Diagnostic system for a closed fluid system

Patent metadata

Field	Value
Publication number	US-11656146-B2
Application number	US-201715833564-A
Country	US
Kind code	B2
Filing date	Dec 6, 2017
Priority date	Dec 6, 2017
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

A diagnostic system for a closed fluid system is provided. The closed fluid system includes a first fluid subsystem and a second fluid subsystem connected using a valve or valve/actuator. The diagnostic system includes a first sensor disposed in the first fluid subsystem, a second sensor disposed in the second fluid subsystem and a computer. The computer receives first time-ordered fluid level measurements and second time-ordered fluid level measurements from respectively the first sensor and the second sensor and performs a comparison of first fluid level of the first fluid subsystem and second fluid level of the second fluid subsystem. The computer produces a notification indicating a predicted transfer of hydraulic fluid when the first time-ordered fluid level measurements and the second time-ordered fluid level measurements have at least a threshold divergence and outputs the notification for display to a user.

First claim

What is claimed is:

1. A diagnostic system for a closed fluid system composed of a first fluid subsystem and a second fluid subsystem connected using a valve, the diagnostic system comprising:
a first sensor disposed in the first fluid subsystem and configured to measure a first fluid level of the first fluid subsystem, and output first time-ordered fluid level measurements corresponding thereto;
a second sensor disposed in the second fluid subsystem and configured to measure a second fluid level of the second fluid subsystem, and output second time-ordered fluid level measurements corresponding thereto; and
a computer coupled to the first sensor and the second sensor, and configured to:
receive the first time-ordered fluid level measurements and the second time-ordered fluid level measurements from respectively the first sensor and the second sensor;
perform a comparison of the first fluid level with the second fluid level from the first time-ordered fluid level measurements and the second time-ordered fluid level measurements;
produce a notification indicating a predicted malfunction of the valve when, based on the comparison, the first time-ordered fluid level measurements and the second time-ordered fluid level measurements have at least a threshold divergence; and
output the notification for display to a user,

wherein the computer configured to perform the comparison includes being configured to determine a correlation and an absolute difference between the first time-ordered fluid level measurements and the second time-ordered fluid level measurements that define a divergence thereof, and
wherein the computer configured to produce the notification includes being configured to produce the notification when the divergence is at least the threshold divergence.

2. The diagnostic system of claim 1 , wherein the divergence is at least the threshold divergence when the correlation is less than a predefined negative correlation, and the absolute difference is greater than a predefined absolute difference.

3. The diagnostic system of claim 1 , wherein the computer is further configured to filter out any of the first time-ordered fluid level measurements and the second time-ordered fluid level measurements that are outside a range of accepted measurements before the comparison of the first fluid level with the second fluid level is performed from only those of the first time-ordered fluid level measurements and the second time-ordered fluid level measurements that are within the range.

4. The diagnostic system of claim 1 , wherein the computer is further
configured to:
perform comparisons of respectively the first time-ordered fluid level measurements and the second time-ordered fluid level measurements;
produce a second notification indicating fluid transfer through the valve when, based on the comparisons, the first time-ordered fluid level measurements or the second time-ordered fluid level measurements indicate an overfill condition of respectively the first fluid subsystem or the second fluid subsystem; and
output the second notification for display to the user.

5. The diagnostic system of claim 4 , wherein the computer configured to perform the comparisons includes being configured to determine a first standard deviation of the first time-ordered fluid level measurements, and a second standard deviation of the second time-ordered fluid level measurements, and
wherein the computer configured to produce the second notification includes being configured to produce the second notification when the first standard deviation is less than a threshold standard deviation and the first time-ordered fluid level measurements are above a threshold fluid level, or the second standard deviation is less than the threshold standard deviation and the second time-ordered fluid level measurements are above the threshold fluid level.

6. The diagnostic system of claim 1 , wherein the diagnostic system is onboard an aircraft, and the first fluid subsystem and the second fluid subsystem are independent hydraulic systems of the aircraft.

7. The diagnostic system of claim 6 , wherein the valve is a brake shuttle valve connecting the independent hydraulic systems, and the predicted malfunction indicates inter-system fluid leakage at the brake shuttle valve when the brake shuttle valve is closed.

8. The diagnostic system of claim 6 , wherein the computer is a component of an aircraft condition monitoring system onboard the aircraft.

9. The diagnostic system of claim 6 , wherein the aircraft includes a datalink system configured to transmit the first time-ordered fluid level measurements and the second time-ordered fluid level measurements to an operations center including the computer.

10. A method of examining a closed fluid system comprised of a first fluid subsystem and a second fluid subsystem connected using a valve, the method implemented by a diagnostic system including a first sensor disposed in the first fluid subsystem, a second sensor disposed in the second fluid subsystem, and a computer coupled to the first sensor and the second sensor, the method comprising:
measuring a first fluid level of the first fluid subsystem, and outputting first time-ordered fluid level measurements corresponding thereto, using the first sensor;
measuring a second fluid level of the second fluid subsystem, and outputting second time-ordered fluid level measurements corresponding thereto, using the second sensor;
performing, using the computer, a comparison of the first fluid level with the second fluid level from the first time-ordered fluid level measurements and the second time-ordered fluid level measurements;
producing, using the computer, a notification indicating a predicted malfunction of the valve when, based on the comparison, the first time-ordered fluid level measurements and the second time-ordered fluid level measurements have at least a threshold divergence; and
outputting, using the computer, the notification for display to a user,
wherein performing the comparison includes determining a correlation and an absolute difference between the first time-ordered fluid level measurements and the second time-ordered fluid level measurements that define a divergence thereof, and
wherein producing the notification includes producing the notification when the divergence is at least the threshold divergence.

11. The method of claim 10 , wherein the divergence is at least the threshold divergence when the correlation is less than a predefined negative correlation, and the absolute difference is greater than a predefined absolute difference.

12. The method of claim 10 , further comprising filtering out any of the first time-ordered fluid level measurements and the second time-ordered fluid level measurements that are outside a range of accepted measurements before the comparison of the first fluid level with the second fluid level is performed from only those of the first time-ordered fluid level measurements and the second time-ordered fluid level measurements that are within the range.

13. The method of claim 10 , further comprising:
performing comparisons of respectively the first time-ordered fluid level measurements and the second time-ordered fluid level measurements;
producing a second notification using the computer, the second notification indicating fluid transfer through the valve when, based on the comparisons, the first time-ordered fluid level measurements or the second time-ordered fluid level measurements indicate an overfill condition of respectively the first fluid subsystem or the second fluid subsystem; and
outputting the second notification for display

Assignees

• Boeing Co

Inventors

• Nakhjavani Omid B
• Coleman Ryan K
• Betz Franz David
• Jackson Greg
• Warlick Sean
• Puigh Darren
• Zaikin Andrey Aleksandrovich
• Schimert James
• Runo Steven C

Classifications

• G05B23/024

  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 · CPC title

• G01M3/2876 Primary

  for valves (G01M3/30 takes precedence) · CPC title