阅读说明：本技术 对起落架运动或起落架舱门的运动的控制 (Control of landing gear movement or movement of landing gear doors ) 是由 肖恩·凯尔 大卫·马尔莱斯 于 2020-06-23 设计创作，主要内容包括：公开了一种对用于飞行器的起落架控制器进行操作的方法。该方法包括起落架控制器从至少一个位置传感器接收一个或更多个信号。所述一个或更多个信号在起落架舱门或起落架分别在行程的两个极限之间部分地通过行程范围时指示起落架舱门和起落架中的一者的位置。该方法还包括起落架控制器基于所述一个或更多个信号来对起落架舱门和起落架中的另一者的运动进行控制。(A method of operating a landing gear controller for an aircraft is disclosed. The method includes the landing gear controller receiving one or more signals from at least one position sensor. The one or more signals indicate a position of one of the landing gear door and the landing gear when the landing gear door or the landing gear, respectively, partially passes through a range of travel between two limits of travel. The method also includes controlling, by the landing gear controller, movement of the other of the landing gear door and the landing gear based on the one or more signals.)

1. An aircraft system comprising:

a landing gear door system having:

landing gear bay door, and

a landing gear door motion system operable to move the landing gear door through a range of travel between a closed position and an open position, wherein the landing gear door at least partially covers a landing gear bay when in the closed position;

a landing gear system having:

landing gear, and

a landing gear movement system operable to move the landing gear within a range of travel between an extended position and a retracted position, wherein the landing gear is at least partially positioned in the landing gear bay when in the retracted position;

at least one position sensor configured to sense a position of a portion of the landing gear door system or a position of a portion of the landing gear system, respectively, and output one or more signals indicative thereof, as one of the landing gear door and the landing gear partially passes through a range of travel of one of the landing gear door and the landing gear; and

a landing gear controller communicatively connected to the at least one position sensor and operatively connected to the landing gear door motion system and the landing gear motion system, wherein the landing gear controller is configured to, in use:

receiving the one or more signals from the at least one position sensor, an

Controlling movement of the other of the landing gear door and the landing gear by controlling operation of the landing gear door movement system or the landing gear movement system, respectively, based on the one or more signals.

2. The aircraft system according to claim 1 wherein, based on the one or more signals, the landing gear controller is configured to vary the speed of movement of the other of the landing gear door and the landing gear, in use, by controlling operation of the landing gear door movement system or the landing gear movement system respectively.

3. The aircraft system according to claim 2 wherein the landing gear door motion system comprises one or more rate controllable actuators operable to move the landing gear door within a range of travel between the closed position and the open position, and the landing gear motion system comprises one or more rate controllable actuators operable to move the landing gear within a range of travel between the extended position and the retracted position; and is

Wherein, based on the one or more signals, the landing gear controller is configured to vary, in use, the speed of movement of the other of the landing gear door and the landing gear by controlling the rate of actuation of the landing gear door movement system or the one or more rate-controllable actuators of the landing gear movement system, respectively.

4. An aircraft system according to claim 2 or claim 3 wherein the landing gear controller is configured to vary the speed of movement of one of the landing gear door and the landing gear based on the position or speed of movement of the other of the landing gear door and the landing gear, in use.

5. The aircraft system according to any one of claims 1 to 4, wherein the at least one position sensor is configured to, in use:

continuously or repeatedly sensing a position of a portion of the landing gear door system or a portion of the landing gear system along a path, respectively; and

continuously or repeatedly outputting one or more signals indicative of a position of a portion of the landing gear door system or a portion of the landing gear system along the path, respectively; and is

Wherein the landing gear controller is configured to receive, in use, the one or more signals output by the at least one position sensor continuously or repeatedly.

6. The aircraft system of claim 5 wherein the landing gear controller is configured to, in use:

determining a speed of movement of a portion of the landing gear door system or a portion of the landing gear system along the path, respectively, based on the one or more signals continuously or repeatedly output by the at least one position sensor; and

controlling movement of the other of the landing gear door and the landing gear by controlling operation of the landing gear door movement system or the landing gear movement system, respectively, based on the determined speed of movement.

7. The aircraft system according to any one of claims 1 to 6 wherein, based on the one or more signals, the landing gear controller is configured to initiate movement of the other of the landing gear door and the landing gear, in use, by controlling operation of the landing gear door movement system or the landing gear movement system respectively.

8. The aircraft system according to any one of claims 1 to 7 wherein the at least one position sensor is configured to sense one or more of an angular position, a linear position, a curvilinear position of a portion of the landing gear door system or a portion of the landing gear system, respectively.

9. The aircraft system according to any one of claims 1 to 8 wherein the portion of the landing gear door system is the landing gear door and the portion of the landing gear system is the landing gear.

10. The aircraft system according to any one of claims 1 to 9, wherein the at least one position sensor comprises:

a landing gear door system position sensor configured to sense a position of a portion of the landing gear door system as the landing gear door partially passes through a range of travel of the landing gear door and output one or more first signals indicative of the position of the portion of the landing gear door system, and

a landing gear system position sensor configured to sense a position of a portion of the landing gear system as the landing gear partially passes through a range of travel of the landing gear and output one or more second signals indicative of the position of the portion of the landing gear system; and is

Wherein the landing gear controller is configured to, in use:

receiving the one or more first signals and the one or more second signals,

determining a relative position of the landing gear door and the landing gear based on the one or more first signals and the one or more second signals, an

Controlling movement of the other of the landing gear door and the landing gear based on the determined relative position.

11. The aircraft system according to any one of claims 1 to 10 comprising a relative position sensor configured to sense the relative position of the landing gear door and the landing gear and output one or more signals indicative of the relative position;

wherein the landing gear controller is configured to, in use:

receiving the one or more signals indicative of relative position, an

Controlling movement of the other of the landing gear door and the landing gear based on the one or more signals indicative of relative position.

12. A method of operating a landing gear controller for an aircraft, the method comprising the landing gear controller:

receiving one or more signals from at least one position sensor, the one or more signals indicating a position of one of a landing gear door and a landing gear as the landing gear door or the landing gear respectively partially passes through a range of travel between two limits of travel; and

controlling movement of the other of the landing gear door and the landing gear based on the one or more signals.

13. The method of claim 12, comprising the landing gear controller:

receiving one or more additional signals, an

Controlling movement of the other of the landing gear door and the landing gear based on the one or more additional signals.

14. The method of claim 13, wherein the one or more additional signals indicate one or more of:

the pitch angle of the landing gear bogie,

the status of another landing gear or another landing gear door,

the state of one or more of the aircraft engines,

a fault or defect in an aircraft component or aircraft system, an

And (4) the yaw angle of the aircraft.

15. The method according to any one of claims 12 to 14, wherein controlling movement comprises initiating movement of one of the landing gear door and the landing gear while the other of the landing gear door and the landing gear partially passes through a range of travel.

16. A non-transitory computer readable storage medium storing instructions to: the instructions, when executed by a processor of a landing gear controller of an aircraft, cause the processor to carry out a method according to any one of claims 12 to 15.

17. A landing gear controller for an aircraft system, the landing gear controller comprising a processor configured to implement the method of any of claims 12 to 15.

18. A landing gear controller for an aircraft, the landing gear controller comprising:

a receiver configured to receive one or more signals from at least one position sensor of a system of the aircraft as a landing gear door or landing gear respectively partially passes between two limits of travel, the one or more signals being indicative of a position of one of the landing gear door and the landing gear;

a determiner configured to determine one or more instructions for controlling movement of the other of the landing gear door and the landing gear based on the one or more signals; and

a transmitter configured to transmit the one or more instructions to a motion system configured to move the other of the landing gear door and the landing gear.

19. An aircraft comprising the aircraft system of any of claims 1 to 11, the non-transitory computer readable storage medium of claim 16, or the landing gear controller of claim 17 or claim 18.

Technical Field

The present invention relates to a landing gear controller for an aircraft, and to a method of operating a landing gear controller for an aircraft.

Background

In some known aircraft, the landing gear is held in an extended position when the aircraft is on the ground and is stowed in a retracted position in the gear well once the aircraft takes off the landing gear. This retraction of the landing gear helps to reduce aircraft drag and noise and the risk of damage to the landing gear in flight. The landing gear is then extended again to the extended position prior to landing of the aircraft. The landing gear door may at least partially cover the landing gear bay when closed, and the landing gear door may be openable to enable movement of the landing gear between the retracted position and the extended position. The movement of the landing gear and landing gear doors is typically controlled by the pilot using the flight controls of the aircraft, such as the landing gear lever.

Disclosure of Invention

A first aspect of the invention provides an aircraft system comprising: a landing gear door system having a landing gear door and a landing gear door motion system operable to move the landing gear door through a range of travel between a closed position and an open position, wherein the landing gear door at least partially covers the landing gear bay when in the closed position; a landing gear system having a landing gear and a landing gear movement system operable to move the landing gear within a range of travel between an extended position and a retracted position, wherein the landing gear is at least partially positioned in the landing gear bay when in the retracted position; at least one position sensor configured to sense a position of a portion of the landing gear door system or a portion of the landing gear system, respectively, as one of the landing gear door and the landing gear partially passes through its range of travel and output one or more signals indicative thereof; and a landing gear controller communicatively connected to the at least one position sensor and operatively connected to the landing gear door movement system and the landing gear movement system, wherein the landing gear controller is configured to, in use: one or more signals are received from the at least one position sensor and movement of the other of the landing gear door and the landing gear is controlled by controlling operation of the landing gear door movement system or the landing gear movement system, respectively, based on the one or more signals.

Optionally, based on the one or more signals, the landing gear controller is configured to vary, in use, the speed of movement of the other of the landing gear door and the landing gear by controlling operation of the landing gear door movement system or the landing gear movement system respectively.

Optionally, the landing gear door movement system comprises one or more rate-controllable actuators operable to move the landing gear door within a range of travel between a closed position and an open position, and the landing gear movement system comprises one or more rate-controllable actuators operable to move the landing gear within a range of travel between an extended position and a retracted position; wherein, based on the one or more signals, the landing gear controller is configured to vary, in use, the speed of movement of the other of the landing gear door and the landing gear by controlling the rate of actuation of the landing gear door movement system or one or more rate-controllable actuators of the landing gear movement system, respectively.

Optionally, the landing gear controller is configured to vary, in use, the speed of movement of one of the landing gear door and the landing gear based on the position or speed of movement of the other of the landing gear door and the landing gear.

Optionally, the at least one position sensor is configured to, in use: continuously or repeatedly sensing a position of a portion of the landing gear door system or a portion of the landing gear system along the path, respectively; and continuously or repeatedly outputting one or more signals indicative of the position of the portion of the landing gear door system or the portion of the landing gear system along the path, respectively; and the landing gear controller is configured to receive, in use, the one or more signals output by the at least one position sensor continuously or repeatedly.

Optionally, the landing gear controller is configured to, in use: determining a speed of movement of a portion of the landing gear door system or a portion of the landing gear system along the path, respectively, based on one or more signals continuously or repeatedly output by the at least one position sensor; and controlling movement of the other of the landing gear door and the landing gear by controlling operation of the landing gear door movement system or the landing gear movement system based on the determined speed of movement.

Optionally, the landing gear controller is configured to initiate movement of the other of the landing gear door and the landing gear, in use, by controlling operation of the landing gear door movement system or the landing gear movement system, respectively, based on the one or more signals.

Optionally, the at least one position sensor is configured to sense one or more of an angular position, a linear position, a curvilinear position of a portion of the landing gear door system or a portion of the landing gear system, respectively.

Optionally, the at least one position sensor comprises one or more of: a variable differential transformer (such as a rotary variable differential transformer or a linear variable differential transformer); a potentiometer (such as a rotary potentiometer or a linear potentiometer) which may be a digital potentiometer; an optical sensor; and a laser position sensor or displacement sensor.

Optionally, the portion of the landing gear door system is a landing gear door and the portion of the landing gear system is landing gear.

Optionally, the at least one position sensor comprises: a landing gear door system position sensor configured to sense a position of a landing gear door when the landing gear door partially passes through a range of travel of the landing gear door and to output one or more first signals indicative of the position of the landing gear door; and a landing gear system position sensor configured to sense the position of the landing gear as the landing gear partially passes through a range of travel of the landing gear and to output one or more second signals indicative of the position of the landing gear; and the landing gear controller is configured to receive, in use, one or more first signals and one or more second signals, determine a relative position of the landing gear door and the landing gear based on the one or more first signals and the one or more second signals, and control movement of the other of the landing gear door and the landing gear based on the determined relative position.

Optionally, the aircraft system comprises a relative position sensor configured to sense the relative position of the landing gear door and the landing gear and output one or more signals indicative thereof; and the landing gear controller is configured to, in use: one or more signals indicative of the relative position are received, and movement of the other of the landing gear door and the landing gear is controlled based on the one or more signals indicative of the relative position.

Optionally, the landing gear controller is configured to receive, in use, one or more additional signals and to control movement of the other of the landing gear door and the landing gear based on the one or more additional signals.

Optionally, the one or more additional signals are indicative of one or more of: a pitch angle of the landing gear bogie, a status of another landing gear and/or another landing gear door, a status of one or more aircraft engines, a fault or defect in an aircraft component or aircraft system, and an aircraft yaw angle.

A second aspect of the invention provides a method of operating a landing gear controller for an aircraft, the method comprising: the landing gear controller receiving one or more signals from the at least one position sensor indicative of the position of one of the landing gear door and the landing gear as the landing gear door or the landing gear respectively partially passes through the range of travel between the two limits of travel; and controlling movement of the other of the landing gear door and the landing gear based on the one or more signals.

Optionally, the method comprises: the landing gear controller receives one or more additional signals and controls movement of the other of the landing gear door and the landing gear based on the one or more additional signals.

Optionally, the one or more additional signals are indicative of one or more of: a pitch angle of the landing gear bogie, a status of another landing gear and/or another landing gear door, a status of one or more aircraft engines, a fault or defect in an aircraft component or aircraft system, and an aircraft yaw angle.

Optionally, controlling the movement comprises initiating movement of one of the landing gear door and the landing gear while the other of the landing gear door and the landing gear partially passes through the range of travel.

Optionally, controlling the movement comprises the landing gear controller varying a speed of movement of the other of the landing gear door and the landing gear based on the one or more signals.

Optionally, the varying the speed of movement of the other of the landing gear door and the landing gear based on the one or more signals comprises the landing gear controller controlling the rate of actuation of one or more rate controllable actuators of the landing gear door movement system or the landing gear movement system, respectively.

Optionally, the varying the speed of movement of the other of the landing gear door and the landing gear is based on the position or speed of movement of the one of the landing gear door and the landing gear.

Optionally, the method comprises the landing gear controller continuously or repeatedly receiving one or more signals from the at least one position sensor.

Optionally, the method comprises the landing gear controller determining a speed of movement of the landing gear door or landing gear along the path, respectively, based on one or more signals continuously or repeatedly received from the at least one position sensor, and wherein controlling movement comprises controlling movement of the other of the landing gear door and landing gear based on the determined speed of movement.

Optionally, the at least one position sensor comprises: a landing gear door system position sensor configured to sense a position of a landing gear door when the landing gear door partially passes through a range of travel of the landing gear door and to output one or more first signals indicative of the position of the landing gear door; and a landing gear system position sensor configured to sense the position of the landing gear as the landing gear partially passes through a range of travel of the landing gear and to output one or more second signals indicative of the position of the landing gear; and receiving comprises receiving one or more first signals and one or more second signals, wherein the method comprises the landing gear controller determining a relative position of the landing gear door and the landing gear based on the one or more first signals and the one or more second signals, and wherein controlling the movement comprises controlling the movement of the other of the landing gear door and the landing gear based on the determined relative position.

Optionally, the method comprises the landing gear controller receiving one or more third signals indicative of the relative position of the landing gear door and the landing gear, and controlling the movement comprises controlling the movement of the other of the landing gear door and the landing gear based on the one or more third signals indicative of the relative position.

A third aspect of the invention provides a non-transitory computer readable storage medium storing instructions for: the instructions, when executed by a processor of a landing gear controller of an aircraft, cause the processor to carry out a method according to the second aspect of the invention.

A fourth aspect of the invention provides a landing gear controller for an aircraft system, the landing gear controller comprising a processor configured to implement a method according to the second aspect of the invention.

A fifth aspect of the invention provides a landing gear controller for an aircraft, the landing gear controller comprising: a receiver configured to receive one or more signals from at least one position sensor of an aircraft system when a landing gear door or landing gear, respectively, partially passes between two limits of travel, the one or more signals being indicative of a position of one of the landing gear door and landing gear; a determiner configured to determine one or more instructions for controlling movement of the other of the landing gear door and the landing gear based on the one or more signals; and a transmitter configured to transmit the one or more instructions to a motion system configured to move the other of the landing gear door and the landing gear.

Optionally, the receiver is configured to receive one or more additional signals, and the determiner is configured to determine the one or more instructions based on the one or more additional signals.

Optionally, the one or more additional signals are indicative of one or more of: a pitch angle of the landing gear bogie, a status of another landing gear or another landing gear door, a status of one or more aircraft engines, a fault or defect in an aircraft component or aircraft system, and an aircraft yaw angle.

Optionally, the one or more instructions are for initiating movement of one of the landing gear door and the landing gear while the other of the landing gear door and the landing gear partially passes through the range of travel.

Optionally, the one or more instructions are for changing a speed of movement of the other of the landing gear door and the landing gear.

Optionally, the one or more instructions for varying the speed of movement of the other of the landing gear door and the landing gear comprise one or more instructions for controlling the rate of actuation of one or more rate-controllable actuators of the landing gear door movement system or the landing gear movement system.

Optionally, the determiner is configured to determine one or more instructions for varying the speed of movement of one of the landing gear door and the landing gear based on the position or speed of movement of the other of the landing gear door and the landing gear.

Optionally, the receiver is configured to receive one or more signals from at least one position sensor continuously or repeatedly.

Optionally, the determiner is configured to determine a speed of movement of one of the landing gear door and the landing gear based on one or more signals continuously or repeatedly received from the at least one position sensor, and the determiner is configured to determine the one or more instructions based on the determined speed of movement.

Optionally, the receiver is configured to receive one or more first signals indicative of the position of the landing gear door when the landing gear door partially passes through its range of travel, and to receive one or more second signals indicative of the position of the landing gear door when the landing gear partially passes through its range of travel; the determiner is configured to determine a relative position of the landing gear door and the landing gear based on the one or more first signals and the one or more second signals, and the determiner is configured to determine one or more instructions based on the determined relative position.

Optionally, the receiver is configured to receive one or more signals indicative of the relative position of the landing gear door and the landing gear, and the determiner is configured to determine the one or more instructions based on the one or more signals indicative of the relative position.

A sixth aspect of the invention provides an aircraft comprising an aircraft system according to the first aspect of the invention, a non-transitory computer readable storage medium according to the third aspect of the invention, or a landing gear controller according to the fourth or fifth aspect of the invention.

It should be noted that, herein, the phrase "movement between a and B" covers movement from a to B and movement from B to a. In some examples, the movement is from a to B, and in other examples the movement is from B to a.

Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic view of an aircraft system;

FIG. 2 is a flow chart illustrating an example of a method of operating a landing gear controller for an aircraft;

FIG. 3 shows a schematic diagram of an example of a non-transitory computer-readable storage medium;

FIG. 4 is a graph comparing a landing gear retraction procedure with a comparative landing gear retraction procedure; and

fig. 5 shows a schematic front view of an aircraft.

Detailed Description

Landing gear may affect aircraft performance. In the extended position, the landing gear may increase aircraft drag, which can reduce the rate of climb of the aircraft during takeoff, and may increase aircraft noise, which can be disturbing to people on the ground in the vicinity of the aircraft. A similar effect may result with landing gear doors in the open position.

Typically, movement of each landing gear and associated landing gear door is initiated by a pilot manually operating a cockpit flight control, such as a landing gear lever. Typically, operation of the cockpit flight control causes one or more landing gear door actuators to drive the landing gear doors to move from a closed position to an open position, then the one or more landing gear actuators extend or retract the landing gear, and then the one or more landing gear door actuators drive the landing gear doors to move from the open position to the closed position. This series of operations is sequential in that the landing gear doors must be fully open before the landing gear can be extended or retracted, and the landing gear doors must be fully extended or retracted (and typically locked) before they can be moved from the open to the closed position. This sequence is typically controlled based on an output from a proximity sensor or switch that detects when the landing gear doors are fully open or closed and the landing gear is fully extended or retracted.

During the takeoff procedure, the pilot will typically manually initiate the gear retraction procedure upon confirming a positive aircraft climb rate. Such confirmation may occur about three seconds after takeoff. Since the takeoff procedure is one of the highest workload flight phases for flight crew, there is a tendency to delay retraction of the landing gear after takeoff to spread the various actions that flight crew must perform during takeoff over a longer period of time. Similarly, since the landing procedure is also one of the highest workload flight phases for the flight crew, there is a tendency to perform the reach landing gear well before landing in order to spread the various actions that the flight crew must perform during landing over a longer period of time.

Some examples discussed herein relate to enabling landing gear retraction to be completed earlier after takeoff, in particular as this can help to reduce aircraft drag. This in turn may enable an increased rate of climb of the aircraft to help avoid obstacles on the ground, and/or may allow an increase in the maximum takeoff weight of the aircraft for a given size of landing gear system, wing capacity and engine thrust. Similarly, enabling landing gear retraction to be completed earlier in a takeoff procedure may help to reduce the overall aircraft noise caused during the takeoff procedure, or at least reduce the period of time during which the aircraft is producing increased noise due to the extended landing gear.

Some examples discussed herein relate to enabling landing gear to extend closer to landing, particularly as this may help to reduce aircraft drag and aircraft noise, or at least reduce the period of time during which the aircraft generates increased noise due to extending the landing gear.

Reducing the time for landing gear extension and landing gear door opening may also reduce the risk of damage to the landing gear or landing gear door, such as from wind or hail impacts, bird strikes, or lightning strikes. While these and other advantages can be achieved, the authority to keep the landing gear retracted or extended depends on the pilot or other operator.

FIG. 1 shows a schematic view of an aircraft system according to an example. Broadly speaking, the aircraft system 100 includes a landing gear door system 110, a landing gear system 120, a plurality of position sensors 131, 132, 133 (which may be considered a plurality of displacement sensors 131, 132, 133), and a landing gear controller 140. Each of these elements is described in more detail below.

The landing gear door system 110 includes a landing gear door 111 and a landing gear door movement system 112. The landing gear door motion system 112 is operable to move the landing gear door 111 within a range of travel 113 between a closed position and an open position. The closed and open positions may be considered to be the limits of travel of the landing gear door 111. In this example, the landing gear door 111 rotates about a pivot between a closed position and an open position, but in other examples the landing gear door 111 may move between the closed position and the open position in other ways, such as linearly or curvilinearly. In fig. 1, the landing gear door 111 is depicted in the closed position using solid lines, and the "ghost (ghost)" of the landing gear door 111 in the open position is depicted using dashed lines. As can be seen in fig. 1, the landing gear door 111 at least partially covers the landing gear bay 115 when in the closed position.

The landing gear system 120 includes a landing gear 121 and a landing gear movement system 122. The landing gear movement system 122 is operable to move the landing gear 121 within a range of travel 123 between an extended position and a retracted position. The extended and retracted positions may be considered to be the limits of travel of the landing gear 121. In this example, the landing gear 121 rotates about a pivot member between the extended and retracted positions, but in other examples the landing gear 121 may move between the extended and retracted positions in other manners, such as linearly or curvilinearly. In fig. 1, the landing gear 121 is depicted in a retracted position using solid lines, and the "ghost shadow (ghost)" of the landing gear 121 in an extended position is depicted using dashed lines. As can also be seen in fig. 1, the landing gear 121 is at least partially positioned in the gear well 115 when in the retracted position.

The landing gear door 111 may be considered to be associated with the landing gear 121 and the landing gear bay 115. When the landing gear door 111 at least partially covers the gear bay 115 when in the closed position, the landing gear door 111 helps to protect the gear bay 115 and the landing gear 121 stowed in the bay 115 from debris that may be thrown towards the bay 115 when the aircraft is moving over the ground. Furthermore, the closed landing gear doors 111 assist in aerodynamic forces when the aircraft is in flight, as the closed landing gear doors 111 help to "clear" the exterior surface of the aircraft.

In this example, the landing gear door motion system 112 includes one or more rate-controllable actuators 114 (only one rate-controllable actuator is schematically depicted in figure 1 for clarity) operable to move the landing gear door 111 within a range of travel 113 between a closed position and an open position. The rate-controllable actuator 114 may be pivotably and/or slidably coupled to the landing gear door 111. A rate-controllable actuator 114 may be used to move the landing gear doors 111 from a closed position to an open position, and from an open position to a closed position. Alternatively, one or more first rate-controllable actuators may be provided for moving the landing gear door 111 from the open position to the closed position, and one or more second rate-controllable actuators may be provided for moving the landing gear door 111 from the closed position to the open position. The or each rate-controllable actuator 114 may take any suitable form, such as a hydraulic actuator, an electro-hydraulic actuator or an electric actuator.

Although not depicted in fig. 1 for clarity, the aircraft system 100 may include one or more landing gear bay door locks for locking the landing gear door 111 in the closed position, and/or one or more landing gear bay door locks for locking the landing gear door 111 in the open position. Each of the one or more landing gear bay door locks may take any suitable form, such as a hydraulically actuated lock, an electro-hydraulically actuated lock, or an electrically actuated lock. In some cases, one or more of the landing gear bay door locks may be omitted. For example, the landing gear doors 111 may be held in a closed position by one or more rate controllable actuators 114.

The landing gear movement system 122 includes one or more rate-controllable actuators 124 (only one rate-controllable actuator 124 is depicted in fig. 1 for clarity) operable to move the landing gear 121 within a range of travel 123 between the extended and retracted positions. The rate-controllable actuator 124 may be pivotably and/or slidably coupled to the landing gear 121. The rate-controllable actuator 124 may be used to move the landing gear 121 from the retracted position to the extended position, and from the extended position to the retracted position. Alternatively, one or more first rate-controllable actuators may be provided for moving the landing gear 121 from the retracted position to the extended position, and one or more second rate-controllable actuators may be provided for moving the landing gear door 111 from the extended position to the retracted position. The or each rate-controllable actuator 124 may take any suitable form, such as a hydraulic actuator, an electro-hydraulic actuator or an electric actuator.

The landing gear door motion system 112 and the landing gear motion system 122 may be supplied with electrical power from a common (e.g., electrical or hydraulic) power source. In other examples, the landing gear door motion system 112 and the landing gear motion system 122 may receive power from respective different (e.g., electrical or hydraulic) power sources.

Although not shown in fig. 1 for clarity, the aircraft system 100 may include one or more landing gear locks for locking the landing gear 121 in the retracted position and/or one or more landing gear locks for locking the landing gear in the extended position. Typically, such landing gear locks are spring-actuated mechanical locks that are unlocked by operation of an actuator. Each of the one or more landing gear locks may take any suitable form, such as a hydraulically actuated lock, an electro-hydraulically actuated lock, or an electrically actuated lock. In some cases, one or more landing gear locks may be omitted. For example, the landing gear 121 may be held in a retracted position by one or more rate-controllable actuators 124.

The first position sensor 131 of the plurality of position sensors is a landing gear door system position sensor. The first position sensor 131 is configured to sense the position of a portion of the landing gear door system 110 as the landing gear door 111 partially passes through its range of travel 113 and output one or more first signals indicative of that position. The position may be, for example, the position of the part of the landing gear door system 110 relative to the landing gear bay 115, or relative to another part of the aircraft that is fixed relative to the landing gear bay 115. In this example, the portion of the landing gear door system 110 is the landing gear door 111 itself. In other examples, the portion of the landing gear door system 110 may be part of one or more rate-controllable actuators 114, for example. In this example, the first position sensor 131 is fixed in the landing gear bay 115 or relative to the landing gear bay 115, and the first position sensor 131 is configured to sense the position of the portion of the landing gear door system 110 (in this example the landing gear door 111) relative to the first position sensor 131. In other examples, the first position sensor 131 may be mounted on the portion of the landing gear door system 110, such as the landing gear door 111, for example, and the first position sensor 131 is configured to sense the position of the portion of the landing gear door system 110 relative to the landing gear bay 115 or another portion of the aircraft that may be fixed relative to the landing gear bay 115.

In some examples, the first position sensor 131 may be configured to continuously or repeatedly sense the position of a portion of the landing gear door system 110, and to continuously or repeatedly output one or more first signals indicative of the position of the portion of the landing gear door system 110, in use. The landing gear controller 140 is communicatively connected (by a wired or wireless connection) to the first position sensor 131 and is configured to receive, in use, one or more first signals from the first position sensor 131, such as one or more first signals continuously or repeatedly output by the first position sensor 131.

The second position sensor 132 of the plurality of position sensors is a landing gear system position sensor. The second position sensor 132 is configured to sense a position of a portion of the landing gear system 120 as the landing gear 121 passes through its range of travel 123 and output one or more second signals indicative of the position. The position may be, for example, the position of the portion of the landing gear system 120 relative to the landing gear bay 115, or another portion of the aircraft that may be fixed relative to the landing gear bay 115. In this example, the portion of the landing gear system 120 is the landing gear 121 itself. In other examples, the portion of the landing gear system 120 may be part of one or more rate-controllable actuators 124, for example. In this example, the second position sensor 132 is fixed in the gear well 115 or relative to the gear well 115, and the second position sensor 132 is configured to sense the position of the portion of the landing gear system 120 (in this example, the landing gear 121) relative to the second position sensor 132. In other examples, the second position sensor 132 may be, for example, mounted on the portion of the landing gear system 120, such as on the landing gear 121, and the second position sensor 132 is configured to sense the position of the landing gear system 120 relative to the landing gear bay 115 or another portion of the aircraft that may be fixed relative to the landing gear bay 115.

In some examples, the second position sensor 132 may be configured to continuously or repeatedly sense a position of a portion of the landing gear system 120, and to continuously or repeatedly output one or more second signals indicative of the position of the landing gear system 120, in use. The landing gear controller 140 is communicatively connected (by a wired or wireless connection) to the second position sensor 132 and is configured to receive, in use, one or more second signals from the second position sensor 132, such as one or more second signals continuously or repeatedly output by the second position sensor 132.

Each of the first and second position sensors 131, 132 may be configured to sense one or more of an angular position, a linear position, and a curvilinear position of a portion of the landing gear door system 110 or a portion of the landing gear system 120, respectively.

A third position sensor 133 of the plurality of position sensors is a relative position sensor configured to sense the relative position of the landing gear door 111 and the landing gear 121 and output one or more third signals indicative of the relative position. The third position sensor 133 is configured to sense the relative position and output one or more third signals indicative of the relative position when the landing gear door 111 partially passes through its range of travel 113 and/or the landing gear 121 partially passes through its range of travel 123. In this example, a third position sensor 133 is mounted on the landing gear door 111 and is configured to sense the position of the landing gear 121 relative to the third position sensor 133. In other examples, the third position sensor 133 may be mounted on the landing gear 121, for example, and configured to sense the position of the landing gear door 111 relative to the third position sensor 133.

In some examples, the third position sensor 133 may be configured to continuously or repeatedly sense the relative positions of the landing gear doors 111 and the landing gear 121, and to continuously or repeatedly output one or more third signals indicative of the relative positions, in use. The landing gear controller 140 is communicatively connected (by a wired or wireless connection) to the third position sensor 133 and is configured to receive, in use, one or more third signals from the third position sensor 133, such as one or more third signals continuously or repeatedly output by the relative position sensor 133.

It should be noted that in some examples, the plurality of position sensors 131, 132, 133 are not proximity sensors (also referred to as proximity switches). Proximity sensors determine the presence or absence of a target in a particular location and generate a simple digital or on/off output accordingly. Examples of proximity sensors are hall effect sensors, microswitches, and laser systems configured to sense the presence of a target through an interrupted path between a laser transmitter and receiver. Instead, each of the plurality of position sensors 131, 132, 133 (or displacement sensors 131, 132, 133) is configured to make a true measurement of position or displacement and output a signal representative of the measurement. Each of the signals output by one of the plurality of position sensors 131, 132, 133 may be proportional to a position relative to the sensor 131, 132, 133 and/or the portion sensed along the path. Knowing the actual positions of the landing gear doors 111 and the landing gear 121 may also facilitate troubleshooting.

Each of the first, second, and third position sensors 131, 132, 133 may, for example, include one or more of the following: a variable differential transformer (such as a rotary variable differential transformer or a linear variable differential transformer); a potentiometer which may be a digital potentiometer (e.g., a rotary potentiometer or a linear potentiometer); an optical sensor; and a laser position sensor or displacement sensor. Other suitable types of position sensors will be apparent to the skilled person.

The landing gear controller 140 is operatively coupled to the landing gear door motion system 112 and to the landing gear motion system 122. The landing gear controller 140 is configured to receive, in use, one or more first signals from the first position sensor 131 and to control movement of the landing gear 121 by controlling operation of the landing gear movement system 122 based on the one or more first signals. Thus, the landing gear controller 140 controls movement of the landing gear 121 based on the received indication of the position of the one or more landing gear doors 111 while the landing gear doors 111 are in a position between the open and closed positions. In some examples, the landing gear controller 140 initiates movement of the landing gear 121 or causes the landing gear 121 to begin movement based on one or more first signals received from the first position sensor 131.

In this example, the landing gear controller 140 is further configured to receive, in use, one or more second signals from the second position sensor 132 and to control movement of the landing gear door 111 by controlling operation of the landing gear door movement system 112 based on the one or more second signals. Thus, the landing gear controller 140 controls movement of the landing gear doors 111 based on the received indication of the position of the one or more landing gears 121 while the landing gears 121 are in a position between the retracted and extended positions. In some examples, the landing gear controller 140 initiates movement of the landing gear door 111 or causes the landing gear door 111 to begin movement based on one or more second signals received from the second position sensor 132.

In some examples, the first position sensor 131 may be omitted, and the landing gear controller 140 may not be configured to control the movement of the landing gear 121 based on the received indication of the position of the one or more landing gear doors 111 while the landing gear doors 111 are in a position between the open and closed positions. In some such examples, the landing gear controller 140 may still be configured to receive one or more second signals from the second position sensor 132 and control movement of the landing gear door 111 by controlling operation of the landing gear door movement system 112 based on the one or more second signals. In some such examples, the third position sensor 133 may also be omitted.

In some examples, the second position sensor 132 may be omitted, and the landing gear controller 140 may not be configured to control movement of the landing gear doors 111 based on the received indication of the position of the one or more landing gears 121 while the landing gears 121 are in a position between the extended and retracted positions. In some such examples, the landing gear controller 140 may still be configured to receive one or more first signals from the first position sensor 131 and control the movement of the landing gear 121 by controlling the operation of the landing gear movement system 122 based on the one or more first signals. In some such examples, the third position sensor 133 may also be omitted.

The landing gear controller 140 may include a receiver 142, a determiner 144, and a transmitter 146, as will be described in more detail below and as shown in fig. 1. The determiner 144 can be communicably coupled to the receiver 142 and to the transmitter 146. The landing gear controller 140, or at least the determiner 144 thereof, may include a processor, such as a microprocessor.

An example landing gear retraction procedure will now be described with reference to figures 1 and 4. FIG. 4 is a graph comparing a landing gear retraction procedure with a comparative landing gear retraction procedure.

Initially, the landing gear 121 is in the extended position shown in dashed lines in fig. 1, and the landing gear doors 111 are in the closed position shown in solid lines in fig. 1.

In response to appropriate instructions from the cockpit flight controller 150 received via a communication link at the landing gear controller 140 (such as at its receiver 142), the landing gear controller 140 controls the movement of the landing gear doors 111 from the closed position to the open position by controlling the operation of the landing gear door movement system 110. More specifically, at time T1 in fig. 4, the landing gear controller 140 initiates movement of the landing gear door 111 from the closed position, or causes the landing gear door 111 to begin moving from the closed position. For example, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for controlling the movement of the landing gear door 111, and the transmitter 146 may be configured to transmit the one or more instructions to the landing gear door movement system 112. Movement of the landing gear door 111 from the closed position to the open position is depicted by line 401 in figure 4.

The landing gear controller 140 receives one or more first signals from the first position sensor 131 during this movement of the landing gear door 111 from the closed position. The one or more first signals are received at the receiver 142 and indicate the position of the landing gear door 111, such as relative to the landing gear bay 115 or relative to the range of travel 113. At time T2 in fig. 4, the landing gear door 111 partially passes through its range of travel. More specifically, in this example, at time T2, the landing gear door 111 has covered approximately 95% of its range of travel from the closed position to the open position. In other embodiments, the percentage may be different, such as another value in the range of 50% to 99% or in the range of 70% to 98%.

Based on the one or more first signals, the landing gear controller 140 is configured to control movement of the landing gear 121 from the extended position toward the retracted position by controlling operation of the landing gear movement system 122. More specifically, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for controlling the movement of the landing gear 121 based on the one or more first signals received at the receiver 142, and the transmitter 146 may be configured to transmit the one or more instructions to the landing gear movement system 122. Movement of the landing gear 121 from the extended position to the retracted position is depicted by line 402 in fig. 4.

For example, the determiner 144 may be configured to initiate movement of the landing gear 121 from the extended position toward the retracted position or to cause the landing gear 121 to begin moving from the extended position toward the retracted position when: when the determiner 144 determines that the landing gear door 111 is in an out of path position for moving the landing gear 121 from the extended position to the retracted position. In some examples, the landing gear controller is configured to determine, in use, a relative position of the landing gear door 111 and the landing gear 121 based on the one or more first signals and the one or more second signals and to control movement of the landing gear 121 based on the determined relative position.

Alternatively, as described above, the first position sensor 131 may be configured to continuously or repeatedly sense the position of the landing gear door 111 and continuously or repeatedly output one or more first signals indicative of the landing gear position for receipt by the receiver 142 of the landing gear controller 140, in use. The landing gear controller 140 (such as the determiner 144 thereof) may be configured to determine the speed of movement of the landing gear door 111 along the path based on one or more first signals output continuously or repeatedly by the first position sensor 131 and received at the receiver 142. The landing gear controller 140 (such as its determiner 144) may be configured to control the movement of the landing gear 121 by controlling the operation of the landing gear movement system 122 based on the determined movement speed. For example, the determiner 144 may be configured to initiate movement of the landing gear 121 from the extended position toward the retracted position or to cause the landing gear 121 to begin moving from the extended position toward the retracted position when: when the determiner 144 determines that the landing gear 121 does not contact the landing gear door 111 during movement of the landing gear 121 from the extended position to the retracted position based on the determined speed of movement of the landing gear door 111. That is, the determiner 144 may be configured to determine, based on the determined speed of movement of the landing gear door 111, that the landing gear door 111 will yield the path of the landing gear 121 when the landing gear 121 reaches a position that intersects the path of the landing gear door 111.

Thus, in this example, the landing gear controller 140 is configured to initiate movement of the landing gear 121 from the extended position toward the retracted position or to cause the landing gear 121 to begin moving from the extended position toward the retracted position at time T2, before the landing gear doors 111 have reached the fully open position at T3.

As can be seen from fig. 4, in this example, movement of the landing gear 121 from the extended position towards the retracted position begins at a relatively low first rate at T2 and then proceeds at a higher second rate. In some examples, the landing gear controller 140 is configured to vary the speed of movement of the landing gear 121 by appropriately controlling the operation of the landing gear movement system 122 based on the one or more first signals indicative of the position of the landing gear door 111. For example, the landing gear controller 140 may control the actuation rate of one or more rate-controllable actuators 124 of the landing gear motion system 122. More specifically, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for moving the landing gear 121, and the transmitter 146 may be configured to then transmit the one or more instructions to the landing gear movement system 122 to cause movement.

In some examples, the landing gear controller 140 is configured to vary the speed of movement of the landing gear 121 based on the position and speed of movement of the landing gear door 111. As described above, the landing gear controller 140 (such as the determiner 144 thereof) may determine the position or speed of movement of the landing gear door 111 based on one or more first signals output continuously or repeatedly by the first position sensor 131 and received at the receiver 142. In some cases, the landing gear controller 140 (such as its determiner 144) is configured to repeatedly determine the position and speed of movement of the landing gear doors 111, and to repeatedly change the speed of movement of the landing gear 121 accordingly.

Thus, the determiner 144 is configured to initiate relatively slow movement of the landing gear 121 from the extended position towards the retracted position or cause relatively slow movement of the landing gear 121 from the extended position towards the retracted position, such as when the landing gear door 111 is away from the landing gear 121 but still occupies a portion of the path of the landing gear 121. The determiner 144 may also be configured to cause the rate of movement of the landing gear 121 to increase when: the determiner 144 determines, based on the rate of movement of the landing gear door 111, that the landing gear door 111 will yield the path of the landing gear 121 when the landing gear 121 reaches a position that intersects the path of the landing gear door 111.

The landing gear door 111 then reaches the open position at time T3, and the landing gear controller 140 stops the movement of the landing gear door 111. For example, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for stopping movement of the landing gear door 111, and the transmitter 146 may be configured to transmit the one or more instructions to the landing gear door movement system 112. Alternatively, the landing gear door 111 or a portion of the landing gear door motion system 112 may simply contact a mechanical stop.

Thus, it will be noted from fig. 4 that in this example, both the landing gear door 111 and the landing gear 121 move between time T2 and time T3. Thus, movement of the landing gear 121 from the extended position begins earlier than during retraction of the landing gear of the comparative example, where movement of the landing gear 121 from the extended position begins after the landing gear door 111 reaches the open position at time T3. The movement of the landing gear 121 from the extended position to the retracted position during retraction of the comparative example landing gear is depicted by line 402' in figure 4.

Although this is not necessarily the case in all examples, the speed of movement of the landing gear door 111 between time T2 and time T3 is less than the speed of movement between time T1 and time T2, as shown in fig. 4. This may help to mitigate the shock experienced by the landing gear door 111 when the landing gear door 111 reaches the open position, and may also help to reduce the load on the power supply that supplies power to both the landing gear door motion system 112 and the landing gear motion system 122 during this period of time. This may be accomplished by providing a buffering system, as will be known and understood by those skilled in the art. Alternatively, in some examples, the landing gear controller 140 may be configured to control movement of the landing gear door 111 based on the one or more first signals by appropriately controlling operation of the landing gear door movement system 112 such that the movement is slowed. More specifically, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for slow movement of the landing gear door 111 based on the one or more first signals received at the receiver 142. The one or more first signals may indicate that the landing gear door 111 has reached a predetermined position or a predetermined percentage, such as 95%, of the range of travel of the landing gear door 111 from the closed position to the open position, or another value in the range of 50% to 99% or in the range of 70% to 98%. The transmitter 146 may be configured to then transmit the one or more instructions to the landing gear door motion system 112 to cause the slow motion. In some examples, the landing gear controller 140 is configured to vary the speed of movement of the landing gear door 111, in use, by controlling the rate of actuation of the one or more rate controllable actuators 114 of the landing gear door movement system 112.

The initiation time or starting time for movement of the landing gear 121 from the extended position may be T2, as shown in fig. 4. In other examples, the actuation time or start time for movement of the landing gear 121 from the extended position is before T2 or after T2. However, preferably, this activation time or start time is at T2 or after T2, such that the load on the (e.g., electrical or hydraulic) power source that simultaneously provides power to the landing gear door motion system 112 and the landing gear motion system 122 is mitigated as compared to the following: the landing gear door 111 is driven to move between the positions of the landing gear door 111 at times T2 and T3 at the same high rate of movement as between times T1 and T2. Furthermore, the start time or starting time for movement of the landing gear 121 from the extended position is preferably before the time T3 when the landing gear doors 111 are fully open, so as to enable the overall time to complete the landing gear retraction process to be reduced. In some examples, the start time or start time of the movement of the landing gear 121 from the extended position itself can cause slow movement of the landing gear door 111 between time T2 and time T3 because the demand for the power source by the landing gear movement system 122 reduces the power available from the power source in order to simultaneously operate the landing gear door movement system 112.

The landing gear controller 140 receives one or more second signals from the second position sensor 132 during movement of the landing gear 121 from the extended position. The one or more second signals are received at the receiver 142 and indicate a position of the landing gear 121, such as relative to the gear well 115 or relative to the range of travel 123. At time T5 in fig. 4, the landing gear 121 partially passes through its range of travel. More specifically, in this example, at time T5, the landing gear 121 has covered approximately 95% of its range of travel from the extended position to the retracted position. In other examples, the percentage may be different, such as in the range of 50% to 99% or another value in the range of 70% to 98%.

Based on the one or more second signals, the landing gear controller 140 is configured to control movement of the landing gear door 111 from the open position towards the closed position by controlling operation of the landing gear door movement system 112. More specifically, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for controlling the movement of the landing gear door 111 based on the one or more second signals received at the receiver 142, and the transmitter 146 may be configured to transmit the one or more instructions to the landing gear door movement system 112. Movement of the landing gear door 111 from the open position to the closed position is depicted by line 403 in figure 4.

For example, the determiner 144 may be configured to initiate movement of the landing gear door 111 from the open position towards the closed position or to cause movement of the landing gear door 111 from the open position towards the closed position, if: the determiner 144 determines that the landing gear 121 is in a path-out position for moving the landing gear door 111 from the open position to the closed position. In some examples, the landing gear controller is configured to determine, in use, the relative position of the landing gear door 111 and the landing gear 121 based on the one or more first signals and the one or more second signals, and to control movement of the landing gear door 111 based on the determined relative position.

Alternatively, as described above, the second position sensor 132 may be configured to continuously or repeatedly sense the position of the landing gear 121 and continuously or repeatedly output one or more second signals indicative of the position of the landing gear 121 for receipt by the receiver 142 of the landing gear controller 140, in use. The landing gear controller 140 (such as the determiner 144 thereof) may be configured to determine a speed of movement of the landing gear 121 along the path based on the one or more second signals output by the second position sensor 132 and received at the receiver 142, either continuously or repeatedly. The landing gear controller 140 (such as its determiner 144) may be configured to control movement of the landing gear door 111 by controlling operation of the landing gear door movement system 112 based on the determined speed of movement. For example, the determiner 144 may be configured to initiate movement of the landing gear door 111 from the open position towards the closed position or to cause movement of the landing gear door 111 from the open position towards the closed position when: when the determiner 144 determines that the landing gear door 111 does not contact the landing gear 121 during movement of the landing gear door 111 from the open position to the closed position based on the determined speed of movement of the landing gear 121. That is, the determiner 144 may be configured to determine, based on the determined speed of movement of the landing gear 121, that the landing gear 121 will yield the path of the landing gear door 111 when the landing gear door 111 reaches a position that intersects the path of the landing gear 121.

Thus, in this example, the landing gear controller 140 is configured to initiate movement of the landing gear doors 111 from the open position towards the closed position or to cause movement of the landing gear doors 111 from the open position towards the closed position at T5, before the landing gear 121 has reached the fully retracted position at time T6.

As can be seen in figure 4, in this example, the movement of the landing gear door 111 from the open position towards the closed position starts at a relatively low rate at T5 and then proceeds at a higher rate. In some examples, the landing gear controller 140 is configured to vary the speed of movement of the landing gear door 111 by appropriately controlling the operation of the landing gear door movement system 112 based on one or more second signals indicative of the position of the landing gear 121. For example, the landing gear controller 140 may control the actuation rate of one or more rate-controllable actuators 114 of the landing gear door motion system 112. More specifically, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for moving the landing gear door 111, and the transmitter 146 may be configured to then transmit the one or more instructions to the landing gear door motion system 112 to cause the motion.

In some examples, the landing gear controller 140 is configured to vary the speed of movement of the landing gear door 111 based on the position and speed of movement of the landing gear 121. As described above, the landing gear controller 140 (such as the determiner 144 thereof) may determine the position or speed of movement of the landing gear 121 based on one or more second signals continuously or repeatedly output by the second position sensor 132 and received at the receiver 142. In some cases, the landing gear controller 140 (such as its determiner 144) is configured to repeatedly determine the position and speed of movement of the landing gear 121, and to repeatedly change the speed of movement of the landing gear door 111 accordingly.

Thus, the determiner 144 may be configured to activate the landing gear door 111 to move relatively slowly from the open position towards the closed position or to cause the landing gear door 111 to move relatively slowly from the open position towards the closed position, such as when the landing gear 121 is away from the landing gear door 111 but still occupies a portion of the path of the landing gear door 111. The determiner 144 may also be configured to cause the rate of movement of the landing gear door 111 to increase when: when the determiner 144 determines, based on the speed of movement of the landing gear 121, that the landing gear 121 will yield the path of the landing gear door 111 when the landing gear door 111 reaches a position that intersects the path of the landing gear 121.

The landing gear 121 then reaches the retracted position at time T6, and the landing gear controller 140 stops the movement of the landing gear 121. For example, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for stopping the movement of the landing gear 121, and the transmitter 146 may be configured to transmit the one or more instructions to the landing gear movement system 122. Alternatively, the landing gear 121 or a portion of the landing gear movement system 122 may simply contact a mechanical stop.

Thus, it will be noted from fig. 4 that in this example, both the landing gear doors 111 and the landing gear 121 move between time T5 and time T6. Thus, movement of the landing gear door 111 from the open position begins earlier than during retraction of the landing gear of the comparative example, where movement of the landing gear door 111 from the open position begins at time T5 '(shown at the top of fig. 4), which is after the landing gear 121 has reached the retracted position at time T6'. The movement of the landing gear door from the open position to the closed position during retraction of the landing gear of the comparative example is depicted by line 403' in figure 4.

Although this need not be the case in all examples, the time T4 is between times T2 and T6, and the speed of movement of the landing gear 121 may be less between times T4 and T6 than between times T2 and T4, as shown in fig. 4. This may help to reduce the shock experienced by the landing gear 121 as the landing gear 121 reaches the retracted position, and may also help to reduce the load on the power supply that simultaneously supplies power to the landing gear door motion system 112 and the landing gear motion system 122 during this period of time. This may be accomplished by providing a buffering system, as will be known and understood by those skilled in the art. Alternatively, in some examples, the landing gear controller 140 may be configured to control the movement of the landing gear 121 based on the one or more second signals by appropriately controlling the operation of the landing gear movement system 122 such that the movement is slowed. More specifically, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for causing slow movement of the landing gear 121 based on the one or more second signals received at the receiver 142. The one or more second signals may indicate that the landing gear 121 has reached a predetermined position or a predetermined percentage, such as 95%, of its range of travel from the extended position to the retracted position, or another value in the range of 50% to 99% or in the range of 70% to 98%. The transmitter 146 may be configured to then transmit the one or more instructions to the landing gear movement system 122 to cause the slow movement. In some examples, the landing gear controller 140 is configured to vary the speed of movement of the landing gear 121, in use, by controlling the rate of actuation of the one or more rate-controllable actuators 124 of the landing gear movement system 122.

The initiation time or starting time for movement of the landing gear door 111 from the open position may be after T4, as shown in figure 4. In other examples, the start time or starting time for movement of the landing gear door 111 from the open position may be at T4. However, preferably, this activation time or start time is at T4 or after T4, such that the load on the (e.g., electrical or hydraulic) power source that simultaneously provides power to the landing gear door motion system 112 and the landing gear motion system 122 is mitigated as compared to the following: the landing gear 121 is driven to move between its positions at times T4 and T6 at the same high rate of motion as between times T2 and T4. Furthermore, the initiation or starting time for movement of the landing gear doors 111 from the open position is preferably before time T6 when the landing gear 121 is fully retracted, so as to enable the overall time to complete the landing gear retraction process to be reduced. In some examples, the initiation of the movement of the landing gear door 111 from the open position or the initiation of the movement itself can cause slow movement of the landing gear 121 between time T4 and time T6 because the demand of the power source by the landing gear door motion system 112 reduces the available power from the power source in order to simultaneously operate the landing gear motion system 122.

The landing gear door 111 then reaches the closed position at time T8, and the landing gear controller 140 stops the movement of the landing gear door 111. For example, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for stopping movement of the landing gear door 111, and the transmitter 146 may be configured to transmit the one or more instructions to the landing gear door movement system 112.

The time T7 is between the times T5 and T8, and the speed of movement of the landing gear door 111 may be less between the times T7 and T8 than between the times T5 and T7, as shown in fig. 4. This may help to reduce the shock experienced by the landing gear door 111 when the landing gear door 111 reaches the closed position. Again, this may be achieved by providing a buffering system, as will be known and understood by those skilled in the art. Alternatively, in some examples, the landing gear controller 140 may be configured to control the movement of the landing gear door 111 by appropriately controlling the operation of the landing gear door motion system 112 based on one or more first signals output by the first position sensor 131 during the closing of the landing gear door 111 such that the movement is slowed. More specifically, the determiner 144 of the landing gear controller 140 may be configured to determine one or more instructions for causing slow movement of the landing gear door 111 based on the one or more first signals received at the receiver 142. The one or more first signals may indicate that the landing gear door 111 has reached a predetermined position or a predetermined percentage, such as 95%, of its range of travel from the open position to the closed position, or another value in the range of 50% to 99% or in the range of 70% to 98%. The transmitter 146 may be configured to then transmit the one or more instructions to the landing gear door motion system 112 to cause slow motion. In some examples, the landing gear controller 140 is configured to vary the speed of movement of the landing gear door 111, in use, by controlling the rate of actuation of the one or more rate controllable actuators 114 of the landing gear door movement system 112.

It will be seen from figure 4 that during the course of the comparative example the landing gear door reaches the closed position at time T8 ', after time T8' at time T8 at which the landing gear door 111 reaches the closed position in this example. That is, the present example enables the overall time to complete the landing gear retraction process to be reduced. This reduction in time is indicated at 404 in fig. 4.

As mentioned above, the reduction in time results from: (a) movement of the landing gear doors 111 from the open position toward the closed position at time T5 is initiated or commenced before the landing gear doors 111 have reached the fully open position at time T3 (b) movement of the landing gear doors 121 from the extended position toward the retracted position at time T2 is initiated or commenced before the landing gear 121 has reached the fully retracted position at time T6. However, in other examples, either (a) or (b) may be omitted and the overall time to complete the landing gear retraction process is still reduced.

As mentioned above, the third position sensor 133 is configured to sense the relative positions of the landing gear door 111 and the landing gear 121, in use. In some examples, the landing gear controller 140 utilizes one or more third signals output by the third position sensor 133 as a safety feature. In some such examples, the receiver 142 of the landing gear controller 140 is configured to receive the one or more third signals, and the determiner 144 is configured to determine one or more instructions for controlling movement of the landing gear door 111 and/or the landing gear 121 based on the one or more third signals indicative of the relative position. For example, the determiner 144 may be configured to: the movement of the landing gear doors 111 and/or the landing gear 121 is delayed or stopped when the determiner 144 determines that movement of the landing gear doors 111 and/or the landing gear 121 may otherwise cause a collision between the landing gear doors 111 and the landing gear 121.

The first position sensor 131 may be omitted in some examples including the second position sensor 132 and/or the third position sensor 133. The second position sensor 132 may be omitted in some examples that include the first position sensor 131 and/or the third position sensor 133. The third position sensor 133 may be omitted in some examples including the first position sensor 131 and/or the second position sensor 132.

In some examples, such as in examples where the third position sensor 133 is omitted, the receiver 142 of the controller 140 may be configured to receive one or more first signals from the first position sensor 131 indicating the landing gear door 111 position when the landing gear door 111 partially passes through its range of travel 113, and the receiver 142 of the controller 140 may be configured to receive one or more second signals from the second position sensor 132 indicating the landing gear 121 position when the landing gear 121 partially passes through its range of travel 123. The determiner 144 of the controller 140 may be configured to determine the relative position of the landing gear door 111 and the landing gear 121 based on the one or more first signals and the one or more second signals, and determine one or more instructions for controlling movement of the landing gear door 111 and/or the landing gear 121 based on the determined relative position. For example, similar to the discussion above, the determiner 144 may be configured to: the movement of the landing gear doors 111 and/or the landing gear 121 is delayed or stopped when the determiner 144 determines that movement of the landing gear doors 111 and/or the landing gear 121 may otherwise cause a collision between the landing gear doors 111 and the landing gear 121.

In some examples, the landing gear controller 140 (such as the receiver 142 thereof) is configured to receive, in use, one or more additional signals, and the landing gear controller 140 (such as the determiner 144 and the transmitter 146 thereof) is configured to control, in use, movement of the landing gear doors 111 and/or the landing gear 121 based on the one or more additional signals. For example, the one or more additional signals may indicate one or more of: the pitch angle of the landing gear bogie, the status of another landing gear and/or another landing gear door, the status of one or more aircraft engines, faults or defects in aircraft components or aircraft systems, and the aircraft inclination angle.

For example, when the landing gear 121 includes a landing gear bogie and one or more additional signals (such as may be obtained from a bogie pitch angle sensor) indicate the pitch angle of the landing gear bogie, then the landing gear controller 140 may be configured to prevent the landing gear 121 from moving to the retracted position when the landing gear 121 is to be fully retracted if the one or more additional signals indicate that the landing gear bogie is at the following pitch angle: this pitch angle will cause or may cause the gear bogie to contact the gear door 111, or potentially contact and damage components in the gear well 115.

In some examples, the landing gear doors 111 and the landing gear 121 are part of a first main landing gear system on one side of the centreline of the aircraft, and the one or more additional signals are indicative of the status of the landing gear doors and/or landing gears of a second main landing gear system on the other side of the centreline of the aircraft. In some such examples, the landing gear controller 140 may be configured to control the movement of the landing gear doors 111 and/or the landing gear 121 such that the landing gear doors 111 and/or the landing gear 121 are positioned in the same manner as the landing gear doors and/or the landing gear of the second main landing gear system. This may provide the aircraft with symmetry that facilitates its control.

In some examples, the landing gear doors 111 and the landing gear 121 are part of a nose gear system, and the one or more additional signals indicate a status of landing gear doors and/or landing gear of the main landing gear system. In some such examples, the landing gear controller 140 may be configured to control the movement of the landing gear doors 111 and/or the landing gear 121 such that the landing gear doors 111 and/or the landing gear 121 of the nose gear system are only open or extended when the main landing gear has extended and the main landing gear doors have closed, respectively. This is because when the landing gear of the nose gear system is at least partially extended, it can create a wake that can cause turbulence that impacts the landing gear doors 111 of the main landing gear system downstream. Avoiding the formation of such turbulence may reduce the likelihood of structural fatigue in the landing gear door 111, or enable the landing gear door 111 to be lighter.

In some examples, the landing gear door 111 and the landing gear 121 are part of a first main landing gear system on one side of a centerline of the aircraft, and the one or more additional signals indicate a status of one or more engines of the aircraft. In some such examples, the landing gear controller 140 may be configured to control the movement of the landing gear doors 111 and/or the landing gear 121 such that the landing gear doors 111 and/or the landing gear 121 are positioned to offset yaw caused by differences in thrust generated by the respective engines, which can facilitate control of the aircraft.

In some examples, the one or more additional signals are indicative of a failure or defect in an aircraft component or aircraft system, a failure or defect in a component or system such as a landing gear or landing gear door (such as the landing gear 121 or landing gear door 111, or another landing gear or landing gear door of the aircraft). In some examples, the one or more additional signals are indicative of a yaw angle of the aircraft. These representative factors may affect the load of one of the landing gear doors 111 and the landing gear 121 and therefore the speed of movement of the landing gear doors 111 and the landing gear 121. Accordingly, the method may comprise controlling movement of the other of the landing gear door 111 and the landing gear 121 based on the one or more additional signals.

For the sake of brevity, the example landing gear extension process will not be described in detail. However, it will be appreciated that in some examples, the landing gear extension process may be the same as the process depicted in fig. 4 and described above, or any variation of the landing gear extension process discussed herein, except that the landing gear 121 is in extension between time T2 and time T6 instead of retraction. Likewise, the reduction in overall time to complete the landing gear extension process may be achieved accordingly by: (a) activating or initiating movement of the landing gear doors 121 from the retracted position toward the extended position at time T2 before the landing gear doors 111 have reached the fully open position at time T3, and (b) activating and initiating movement of the landing gear doors 111 from the open position toward the closed position at time T5 before the landing gear doors 121 have reached the fully extended position at time T6. However, in other examples, either (a) or (b) may be omitted and the overall time still used to complete the landing gear extension process is reduced.

An example method of operating a landing gear controller for an aircraft will now be described with reference to figure 2. For example, the landing gear controller 140 may be the landing gear controller depicted in fig. 1 and described above with reference to fig. 1 and 4, or any variation of the landing gear controller 140 discussed herein.

Broadly, the method comprises: the landing gear controller receives 210 one or more signals from the at least one position sensor indicating a position of one of the landing gear door and the landing gear as the landing gear door or the landing gear respectively partially passes through the range of travel between the two extremes of travel. The at least one position sensor may be the first position sensor 131 and/or the second position sensor 132 described above, or any variation of the position sensors discussed herein. The landing gear door may be the landing gear door 111 described above, or any of the variations of the landing gear door 111 discussed herein. The landing gear may be the landing gear 121 described above, or any of the variations of the landing gear 121 discussed herein.

The method further comprises the following steps: the landing gear controller controls 260 the movement of the other of the landing gear door and the landing gear based on the one or more signals. The control 260 may include initiating movement of one of the landing gear door and the landing gear while the other of the landing gear door and the landing gear partially passes through the range of travel.

In some examples, the control 260 includes: the landing gear controller varies a speed of movement of the other of the landing gear door and the landing gear based on the one or more signals. In some examples, this includes the landing gear controller controlling the rate of actuation of one or more rate-controllable actuators of the landing gear door motion system or the landing gear motion system, respectively.

In some examples, the method includes the landing gear controller receiving 220 one or more additional signals, and controlling 260 based on the one or more additional signals. As described above, the one or more additional signals may, for example, indicate one or more of: the pitch angle of the landing gear bogie, the status of another landing gear or another landing gear bay door, and the status of the aircraft engine.

In some examples, receiving 210 includes the landing gear controller continuously or repeatedly receiving one or more signals from the at least one position sensor. In some such examples, the method includes: the landing gear controller determines 230 a speed of movement of the landing gear door or landing gear respectively along the path based on the one or more signals continuously or repeatedly received from the at least one position sensor, and controlling 260 comprises controlling movement of the other of the landing gear door and landing gear based on the determined speed of movement.

In some examples, the at least one position sensor includes: a landing gear door system position sensor configured to sense the position of a landing gear door as it partially passes through its range of travel and to output one or more first signals indicative of the position of the landing gear door; and a landing gear system position sensor configured to sense the position of the landing gear as the landing gear partially passes through its range of travel and output one or more second signals indicative of the position of the landing gear. In some such examples, receiving 210 includes receiving the one or more first signals and the one or more second signals. In some such examples, the method includes the landing gear controller determining 240 a relative position of the landing gear door and the landing gear based on the one or more first signals and the one or more second signals, and controlling 260 includes controlling movement of the other of the landing gear door and the landing gear based on the determined relative position.

In some examples, the method includes the landing gear controller receiving 250 one or more third signals indicative of the relative positions of the landing gear door and the landing gear, and controlling 260 includes controlling movement of the other of the landing gear door and the landing gear based on the one or more third signals indicative of the relative positions.

Fig. 3 illustrates a schematic block diagram of a non-transitory computer-readable storage medium 300 according to an example. The non-transitory computer readable storage medium 300 stores instructions 330, which instructions 330, if executed by the processor 320 of the aircraft's landing gear controller 310, cause the processor 320 to implement one of the methods described herein. In some examples, the landing gear controller 310 is the landing gear controller 140 described above with reference to fig. 1 or any variation of the landing gear controller 140 described herein. In some examples, the processor 320 is the determiner 144 of the landing gear controller 140 described above with reference to fig. 1 or any variation of the determiner 144 described herein. The instructions 330 may include instructions to implement any of the methods 200 described above with reference to fig. 2.

Fig. 5 is a schematic front view of the aircraft 1. The aircraft 1 comprises two main landing gears 20 and a nose landing gear 30. The aircraft 1 also includes the aircraft system 100 discussed herein with reference to fig. 1 or any variation of the aircraft system 100 discussed herein. The landing gear 121 of the aircraft system 100 may be one of the main landing gear 20 or the nose landing gear 30. The aircraft 1 further includes the non-transitory computer-readable storage medium 300 discussed herein with reference to fig. 3 or any variation of the non-transitory computer-readable storage medium 300 discussed herein. The aircraft 1 also includes the landing gear controller 140 discussed herein with reference to fig. 1 or any variation of the landing gear controller 140 discussed herein.

It is noted that the term "or" as used herein is to be interpreted to mean "and/or" unless explicitly stated otherwise.