Fuel leak estimator

• US 7,603,242 B2
• Filed: 09/21/2005
• Issued: 10/13/2009
• Est. Priority Date: 09/21/2005
• Status: Active Grant

• Current Assignee: Airbus Operations Limited (Airbus SE)
• Original Assignee: Airbus UK Limited (Airbus SE)
• Inventors: Tichborne, Franklin George, Clarke, Raymond, Brown, Michael Daniel
• Primary Examiner(s): Nghiem; Michael P.
• Assistant Examiner(s): KHUU, HIEN DIEU THI
• Application Number:
  US11/663,465
• Publication Number:
  US 20080103703A1
• Time in Patent Office: 1,483 Days
• Field of Search: 702/51, 702/45, 702/50, 702/55, 73/40, 73/405.R
• US Class Current: 702/51
• CPC Class Codes: G01F 23/263 by measuring variations in capacitance of capacitors
• CPC Class Codes: G01F 9/008 where the other variable is the flight or running time
• CPC Class Codes: G01M 3/3245 using a level monitoring device G01M3/3272 takes precedence
• CPC Class Codes: G01M 3/3254 using a flow detector G01M3/3245, G01M3/3272 take precedence

Abstract

A method of detecting a fuel leak from a fuel store of an aircraft where a processor receives inputs relating to the amount of fuel in the fuel store and to the rate of fuel used by the aircraft. The processor defines a fuel flow system state defined by a noise-compensated measures of the amount of fuel in the fuel store, a fuel leak amount estimate and a fuel leak rate estimate. The processor periodically calculates a new estimated state of the system in view of a previous estimated state and values of the inputs. The processor monitors the fuel leak amount estimate and the fuel leak rate estimate and if either exceeds a respective threshold value send a signal to a fuel leak warning device.

Claims

1. A method of detecting a fuel leak from a fuel store, the method comprising the steps of:

(i) receiving at a circuit signals representative of physical measurements made at a plurality of successive times of the amount of fuel in the fuel store of an aircraft and of the rate of fuel flowing from the fuel store, the measurements each being subject to noise,

(ii) the circuit defining, in state-space, a fuel flow system state, the fuel flow state of the system being defined by a set of variables including at least one variable relating to a quantity represented by the signals received in step (i) and a variable relating to fuel leakage from the fuel source,

(iii) the circuit ascertaining a new fuel flow state of the system in view of a previously ascertained fuel flow state of the system and a plurality of the measurements represented by the signals received in step (i),

(iv) the circuit identifying from the new fuel flow state of the system whether there might be a fuel leakage, and, when a fuel leakage is determined,

(v) causing an indication that there is a suspected fuel leak to be made.

2. A method according to claim 1, wherein step (iv) comprises ascertaining a fuel leak amount from one or more values of the fuel flow state of the system.

3. A method according to claim 2, including a step of the circuit deeming a leak present in the event that the fuel leak amount is greater than a preset threshold.

4. A method according to claim 1, wherein step (iv) comprises ascertaining a fuel leak rate from one or more values of the fuel flow state of the system.

5. A method according to claim 4, including a step of the circuit deeming a leak present in the event that the fuel leak rate is greater than a preset threshold.

6. A method according to claim 1, wherein step (iv) comprises ascertaining a fuel leak amount from one or more values of the fuel flow state of the system and ascertaining a fuel leak rate from one or more values of the fuel flow state of the system and the method includes a step of the circuit deeming a leak present in the event that the fuel leak amount is greater than a preset threshold or in the event that the fuel leak rate is greater than a preset threshold.

7. A method according to claim 1, wherein the ascertaining of the new fuel flow state of the system takes into account only one previous ascertained fuel flow state of the system.

8. A method according to claim 1, wherein during step (iii) the plurality of the measurements taken into account by the circuit when ascertaining the new fuel flow state of the system are representative of a plurality of different quantities, and wherein in respect of all of the respective different quantities taken into account when ascertaining the new fuel flow state of the system, the time of each physical measurement is identical in respect of a single quantity being measured.

9. A method according to claim 8, wherein at least two of the measurements taken into account when ascertaining the new fuel flow state of the system are derived from physical measurements of different quantities taken at different times.

10. A method according to claim 1, wherein the step of ascertaining the new fuel flow state of the system includes taking into account a single previous ascertained fuel flow state of the system, a single previous physical measurement of the rate of fuel used by the aircraft and a single current physical measurement of the amount of fuel in the fuel store.

11. A method according to claim 1, wherein the variables defining the fuel flow state of the system include a measure of a quantity or fuel, a fuel leak rate and a fuel leak amount.

12. A method according to claim 1, wherein the step of ascertaining the new fuel flow state of the system is in the form of a recursive state estimation method.

13. A method according to claim 1, wherein the step of ascertaining the new fuel flow state of the system is achieved by means of a Kalman filter algorithm.

14. A method according to claim 1, including a step of ascertaining the probable flow-rate of the leak and the probable amount of fuel that has leaked.

15. A software product comprising a computer usable medium carrying a software code embodied therein enabling a processor to perform the method of claim 1.

16. A circuit arranged to perform the method of claim 1.

17. A circuit according to claim 16 arranged to receive inputs representative of the amount of fuel in the fuel store of an aircraft, and of the rate of fuel used by the aircraft and also arranged to provide an output indicative of whether there might be a fuel leak.

18. A circuit according to claim 17, wherein the circuit comprises a suitably programmed processor.

19. A circuit for detecting a fuel leak from a fuel store, the circuit comprising:

(i) an input device connected to receive signals representative of physical measurements of the amount of fuel in the fuel store of an aircraft and of the rate of fuel flowing from the fuel store,

(ii) a memory adapted to store data representative of a fuel flow system state, in state-space, the fuel flow state of the system being defined by a set of variables including at least one variable relating to a quantity represented by the signals received at the input device, and a variable relating to fuel leakage from the fuel source,

(iii) a processor adapted to calculate a new fuel flow state of the system in view of a previously calculated fuel flow state of the system and a plurality of the measurements represented by the signals received at the input device and adapted to identify from the new fuel flow state of the system calculated by the processor whether there might be a fuel leak and

(iv) an output device connected to the processor adapted to output a signal to indicate that there is a suspected fuel leak in dependence on the calculations performed by the processor.

20. A software product comprising a computer usable medium carrying a software code embodied therein enabling a processor to be programmed to function as the processor of the circuit of claim 19, wherein the software product includes a Kalman filter module for calculating the state of the system.