METHOD FOR ANALYZING FAULTS PRESENT ON A PLATFORM AND ASSOCIATED SYSTEM

• US 20120259505A1
• Filed: 04/05/2012
• Published: 10/11/2012
• Est. Priority Date: 04/06/2011
• Status: Active Grant

• Current Assignee: Dassault Aviation (Groupe Industriel Marcel Dassault)
• Original Assignee: Dassault Aviation (Groupe Industriel Marcel Dassault)
• Inventors: TURBAN, Laurent, TURCO, Walter
• Granted Patent: US 8,838,327 B2
• Time in Patent Office: Days
• US Class Current: 701/31.8
• CPC Class Codes: G05B 23/0278 Qualitative, e.g. if-then rules; Fuzzy logic; Lookup tables; Symptomatic search; FMEA
• CPC Class Codes: G06F 11/0739 in a data processing system embedded in automotive or aircraft systems
• CPC Class Codes: G06F 11/079 Root cause analysis, i.e. error or fault diagnosis in a hardware test environment G06F11/22; in a software test environment G06F11/36

Abstract

A method for analyzing faults present on a platform includes the following steps:

(a) providing a table of correspondence between a plurality of observable symptoms on the platform (10) and the fault modes capable of creating each observable symptom;

(b) measuring the observable symptoms present on the platform (10);

(c) establishing at least one family of faults, including determining a list of fault modes capable of creating, alone or in combination, all of the selected present symptoms, placing each given fault mode of the group in a fault family, and grouping all of the fault modes capable of creating at least one selected present symptom shared with the given fault mode together in the same fault family as the given fault mode. The method is applicable to fault analyses on aircrafts.

Claims

1. A method for analyzing faults present on a platform (10), in particular an aircraft, including the following steps:

(a) providing (40) a table of correspondence (60) between a plurality of observable symptoms on the platform (10) and the fault modes capable of creating each observable symptom;

(b) measuring (42) the symptoms present on the platform (10) and selecting at least part of the measured present symptoms;

(c) establishing (44) at least one family of faults, the establishment step comprising the following phases;

obtaining (100), from the table of correspondence (60), a list of fault modes capable of creating, alone or in combination, all of the selected symptoms that are present; and

, for each given fault mode of said list;

placing (108, 110) a given fault mode in a fault family;

grouping together (114, 116), within the same fault family as the given fault mode, all of the fault modes of said list capable of creating at least one selected present symptom in common with the given fault mode.

2. The method according to claim 1, characterized in that the grouping phase comprises checking off (112) each selected present symptom capable of being created by the given fault mode and placing, in said fault family, all of the fault modes from said list capable of being created by each checked symptom.

3. The method according to claim 1, characterized in that step (c) creates a single fault family, the single fault family comprising at least one fault mode, the or each fault mode of the fault family being capable of creating each present symptom selected in step (b).

4. The method according to claim 1, characterized in that step (c) creates a plurality of separate fault families, each fault mode of the first fault family not having any selected present symptoms in common with each fault mode of a second fault family.

5. The method according to claim 1, characterized in that step (c) comprises the following phases:

(c1) scanning (102) each fault mode listed in the list of fault modes to determine whether the scanned fault mode already belongs to a fault family;

(c2) if the scanned fault mode does not already belong to a fault family, creating (108) a new fault family comprising the scanned fault mode;

(c3) scanning (112) all of the selected present symptoms capable of being created by the scanned fault mode of the new fault family;

(c4) checking off, based on the table of correspondence, other fault modes capable of creating said selected present symptoms;

(c5) determining (114, 116), for each other checked fault mode, whether that fault mode belongs to another fault family.

6. The method according to claim 5, characterized in that in step (c5), if the fault mode belongs to another fault family, the method includes merging (116) the other fault family with the newly-created fault family, and if not, the method comprises integrating the checked fault mode into the existing family.

7. The method according to claim 1, characterized in that it comprises, between step (b) and step (c), separating (70) the fault modes capable of creating each selected present symptom into a first group of potentially active fault modes and a second group of potentially inactive fault modes, the list of fault modes determined in step (c) including only the potentially active fault modes.

8. The method according to claim 7, characterized in that the table of correspondence (60) includes, for each fault mode, the assignment to each symptom associated with that fault mode of a deterministic criterion of the symptom, to distribute the symptoms of that fault mode between at least a first group of systematic symptoms and potentially at least one second group of non-systematic symptoms,

the separating step (70) comprising the classification, in the second group of potentially inactive fault modes, of each fault mode not including all of the systematic symptoms from among the list of present symptoms measured in step (b).

9. The method according to claim 1, characterized in that it comprises a step (72) for calculating the overall likelihood of each fault mode associated with at least one present symptom selected in step (b), based on a predetermined representative value of the occurrence of the appearance of the fault mode and a vector representative of the number of present symptoms selected in step (b) among the symptoms associated with fault mode in the table of correspondence (60).

10. The method according to claim 1, characterized in that it comprises, for each fault family, a step (48) for determining the or each subset of minimum fault modes capable of creating, by themselves, all of the selected present symptoms in the fault family.

11. The method according to claim 10, characterized in that the determination step (48) includes the following sub-steps:

creating (154) a plurality of initial subsets, each subset containing at least one fault mode associated with a selected present symptom of the family;

iterative intersection (156, 160) of the initial subsets to determine the fault modes shared between the subsets;

eliminating (170) the redundant subsets present in the shared fault modes.

12. The method according to claim 10, characterized in that it comprises, for each subset, the calculation of a probability of the occurrence of each of the fault modes present in the subset as a function of a predetermined occurrence value of each fault mode.

13. The method according to claim 1, characterized in that it comprises a first phase for establishing at least one fault family, based on a first set of present symptoms selected in step (b) and from the table of correspondence (60);

then a second phase for establishing at least one second fault family based on the table of correspondence and a second set of selected present symptoms including some of the symptoms from the first set of selected present symptoms, the second set of present symptoms being distinct from the first set of selected present symptoms.

14. The method according to claim 1, characterized in that it comprises carrying out a maintenance step on the platform based on the or each fault family obtained in step (c).

16. The method according to claim 2, characterized in that step (c) creates a single fault family, the single fault family comprising at least one fault mode, the or each fault mode of the fault family being capable of creating each present symptom selected in step (b).

17. The method according to claim 2, characterized in that step (c) creates a plurality of separate fault families, each fault mode of the first fault family not having any selected present symptoms in common with each fault mode of a second fault family.

18. The method according to claim 2, characterized in that step (c) comprises the following phases:

(c1) scanning (102) each fault mode listed in the list of fault modes to determine whether the scanned fault mode already belongs to a fault family;

(c2) if the scanned fault mode does not already belong to a fault family, creating (108) a new fault family comprising the scanned fault mode;

(c3) scanning (112) all of the selected present symptoms capable of being created by the scanned fault mode of the new fault family;

(c4) checking off, based on the table of correspondence, other fault modes capable of creating said selected present symptoms;

(c5) determining (114, 116), for each other checked fault mode, whether that fault mode belongs to another fault family.

19. The method according to claim 11, characterized in that it comprises, for each subset, the calculation of a probability of the occurrence of each of the fault modes present in the subset as a function of a predetermined occurrence value of each fault mode.

15. A system (12) for analyzing faults present on a platform, comprising:

means (22) for storing a table of correspondence (60) between a plurality of observable symptoms on the platform (10) and the fault modes capable of creating each observable symptoms;

means (20A to 20C) for measuring the observable symptoms present on the platform (10) and selecting at least some of the measured present symptoms;

means (22) for establishing at least one fault family, the establishment means comprising;

means for obtaining, from the table of correspondence (60), a list of fault modes capable of creating, alone or in combination, all of the selected present symptoms;

means for placing each given fault mode of said list in a fault family;

means for grouping together, in the same fault family as the given fault, all of the fault modes from the list capable of creating at least one selected present symptom shared with the given fault mode.