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EP-4506245-B1 - HEALTH MONITORING SYSTEM

EP4506245B1EP 4506245 B1EP4506245 B1EP 4506245B1EP-4506245-B1

Inventors

  • Boche, Adèle
  • BOULOC, ROMAIN

Dates

Publication Date
20260513
Application Date
20230809

Claims (15)

  1. A method of performing health monitoring for an aircraft (10) having a variable pitch propeller system (12), the method comprising: receiving aircraft flight information; performing a virtual pitch calculation to determine a virtual propeller pitch or virtual blade angle from the aircraft flight information; receiving a measured propeller pitch or blade angle from at least one physical sensor associated with the propeller; and using the virtual propeller pitch or virtual blade angle and the measured propeller pitch or blade angle to perform a health monitoring process to determine a health condition of at least one component of the aircraft, wherein the at least one component is distinct from the blades.
  2. A method according to claim 1, wherein the determining the health condition comprises propeller gearbox failure detection and/or propeller pitch change actuator failure detection.
  3. A method according to claim 1 or 2, wherein the aircraft flight information comprises air information, the virtual pitch calculation comprising an air information computation performed on the air information to determine the virtual propeller pitch or virtual blade angle.
  4. A method according to claim 3, wherein the method comprises sensing the air information.
  5. A method according to claim 3 or 4, wherein the air information comprises aircraft speed information.
  6. A method according to any of the preceding claims, wherein the aircraft flight information comprises propeller driving power information, the virtual pitch calculation comprising a propeller power computation performed on the propeller driving power information to determine the virtual propeller pitch or virtual blade angle.
  7. A method according to claim 6 and comprising sensing the propeller driving power information from an engine of the aircraft, the engine configured to drive the propeller.
  8. A method according to any of the preceding claims, wherein the health monitoring process may comprise comparing the virtual propeller pitch or virtual blade angle to a measured propeller pitch.
  9. A method according to any of the preceding claims, wherein the health monitoring process comprises determining a failure or a wear condition of the component of the aircraft.
  10. A method according to any of the preceding claims, wherein the virtual pitch calculation comprises performing an aircraft flight information verification process to verify that the aircraft flight information is valid.
  11. A method according to any of the preceding claims, wherein the health monitoring process is at least partially performed during flight.
  12. A method according to any of the preceding claims, wherein the health monitoring process is at least partially performed when the aircraft is not flying.
  13. A health monitoring system (118) for a variable pitch propeller system (12) of an aircraft (10), the health monitoring system comprising: a virtual pitch sensor (22) configured to receive aircraft flight information and perform a virtual pitch calculation to determine a virtual propeller pitch or virtual blade angle from the aircraft flight information; at least one physical sensor (140) configured to measure propeller pitch or blade angle; and a health monitoring processor (124) configured to use the virtual propeller pitch or virtual blade angle and the measured propeller pitch or blade angle to perform a health monitoring process to determine a health condition of at least one component of the aircraft, characterised in that the at least one component is distinct from the blades.
  14. A variable pitch propeller system comprising a health monitoring system according to claim 13 and comprising the propeller.
  15. An aircraft comprising the variable pitch propeller system according to claim 14.

Description

FIELD OF THE INVENTION This application relates to pitch protection systems, pitch control systems, health monitoring systems, variable pitch propeller systems, aircraft and methods. BACKGROUND It is important to monitor the health of an aircraft and its systems to reduce the likelihood of components failing during flight. However, it can be difficult to obtain data to enable health monitoring to be reliably performed. US 2018/079522 A1 discloses a system and method for detecting failure of a propeller control unit. SUMMARY According to a first aspect, there is provided a method of performing health monitoring for an aircraft having a variable pitch propeller system, the method comprising: receiving aircraft flight information; performing a virtual pitch calculation to determine a virtual propeller pitch or virtual blade angle from the aircraft flight information; receiving a measured propeller pitch or blade angle from at least one physical sensor associated with the propeller; and using the virtual propeller pitch or virtual blade angle and the measured propeller pitch or blade angle to perform a health monitoring process to determine a health condition of at least one component of the aircraft, wherein the at least one component is distinct from the blades. By performing the virtual pitch calculation to determine the virtual propeller pitch or virtual blade angle, a useful source of data for aircraft health monitoring may be provided e.g. with a discrepancy between a measured value and a virtual value to indicate that components of the aircraft are not operating as would be expected. The determining the health condition may comprise propeller gearbox failure detection and/or propeller pitch change actuator failure detection. The health monitoring process may be performed during flight. The health monitoring process may be performed when the aircraft is on the ground. The health monitoring process may comprise comparing the virtual propeller pitch or virtual blade angle to a measured propeller pitch or blade angle. A poor health condition may be determined where a discrepancy between a virtual value and a measured value exceeds a threshold. The measured propeller pitch may be determined using measured blade angle and propeller speed. The method may comprise measuring the blade angle and propeller speed. The health monitoring process may comprise determining a failure of the component. The health monitoring process may comprise determining a wear condition of the component. The component of the aircraft may be an aircraft system. The aircraft system may comprise a mechanical system of the propeller. The aircraft system may comprise a hydraulic system of the propeller. The aircraft system may comprise an electrical system of the propeller. The aircraft system may comprise a propeller gearbox. The aircraft flight information may comprise air information. The virtual pitch calculation may comprise an air information computation performed on the air information to determine the virtual propeller pitch or virtual blade angle. The method may comprise sensing the air information. The air information may comprise aircraft speed information. The aircraft speed information may comprise indicated airspeed. The aircraft speed information may comprise Mach number. The aircraft speed information may comprise true airspeed. The air information may comprise ambient information. The ambient information may comprise aircraft altitude. The ambient information may comprise ambient air density. The ambient information may comprise ambient temperature. the air information may comprise any additional information like pitch, yaw and roll angles, angel of attack, X, Y or Z accelerations, weight, etc.... The aircraft flight information may comprise propeller driving power information. The propeller driving power information may comprise engine parameters. The engine parameters may comprise engine torque. The engine parameters may comprise engine rotational speed. The engine parameters may comprise engine power. The propeller driving power information may comprise propeller parameters. The propeller parameters may comprise propeller rotational speed. The propeller parameters may comprise propeller driving torque. The propeller parameters may comprise propeller driving power. The virtual pitch calculation may comprise a propeller power computation performed on the propeller driving power information to determine the virtual propeller pitch or virtual blade angle. The input shaft propeller power may be computed with the propeller rotational speed and the absorbed propeller torque. The input shaft propeller power may be computed with the aircraft airspeed, the propeller thrust and the propeller efficiency. The input shaft propeller power may be computed with the engine rotational speed and the engine torque. The computation with the propeller rotational speed and the absorbed propeller torque is preferred. The aircraft flight informati