical flight configuration. In some embodiments, the actuator can be controlled to act in multiple directions and / or over multiple entire stroke ranges. For example, the actuator can be controlled to act so that the propulsion system tilts from the starting position of the vertical flight configuration to the forward flight configuration, and then returns from the forward flight configuration to the vertical flight configuration.

[0120] The actuator can be operated at any appropriate speed so that the propulsion system tilts at any appropriate corresponding speed. For example, the actuator may be controlled to operate at a speed sufficient to produce a measurable, detectable, or otherwise appropriate response force from the damping unit for testing the damping unit. In some embodiments, the actuator may be controlled to operate at maximum speed. The operating speed used during testing may be greater than the operating speed (and corresponding tilting speed) used during flight operation. In some embodiments, the operating and tilting speeds may vary throughout the test process due to the time for acceleration and / or deceleration. In addition, the operating and tilting speeds may be maximum in a particular tilting range of the propulsion system that can produce the maximum movement of the damping unit (e.g., a tilt angle close to a vertical flight configuration).

[0121] According to the embodiment, the aircraft may remain stationary during step 1 and / or other steps of Method 300. When the aircraft is stationary, the propulsion system and actuators may experience known relatively static conditions. For example, external forces such as wind force may be small enough to be negligible when the aircraft is stationary, or they may be of significant consideration. In contrast, during flight, there may be considerable additional forces on the propulsion system and / or actuators, such as the force due to the thrust generated by the actuators and / or air resistance due to the movement of the aircraft.

[0122] In step 2, the load on the actuator can be determined. For example, a load measuring device can measure a parameter while the actuator is operating and / or while the movable element is in motion (e.g., while the propulsion system is tilting). For example, if the load measuring device is configured to measure the current drawn from the power supply by the actuator, the parameter can be the amount of current. The load measuring device may also measure the parameter as a function of time. For example, since the amount of current can change over time, the parameter could be the amount of current drawn throughout the entire operation and tilt.

[0123] According to the embodiment, the load measuring device can provide the measured parameters to a control system, which can then calculate or otherwise determine the load on the actuator based on the measured parameters. The control system can determine the load as a function of time based on the parameters as a function of time (e.g., the rate of change of force applied by the actuator). For example, the amount of current drawn by the actuator can indicate the amount of power used by the actuator to support the load on the actuator (e.g., providing a rate of change of force sufficient to cause tilting motion). The control system can store any appropriate information regarding power consumption in the actuator and calculate the load based on the measured current. In some embodiments, the load measuring device can determine the load using its own integrated processor and then provide the determined load to the control system.

[0124] In step 3, the load applied to the actuator can be compared to a predetermined threshold. In some embodiments, the maximum value can be determined from the load as a function of time. The determined maximum value of the load is compared to a predetermined threshold to determine whether the determined maximum value of the load exceeds the predetermined threshold.

[0125] The embodiment makes available any appropriate predetermined threshold during step 3. For example, the calibration process may be performed earlier, before method 300. During the calibration process, the damping unit may be removed, disconnected, or otherwise disengaged. With the damping unit disconnected, the actuator can be operated in the same manner as or identical to that in step 1 (e.g., to give the same or identical tilting speed), and the load can be measured in the same manner as or identical to that in step 2. As a result, the control system can determine the maximum load value or the load as a function of time when the damping unit is disconnected. According to the embodiment, the predetermined threshold can be determined based on this calibration process. For example, the predetermined threshold can be set to or based on the maximum load value from the calibration process, or the average rate of change of force over time during the calibration process.

[0126] In some embodiments, a predetermined threshold can be the maximum load value, or the average power value from the calibration process plus a buffer amount (e.g., 10%, 20%, or 30% of the maximum load). The added buffer can account for fluctuating wind loads or other variations in test conditions, account for potential inaccuracies in the measurement, ensure that at least a certain amount of damping force is applied, and / or otherwise improve the reliability in step 3 that, for a given speed of tilting motion, the load on the actuator by the damping unit is sufficiently increased (e.g., by a predetermined minimum amount).

[0127] In this manner, a predetermined threshold can be based on the previous load applied to the actuator during the previous motion of the movable element when the damping unit was disengaged. Furthermore, in some embodiments, the predetermined threshold can be determined based on multiple calibration processes performed at different times and / or under different conditions (e.g., wind speed). The predetermined threshold may be based on the average of the calibration processes or on the maximum load result within the calibration process.

[0128] In other embodiments, the damping unit may be connected during the calibration process. In this case, the damping unit can be verified to be functioning by manual inspection or any other suitable means. As a result, the maximum load value determined during the calibration process may be the maximum load value produced when the damping unit is known to be functioning. In this case, a predetermined threshold can be set to the maximum load value from the calibration process. Alternatively, the predetermined threshold can be the maximum load value from the calibration process plus or minus a buffer amount (e.g., 1%, 5%, or 10% of the maximum load). The subtracted buffer can provide room for variation across different damping units and / or different test conditions.

[0129] In step 4, if the load on the actuator is greater than a predetermined threshold, it can be determined that the damping unit is operating (e.g., functioning normally and / or providing sufficient damping force, or providing at least the minimum damping force for a constant speed of tilting motion). For example, if the load on the actuator is greater than a predetermined threshold, or substantially equal to a predetermined threshold, the control system and / or human operator can conclude that the damping unit is operating. As mentioned above, the predetermined threshold may include a buffer amount and / or can be set in a way that ensures the damping unit is functioning normally, even if there is some possibility of load variation due to variations in test conditions, measurement accuracy, actuator performance, and / or damping unit performance.

[0130] According to the embodiment, if the damping unit is determined to be faulty or otherwise not functioning properly, the control system can generate a warning indicator. In response, a human operator can begin manually inspecting, repairing, and / or replacing the damping unit before the next flight.

[0131] In step 5, the control system and / or human operator may initiate the flight process in response to determining that the damping unit is operational and / or to completing any other appropriate pre-flight tests and checks. In some embodiments, after the damping unit and / or any other appropriate components have been checked, the aircraft is marked as ready for flight (for example, the control system may update its database to indicate that the aircraft is ready).

[0132] According to the embodiment, each step of Method 300 can be automated and performed by a control system. In addition, since the calculations from steps 2 to 4 can be performed instantaneously by the control system, the process can be completed in less than a few seconds (e.g., the time to complete the tilting process in step 1). Thus, the embodiment provides an efficient and simple method for testing the operating condition of a damping unit compared to manual inspection, which can be built into an aircraft with little human involvement (e.g., a control system can perform this method), and this method does not require additional separate sensors (e.g., an ammeter may already be included in the aircraft for other purposes such as actuator control), measuring instruments, or weight. Such improvements in efficiency make periodic testing of the damping unit (e.g., before each flight) possible at minimal cost in terms of time and effort. Periodic testing can increase the reliability of the damping unit, reduce the chance of missing potential failures, and / or improve flight safety.

[0133] In some embodiments, step 1 and / or other steps of Method 300 may occur during flight. In such embodiments, Method 300 may be performed during a flight phase in which typical forces acting on the propulsion system and / or actuators have been measured in advance and are known to be within a certain range. For example, the expected load, typical load, or maximum load acting on the actuators, resulting from a known combination of thrust magnitude, aircraft speed, tilt position, rotor blade pitch, altitude, temperature, and / or wind speed, may be known or approximated (e.g., based on one or more pre-calibration processes performed during flight). In some embodiments, each time the tilting propulsion system tilts during flight, the damping unit may be tested according to Method 300.

[0134] Referring back to Step 3, the embodiment allows for alternative ways of comparing the measured load to a threshold. For example, instead of comparing the maximum load, the control system may compare the shape of the load over time. A damping unit may create an increase in damping force, thereby increasing the load on the actuator as a function of tilting speed. In contrast, during a calibration process without a damping unit, the actuator may be controlled to exert a substantially constant force on the propulsion system throughout the entire tilting process, regardless of the tilting speed. Thus, a damping unit can affect the shape of the load-versus-time plot. For example, to verify that the damping unit is functioning correctly, the control system may determine whether the actuator load increases by a predetermined threshold amount (e.g., 2%, 5%, 10%, 20%) during the maximum tilting speed compared to a lower tilting speed (e.g., during the start or end of the tilting process).

[0135] The embodiments described herein primarily relate to testing the condition of damping units connected to tilting propulsion systems. The embodiments are also applicable to any other suitable actuators and / or movable elements located on or off an aircraft. For example, the damping unit may be connected to any other suitable flight control elements, such as ailerons, elevators, rudders, spoilers, flaps, slats, and air brakes, and / or any suitable elements or lift surfaces, used for steering the aircraft and for controlling the aircraft's movement, speed, and / or altitude. Such elements can similarly be driven by actuators that operate between an extended position and a retracted position. The above-described method for testing damping units connected to tilting propulsion systems can also be carried out for damping units connected to any other suitable type of movable element.

[0136] control system Referring back to Figures 1A and 1B, as described above, the aircraft 100 may include a control system 107, such as a flight control system, configured to control the aircraft 100. The control system 107 may be configured to control the aircraft 100 automatically and / or remotely (e.g., via control signals received from a remote entity such as a remote controller, remote pilot, or remote control tower). In various embodiments, the control system 107 may include one or more computers having one or more non-temporary computer-readable media for storing instructions and one or more processors configured to execute instructions to perform the processing and control functions described herein.

[0137] For example, the control system 107 can control when the propulsion systems 101(A) to (L) should be activated and / or the amount of power supplied to the propulsion systems 101(A) to (L). The control system 107 may be configured to control the propulsion systems 101(A) to (L) independently of each other. According to various embodiments, the control system 107 can control the propulsion systems 101(A) to (L) based on inputs received from a remote controller (e.g., a remote pilot), inputs received from an autopilot, sensor data and / or flight data received from sensors (e.g., sensors measuring air temperature, electric motor temperature, aircraft airspeed, etc.), a computer, and other input / output devices connected to the aircraft.

[0138] The control system 107 can also control one or more tilting mechanisms to switch the position of one or more tilting fans from a forward flight configuration to a vertical flight configuration, from a vertical flight configuration to a forward flight configuration, to one or more intermediate tilt angles, and / or to continuously change within a range of tilt angles, as required by the flight plan. For example, the control system 107 communicates with and controls one or more actuators (e.g., actuator 230 shown in Figure 2) configured to cause tilting for one or more propulsion systems 101(A) to (L). As a result, the control system can control the tilt configuration of the propulsion systems via the corresponding actuators. According to various embodiments, the control system (e.g., a flight control system) can control the angle of the tilting fans based on sensor data and / or flight data received from sensors connected to the aircraft (e.g., sensors measuring air temperature, electric motor temperature, aircraft airspeed, etc.), a computer, and other input / output devices.

[0139] The control system 107 can further control one or more pitching mechanisms to switch the position of one or more rotor blades between two or more pitch positions. According to various embodiments, the control system 107 can control the pitch position of the rotor blades based on sensor data and / or flight data received from sensors (e.g., sensors measuring air temperature, motor temperature, aircraft airspeed, etc.), a computer, and other input / output devices connected to the aircraft. The pitch of the rotor blades may be set based on the current flight stage and / or the needs of the flight. For example, a first pitch, which may be a low pitch, may be selected when the aircraft is accelerating (e.g., forward or upward), hovering, taking off, and / or landing. A second pitch, which may be a high pitch, may be selected when the aircraft has reached cruising flight (e.g., has reached a preset forward speed).

[0140] Accordingly, the control system 107 may be configured to convert pilot or other operator inputs and / or corrections calculated by the onboard computer into forces and moments, and / or further convert such forces and moments into a set of actuators (e.g., control surfaces such as vertical lift rotors, propellers, and ailerons) and / or associated parameters (e.g., lift fan output, tilt angle, rotor blade pitch, speed, or torque) to provide the required forces and moments. For example, pilot or other operator inputs may indicate a desired change in the aircraft's speed, direction, and / or orientation, and / or wind or other forces may act on the aircraft, requiring the propulsion system and / or other actuators to be used to maintain a desired aircraft altitude (roll / pitch / yaw), speed, and / or altitude.

[0141] According to various embodiments, the control system 107 can be configured to receive flight commands such as takeoff, hovering, cruising, or landing commands. The control system 107 can then determine the current location and / or speed of the aircraft 100 and control the operation of the propulsion systems 101(A) to (L) based on the flight commands. During the operation of the aircraft 100, the control system 107 may be configured to continuously monitor the operating status of the propulsion systems 101(A) to (L) in light of the flight commands.

[0142] The aircraft 100 may further include landing gear 130. The landing gear 130 may include one or more skids, wheels, skis, pontoons, shock absorbers, struts, and / or any other suitable components, in any suitable combination, for supporting the aircraft 100 during and / or landing on the ground. In some embodiments, the landing gear 130 may be retractable into a compartment within the fuselage 104.

[0143] The aircraft 100 may include other suitable control structures and control surfaces. These may include any suitable number of ailerons, rudders, elevators, slats, flaps, spoilers, and / or stabilizers. For example, a horizontal stabilizer 140 (e.g., tail fin) may be connected to the rear end or tail of the fuselage 104. The horizontal stabilizer 140 may be of any suitable shape or form. For example, as shown in Figures 1A and 1B, the horizontal stabilizer 140 may include two stabilizer surfaces projecting horizontally from the tail. In some embodiments, each of the stabilizer surfaces may further include a control surface hinged to its trailing edge. In addition, as shown in Figures 1A and 1B, an additional (e.g., a third) vertical stabilizer surface extending vertically upward and / or downward may be installed on the tail fin. The introduction of the horizontal stabilizer 140 can provide further stability and control of the aircraft 100. This is particularly useful when the vertical fan is disabled or when it is not used or relied upon for control and stability purposes (e.g., during cruising flight).

[0144] Flight process According to various embodiments, the control system can control the flight of an aircraft configured for vertical takeoff and landing.

[0145] Aircraft may remain stationary on the ground. For example, an aircraft may be parked at a charging station to recharge its batteries. Alternatively, an aircraft may be parked in a location while awaiting the acceptance of cargo or passengers.

[0146] Before commencing the flight process, the aircraft's flight control system may perform one or more pre-flight tests and checks, and / or the operator may perform one or more tests and checks on the aircraft. For example, as described above with respect to Figure 3, the condition of the damping unit may be tested. If the damping unit is determined to be operational, and / or any other appropriate tests are completed and passed, the aircraft may be marked as ready for flight.

[0147] The aircraft's flight control system can receive a flight plan (e.g., from the autopilot, pilot, or remote controller pilot) to reach a predetermined destination. The flight plan may include instructions for takeoff from the ground. The flight control system can control and activate one or more propulsion systems. For example, the aircraft's thrust-generating components may be deactivated or in standby mode. The flight control system can power on the propulsion system from deactivated mode so that it is ready to generate vertical lift.

[0148] The control system can actuate a first set of one or more propulsion systems coupled to the aircraft. Each of the first set of one or more propulsion systems may have two or more rotor blades and a fixed vertical orientation or a tiltable orientation that is currently set in a vertical flight configuration.

[0149] For example, a flight control system can initiate a takeoff sequence to lift the aircraft off the ground. The flight control system can activate a first set of one or more propulsion systems to provide vertical thrust so that the aircraft leaves the ground. The flight control system can continue to activate the first set of one or more propulsion systems in this manner until a certain amount of time has elapsed or a certain altitude (e.g., a safe distance from the landing pad) has been reached. The control system can continue to activate the first set of one or more propulsion systems to provide vertical thrust during liftoff, hovering, landing, or any other appropriate flight phase.

[0150] The control system may, at some point, control one or more of a first set of propulsion systems, such as fixed vertical fans, to deactivate during other flight phases, such as forward cruising flight, where additional and / or alternative vertical lift may be provided by the aircraft's wings. For example, after a certain length of time has elapsed and / or altitude has been gained, the flight control system may receive a command to transition to forward flight. Before switching to forward flight mode, the control system may check one or more of the aircraft's altitude, speed, and orientation to ensure that the parameters are within a predetermined desirable range. In some embodiments, the control system may communicate the parameters to a remote entity (e.g., a remote control tower or remote pilot).

[0151] The control system can actuate a second set of one or more propulsion systems. Each of the second set of one or more propulsion systems has a tiltable orientation that is set to a fixed horizontal orientation or a forward flight configuration. Each of the second set of one or more propulsion systems may have two or more rotor blades. In some embodiments, one or more propulsion systems, such as tilting fans, may be included in both the first set of one or more propulsion systems and the second set of one or more propulsion systems.

[0152] For example, upon receiving a flight command to transition to forward flight, the control system may activate a second set of one or more propulsion systems to generate forward thrust for the aircraft. The flight control system may control forward acceleration in any appropriate manner, such as gradually increasing the power supplied to the second set of one or more propulsion systems so that the aircraft gradually gains forward speed.

[0153] In some embodiments, a second set of one or more propulsion systems may be activated and begin providing forward thrust while the aircraft is still in the process of gaining altitude from the vertical lift fan. As a result, forward movement and vertical lifting may overlap. In addition, the flight control system may adjust the power of the first set of one or more propulsion systems as needed so that the second set of one or more propulsion systems increases forward airspeed while maintaining stability and altitude.

[0154] In some embodiments, one or more of the first set of propulsion systems and / or a second set of one or more propulsion systems may be operated to tilt between a forward flight configuration and a vertical flight configuration. Such a tilting propulsion system can be operated in both one or more steps that provide vertical thrust and one or more steps that provide horizontal thrust.

[0155] In some embodiments, one or more tilt propulsion systems may be actuated to tilt gradually, iteratively, and / or continuously from a vertical flight configuration to a forward flight configuration. When a tilt propulsion system is set to one or more intermediate tilt angles, thrust may be provided at an angle having a partial vertical component and a partial horizontal component. As the tilt propulsion system tilts through one or more intermediate tilt angles, the horizontal thrust component increases and the vertical thrust component decreases. In some embodiments, one or more tilt propulsion systems may be actuated to temporarily pause movement and tilting at a predefined intermediate tilt angle (referred to as a third tilt angle, critical tilt angle, or threshold tilt angle) that is close to but above horizontal, while continuing to actuate the propulsion system and provide thrust. Once a predefined speed and / or altitude is achieved, one or more tilt propulsion systems may be actuated to resume the progression of tilting until a forward flight configuration is reached. In some embodiments, the tilting propulsion system can be operated to tilt at a predetermined speed or less such that the resistance generated by the damping unit connected to the tilting propulsion system is less than a predetermined resistance.

[0156] The control system may set and / or modify the pitch position setting of one or more rotor blades of one or more propulsion systems (e.g., from a first set and / or a second set). In some embodiments, one or more rotor blades may initially be set to a first pitch position. The first pitch position may be maintained during one or more stages of flight, such as takeoff and / or forward acceleration. The control system may later adjust one or more rotor blades to have a second pitch position. For example, once cruising flight is reached (e.g., after reaching a certain forward speed), the pitch setting may be changed to a second pitch position. In some embodiments, the pitch setting may be changed gradually and / or iteratively from the first pitch position to the second pitch position as the forward speed increases, and gradually from the second position to the first pitch position as the forward speed decreases.

[0157] The control system may keep a second set of one or more propulsion systems activated during forward cruising, forward acceleration, deceleration, or any other appropriate flight phase to provide horizontal thrust. The control system may control at some point to deactivate the first set of one or more propulsion systems during other flight phases such as liftoff, hovering, and / or landing. At some point, the control system may activate both the first set of one or more propulsion systems and the second set of one or more propulsion systems simultaneously.

[0158] Subsequently, the flight control system may deactivate one or more of the first set of propulsion systems, or reduce the power supplied to the first set of propulsion systems. For example, once a second set of propulsion systems has generated a predetermined speed and the wings are providing sufficient lift to maintain altitude, the first set of propulsion systems may no longer be needed for vertical lift. Thus, one or more of the first set of propulsion systems may be powered down, deactivated, put into standby mode, or operated at a reduced power level during the forward flight of the aircraft.

[0159] The control system can continuously alternate between operating one or more of the first set of one or more propulsion systems and / or the second set of one or more propulsion systems, continuously tilt one or more tilting propulsion systems, and / or continuously adjust the pitch position of one or more rotor blades (for example, by adjusting the linked tilt angle of the propulsion systems).

[0160] In the event of a potential failure of the propulsion system's tilting mechanism during flight, a linked damping unit can be pre-configured to slow down any uncontrolled tilting motion and prevent damage.

[0161] In the above specification, the embodiments of the Disclosure have been described with reference to numerous specific details, which may vary from implementation to implementation. Therefore, this specification and the drawings are intended to be illustrative rather than restrictive. The sole and exclusive indicator of the scope of the Disclosure, and what the Applicant intends to be the scope of the Disclosure, is the literal and equivalent scope of the claims arising from this application, including any subsequent amendments, as they are in the specific form from which such claims arise. Specific details of particular embodiments can be combined in any appropriate manner without departing from the spirit and scope of the embodiments of the Disclosure.

[0162] In addition, spatially relative terms such as “bottom” or “top” can be used to describe the relationship between an element and / or another element and / or feature, as shown in the drawings, for example. It should be understood that spatially relative terms are intended to include different orientations of the device in use and / or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawing is turned upside down, an element described as the “bottom” side may face “top” of another element or feature. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein will be interpreted accordingly.

[0163] The methods, systems, and devices discussed herein are examples. Various embodiments may omit, replace, or add various procedures or components as appropriate. For example, features described in relation to a particular embodiment can be combined in various other embodiments. Different aspects and elements of embodiments may be combined in similar ways. Furthermore, as technology evolves, many elements are examples, and these do not limit the scope of this disclosure to these specific examples.

[0164] The terms “and,” “or,” and “and / or,” as used herein, can have a variety of meanings, but this meaning is also expected to depend, at least in part, on the context in which such terms are used. Typically, when “or” is used to relate an enumeration such as A, B, or C, it is intended to mean A, B, and C, as used here in an inclusive sense, not just A, B, or C, as used here in an exclusive sense. In addition, as used herein, the term “one or more” may be used to describe any feature, structure, or characteristic in the singular, or to describe any combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example, and the claimed subject matter is not limited to this example. Furthermore, when the term “at least one of” is used to relate an enumeration such as A, B, or C, it can be interpreted to mean any combination of A, B, and / or C, such as A, B, C, AB, AC, BC, AA, AAB, ABC, AABBCCC, etc.

[0165] Throughout this specification, any reference to “one example,” “example,” “a specific example,” or “exemplary implementation” means that any particular feature, structure, or characteristic described in conjunction with the feature and / or example may be included in at least one feature and / or example of the claimed subject matter. Therefore, the appearance of phrases such as “one example,” “example,” “a specific example,” “in a particular implementation,” or other similar phrases in various places throughout this specification does not necessarily refer to the same feature, example, and / or limitation. Furthermore, any particular feature, structure, or characteristic may be combined with one or more examples and / or features.

[0166] In the detailed description above, numerous specific details were given to provide a full understanding of the claimed subject matter. However, a person skilled in the art will understand that the claimed subject matter can be put into practice even without such specific details. In other cases, methods and apparatus that would be known to a person skilled in the art are not described in detail in order to avoid obscuring the claimed subject matter. Therefore, it is intended that the claimed subject matter is not limited to the specific examples disclosed, and that such claimed subject matter may also include all embodiments and equivalents contained in the attached claims.

[0167] The above description is illustrative and not limiting. Many modifications of the invention will become apparent to those skilled in the art by examining this disclosure. Therefore, the scope of the invention should not be determined by reference to the above description, but rather by reference to the pending claims and their entirety or equivalents.

[0168] One or more features from any embodiment can be combined with one or more features from any other embodiment without departing from the scope of the present invention.

[0169] In this specification, the use of “a,” “an,” or “the” shall mean “at least one” unless specifically stated otherwise.

Claims

1. A movable element configured to move between a first position and a second position, Fixed elements and, An actuator configured to operate between an extended position and a retracted position, A primary load path between the movable element and the fixed element, including the actuator configured to move the movable element between the first position and the second position, A damping unit configured to passively extend or contract in order to apply a damping force to the movable element to counteract the movement of the movable element, A secondary load path between the movable element and the fixed element, having a damping unit configured to dampen the movement of the actuator and the movable element along the primary load path, A system that has

2. A first coupler provides a first connection between the actuator and the movable element such that the operation of the actuator between the extended position and the retracted position causes the movement of the movable element between the first position and the second position, A second coupler providing a second connection between the actuator and the fixed element, A third coupler provides a third connection between the damping unit and the movable element such that the movement of the movable element causes the damping unit to extend or contract, A fourth coupler providing a fourth connection between the damping unit and the fixed element, The system according to claim 1, further comprising:

3. The system according to claim 2, wherein the movable element includes a truss structure, the truss structure includes a first coupler and a third coupler, and the third coupler is positioned above the first coupler.

4. The system according to claim 1, wherein the secondary load path is configured to oppose the primary load path while the actuator is operating.

5. The system according to claim 1, wherein the motion of the movable element is the first motion of the movable element, and the secondary load path is configured to decelerate the second motion of the movable element in the event of a failure of the primary load path.

6. The system according to claim 1, wherein the actuator is a linear actuator that extends or retracts linearly, and the damping unit is configured to passively extend or retract linearly.

7. The system according to claim 1, further comprising an aircraft, wherein the movable element is a tiltable propulsion system for the aircraft.

8. The movable element is a tiltable propulsion system, and the fixed element, support structure, The aforementioned system Torso and, A pair of wings connected to both sides of the fuselage, The support structure is connected to one of the pair of wings, The tiltable propulsion system connected to the support structure and aircraft including The system according to claim 1, further comprising:

9. The system according to claim 8, wherein the first position is a vertical flight configuration and the second position is a forward flight configuration.

10. A load measuring device configured to measure the load applied to the actuator, A control system configured to control the actuator, Control the actuator to operate, The load measuring device receives information regarding the load applied to the actuator, and The state of the damping unit is determined based on the load applied to the actuator. A control system further configured as follows: The system according to claim 9, further comprising the above.

11. A control system controls an actuator to move a movable element, wherein the actuator is connected to the movable element, and a damping unit is connected to the movable element, and the damping unit is configured to provide a damping force to counteract the motion of the movable element. The control system includes the steps of determining the load applied to the actuator during the motion of the movable element, The control system includes the steps of comparing the load applied to the actuator with a predetermined threshold value, The control system determines that the damping unit is operating when the load applied to the actuator exceeds the predetermined threshold. A method having

12. During the motion of the movable element, the step of determining the load applied to the actuator is performed Receiving measurement parameters from a load measuring device, Based on the measurement parameters, the load applied to the actuator is calculated. The method according to claim 11, including the method described in claim 11.

13. The method according to claim 12, wherein the load measuring device is an ammeter, and the measurement parameter is the amount of current drawn in by the actuator.

14. The method according to claim 11, wherein the degree of damping force is based on the speed of the motion of the movable element, with higher speeds resulting in a greater degree of damping force.

15. The method according to claim 11, wherein the damping unit is applying the damping force to the movable element and the actuator due to the load applied to the actuator that exceeds the predetermined threshold, it is shown that the damping unit is applying the damping force to the movable element and the actuator.

16. The method according to claim 11, wherein the predetermined threshold is based on the previous load applied to the actuator during the previous movement of the movable element when the damping unit was disengaged.

17. The method according to claim 11, wherein the actuator operates linearly between an extended position and a retracted position, the damping unit is configured to passively extend or retract linearly, the damping unit is configured to resist extension or retraction, and the movement of the movable element causes the extension or retraction of the damping unit.

18. The method of claim 11, wherein the actuator provides a primary load path between the movable element and the fixed element, the damping unit provides a secondary load path between the movable element and the fixed element, the secondary load path opposes the primary load path, and the step of determining that the damping unit is operating includes determining that the secondary load path is functioning.

19. The method according to claim 18, wherein the motion of the movable element is the first motion of the movable element, and in the event of a failure of the primary load path, the secondary load path decelerates the second motion of the movable element.

20. The movable element is a tiltable propulsion system connected to an aircraft, the motion is a tilting motion, the step of controlling the actuator to actuate is performed while the aircraft is stationary on a plane, and the method is After determining that the damping unit is operating, the step of starting the flight process The method according to claim 11, further comprising:

Images