Engine monitoring

• US 9,104,199 B2
• Filed: 01/20/2011
• Issued: 08/11/2015
• Est. Priority Date: 02/01/2010
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Whatley, Paul D, Gopsill, James A
• Primary Examiner(s): Karmis, Stefanos
• Assistant Examiner(s): Butler, Michael E
• Application Number:
  US13/010,151
• Publication Number:
  US 20110191002A1
• Time in Patent Office: 1,664 Days
• Field of Search: 701/99, 701/100, 701/101, 701/102
• US Class Current: 1/1
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/2496 the memory being part of a closed loop
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor
• CPC Class Codes: G05B 23/024 Quantitative history assessment, e.g. mathematical relationships between available data; Functions therefor; Principal component analysis [PCA]; Partial least square [PLS]; Statistical classifiers, e.g. Bayesian networks, linear regression or correlation analysis; Neural networks

Abstract

A method of monitoring a device, the method comprising: measuring one or more device operating parameters and a device performance parameter during one or more device operational periods; recording a plurality of data points, each data point comprising the device operating parameters and the associated device performance parameter; identifying one or more steady state regions in the device performance parameter and selecting a plurality of the data points from the one or more steady state regions in the device performance parameter; selecting one or more groups (40) of the steady state data points in the device operating parameter space by virtue of a predetermined density of the steady state data points in the device operating parameter space; and comparing the device performance parameter within the groups so as to identify a change in the performance of the device.

Claims

1. A method comprising:

monitoring, by a processor, a gas turbine engine across a flight envelope of an aircraft powered by the gas turbine engine, the monitoring comprising;

measuring, by a processor, one or more operating parameters of the gas turbine engine and a performance parameter of the gas turbine engine during one or more operational periods of the gas turbine engine;

recording, by a processor, a plurality of data points, each data point comprising the operating parameters and the associated performance parameter;

identifying, by a processor, one or more steady state regions in the performance parameter and selecting a plurality of the data points from the one or more steady state regions in the performance parameter;

selecting, by a processor, one or more groups of the steady state data points in the operating parameter space by virtue of a predetermined density of the steady state data points in the operating parameter space;

comparing, by a processor, the performance parameter within the groups so as to identify a change in the performance of the gas turbine engine;

counting, by a processor, the number of steady state data points neighbouring a particular steady state data point within a predetermined domain about the particular steady state data point in the operating parameter space;

repeating, by a processor, for each steady state data point; and

grouping, by a processor, steady state data points with a number of neighbouring steady state data points above a predetermined threshold into the one or chore groups, wherein all points defining a boundary of the predetermined domain in the operating parameter space are equidistant from the particular steady state data point.

2. A method as claimed in claim 1, wherein the method further comprises:

calculating differences between successive performance parameter values; and

identifying regions in which the absolute value of the differences are below a threshold value in order to identify the one or more steady state regions in the performance parameter.

3. A method as claimed in claim 1, wherein the method further comprises:

calculating a first ratio of the change in the performance parameter over a time period with respect to a datum steady state data point and a first successive performance parameter;

calculating a second ratio of the change in the performance parameter to a time period with respect to the datum steady state data point and a second successive performance parameter;

calculating differences between the first and second ratios for a range of datum steady state data points; and

identifying regions in which the absolute value of the differences are below a threshold value in order to identify the one or more steady state regions in the performance parameter.

4. A method as claimed in claim 3, wherein the method further comprises:

calculating changes in the differences between first and second ratios for successive datum data points; and

identifying regions in which the absolute value of the changes are below a threshold value in order to identify the one or more steady state regions in the performance parameter.

5. A method as claimed in claim 1, wherein the predetermined domain about the particular steady state data point in the operating parameter space is determined by a predetermined range for each of the one or more operating parameters in the operating parameter space.

6. A method as claimed in claim 5, wherein the predetermined range is the same for two or more of the operating parameters.

7. A method as claimed in claim 5, wherein the predetermined range for a particular operating parameter varies according to the value of the operating parameter.

8. A method as claimed in claim 1, wherein the method further comprises:

adjusting a control parameter in response to the change in the performance of the gas turbine engine.

9. A method as claimed in claim 1, wherein the method further comprises:

performing maintenance on the gas turbine engine in response to the change in the performance of the gas turbine engine.

10. A method as claimed in claim 1, wherein the method further comprises:

monitoring a second gas turbine engine; and

comparing the performance parameter within the groups and between the gas turbine engines so as to identify a change in the performance of either of the gas turbine engines.

11. A method as claimed in claim 1, wherein the performance parameter comprises one or more of a power output, a shaft speed, flow rates, fluid temperatures, fluid pressures, lubricant temperatures, lubricant pressures, component temperatures, vibration levels, noise levels, strain levels and any other indicator of gas turbine engine performance.

12. A method as claimed in claim 1, wherein the one or more operating parameters comprises one or more of ambient pressure, ambient temperature, ambient humidity, power input, power demand, fuel consumption rate, fuel calorific value, altitude, speed and any other indicator of operating conditions.

13. A method as claimed in claim 1, wherein the method is applied to a plurality of performance parameters.

14. A non-transitory computer-readable medium containing instructions, which when executed on a computer, carries out the following:

monitoring, by a processor, a gas turbine engine across a flight envelope of an aircraft powered by the gas turbine engine, the monitoring comprising;

measuring, by the processor, one or more operating parameters of the gas turbine engine and a performance parameter of the gas turbine engine during one or more operational periods of the gas turbine engine;

recording, by the processor, a plurality of data points, each data point comprising the operating parameters and the associated performance parameter;

identifying, by the processor, one or more steady state regions in the performance parameter and selecting a plurality of the data points from the one or more steady state regions in the performance parameter;

selecting, by the processor, one or more groups of the steady state data points in the operating parameter space by virtue of a predetermined density of the steady state data points in the operating parameter space;

comparing, by the processor, the performance parameter within the groups so as to identify a change in the performance of the gas turbine engine;

counting, by the processor, the number of steady state data points neighbouring a particular steady state data point within a predetermined domain about the particular steady state data point in the operating parameter space;

repeating, by the processor, for each steady stat data point; and

grouping, by the processor, steady state data points with a number of neighbouring steady state data points above a predetermined threshold into the one or more groups, wherein all points defining a boundary of the predetermined domain in the operating parameter space are equidistant from the particularly steady state data point.

15. An apparatus for monitoring a gas turbine engine, the apparatus comprising a computer storage medium configured to store a computer program and a processor configured to execute the program to:

monitor a gas turbine engine across a flight envelope of an aircraft powered by the gas turbine engine,

receive one or more operating parameters of the gas turbine engine and a performance parameter of the gas turbine engine during one or more operational periods of the gas turbine engine;

record a plurality of data points, each data point comprising the operating parameters and the associated performance parameter;

identify one or more steady state regions in the performance parameter and select a plurality of the data points from the one or more steady state regions in the performance parameter;

select one or more groups of the steady state data points in the operating parameter space by virtue of a predetermined density of the steady state data points in the operating parameter space;

compare the performance parameter within the groups so as to identify a change in the performance of the gas turbine engine;

count the number of steady state data points neighbouring a particular steady state data point within a predetermined domain about the particular steady state data point in the operating parameter space;

repeat for each steady state data point; and

group steady state data points with a number of neighbouring steady state data points above a predetermined threshold into the one or more groups, wherein all points defining a boundary of the predetermined domain in the operating parameter space are equidistant from the particular steady state data point.

16. A method comprising:

monitoring, by a processor, a gas turbine engine across a flight envelope of an aircraft powered by the gas turbine engine, the monitoring comprising;

measuring, by a processor, one or more operating parameters of the gas turbine engine and a performance parameter of the gas turbine engine during one or more operational periods of the gas turbine engine;

recording, by a processor, a plurality of data points, each data point comprising the operating parameters and the associated performance parameter;

identifying, by a processor, one or more steady state regions in the performance parameter and selecting a plurality of the data points from the one or more steady state regions in the performance parameter;

selecting, by a processor, one or more groups of the steady state data points in the operating parameter space by virtue of a predetermined density of the steady state data points in the operating parameter space;

comparing, by a processor, the performance parameter within the groups so as to identify a change in the performance of the gas turbine engine;

counting, by a processor, the number of steady state data points neighboring a particular steady state data point within a predetermined domain about the particular steady state data point in the operating parameter space;

repeating, by a processor, for each steady state data point;

grouping, by a processor, steady state data points with a number of neighboring steady state data points above a predetermined threshold into the one or more groups;

calculating the distances between a steady state data point within the one or more groups and each of the remaining steady state data points within the one or more groups in the operating parameter space; and

identifying the steady state data points within a group by virtue of their proximity to one another so as to distinguish between the one or more groups.