PERFORMANCE MONITORING AND PROGNOSTICS FOR AIRCRAFT PNEUMATIC CONTROL VALVES

• US 20100155634A1
• Filed: 12/11/2009
• Published: 06/24/2010
• Est. Priority Date: 12/23/2008
• Status: Active Grant

• Current Assignee: Embraer S.A.
• Original Assignee: Embraer-Empresa Brasileira de Aeronã¡Utica SA
• Inventors: Puttini, Lucas Campos, do Amaral, Tiago Moraes
• Granted Patent: US 8,955,365 B2
• Time in Patent Office: Days
• US Class Current: 251/129.10
• CPC Class Codes: F16K 37/0091 by measuring fluid parameters
• CPC Class Codes: G05B 2219/24077 Module detects wear, changes of controlled device, statistical evaluation
• CPC Class Codes: G05B 2219/25312 Pneumatic, hydraulic modules, controlled valves
• CPC Class Codes: G05B 23/0237 based on parallel systems, e.g. comparing signals produced at the same time by same type systems and detect faulty ones by noticing differences among their responses
• 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
• CPC Class Codes: G05B 23/0283 Predictive maintenance, e.g. involving the monitoring of a system and, based on the monitoring results, taking decisions on the maintenance schedule of the monitored system; Estimating remaining useful life [RUL] preventive maintenance, i.e. planning maintenance according to the available resources without monitoring the system G06Q10/06

Abstract

A method estimates the health state of an aircraft pneumatic control valve through indirect measurements of available sensors. Measurements from identical valves operating under the same condition are compared. Residues are translated into estimates of individual valve degradation state. Historical degradation states can be used to predict expected time to failure.

Claims

1. A method of assessing the health of a pneumatic valve controlled system onboard an aircraft, comprising:

monitoring the states of a first process controlled by a first pneumatic valve;

monitoring the states of a second process controlled by a second pneumatic valve;

comparing the monitored states of the first process with the monitored states of the second process to derive at least one comparison result; and

ascertaining at least one parameter associated with the health of at least one of the first pneumatic valve and the second pneumatic valve in response at least in part to said comparison result.

2. The method of claim 1 further including monitoring the states of multiple processes, each controlled by a corresponding pneumatic valve, and using said states of said processes controlled by said corresponding pneumatic valves to obtain the comparison results.

3. The method of claim 1 wherein said first process controlled by said first pneumatic valve is performed on a first aircraft, and said second performed by said second pneumatic valve is performed on a second aircraft different from said first aircraft.

4. The method of claim 1 further including calculating said comparison based on a reference value selection.

5. A system for assessing the health of a pneumatic valve controlled system, comprising:

means for monitoring the states of a first process controlled by a first pneumatic valve;

means for monitoring the states of a second process controlled by a second pneumatic valve;

means for comparing the monitored states of the first process with the monitored states of the second process to derive at least one comparison result; and

means for ascertaining at least one parameter associated with the health of at least one of the first pneumatic valve and the second pneumatic valve in response at least in part to said comparison result.

6. The system of claim 5 further including means for monitoring the states of multiple processes, each controlled by a corresponding pneumatic valve, and wherein said means for comparing uses said states of said processes controlled by said corresponding pneumatic valves to obtain the comparison results.

7. The system of claim 5 wherein said first-mentioned monitoring means is disposed on a first aircraft, and said second-mentioned monitoring means is disposed on a second aircraft different from said first aircraft.

8. The system of claim 5 further including means for calculating said comparison based on a reference value selection.

9. An aircraft comprising:

a closed loop control system including at least one pneumatic valve configured to control a thermodynamic process, at least one sensor that monitors at least one state of said controlled process, and a closed loop controller coupled to electrically control said at least one pneumatic valve at least in part in response to said at least one sensor; and

a pneumatic valve health monitoring system coupled to receive outputs generated by said sensor, said monitoring system comparing sensor outputs and generating a health indication of the health of said at least one pneumatic valve.

10. The aircraft of claim 9 wherein said monitoring system is at least in part ground based.

11. The aircraft of claim 9 wherein said health monitoring system includes a residue evaluator, a principal component extractor and a health estimator.

12. The aircraft of claim 11 wherein said residue evaluator comprises at least one summer.

13. The aircraft of claim 11 wherein said residue evaluator is at least in part responsive to at least one reference value selector.

14. A method of calibrating the health condition estimation of a pneumatic valve based control system comprising:

Acquiring historical measurements concerning the operation of at least one pneumatic valve;

Extracting residues and principal components;

Identifying times of next failure;

Normalizing failure times;

Estimating extreme and median failure times; and

Applying a curve fitting function to relate principal component and degradation index.

15. A system for calibrating the health condition estimation of a pneumatic valve based control system comprising:

Means for acquiring historical measurements concerning the operation of at least one pneumatic valve;

Means for extracting residues and principal components;

Means for identifying times of next failure;

Means for normalizing failure times;

Means for estimating extreme and median failure times; and

Means for applying a curve fitting function to relate principal component and degradation index.