A controller for an aircraft system

Abstract

A controller 116 for an aircraft system, the system includes an aircraft component and an electromechanical actuator 112 including an electric motor (120,fig.3) configured to cause movement of the air

Description

TECHNICAL FIELD

[0001] The present invention relates to a controller for an aircraft system, an aircraft system, an aircraft, and a computer-implemented method. BACKGROUND

[0002] Some aircraft landing gear are movable between a retracted position, in which the landing gear is at least partially stored in a body of the aircraft, and an extended position, in which the landing gear is deployed so that the aircraft can rest on the landing gear. Electro-hydraulic actuation utilises electric motors to drive hydraulic pumps, which in turn provide pressurised fluid to hydraulic actuators to extend or retract the landing gear. Electromechanical actuation utilises electric motors to extend or retract the landing gear via mechanical speed reducers. SUMMARY

[0003] A first aspect of the present invention provides a controller for an aircraft system, the aircraft system comprising an aircraft component and an electromechanical actuator comprising an electric motor configured to cause movement of the aircraft component, wherein the controller is configured to: receive torque-indicative data indicative of a torque produced by the electric motor when the electric motor is causing movement of the aircraft component; and cause, when the torque-indicative data is indicative of an altered operational mode of the electromechanical actuator, an action to be performed, wherein the action comprises at least one of: the electric motor causing movement of the aircraft component; at least one of the aircraft system, a further aircraft system of an aircraft comprising the aircraft system, and a remote system, issuing an alert; storing, in a memory, at least one of the torque-indicative data and further data derived from the torque-indicative data; and at least one of scheduling a maintenance action for, and performing a maintenance action on, the electromechanical actuator.

[0004] By receiving the torque-indicative data indicative of a torque produced by the electric motor when the electric motor is causing movement of the aircraft component, and causing, when the torque-indicative data is indicative of an altered operational mode of the electromechanical actuator, the action to be performed, appropriate action may be taken when the electromechanical actuator is operating in an altered operational mode. Torque produced by the electric motor when the electric motor is causing movement of the aircraft component may provide a reasonable indicator as to whether or not the electromechanical actuator is operating in an altered operational mode. For example, where a magnitude and / or a polarity of the torque is different to an expected magnitude and / or an expected polarity of the torque during normal operation, this may be an indicator that the electromechanical actuator is operating in an altered operational mode.

[0005] An altered operational mode may comprise a mode in which the electromechanical actuator is operating with reduced functionality compared to a normal operational mode, and / or may comprise a mode in which the electromechanical actuator is operating with one or more components of the electromechanical actuator experiencing, or having experienced, an unexpected level of degradation.

[0006] The controller may be configured to determine, based on the torque-indicative data, whether the electromechanical actuator is operating in the altered operational mode. The controller may be configured to cause the action to be performed when the controller determines that the electromechanical actuator is operating in the altered operational mode.

[0007] The controller may be configured to generate, based on the torque-indicative data, a control signal for causing the action to be performed.

[0008] When the action comprises the electric motor causing movement of the aircraft component, the control signal may comprise a motor control signal for a motor controller of the electric motor. The motor control signal may cause the motor controller to control the electric motor to move the aircraft component.

[0009] When the action comprises at least one of the aircraft system, the further aircraft system of the aircraft comprising the aircraft system, and the remote system, issuing the alert, the control signal may comprise an alert signal that causes an indicator of the aircraft system, the further aircraft system, and the remote system, to provide the alert. The alert may comprise at least one of a visual alert and an audible alert. The further aircraft system may comprise a cockpit system, for example such that the alert is issued within a cockpit of the aircraft comprising the aircraft system. The remote system may comprise a remote maintenance system, for example such that the alert is issued to at least one of ground crew and maintenance personnel.

[0010] When the action comprises storing, in the memory, at least one of the torqueindicative data and further data derived from the torque-indicative data, the control signal may comprise a memory control signal that causes the at least one of the torque-indicative data and the further data to be stored in the memory. The memory may comprise a local memory, for example a memory local to the aircraft system and / or local to the aircraft comprising the aircraft system. The memory may comprise a remote memory, for example a memory located remotely from the aircraft. At least one of the aircraft system, and the aircraft comprising the aircraft system, may comprise a transmitter for transmitting the at least one of the torque-indicative data and the further data to the remote memory.

[0011] When the action comprises scheduling the maintenance action for the electromechanical actuator, the control signal may comprise a maintenance scheduling control signal configured to set and / or modify a maintenance schedule for the electromechanical actuator stored in a maintenance system. The maintenance schedule may be located locally to, or remotely from, the aircraft comprising the aircraft system. Causing performance of a maintenance action on the electromechanical actuator may comprise indicating, via a maintenance schedule, to maintenance personnel that the maintenance action needs to be performed.

[0012] Optionally, the controller is configured to: determine, based on the torqueindicative data, whether the torque is greater than a torque threshold; and cause, when the torque is greater than the torque threshold, the action to be performed. Optionally, the torque threshold corresponds to a maximal expected torque during operation of the electromechanical actuator in a normal operational mode. Optionally the controller is configured to determine, when the torque is greater than the torque threshold, that the electromechanical actuator is operating in the altered operational mode.

[0013] Optionally, the torque threshold is dependent on at least one of a status of the electromechanical actuator when the torque-indicative data indicative of the torque was obtained, a status of the aircraft component when the torque-indicative data indicative of the torque was obtained, a flight phase of the aircraft comprising the aircraft system when the torque-indicative data indicative of the torque was obtained, ambient conditions of at least one of the aircraft system and the aircraft comprising the aircraft system when the torque-indicative data indicative of the torque was obtained, a speed of the aircraft comprising the aircraft system when the torque-indicative data indicative of the torque was obtained, and an acceleration of the aircraft comprising the aircraft system when the torque-indicative data indicative of the torque was obtained. Optionally, the ambient conditions comprise ambient conditions that have a potential to impact torque produced by the electric motor, such as air speed.

[0014] The status of the electromechanical actuator may comprise at least one of an age of the electromechanical actuator, a type of the electromechanical actuator, a number of previous uses of the electromechanical actuator, a recorded condition of the electromechanical actuator, and an operation performed by the electromechanical actuator when the data indicative of the torque was obtained.

[0015] The torque threshold may comprise a dynamic threshold that varies over time and / or varies with position of the aircraft comprising the aircraft system.

[0016] Optionally, the controller is configured to: determine, based on the torqueindicative data, whether the torque is greater than the torque threshold for more than a pre-determined time, and cause, when the torque is greater than the torque threshold for more than the pre-determined time, the action to be performed. Optionally the controller is configured to determine, when the torque is greater than the torque threshold for more than the pre-determined time, that the electromechanical actuator is operating in the altered operational mode.

[0017] Optionally, the torque-indicative data is indicative of respective torques produced by the electric motor when the electric motor is causing movement of the aircraft component over a plurality of actuations of the electromechanical actuator, and the controller is configured to: determine, based on the torque-indicative data, whether the torque is greater than a torque threshold for more than a predetermined number of actuations of the plurality of actuations; and cause, when the torque is greater than the torque threshold for more than the predetermined number of actuations of the plurality of actuations, the action to be performed. Optionally the controller is configured to determine, when the torque is greater than the torque threshold for more than the predetermined number of actuations of the plurality of actuations, that the electromechanical actuator is operating in the altered operational mode.

[0018] Optionally, the torque-indicative data is indicative of respective torques produced by the electric motor when the electric motor is causing movement of the aircraft component over a plurality of flights determine, based on the torque-indicative data, whether the torque is greater than a torque threshold for more than a predetermined number of flights of the plurality of flights; and cause, when the torque is greater than the torque threshold for more than the predetermined number of flights of the plurality of flights, the action to be performed. Optionally the controller is configured to determine, when the torque is greater than the torque threshold for more than the predetermined number of flights of the plurality of flights, that the electromechanical actuator is operating in the altered operational mode.

[0019] Optionally, the controller is configured to: determine, based on the torqueindicative data, whether the torque is greater than any of a plurality of torque thresholds; and determine, when the torque is greater than any of the plurality of torque thresholds, a largest one of the plurality of torque thresholds that the torque is greater than; and cause, based on the largest one of the plurality of torque thresholds that the torque is greater than, the action to be performed.

[0020] Optionally the controller is configured to select, based on the largest one of the plurality of torque thresholds that the torque is greater than, an action to be performed from a plurality of pre-determined actions. Optionally, the torque thresholds correspond to a priority ranked list of actions, for example with higher torque thresholds corresponding to higher priority actions.

[0021] Optionally, the torque-indicative data is indicative of a polarity of the torque, and the controller is configured to cause, based on the polarity of the torque, the action to be performed. Optionally the controller is configured to compare the polarity of the torque to an expected polarity of torque for an operation performed by the electric motor to cause the movement of the aircraft component. Optionally the controller is configured to determine, when the polarity of the torque does not match the expected polarity of torque, that the electromechanical actuator is operating in the altered operational mode.

[0022] Optionally, the controller is configured to: determine, based on the torqueindicative data, whether the polarity of the torque does not match the expected polarity of torque for more than a pre-determined time, and cause, when the polarity of the torque does not match the expected polarity of torque for more than the pre-determined time, the action to be performed. Optionally the controller is configured to determine, when the polarity of the torque does not match the expected polarity of torque for more than a predetermined time, that the electromechanical actuator is operating in the altered operational mode.

[0023] Optionally, the torque-indicative data is indicative of a respective polarity of torque produced by the electric motor when the electric motor is causing movement of the aircraft component over a plurality of actuations of the electromechanical actuator, and the controller is configured to: determine, based on the torque-indicative data, whether the polarity of the torque does not match the expected polarity of torque for more than a predetermined number of actuations of the plurality of actuations; and cause, when the polarity of the torque does not match the expected polarity of torque for more than the predetermined number of actuations of the plurality of actuations, the action to be performed. Optionally the controller is configured to determine, when the polarity of the torque does not match the expected polarity of torque for more than the predetermined number of actuations of the plurality of actuations, that the electromechanical actuator is operating in the altered operational mode.

[0024] Optionally, the torque-indicative data is indicative of a respective polarity of torque produced by the electric motor when the electric motor is causing movement of the aircraft component over a plurality of flights, and the controller is configured to: determine, based on the torque-indicative data, whether the polarity of the torque does not match the expected polarity of torque for more than a predetermined number of flights of the plurality of flights; and cause, when the polarity of the torque does not match the expected polarity of torque more than the predetermined number of flights of the plurality of flights, the action to be performed. Optionally the controller is configured to determine, when the polarity of the torque does not match the expected polarity of torque for more than the predetermined number of flights of the plurality of flights, that the electromechanical actuator is operating in the altered operational mode.

[0025] Optionally, the controller is configured to: receive ambient data indicative of ambient conditions of the aircraft system, the ambient conditions having occurred when the torque-indicative data indicative of the torque produced by the electric motor was obtained; and determine, based on the torque-indicative data and the ambient data, whether the electromechanical actuator is operating in the altered operational mode. Optionally, the ambient conditions are at least one of temperature and windspeed.

[0026] Optionally, the controller is configured to receive aircraft data indicative of operation of the aircraft comprising the aircraft system at a time period in which the data indicative of the torque produced by the electric motor was obtained, and determine, based on the torque-indicative data and the aircraft data, whether the electromechanical actuator is operating in the altered operational mode. Optionally, the aircraft data is indicative of one or more movements of the aircraft during the time period.

[0027] Optionally, the controller is configured to receive position data indicative of an extent of actuation of the electromechanical actuator at a time period in which the data indicative of the torque produced by the electric motor was obtained, and determine, based on the torque-indicative data and the position data, whether the electromechanical actuator is operating in the altered operational mode.

[0028] Optionally, the aircraft component is an aircraft landing gear, and the torqueindicative data is indicative of a torque produced by the electric motor when the electric motor is causing at least one of extension and retraction of the aircraft landing gear. Optionally, the torque-indicative data is indicative of a magnitude of the torque produced by the electric motor when the electric motor is causing retraction of the aircraft landing gear. Optionally, the torque-indicative data is indicative of a polarity of the torque produced by the electric motor when the electric motor is causing extension of the aircraft landing gear.

[0029] Optionally, the aircraft component is an aircraft landing gear door, and the torqueindicative data is indicative of a torque produced by the electric motor when the electric motor is causing at least one of opening and closing of the aircraft landing gear door. Optionally, the torque-indicative data is indicative of a magnitude of the torque produced by the electric motor when the electric motor is causing closing of the aircraft landing gear door. Optionally, the torque-indicative data is indicative of a polarity of the torque produced by the electric motor when the electric motor is causing opening of the aircraft landing gear door.

[0030] Optionally, the torque-indicative data is indicative of a torque produced by the electric motor when the electric motor is causing retraction of the aircraft landing gear, and the action comprises the electric motor causing extension of the landing gear.

[0031] Optionally, the aircraft system comprises a current sensor configured to monitor current flowing through a stator winding of the electric motor, and the torque-indicative data comprises, or is based on, current monitored by the current sensor.

[0032] Optionally, the controller is configured to receive the torque-indicative data in real-time. Optionally the controller is configured to receive the torque-indicative data during flight of the aircraft comprising the aircraft system. Optionally, the controller is configured to cause the action to be performed in real-time. Optionally, the controller is configured to cause the action to be performed during flight of the aircraft comprising the aircraft system.

[0033] A second aspect of the present invention provides an aircraft system comprising: the controller according to the first aspect of the present invention; the aircraft component; and the electromechanical actuator comprising the electric motor configured to cause movement of the aircraft component.

[0034] The electromechanical actuator may comprise a converter for converting rotatory motion of a rotor of the electric motor into linear motion, for example such as a ball screw or a roller screw that drives linear translation of a nut. The electromechanical actuator may comprise a direct drive electromechanical actuator, for example with the electric motor directly coupled to the converter without an intervening gearbox.

[0035] A third aspect of the present invention provides aircraft comprising the aircraft system according to the second aspect of the present invention.

[0036] A fourth aspect of the present invention provides a computer-implemented method comprising: receiving torque-indicative data indicative of a torque produced by an electric motor of an electromechanical actuator of an aircraft system, the electromechanical actuator configured to move an aircraft component of the aircraft system; and causing, when the torque-indicative data is indicative of an altered operational mode of the electromechanical actuator, an action to be performed, wherein the action comprises at least one of: the electric motor causing movement of the aircraft component; at least one of the aircraft system, a further aircraft system of an aircraft comprising the aircraft system, and a remote system, issuing an alert; storing, in a memory, at least one of the torque-indicative data and further data derived from the torque-indicative data; and at least one of scheduling a maintenance action for, and performing a maintenance action on, the electromechanical actuator.

[0037] Optionally, the receiving and the causing occur at a controller of the aircraft system.

[0038] Optionally, the computer-implemented method comprises: determining, based on the torque-indicative data, whether the torque is greater than a torque threshold; and causing, when the torque is greater than the torque threshold, the action to be performed.

[0039] Optionally, the computer-implemented method comprises: determining, based on the torque-indicative data, whether the torque is greater than the torque threshold for more than a pre-determined time, and causing, when the torque is greater than the torque threshold for more than the pre-determined time, the action to be performed.

[0040] Optionally, the torque-indicative data is indicative of respective torques produced by the electric motor when the electric motor is causing movement of the aircraft component over a plurality of actuations of the electromechanical actuator, and the computer-implemented method comprises; determining, based on the torque-indicative data, whether the torque is greater than a torque threshold for more than a predetermined number of actuations of the plurality of actuations; and causing, when the torque is greater than the torque threshold for more than the predetermined number of actuations of the plurality of actuations, the action to be performed.

[0041] Optionally, the method comprises monitoring current flowing through a stator winding of the electric motor, and the data indicative of a torque at least one of comprises, or is based on, the monitored current.

[0042] Optionally, the aircraft component is an aircraft landing gear, and the torqueindicative data is indicative of a torque produced by the electric motor when the electric motor is causing at least one of extension and retraction of the aircraft landing gear.

[0043] Optional features of aspects of the present invention may be equally applied to other aspects of the present invention, where appropriate. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0045] Figure 1 shows a schematic view of an aircraft;

[0046] Figure 2 shows a schematic view of a landing gear extension and retraction system (LGERS) of the aircraft of Figure I;

[0047] Figure 3 shows a schematic view of an electromechanical actuator of the LGERS of Figure 2; and

[0048] Figure 4 is a flow diagram illustrating a method according to an example. DETAILED DESCRIPTION

[0049] An aircraft 100 is shown in Figure I. The aircraft 100 has two main landing gears 102 and a nose landing gear 104, each comprising plural respective wheels 106. The aircraft 100 further has a cockpit 108, and an retraction systems (LGERS) 110, that controls each of the two main landing gears 102 and the nose landing gear 104.

[0050] Each main landing gear 102 and the nose landing gear 104 is respectively movable between an extended position, shown in Figure 1, and a retracted position in which the landing gear 102,104 is at least partly housed within a main body of the aircraft 100.

[0051] The LGERS 110 is illustrated schematically in Figure 2. It will be appreciated that the LGERS 110 can be considered an aircraft system in the context of the present disclosure, and also that the main landing gears 102 and the nose landing gear 104 can be considered to form part of the LGERS 110.

[0052] The LGERS 110 of Figure 2 has the nose landing gear 104, an electromechanical actuator 112, a current sensor 114, a controller 116, and a memory 118.

[0053] The electromechanical actuator 112 is illustrated schematically in Figure 3, and has an electric motor 120 and a ball screw 122. Arrangements where a roller screw or the like replaces the ball screw 122 are also envisaged.

[0054] The electric motor 120 is a brushless DC motor, and has a stator winding 124, a rotor assembly 126, and control circuitry 128. It will be appreciated that further components of the electric motor 120 are not illustrated here for sake of clarity. The stator winding 124 is configured to be energised by the control circuitry 128 driving a current through the stator winding 124 in use, such that a time varying magnetic field is created. The rotor assembly 126 has a permanent magnet that interacts with the time varying magnetic field to cause rotation of the rotor assembly 126.

[0055] The ball screw 122 has a screw thread 130 and a nut 132 coupled to the screw thread 130 with ball bearings located between the screw thread 130 and a corresponding screw thread of the nut 132. The screw thread 130 is directly coupled to the rotor assembly 126, such that rotation of the rotor assembly 126 causes rotation of the screw thread 130. The nut 132 is fixed to a housing of the electromechanical actuator 112, and via the ball bearings rotation of the screw thread 130 causes linear motion of the nut 132. The nut 132 is coupled to the nose landing gear 104 via an output shaft 134, such that liner motion of the nut 132 causes extension and retraction of the nose landing gear 104.

[0056] The current sensor 114 is configured to sense a current flowing through the stator winding 124, and is configured to transmit sensed current values ISENSE to the controller 116 of the LGERS 110. Such sensed current values ISENSE may be considered torqueindicative data, as will be discussed in further detail hereinafter. The current sensor 114 can be any appropriate current sensor, for example such as a shunt resistor, for sensing current flowing through the stator winding 124. It will be appreciated that although illustrated separately to the control circuitry 128 of the electric motor 120 in Figure 2, in practice the current sensor 114 may form part of the control circuitry 128.

[0057] The controller 116 is in communication with the current sensor 114, the control circuitry 128, and the cockpit 108. Such communication may be wired or wireless, as appropriate. The controller 116 is configured to perform several processes, and to send and receive various data and control signals, as will be discussed in further detail hereinafter.

[0058] The memory 118 is in communication with the controller 116, and comprises any appropriate non-transitory memory.

[0059] During a flight of the aircraft 100, the LGERS 110 is used to retract and extend the nose landing gear 104, after take-off and before landing respectively. To achieve this, one or both of the controller 116 and the control circuitry 128 receives a command from the cockpit 108, which causes the electric motor 120 to drive the ball screw 122 to cause retraction or extension of the nose landing gear 104.

[0060] In certain circumstances, the electromechanical actuator 112 may operate in an altered operational mode in which the electromechanical actuator is operating with reduced functionality compared to a normal operational mode, and / or in which the electromechanical actuator 112 is operating with one or more components of the electromechanical actuator 112 experiencing, or having experienced, an unexpected level of degradation. It has been recognised that an increased torque associated with operation of the electric motor 120 may be indicative of operation of the electromechanical actuator 112 in such an altered operational mode. The altered operational mode may be currently occurring, or may be a predicted altered operational mode that will occur during future operation of the electromechanical actuator 112.

[0061] Thus, during operation of the electromechanical actuator 112 to retract and / or extend the nose landing gear 104, the current sensor 114 monitors current flowing through the stator winding 124, and transmits the sensed current values ISENSE to the controller 116. Such sensed current values ISENSE are indicative of the torque produced by the electric motor 120. The controller 116 then utilises the sensed current values ISENSE, and where the sensed current values ISENSE are indicative of the electromechanical actuator 112 operating in an altered operational mode, the controller 116 causes an action to be performed. Such an action may take several forms, as will be discussed in further detail hereinafter. To cause performance of the action, the controller 116 issues one or more control signals, and it will be appreciated that these control signals may be labelled in accordance with the action they are intended to perform. In some examples, the controller 116 performs a specific process of determining whether or not the electromechanical actuator 112 is operating in the altered operational mode based on the sensed current values ISENSE.

[0062] A method 200 in accordance with the above is illustrated in the flow diagram of Figure 4. The method 200 includes receiving 202 torque-indicative data indicative of a torque produced by the electric motor 120 of the electromechanical actuator 112 of the LGERS 110. The method 200 includes causing 204, when the torque-indicative data is indicative of an altered operational mode of the electromechanical actuator 112, an action to be performed. It will be appreciated that the method 200 is performed by the controller 116 of the LGERS 110.

[0063] A first example action that the controller 116 can cause to be performed is the electric motor 120 causing movement of the nose landing gear 104. Where the controller 116 receives the sensed current values ISENSE during retraction of the nose landing gear 104, and the sensed current values ISENSE indicate that the electromechanical actuator 122 is operating in an altered operational mode, the controller 116 causes the control circuitry 128 to control the electric motor 120 to extend the nose landing gear 104. Here, a relatively high torque experienced during retraction could be indicative of a possible jam condition occurring for the electromechanical actuator 112. As the torque required to extend the nose landing gear 104 is typically less than the torque required to retract the nose landing gear 104, for example due to gravity assisting with extension, it may be possible, and preferable, to extend the nose landing gear 104 when an altered operational mode is detected and / or determined.

[0064] As described above, the movement of the nose landing gear 104 is automatically performed by virtue of control signals sent from the controller 116 to the control circuitry 128. It will be appreciated, however, that embodiments where a signal is sent to the cockpit 108 that prompts or causes a pilot or other crew member to control the electric motor 120 to move the nose landing ear 104 are also envisaged. In such embodiments, the controller 116 still causes movement of the electric motor 120 by virtue of the signal sent to the cockpit 108.

[0065] A second example action that the controller 116 can cause to be performed is at least one of the LGERS 110, a further aircraft system of the aircraft 100, and a remote system, issuing an alert. Such an alert can take any of a visual and an audible format. In some examples, the LGERS 110 can issue the alert itself, via an appropriate visual indicator such as a light source, and / or via an appropriate audible indicator such as a transducer, with such an alert issued to ground crew and / or maintenance personnel when the aircraft 100 is next on the ground. The ground crew and / or maintenance personnel can then take appropriate further action, such as by scheduling a maintenance action for, or performing a maintenance action on, the electromechanical actuator 112. In some examples, the further aircraft system can be a cockpit system disposed in the cockpit 108, and includes an appropriate visual indicator such as a light source, and / or an appropriate audible indicator such as a transducer, to provide the alert to the pilot or other flight crew. The pilot or other flight crew can then take appropriate further action, such as by causing the electric motor 120 to cause movement of the nose landing gear 104, and scheduling a maintenance action for the electromechanical actuator 112.

[0066] Where the alert is issued by a remote system remote from the aircraft 100, the controller 116 can cause data to be transmitted to the remote system, for example either in real-time, or in response to data being downloaded by ground crew or maintenance personnel, with the alert based on such data.

[0067] A third example action that the controller 116 can cause to be performed is storing in the memory 118 the sensed current values ISENSE, or further data derived from the sensed current values ISENSE. Such further data can include, for example, any of torque values, indicators that the electromechanical actuator 112 has been operating in an altered operational mode, timestamps, or the like. Any stored data can be downloaded from the memory 118 at a later time, for example by ground crew or maintenance personnel when the aircraft 100 is on the ground. Additionally, or alternatively, stored data can be transmitted from the aircraft 100 to a remote system, such as a remote maintenance system, for further analysis.

[0068] In some examples, the controller 116 can cause the sensed current values ISENSE, or further data derived from the sensed current values ISENSE, to be stored in a memory other than the memory 118 of the LGERS 110. For example, such data can be stored in a memory of another aircraft system, or in a memory of a remote system remote from the aircraft.

[0069] A fourth example action that the controller 116 can cause to be performed is at least one of scheduling a maintenance action for, and performing a maintenance action on, the electromechanical actuator 112. Such scheduling or performing of a maintenance action can take place in any of the manners descried above. Additionally, or alternatively, the controller 116 can cause a locally stored maintenance schedule, for example stored in one or more memories aboard the aircraft 100, to be updated.

[0070] Other example actions are also envisaged.

[0071] As noted above, the controller 116 causing the action to take place is based on the sensed current values ISENSE being indicative of the electromechanical actuator 112 operating in an altered operational mode.

[0072] In some examples, the controller 116 determines whether the sensed current values ISENSE indicate that the torque is greater than a torque threshold, for example by determining whether the sensed current values ISENSE are greater than a current threshold. When the torque is greater than the torque threshold, the controller 115 causes the action to be performed. For example, when the torque is determined to be greater than a torque threshold during retraction of the nose landing gear 104, the controller 116 causes the nose landing gear 104 to be extended, rather than continuing with retraction.

[0073] The value of the torque threshold depends on a number of factors, including any of a status of the electromechanical actuator 112 when the sensed current values ISENSE were obtained, a status of the nose landing gear 104 when the sensed current values ISENSE were obtained, a flight phase of the aircraft 100 when the sensed current values ISENSE were obtained, ambient conditions of at the aircraft 100 when the sensed current values ISENSE were obtained, a speed of the aircraft 100 when the sensed current values ISENSE were obtained, and an acceleration of the aircraft 100 when the sensed current values ISENSE were obtained. For example, the status of the electromechanical actuator 112 can include any of an age of the electromechanical actuator 112, a type of the electromechanical actuator 112, a number of previous uses of the electromechanical actuator 112, a recorded condition of the electromechanical actuator 112, and an operation performed by the electromechanical actuator 112 when the sensed current values ISENSE were obtained. Each of those factors may have an impact on the sensed current values ISENSE, and by accounting for these factors a more accurate indication as to whether the electromechanical actuator 112 is operating in the altered operational mode may be obtained. It will also be appreciated that the torque threshold may vary over time.

[0074] In some examples, the controller 116 causes the action to be performed when the sensed current values INSENSE indicate that the torque is over the torque threshold for more than a pre-determined amount of time. This may remove the effect of transient conditions. In a similar manner, in some examples, the controller 116 causes the action to be performed when the sensed current values INSENSE indicate that the torque is over the torque threshold for more than a pre-determined number of actuations of the electromechanical actuator 112, and / or for more than a pre-determined number of flights of the aircraft 100. In some examples, the controller 116 causes the action to be performed when the sensed current values INSENSE indicate a trend in torque over a pre-determined number of flights.

[0075] In some examples, the controller 116 is programmed to determine which of a plurality of actions is to be performed based on the sensed current values ISENSE. For example, the controller 116 can employ a number of torque thresholds, and which action is chosen can depend on which threshold is met. In some examples, when a first lowest threshold is met, the controller 116 can cause a maintenance action to be scheduled, or a flag to be set in memory for a maintenance action to be performed. When a second, higher, threshold is met, the controller 116 can cause an alert to be emitted in the cockpit 108. When a third, highest, threshold is met, the controller 116 can cause the electric motor 120 to actuate the nose landing gear 104. For example, where the toque experienced is too high to retract the nose landing gear 104, the controller 116 can cause the electric motor 120 to extend the nose landing gear 104. It will be appreciated that the action taken in response to different thresholds being met can be tailored depending on desired functionality. For example, in some circumstances it may be desired to emit an alert at a lowest threshold, and to schedule maintenance at a relatively higher threshold.

[0076] In some examples, the controller 116 considers the polarity of the sensed current values ISENSE, and hence the equivalent polarity of the torque, and when the polarity does not match an expected polarity for the given operation of the electromechanical actuator 112, the controller 116 causes the action to be performed. For example, during extension of the nose landing gear 104, an expected torque will likely be negative, with the electromechanical actuator 112 being used to slow extension of the nose landing gear. If the sensed current values ISENSE instead indicate a positive torque, then this may be indicative of the electromechanical actuator 112 operating in an altered operational mode, and accordingly the controller 116 may cause the action to be performed.

[0077] It will be appreciated that examples in which the controller 116 considers both magnitude and polarity are envisaged, as are examples in which the controller 116 only considers magnitude, or only considers polarity.

[0078] In a similar manner to the way in which the controller 116 can monitor current magnitude over time, number of actuations, and number of flights, the controller 116 can also consider the polarity of the torque over time, number of actuations, and number of flights, and only cause the action to be performed where a threshold time or number of instances is met.

[0079] Other factors that can impact on the sensed current values ISENSE include ambient conditions of the aircraft 100, as well as movement of the aircraft 100. For example, wind and / or temperature, as well as motion of the aircraft, can impact on the sensed current values ISENSE, as such factors may impact the electromechanical actuator 112 during extension and / or retraction of the nose landing gear 104. In some examples, the controller 116 receives, from other systems of the aircraft, ambient data that indicates the ambient conditions, and / or aircraft data that indicates operation of the aircraft data when the sensed current values ISENSE were obtained, and / or position data that indicates an extent of actuation of the electromechanical actuator 112 when the sensed current values ISENSE were obtained. This data can inform the torque threshold or the expected torque, for example with the torque threshold or expected torque then accounting for what the expected torque for certain operating conditions would have been.

[0080] In each of the examples described above, the controller 116 receives sensed current values ISENSE indicative of the torque produced by the electric motor 120. The controller 116 then, when the sensed current values ISENSE are indicative of the electromechanical actuator 112 operating in an altered operational mode, causes an action to be performed. Other examples utilising additional or alternative data indicative of the torque produced by the electric motor 120 are also envisaged. For example, power values may be utilised instead of current values, and are still indicative of torque. Other examples where aircraft component is a different component, such as a landing gear door, are also envisaged.

[0081] It is to noted that the term “or” as used herein is to be interpreted to mean “and / or”, unless expressly stated otherwise.

Claims

1. A controller for an aircraft system, the aircraft system comprising an aircraft component and an electromechanical actuator comprising an electric motor configured to cause movement of the aircraft component, wherein the controller is configured to: receive torque-indicative data indicative of a torque produced by the electric motor when the electric motor is causing movement of the aircraft component; andcause, when the torque-indicative data is indicative of an altered operational mode of the electromechanical actuator, an action to be performed,wherein the action comprises at least one of:the electric motor causing movement of the aircraft component;at least one of the aircraft system, a further aircraft system of an aircraft comprising the aircraft system, and a remote system, issuing an alert;storing, in a memory, at least one of the torque-indicative data and further data derived from the torque-indicative data; andat least one of scheduling a maintenance action for, and performing a maintenance action on, the electromechanical actuator.

2. The controller according to Claim 1, wherein the controller is configured to: determine, based on the torque-indicative data, whether the torque is greater than a torque threshold; andcause, when the torque is greater than the torque threshold, the action to be performed.

3. The controller according to Claim 2, wherein the controller is configured to: determine, based on the torque-indicative data, whether the torque is greater than the torque threshold for more than a pre-determined time, andcause, when the torque is greater than the torque threshold for more than the pre-determined time, the action to be performed.

4. The controller according to any one of Claim 2 or Claim 3, wherein the torqueindicative data is indicative of respective torques produced by the electric motor when the electric motor is causing movement of the aircraft component over a plurality of actuations of the electromechanical actuator, and the controller is configured todetermine, based on the torque-indicative data, whether the torque is greater than a torque threshold for more than a predetermined number of actuations of the plurality of actuations; andcause, when the torque is greater than the torque threshold for more than the predetermined number of actuations of the plurality of actuations, the action to be performed.

5. The controller according to any one of Claims 2 to 4, wherein the torqueindicative data is indicative of respective torques produced by the electric motor when the electric motor is causing movement of the aircraft component over a plurality of flights, and the controller is configured to:determine, based on the torque-indicative data, whether the torque is greater than a torque threshold for more than a predetermined number of flights of the plurality of flights; andcause, when the torque is greater than the torque threshold for more than the predetermined number of flights of the plurality of flights, the action to be performed.

6. The controller according to any one of Claims 2 to 5, wherein the controller is configured to:determine, based on the torque-indicative data, whether the torque is greater than any of a plurality of torque thresholds; anddetermine, when the torque is greater than any of the plurality of torque thresholds, a largest one of the plurality of torque thresholds that the torque is greater than; andcause, based on the largest one of the plurality of torque thresholds that the torque is greater than, the action to be performed.

7. The controller according to any one of the preceding claims, wherein the torqueindicative data is indicative of a polarity of the torque, and the controller is configured to cause, based on the polarity of the torque, the action to be performed.

8. The controller according to any one of the preceding claims, wherein the controller is configured to:receive ambient data indicative of ambient conditions of the aircraft system, the ambient conditions having occurred when the torque-indicative data indicative of the torque produced by the electric motor was obtained; anddetermine, based on the torque-indicative data and the ambient data, whether the electromechanical actuator is operating in the altered operational mode.

9. The controller according to any one of the preceding claims, wherein the aircraft component is an aircraft landing gear or an aircraft landing gear door, and the torqueindicative data is indicative of a torque produced by the electric motor when the electric motor is causing at least one of extension and retraction of the aircraft landing gear or at least one of opening and closing of the aircraft landing gear door.

10. The controller according to Claim 9, wherein the torque-indicative data is indicative of a torque produced by the electric motor when the electric motor is causing retraction of the aircraft landing gear, and the action comprises the electric motor causing extension of the aircraft landing gear, or the torque-indicative data is indicative of a torque produced by the electric motor when the electric motor is causing closing of the aircraft landing gear door, and the action comprises the electric motor causing opening of the aircraft landing gear door.

11. The controller according to any one of the preceding claims, wherein the aircraft system comprises a current sensor configured to monitor current flowing through a stator winding of the electric motor, and the torque-indicative data comprises, or is based on, current monitored by the current sensor.

12. The controller according to any one of the preceding claims, wherein the controller is configured to receive the torque-indicative data in real-time.

13. An aircraft system comprising:the controller according to any one of the preceding claims;the aircraft component: andthe electromechanical actuator comprising the electric motor configured to cause movement of the aircraft component.

14. An aircraft comprising the aircraft system according to Claim 13.

15. A computer-implemented method comprising:receiving torque-indicative data indicative of a torque produced by an electric motor of an electromechanical actuator of an aircraft system, the electromechanical actuator configured to move an aircraft component of the aircraft system; andcausing, when the torque-indicative data is indicative of an altered operational mode of the electromechanical actuator, an action to be performed,wherein the action comprises at least one of:the electric motor causing movement of the aircraft component;at least one of the aircraft system, a further aircraft system of an aircraft comprising the aircraft system, and a remote system, issuing an alert;storing, in a memory, at least one of the torque-indicative data and further data derived from the torque-indicative data; andat least one of scheduling a maintenance action for, and performing a maintenance action on, the electromechanical actuator.

16. The computer-implemented method according to Claim 15, wherein the computer-implemented method comprises:determining, based on the torque-indicative data, whether the torque is greater than a torque threshold; andcausing, when the torque is greater than the torque threshold, the action to be performed.

17. The computer-implemented method according to Claim 16, wherein the computer-implemented method comprises:determining, based on the torque-indicative data, whether the torque is greater than the torque threshold for more than a pre-determined time, andcausing, when the torque is greater than the torque threshold for more than the pre-determined time, the action to be performed.

18. The computer-implemented method according to any one of Claim 16 or Claim 17, wherein the torque-indicative data is indicative of respective torques produced by the electric motor when the electric motor is causing movement of the aircraft component over a plurality of actuations of the electromechanical actuator, and the computer-implemented method comprises:determining, based on the torque-indicative data, whether the torque is greater than a torque threshold for more than a predetermined number of actuations of the plurality of actuations; andcausing, when the torque is greater than the torque threshold for more than the predetermined number of actuations of the plurality of actuations, the action to be performed.

19. The computer-implemented method according to any one of Claims 15 to 18, wherein method comprises monitoring current flowing through a stator winding of the electric motor, and the torque-indicative data indicative of a torque at least one of comprises, or is based on, the monitored current.

20. The computer-implemented method according to any one of Claims 15 to 19, wherein the aircraft component is an aircraft landing gear or an aircraft landing gear door, and the torque-indicative data is indicative of a torque produced by the electric motor when the electric motor is causing at least one of extension and retraction of the aircraft landing gear or at least one of opening and closing of the aircraft landing gear door.

Images