Diagnostic expert system for hierarchically decomposed knowledge domains
First Claim
1. A method for analyzing data comprising:
- establishing a hierarchical decomposition of a device into a plurality of components, each of the components outputting diagnostic data items, said hierarchical decomposition including a plurality of levels of said components of the device with each lower level component having a related higher level component such that a lower level component provides a functional capability of its related higher level component;
storing in storage means a rule set hierarchy having a plurality of rule sets, said rule set hierarchy having a hierarchical relationship between rule sets of said plurality of rule sets wherein;
(A1) each rule set of said plurality of rule sets includes rules for inferring a performance of a related component of said plurality of components; and
(A2) for each pair, R1 and R2, of said rule sets, R1 is a lower level rule set related to R2 as a higher level rule set, when said related component for R1 is a lower level component to said related component for R2 ;
selecting, as a designated rule, an eligible rule from a current rule set of said plurality of the rule sets, when such an eligible rule exists, wherein said designated rule has a premise with a maximal number of predicates for evaluation using informational data items stored in a fact base;
evaluating said premise of said designated rule for determining a premise value;
performing, when said premise value is a predetermined value, a consequent of said designated rule for determining additional informational data items using said diagnostic data items, said performance of said consequent at least providing a result;
using said result for determining whether to add said additional informational data items to said fact base and for determining a new instantiation of said current rule set, wherein;
(B1) when Said result includes a first predetermined value, said new instantiation of said current rule set must be a predetermined eligible rule set that is at a lower level to said current rule set;
(B2) when said result includes a second predetermined value, said new instantiation of said current rule set must be an eligible rule set that is;
(a) unrelated to said current rule set, and(b) is at a lower level than each previous instantiation of said current rule set;
setting said current rule set to ineligible for reconsideration as said current rule set;
repeating said steps of selecting, evaluating, performing, using, and setting until a rule cannot be selected for said designated rule;
stopping the analysis of the diagnostic data items output by components of the device; and
outputting an analysis related to a performance of the device using information from performing a consequent of at least one rule selected as said designated rule.
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Accused Products
Abstract
A forward chaining expert system is disclosed for use in analyzing categorization problems such as in diagnosing device malfunctions. The expert system is particularly useful in diagnosing malfunctions in a knowledge domain having a hierarchical functional decomposition. In such a knowledge domain, the hierarchical decomposition is used in constructing a collection hierarchically related rule sets which constitute the rule base for the expert system. The novel inferencing engine of the expert system iteratively examines rules within a selected rule set and: (a) determines the veracity of rule premises when compared with data within a fact base and (b) examines any statuses returned from the performance of rule consequents. Thus, upon encountering a rule consequent returning success, the inferencing engine selects a new rule set at a lower level in the rule set hierarchy and applies the new rule set to the data retained in the fact base. By allowing the inferencing engine to iteratively select one or more rule sets from a partially ordered collection of rule sets whereby the partial order is related to the knowledge domain hierarchical decomposition, the inferencing engine is able to provide problem solutions in increasingly greater detail when selecting increasingly more specific rule sets. Thus, the inferencing engine need not backtrack to examine alternative solutions.
98 Citations
22 Claims
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1. A method for analyzing data comprising:
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establishing a hierarchical decomposition of a device into a plurality of components, each of the components outputting diagnostic data items, said hierarchical decomposition including a plurality of levels of said components of the device with each lower level component having a related higher level component such that a lower level component provides a functional capability of its related higher level component; storing in storage means a rule set hierarchy having a plurality of rule sets, said rule set hierarchy having a hierarchical relationship between rule sets of said plurality of rule sets wherein; (A1) each rule set of said plurality of rule sets includes rules for inferring a performance of a related component of said plurality of components; and (A2) for each pair, R1 and R2, of said rule sets, R1 is a lower level rule set related to R2 as a higher level rule set, when said related component for R1 is a lower level component to said related component for R2 ; selecting, as a designated rule, an eligible rule from a current rule set of said plurality of the rule sets, when such an eligible rule exists, wherein said designated rule has a premise with a maximal number of predicates for evaluation using informational data items stored in a fact base; evaluating said premise of said designated rule for determining a premise value; performing, when said premise value is a predetermined value, a consequent of said designated rule for determining additional informational data items using said diagnostic data items, said performance of said consequent at least providing a result; using said result for determining whether to add said additional informational data items to said fact base and for determining a new instantiation of said current rule set, wherein; (B1) when Said result includes a first predetermined value, said new instantiation of said current rule set must be a predetermined eligible rule set that is at a lower level to said current rule set; (B2) when said result includes a second predetermined value, said new instantiation of said current rule set must be an eligible rule set that is; (a) unrelated to said current rule set, and (b) is at a lower level than each previous instantiation of said current rule set; setting said current rule set to ineligible for reconsideration as said current rule set; repeating said steps of selecting, evaluating, performing, using, and setting until a rule cannot be selected for said designated rule; stopping the analysis of the diagnostic data items output by components of the device; and outputting an analysis related to a performance of the device using information from performing a consequent of at least one rule selected as said designated rule. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An expert system for analyzing data comprising:
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fact storage means for storing data input to and updated by said expert system during an analysis of data; rule storage means for storing a plurality of rules, each rule in said plurality of rules having a premise with one or more conditions for evaluation using data in said fact storage means and a consequent, for determining at least one of; (A1) new data for said fact storage means; (A2) a conclusion inferred from data residing in said fact storage means; rule grouping means for grouping said plurality of rules in said rule storage means into a plurality of rule sets; inferencing means for performing each of; (B1) selecting a rule set from said plurality of rule sets as a current rule set, said current rule set to be used in analyzing data within said fact storage means; (B2) selecting an eligible rule from said current rule set of as a designated rule wherein said designated rule is selected whose premise has a maximal number of said conditions among eligible rules in said current set; (B3) evaluating a premise of said designated rule, and performing a consequent of said designated rule when a premise of said designated rule is satisfied by data in said fact storage means, thereby determining at least one of (A1) and (A2) when said consequent of said current rule performs successfully; rule set relating means for relating a first rule set in said plurality of rule sets to one or more other rule sets in said plurality of rule sets so that each second rule set of said other rule sets is associated with a predetermined rule in said first rule set, wherein when; (C1) said first rule set is selected as said current rule set in (B1); (C2) a predetermined second rule set of said other rule sets is associated with said designated rule selected in (B2); and (C3) said consequent of said designated rule performs successfully in (B3), then said second rule set must be selected as said current rule set in a further performance of (B1) through (B3) by said inferencing means and said first rule set is designated as ineligible for reconsideration as said current rule set; means for outputting resultant data when at least one of said designated rules cannot be selected in (B2) and a current rule set cannot be selected in (B1), said resultant data providing information related to one of; (D1) data stored in said fact storage means; and (D2) a conclusion related to said analysis of data. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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Specification