Method for creating, maintaining and using an expert system by recursively modifying calibration file and merging with standard file

• US 5,121,496 A
• Filed: 07/25/1988
• Issued: 06/09/1992
• Est. Priority Date: 07/25/1988
• Status: Expired due to Fees

• Current Assignee: Westinghouse Electric Sweden AB (Brookfield Asset Management Incorporated)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Harper, Karl E.
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): Coleman, Eric
• Application Number:
  US07/224,508
• Time in Patent Office: 1,415 Days
• Field of Search: 364/200, 364/200 MS File, 364/900 MS File, 364/513, 364/550
• US Class Current: 1/1
• CPC Class Codes: G06N 5/022 Knowledge engineering; Knowledge acquisition

Abstract

A method for creating, maintaining and using an expert system segregates the rulebase for the expert system into a standard rulebase and a calibration rulebase. The standard rulebase is stored in a read-only file, while the calibration rulebase is stored in a read/write file. An identical standard rulebase is provided for several units of a model or pieces of equipment of one type, while each unit has its own calibration rulebase. The operator of a unit is given access to the calibration rulebase to make modifications to the calibration properties for that particular unit. The calibration rulebase for a specific unit is then merged with the standard rulebase to form the application rulebase used in evaluating the unit.

Claims

1. A method of creating, maintaining and using a computerized expert system rulebase on a domain, said method comprising the steps of:

(a) creating a read-only standard file containing standard properties commonly used for different units within the domain of the rulebase;

(b) storing calibration properties, expected to be unique for different units within the domain of the rulebase, in at least one subsequently modifiable calibration file;

(c) merging the standard and calibration files to produce a first application file for application to a single unit within the domain of the rulebase;

(d) modifying the calibration file by at least one of (i) changing previously stored calibration properties and (ii) adding new calibration properties; and

(e) repeating said merging in step (c) after said modifying in step (d).

2. A method as recited in claim 1, further comprising the step of (f) modifying one of the standard properties for application to the single unit by performing the steps of:

(fi) recreating the standard file without the one of the standard properties;

(fii) adding the one of the standard properties to the calibration file as a new calibration property; and

(fiii) repeating said merging in step (c).

3. A method as recited in claim 1, wherein step (b) comprises the step of storing as one of the calibration properties a rule establishing a first confidence level for a first condition in response to at least a second confidence level of a second condition.

4. A method as recited in claim 1, wherein step (b) comprises the step of storing as one of the calibration properties a rule establishing exclusion of a diagnosis in reports produced by application of the rulebase.

5. A method as recited in claim 1,

wherein said storing in step (b) comprises:

(bi) creating first and second calibration files for first and second units;

(bii) storing as one of the calibration properties in the first calibration file a rule establishing a first confidence level for a first condition in response to at least a second confidence level of a second condition; and

(biii) storing as one of the calibration properties in the second calibration file a rule stating a suficiency condition for establishing the first confidence level in dependence upon the second confidence level, and

wherein step (c) comprises merging each of the first and second calibration files separately with the standard file to produce the first application file and a second application file for application to the first and second units, respectively.

6. A method of creating, maintaining and using a computerized expert system rulebase on a domain, said method comprising the steps of:

(a) creating a read-only standard file containing standard properties commonly used for different units within the domain of the rulebase;

(b) storing calibration properties, expected to be unique for different units within the domain of the rulebase, in at least one subsequently modifiable calibration file;

(c) merging the standard and calibration files to produce a first application file for application to a single unit within the domain of the rulebase.

(d) creating a new calibration file; and

(e) merging the new calibration and standard files to produce a second application file for application to another of the different units within the domain of the rulebase.

7. A method of creating, maintaining and using a computerized expert system for evaluation of at least one of construction and operation of equipment, said method comprising the steps of:

(a) creating a standard rulebase for the evaluation of a type of equipment, the standard rulebase being stored in a read-only file;

(b) creating a calibration rulebase for properties expected to vary for different pieces of equipment of the type corresponding to the standard rulebase created in step (a), the calibration rulebase being stored in a read/write file;

(c) merging the standard and calibration rulebases to form a read-only application rulebase for evaluating a selected piece of equipment; and

(d) maintaining the computerized expert system, said maintaining comprising the steps of;

(di) modifying the calibration rulebase without modifying the standard rulebase, and

(dii) repeating said merging in step (c) after performing step (di).