Control of a machine using relaxed abduction method

• US 9,897,983 B2
• Filed: 10/28/2011
• Issued: 02/20/2018
• Est. Priority Date: 10/28/2011
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Grimm, Stephan, Hubauer, Thomas, Roshchin, Mikhail, Stender, Holger, Watson, Stuart
• Primary Examiner(s): Karim, Ziaul
• Application Number:
  US14/353,039
• Publication Number:
  US 20140277755A1
• Time in Patent Office: 2,307 Days
• Field of Search: 700275
• CPC Class Codes: G05B 13/0265 the criterion being a learning criterion
• CPC Class Codes: G05B 13/04 involving the use of models or simulators
• CPC Class Codes: G05B 23/0278 Qualitative, e.g. if-then rules; Fuzzy logic; Lookup tables; Symptomatic search; FMEA

Abstract

A method and apparatus for actuating a machine is provided in which a relaxed abduction problem is determined in order to explain the greatest possible part of the observations with the fewest possible assumptions. Based upon two preference orders over a subset of observations and a subset of assumptions, tuples are determined so that the theory together with the subset of assumptions explains the subset of observations. On the basis of the formal validity of the approach certain characteristics of the set of results (such as correctness, completeness, etc.) are checked. By the choice of underlying representational language and the preference relations, the complexity of the problem-solving process is influenced and thus flexibly adapted with regard to domain requirements. The invention may be used for any machines, e.g. gas turbines or steam turbines.

Claims

1. A method for actuating a machine, comprising:

determining, by a processing unit, a solution using relaxed abduction for a defined problem related to incorrect information or incomplete models associated with diagnosis of the machine using automatically joint optimization of sets of explained observations and required assumptions to determine a relaxed abduction problem,

solving, by a processing unit, the relaxed abduction problem so that the machine is actuated,

wherein the relaxed abduction problem is determined by description logic, and

actuating, by a processing unit, the machine for the diagnosis,

wherein two orders of preference over a subset of the observations and a subset of the assumptions are taken as a basis for determining tuples, so that the theory together with the subset of the assumptions explains the subset of the observations;

wherein the relaxed abduction problem is solved by transforming the relaxed abduction problem into a hypergraph, so that tuples (A,O) are encoded by pareto-optimal paths in the hypergraph;

wherein hyperedges of the hypergraph are induced by transcriptions of prescribed rules; and

wherein a weighted hypergraph H_RAP=(V,E), which is induced by the relaxed abduction problem, is determined by

2. The method as claimed in claim 1, wherein the machine comprises a turbine, a gas turbine or a steam turbine.

3. The method as claimed in claim 1, wherein the relaxed abduction problem (RAP) determined to be RAP=(T, A, O, ≦

_A, ≦

_O),

wherein

the theory T,

a set of abducible axioms A,

a set O of observations,

with

T|=O and

the orders of preference

≦

_A⊂

P(A)×

P(A) and

≦

_O⊂

P(O)×

P(O)

are taken as a basis for determining ≦

-minimal tuples (A,O)ε

P(A)×

P(O), so that T∪

A is consistent and T∪

A|=O holds.

4. The method as claimed in claim 1, wherein the pareto-optimal paths are determined by a label approach.

5. The method as claimed in claim 1, wherein the prescribed rules are determined as follows:

6. The method as claimed in claim 1, wherein

7. The method as claimed in claim 6, wherein shortest hyperpaths are determined by taking account of two preferences.

8. The method as claimed in claim 7, wherein the shortest hyperpaths are determined by taking account of two preferences by a label correction algorithm.

9. The method as claimed in claim 8, wherein the labels encode pareto-optimal paths to the hitherto found nodes of the hypergraph.

10. The method as claimed in claim 9, wherein alterations along the hyperedges are propagated by means of a meet operator and/or by means of a join operator.

11. An apparatus for actuating a machine, comprising:

a processing unit adapted to

determine a solution using relaxed abduction for a problem related to incorrect information or incomplete models associated with diagnosis of the machine using automatically joint optimization of sets of explained observations and required assumptions to determine a relaxed abduction problem,

solve the relaxed abduction problem so that the machine can be actuated, wherein the relaxed abduction problem is determined by description logic, and

actuate the machine for the diagnosis,

wherein two orders of preference over a subset of observations and a subset of assumptions are taken as a basis for determining tuples, so that a theory together with the subset of the assumptions explains the subset of the observations;

wherein the relaxed abduction problem is solved by transforming the relaxed abduction problem into a hypergraph, so that tuples (A,O) are encoded by pareto-optimal paths in the hypergraph;

wherein hyperedges of the hypergraph are induced by transcriptions of prescribed rules; and

wherein a weighted hypergraph H_RAP=(V,E), which is induced by the relaxed abduction problem, is determined by

12. The apparatus as claimed in claim 11, wherein the machine comprises a turbine, a gas turbine or a steam turbine.