METHOD AND A DEVICE FOR MONITORING A REDUNDANT MEASUREMENT SYSTEM

• US 20120109486A1
• Filed: 10/25/2011
• Published: 05/03/2012
• Est. Priority Date: 11/02/2010
• Status: Abandoned Application

• Current Assignee: Snecma (Safran SA)
• Original Assignee: Snecma (Safran SA)
• Inventors: Flandrois, Xavier, ECOUTIN, Stéphane, Masse, Jean-Rémi André
• Application Number:
  US13/280,796
• Publication Number:
  US 20120109486A1
• Time in Patent Office: Days
• US Class Current: 701/100
• CPC Class Codes: G05B 23/0232 based on qualitative trend analysis, e.g. system evolution

Abstract

The invention relates to monitoring a redundant measurement system of an aeroengine by means of an electronic unit. The monitoring comprises a step of obtaining first measurements of a physical magnitude measured in said engine, and a step of obtaining second measurements of said physical magnitude. According to the invention, the method includes a step of calculating detection residues as a function of differences between the first and second measurements, a step of determining a mean-jump flag, a step of determining a variance-jump flag, a step of determining a change-of-slope flag, and a step of generating a diagnostic notice as a function of said mean-jump flag, of said variance-jump flag, and of said change-of-slope flag.

Claims

1. A method of monitoring a redundant measurement system for an aeroengine, the method being executed by an electronic unit of said engine, said monitoring method comprising:

a step of obtaining first measurements of a physical magnitude measured in said engine; and

a step of obtaining second measurements of said physical magnitude;

wherein the method comprises;

a step of calculating detection residues as a function of differences between the first measurements and the second measurements;

a step of determining a mean-jump flag representing a difference between the mean of the distribution of detection residues and the mean of a reference distribution;

a step of determining a variance-jump flag representing a difference between the variance of the distribution of the detection residues and the variance of the reference distribution;

a step of determining a change-of-slope flag representing a difference between the slope of the distribution of the detection residues and the slope of the reference distribution; and

a step of generating a diagnostic notice as a function of said mean-jump flag, of said variance-jump flag, and of said change-of-slope flag.

2. A monitoring method according to claim 1, comprising:

a step of obtaining modeled values of said physical magnitude;

a step of calculating first location residues as a function of differences between the first measurements and the modeled values;

a step of calculating second location residues as a function of the differences between the second measurements and the modeled values;

a step of determining a first mean-jump flag representing a difference between the mean of the distribution of the first location residues and the mean of a first reference distribution;

a step of determining a second mean-jump flag representing a difference between the mean of the distribution of the second location residues and the mean of a second reference distribution;

a step of determining a first variance-jump flag representing a difference between the variance of the distribution of the first location residues and the variance of the first reference distribution;

a step of determining a second variance-jump flap representing a difference between the variance of the distribution of the second location residues and the variance of the second reference distribution;

a step of determining a first change-of-slope flag representing a difference between the slope of the distribution of the first location residues and the slope of the first reference distribution;

a step of determining a second change-of-slope flag representing a difference between the slope of the distribution of the second location residues and the slope of the second reference distribution; and

a step of generating a notice concerning the location of a fault as a function of said first and second mean-jump flags, of said first and second variance-jump flags, and of said first and second change-of-slope flags.

3. A monitoring method according to claim 1, wherein said mean-jump flag is determined by a Wald test.

4. A monitoring method according to claim 1, wherein said variance-jump flag is determined by a Wald test.

5. A monitoring method according to claim 1, wherein said change-of-slope flag is determined by a Student'"'"'s test.

6. A monitoring method according to claim 1, including a detection step of detecting a stabilized stage, said detection residues being calculated as a function of differences between the first measurements and the second measurements as obtained during the stabilized stage.

7. A monitoring method according to claim 1, wherein the step of determining a mean-jump flag, the step of determining a variance-jump flag, and the step of determining a change-of-slope flag are repeated throughout a flight of the aircraft, the method including a step of generating a maintenance notice as a function of the flags determined during successive repeats.

8. A computer program including instructions for executing steps of the monitoring method according to claim 1 when said program is executed by a computer.

9. A computer readable storage medium having a computer program stored therein that includes instructions for executing the steps of the monitoring method according to claim 1.

10. A monitoring device for monitoring a redundant measurement system of an aeroengine, the device comprising:

means for obtaining first measurements of a physical magnitude that is measured in said engine; and

means for obtaining second measurements of said physical magnitude;

wherein the device comprises;

means for calculating detection residues as a function of differences between the first measurements and the second measurements;

means for determining a mean-jump flag representing a difference between the mean of the distribution of detection residues and the mean of a reference distribution;

means for determining a variance-jump flag representing a difference between the variance of the distribution of the detection residues and the variance of the reference distribution;

means for determining a change-of-slope flag representing a difference between the slope of the distribution of the detection residues and the slope of the reference distribution; and

means for generating a diagnostic notice as a function of said mean-jump flag, of said variance-jump flag, and of said change-of-slope flag.