Fault diagnosis

• US 8,219,275 B2
• Filed: 06/19/2007
• Issued: 07/10/2012
• Est. Priority Date: 06/22/2006
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Nyberg, Mattias
• Primary Examiner(s): Algahaim, Helal A
• Application Number:
  US11/765,110
• Publication Number:
  US 20070299574A1
• Time in Patent Office: 1,848 Days
• Field of Search: 701/1, 701 29- 31, 701 33- 35
• US Class Current: 701/29.1
• CPC Class Codes: G06F 11/2257 using expert systems

Abstract

Status of an entity having a plurality of components is determined from a listing of enhanced diagnostic expressions. For each combination of diagnostic expressions, a current joint diagnostic expression is generated representing a conjunction of first and second diagnostic expressions from respective first and second received listings. This expression is compared with each diagnostic expression in a generated listing of enhanced diagnostic expressions, and is discarded if: there exists a previous expression in the listing that implies the previous expression or there exists either a first or second diagnostic expression in the respective first or second listing that has not yet been included in a joint diagnostic expression and the current joint diagnostic expression implies either the first or second diagnostic expression. Any other joint diagnostic expressions are stored in the listing of enhanced diagnostic expressions. A status report is generated based on the listing of enhanced diagnostic expressions.

Claims

1. A diagnosis engine (100) configured for estimating a status of an entity (150, 200) with a plurality of components (c₁, . . . , c_n) wherein at least one of the components is assumed to be in either a fault-free mode or be in exactly one of at least two fault modes, the diagnosis engine (100) comprising a processing unit (110) configured to receive first (D) and second (E) listings of respective diagnostic expressions (D₁, . . . , D_n) and (E₁, . . . , E_m) indicating at least one of said modes for at least one of said components (c₁, . . . , c_n), and generate a status report (R) based on said first (D) and second (E) listings of respective diagnostic expressions (D₁, . . . , D_n) and (E₁, . . . , E_m), wherein the diagnosis engine (100) comprises:

a first storage area (120) configured to store said first listing (D) of diagnostic expressions (D₁, . . . , D_n) constituting a first part of said diagnostic expressions, and store said second listing (E) of diagnostic expressions (E₁, . . . , E_m) constituting a second part of said diagnostic expressions; and

a second storage area (130) configured to store a listing of enhanced diagnostic expressions (Q) indicating at least one of said modes for at least one of said components (c₁, . . . , c_n), and

the processing unit (110) is configured to;

receive said first listing (D) of diagnostic expressions (D₁, . . . , D_n);

receive said second listing (E) of diagnostic expressions (E₁, . . . , E_m);

store said first and second listings (D;

E) in the first storage area (120);

create an empty listing of enhanced diagnostic expressions (Q) by clearing any contents of the second storage area (130), and thereafter, for each combination of diagnostic expressions (D_i, E_j) in said first and second listings (D;

E);

generate a current joint diagnostic expression (Q_new) representing a conjunction of a first diagnostic expression (D_i) from said first listing (D) of diagnostic expressions (D₁, . . . , D_n) and a second diagnostic expression (E_j) from said second listing (E) of diagnostic expressions (E₁, . . . , E_m);

compare the current joint diagnostic expression (Q_new) with each diagnostic expression in the listing of enhanced diagnostic expressions (Q) stored in the second storage area (130);

discard the current joint diagnostic expression (Q_new), if there exists a previous expression (Q_k) in the listing of enhanced diagnostic expressions (Q), and the current joint diagnostic expression (Q_new) implies the previous expression (Q_k);

discard the current joint diagnostic expression (Q_new), if there exists a first diagnostic expression (D_k) in said first listing (D) of diagnostic expressions (D₁, . . . , D_n), the first diagnostic expression (D_k) having not yet been included in a joint diagnostic expression and the current joint diagnostic expression (Q_new) implies the first diagnostic expression (D_k);

discard the current joint diagnostic expression (Q_new), if there exists a second diagnostic expression (E_k) in said second listing (E) of diagnostic expressions (E₁, . . . , E_m), the second diagnostic expression (E_k) having not yet been included in a joint diagnostic expression and the current joint diagnostic expression (Q_new) implies the second diagnostic expression (E_k);

otherwise

store the joint diagnostic expression (Q_new) as an addition to the listing of enhanced diagnostic expressions (Q) in the second storage area (130); and

generate a status report (R) based on the listing of enhanced diagnostic expressions (Q).

2. The diagnosis engine (100) according to claim 1, wherein the processing unit (110) is configured to receive at least one of said first and second listings (D;

E) from at least one sensor unit being associated with at least one of said components (c₁, . . . , c_n), said at least one listing (D;

E) reflecting test results in respect of at least one of said components (c₁, . . . , c_n) to which the at least one sensor unit is associated.

3. The diagnosis engine (100) according to claim 1, wherein the processing unit (110) is configured to receive at least one of said first and second listings (D;

E) from at least one auxiliary diagnosis engine being associated with at least a sub-group of said components (c₁, . . . , c_n), said at least one listing (D;

E) including status reports in respect of the sub-group of said components (c₁, . . . , c_n) to which the at least one auxiliary diagnosis engine is associated.

4. A computer implemented method of diagnosing an entity with a plurality of components (c₁, . . . , c_n) wherein at least one of the components is assumed to be in either a fault-free mode or be in exactly one of at least two fault modes, the method comprising receiving first (D) and second (E) listings of respective diagnostic expressions (D₁, . . . , D_n) and E₁, . . . , E_m) indicating at least one of said modes for at least one of said components (c₁, . . . , c_n), and generating a status report (R) based on said first (D) and second (E) listings of respective diagnostic expressions (D₁, . . . , D_n) and (E₁, . . . , E_m), wherein said method comprises:

receiving said first listing (D) of diagnostic expressions (D₁, . . . , D_n) constituting a first part of said diagnostic expressions;

receiving said second listing (E) of diagnostic expressions (E₁, . . . , E_m) constituting a second part of said diagnostic expressions;

storing said first and second listings (D, E) in a first storage area (120);

creating an empty listing of enhanced diagnostic expressions (Q) by clearing any contents of a second storage area (130), and thereafter, for each combination of diagnostic expressions (D_i, E_j) in said first and second listings (D, E);

using a computer processing device to;

generating a current joint diagnostic expression (Q_new) as a conjunction of a first diagnostic expression (D_i) from said first listing (D) of diagnostic expressions (D₁, . . . , D_n) and a second diagnostic expression (E_j) from said second listing (E) of diagnostic expressions (E₁, . . . , E_m);

comparing the current joint diagnostic expression (Q_new) with each diagnostic expression in the listing of enhanced diagnostic expressions (Q) stored in the second storage area (130);

discarding the current joint diagnostic expression (Q_new), if there exists a previous expression (Q_k) in the listing of enhanced diagnostic expressions (Q), and the current joint diagnostic expression (Q_new) implies the previous expression (Q_k);

discarding the current joint diagnostic expression (Q_new), if there exists a first diagnostic expression (D_k) in said first listing (D) of diagnostic expressions (D₁, . . . , D_n), the first diagnostic expression (D_k) having not yet been included in a joint diagnostic expression and the current joint diagnostic expression (Q_new) implies the first diagnostic expression (D_k);

discarding the current joint diagnostic expression (Q_new), if there exists a second diagnostic expression (E_k) said second listing (E) of diagnostic expressions (E₁, . . . , E_m), the second diagnostic expression (E_k) having not yet been included in a joint diagnostic expression and the current joint diagnostic expression (Q_new) implies the second diagnostic expression (E_k);

otherwise

storing the joint diagnostic expression (Q_new) as an addition to the listing of enhanced diagnostic expressions (Q) in the second storage area (130); and

generating a status report (R) based on the listing of enhanced diagnostic expressions (Q).

5. The computer implemented method according to claim 4, wherein at least one of the respective receiving first and second listing steps receives a respective said first or second listing (D;

E) that reflects test results from at least one sensor unit associated with at least one of said components (c₁, . . . , c_n).

6. The computer implemented method according to claim 4, wherein at least one of the respective receiving first and second listing steps receives a respective said first or second listing (D;

E) that includes diagnostic expressions generated by at least one auxiliary diagnosis engine configured to generate status reports with respect to at least a sub-group of said components (c₁, . . . , c_n).

7. A motor vehicle (200) comprising a plurality of components (c₁, . . . , C_n, . . . , c_s) and a diagnosis engine configured for estimating a respective status of at least a sub-group (c₁, . . . , c_n) of said components wherein at least one of the components is assumed to be in either a fault-free mode or be in exactly one of at least two fault modes, the diagnosis engine (100) comprising a processing unit (110) configured to receive first (D) and second (E) listings of respective diagnostic expressions (D₁, . . . , D_n) and (E₁, . . . , E_m) indicating at least one of said modes for at least one of said components (c₁, . . . , c_n), and generate a status report (R) based on said first (D) and second (E) listings of respective the diagnostic expressions (D₁, . . . , D_n) and (E₁, . . . , E_m), wherein the diagnosis engine (100) comprises:

a first storage area (120) configured to store said a first listing (D) of diagnostic expressions (D₁, . . . , D_n) constituting a first part of said diagnostic expressions, and store said second listing (E) of diagnostic expressions (E₁, . . . , E_m) constituting a second part of said diagnostic expressions; and

a second storage area (130) configured to store a listing of enhanced diagnostic expressions (Q) indicating at least one of said modes for at least one of said components (c₁, . . . , c_n), and

the processing unit (110) is configured to;

receive said first listing (D) of diagnostic expressions (D₁, . . . , D_n);

receive said second listing (E) of diagnostic expressions (E₁, . . . , E_m);

store said first and second listings (D;

E) in the first storage area (120);

create an empty listing of enhanced diagnostic expressions (Q) by clearing any contents of the second storage area (130), and thereafter, for each combination of diagnostic expressions (D_i, E_j) in said first and second listings (D;

E);

generate a current joint diagnostic expression (Q_new) representing a conjunction of a first diagnostic expression (D_i) from said first listing (D) of diagnostic expressions (D₁, . . . , D_n) and a second diagnostic expression (E_j) from said second listing (E) of diagnostic expressions (E₁, . . . , E_m);

compare the current joint diagnostic expression (Q_new) with each diagnostic expression in the listing of enhanced diagnostic expressions (Q) stored in the second storage area (130);

discard the current joint diagnostic expression (Q_new), if there exists a previous expression (Q_k) in the listing of enhanced diagnostic expressions (Q), and the current joint diagnostic expression (Q_new) implies the previous expression (Q_k);

discard the current joint diagnostic expression (Q_new), if there exists a first diagnostic expression (D_k) in said first listing (D) of diagnostic expressions (D₁, . . . , D_n), the first diagnostic expression (D_k) having not yet been included in a joint diagnostic expression and the current joint diagnostic expression (Q_new) implies the first diagnostic expression (D_k);

discard the current joint diagnostic expression (Q_new), if there exists a second diagnostic expression (E_k) in said second listing (E) of diagnostic expressions (E₁, . . . , E_m), the second diagnostic expression (E_k) having not yet been included in a joint diagnostic expression and the current joint diagnostic expression (Q_new) implies the second diagnostic expression (E_k);

otherwise

store the joint diagnostic expression (Q_new) as an addition to the listing of enhanced diagnostic expressions (Q) in the second storage area (130); and

generate a status report (R) based on the listing of enhanced diagnostic expressions (Q).

8. The motor vehicle according to claim 7, wherein the processing unit (110) is configured to receive at least one of said first and second listings (D;

E) from at least one sensor unit being associated with at least one of said components (c₁, . . . , c_n), said at least one listing (D;

E) reflecting test results in respect of at least one of said components (c₁, . . . , c_n) to which the at least one sensor unit is associated.

9. The motor vehicle according to claim 7, wherein the processing unit (110) is configured to receive at least one of said first and second listings (D;

E) from at least one auxiliary diagnosis engine being associated with at least a sub-group of said components (c₁, . . . , c_n), said at least one listing (D;

E) including status reports in respect of the sub-group of said components (c₁, . . . , c_n) to which the at least one auxiliary diagnosis engine is associated.

10. A computer program product comprising a non-transitory computer readable medium, the non-transitory computer readable medium comprising computer-executable program code stored therein configured for diagnosing an entity with a plurality of components (c₁, . . . , c_n) wherein at least one of the components is assumed to be in either a fault-free mode or be in exactly one of at least two fault modes, the computer program product receiving first (D) and second (E) listings of respective diagnostic expressions (D₁, . . . , D_n) and (E₁, . . . , E_m) indicating at least one of said modes for at least one of said components (c₁, . . . , c_n), and generating a status report (R) based on said first (D) and second (E) listings of respective diagnostic expressions (D₁, . . . , D_n) and (E₁, . . . , E_m), the computer executable code comprising:

a first executable portion configured for receiving said first listing (D) of diagnostic expressions (D₁, . . . , D_n) constituting a first part of said diagnostic expressions;

a second executable portion configured for receiving said second listing (E) of diagnostic expressions (E₁, . . . , E_m) constituting a second part of said diagnostic expressions;

a third executable portion configured for storing said first and second listings (D, E) in a first storage area (120);

a fourth executable portion configured for creating an empty listing of enhanced diagnostic expressions (Q) by clearing any contents of a second storage area (130), and thereafter, for each combination of diagnostic expressions (D_i, E_j) in said first and second listings (D, E);

a fifth executable portion configured for generating a current joint diagnostic expression (Q_new) as a conjunction of a first diagnostic expression (D_i) from said first listing (D) of diagnostic expressions (D₁, . . . , D_n) and a second diagnostic expression (E_j) from said second listing (E) of diagnostic expressions (E₁, . . . , E_m);

a sixth executable portion configured for comparing the current joint diagnostic expression (Q_new) with each diagnostic expression in the listing of enhanced diagnostic expressions (Q) stored in the second storage area (130);

a seventh executable portion configured for discarding the current joint diagnostic expression (Q_new), if there exists a previous expression (Q_k) in the listing of enhanced diagnostic expressions (Q), and the current joint diagnostic expression (Q_new) implies the previous expression (Q_k);

an eighth executable portion configured for discarding the current joint diagnostic expression (Q_new), if there exists a first diagnostic expression (D_k) in said first listing (D) of diagnostic expressions (D₁, . . . , D_n), the first diagnostic expression (D_k) having not yet been included in a joint diagnostic expression and the current joint diagnostic expression (Q_new) implies the first diagnostic expression (D_k);

a ninth executable portion configured for discarding the current joint diagnostic expression (Q_new), if there exists a second diagnostic expression (E_k) said second listing (E) of diagnostic expressions (E₁, . . . , E_m), the second diagnostic expression (E_k) having not yet been included in a joint diagnostic expression and the current joint diagnostic expression (Q_new) implies the second diagnostic expression (E_k);

otherwise

a tenth executable portion configured for storing the joint diagnostic expression (Q_new) as an addition to the listing of enhanced diagnostic expressions (Q) in the second storage area (130); and

an eleventh executable portion configured for generating a status report (R) based on the listing of enhanced diagnostic expressions (Q).

11. The computer program product according to claim 10, wherein at least one of the respective first and second executable portions receives a respective said first or second listing (D;

E) that reflects test results from at least one sensor unit associated with at least one of said components (c₁, . . . , c_n).

12. The computer program product according to claim 10, wherein at least one of the respective first and second executable portions receives a respective said first or second listing (D;

E) that includes diagnostic expressions generated by at least one auxiliary diagnosis engine configured to generate status reports with respect to at least a sub-group of said components (c₁, . . . , c_n).