Method for diagnosing a remaining lifetime, apparatus for diagnosing a remaining lifetime, method for displaying remaining lifetime data, display apparatus and expert system

• US 5,608,845 A
• Filed: 11/29/1993
• Issued: 03/04/1997
• Est. Priority Date: 03/17/1989
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ohtsuka, Hisao, Utamura, Motoaki
• Primary Examiner(s): Downs, Robert W.
• Application Number:
  US08/158,439
• Time in Patent Office: 1,191 Days
• Field of Search: 364/551.01, 364/184, 364/185, 364/186, 364/187, 364/550, 395/50, 395/183.02, 395/911, 395/912, 395/913, 395/914, 395/915, 395/916, 395/917, 395/918
• US Class Current: 706/45
• CPC Class Codes: G07C 3/00 Registering or indicating the condition or the working of machines or other apparatus, other than vehicles

Abstract

In a method for determining a remaining lifetime of an aggregate constructed of a plurality of components and having at least one function, and an apparatus thereof, a first remaining lifetime of the aggregate is acquired based upon experimental aging degradation data on one characteristic of at least one component of the aggregate; a second remaining lifetime of the aggregate is acquired based upon experimental aging data with respect to at least one function of the aggregate; a third remaining lifetime of the aggregate is acquired based on both the experimental aging degradation data on the one characteristic of at least one component of the aggregate and the experimental aging data on at least one function of the aggregate; and, a remaining lifetime having the shortest lifetime from the first through third remaining lifetimes is output as the remaining lifetime of the aggregate.

Claims

1. An expert system for determining a remaining lifetime of an aggregate constructed of a plurality of components and having at least one function and inferring information concerning said aggregate based on said remaining lifetime, comprising:

first means for receiving experimental aging degradation data on one characteristic of at least one component of said aggregate, information on at least a maintenance of said aggregate, and experimental aging data on said at least one function of said aggregate;

second means for receiving history data representing a history of operation of said aggregate;

a data base for storing said experimental aging degradation data on said one characteristic of said at least one component, said experimental aging data on said at least one function from said first receiving means and said history data representing a history of operation of said aggregate from said second receiving means;

a remaining lifetime determining apparatus for acquiring said remaining lifetime of said aggregate by reading data stored in said data base, said remaining lifetime determining apparatus comprises;

means for acquiring a first remaining lifetime of said aggregate based upon said experimental aging degradation data on said one characteristic of said at least one component of said aggregate and said history data representing a history of operation of said aggregate,

means for acquiring a second remaining lifetime of said aggregate based upon said experimental aging data on said at least one function of said aggregate,

means for acquiring a third remaining lifetime of said aggregate based on said experimental aging degradation data on said one characteristic of said at least one component of said aggregate and said history data relative to said experimental aging data on said at least one function of said aggregate, and

means for acquiring as said remaining lifetime one of said first, second and third remaining lifetimes having the shortest lifetime and outputting said remaining lifetime of said aggregate;

a knowledge base for storing as knowledge data said information on at least a maintenance of said aggregate received from said first means for receiving relative to a value of remaining lifetime;

inferring means for performing an inference based upon the value of said acquired remaining lifetime and said knowledge data so as to obtain an inference result representing information concerning said aggregate; and

means for outputting said inference result.

2. An expert system as claimed in claim 1, wherein said knowledge data includes information for indicating that a maintenance of said aggregate is required if the remaining lifetime is within a predetermined time period.

3. An expert system as claimed in claim 1, wherein said knowledge data includes information for representing that a maintenance of said aggregate is required if the experimental aging degradation data value for said at least one function is out of a predetermined range.

4. An expert system for determining a remaining lifetime of an aggregate constructed of a plurality of components and having at least one function, comprising:

first means for receiving experimental aging degradation data on one characteristic of at least one component of said aggregate, information on at least a maintenance of said aggregate, and experimental aging data on said at least one function of said aggregate;

second means for receiving history data representing a history of operation of said aggregate;

a data base for storing said experimental aging degradation data on said one characteristic of said at least one component, said experimental aging data on said at least one function from said receiving means and said history data representing a history of operation of said aggregate from said second receiving means;

a remaining lifetime determining apparatus for acquiring said remaining lifetime of said aggregate by reading data stored in said data base and outputting the acquired remaining lifetime, said remaining lifetime determining apparatus comprises;

means for acquiring a first remaining lifetime of said aggregate based upon said experimental aging degradation data on said one characteristic of said at least one component of said aggregate and said history data representing a history of operation of said aggregate,

means for acquiring a second remaining lifetime of said aggregate based upon said experimental aging data on said at least one function of said aggregate,

means for acquiring a third remaining lifetime of said aggregate based on said experimental aging degradation data on said one characteristic of said at least one component of said aggregate and said history data relative to said experimental aging data on said at least one function of said aggregate, and

means for acquiring as said remaining lifetime one of said first, second and third remaining lifetimes having the shortest lifetime and outputting said remaining lifetime of said aggregate.

5. An expert system for diagnosing a remaining lifetime (L) of an apparatus included in a plant and selecting an apparatus to be inspected, said expert system comprising:

an external system interface for taking history data of the plant under on line operation from an external sensor;

a terminal system for taking data including knowledge data through an input/output apparatus;

a user interface connected to said external system interface and said terminal system;

a data base connected to said user interface for managing data including the history data supplied from said external system interface and said terminal system via said user interface;

a knowledge acquire support apparatus connected to said user interface for receiving the knowledge data from said terminal system via said user interface;

a knowledge base connected to said knowledge acquire support apparatus for storing the knowledge data supplied from said knowledge acquire support apparatus; and

an inference apparatus connected to said knowledge base and said data base for diagnosing the remaining lifetime (L) of an apparatus of the plant based on said data including the history data and the knowledge data respectively stored in said data base and said knowledge base;

wherein said terminal system takes two kinds of data including;

function test data which is acquired in a function test of a constructive apparatus of the plant during a periodical check and is stored in said data base every time the periodical check is carried out, and

parts degradation characteristic data which is acquired in an accelerated lifetime test of parts of the constructive apparatus or materials of the plant and is stored in said data base,

wherein knowledge data is obtained from specification of the constructive apparatus and parts, performance, and maintenance information, or from past experience of experts concerning preventive maintenance work.

6. An expert system according to claim 5 wherein an output section of said terminal system has a function for displaying a result of diagnosis including the remaining lifetime (L) obtained by said inference apparatus, for each part of the constructive apparatus or for each apparatus to be inspected together with a disposition thereof.

7. An expert system according to claim 6 wherein said diagnosis result is numerical data of the remaining lifetime (L).

8. An expert system according to claim 6 wherein said diagnosis result is color data displayed by different colors depending on a difference in length of the remaining lifetime.

9. An expert system according to claim 5 wherein an output section of said terminal system has a function to clearly indicate the apparatus to be inspected which is selected by said inference apparatus.

10. An expert system according to claim 5 wherein an output section of said terminal system has a function for displaying a sentence stating a reason why the apparatus to be inspected is selected.

11. An expert system for diagnosing a remaining lifetime (L) of an apparatus included in a plant and selecting an apparatus to be inspected, said expert system comprising:

an external system interface for taking history data of the plant under on line operation from an external sensor;

a terminal system for taking data including knowledge data through an input/output apparatus;

a user interface connected to said external system interface and said terminal system;

a data base connected to said user interface for managing data including the history data supplied from said external system interface and said terminal system via said user interface;

a knowledge acquire support apparatus connected to said user interface for receiving the knowledge data from said terminal system via said user interface;

a knowledge base connected to said knowledge acquire support apparatus for storing the knowledge data supplied from said knowledge acquire support apparatus; and

an inference apparatus connected to said knowledge base and said data base for diagnosing the remaining lifetime (L) of an apparatus of the plant based on said data including the history data and the knowledge data respectively stored in said data base and said knowledge base;

wherein said terminal system takes two kinds of data including;

function test data which is acquired in a function test of a constructive apparatus of the plant during a periodical check and is stored in said data base every time the periodical check is carried out, and

parts degradation characteristic data which is acquired in an accelerated lifetime test of parts of the constructive apparatus or materials of the plant and is stored in said data base,

wherein knowledge data is obtained from specification of the constructive apparatus and parts, performance, and maintenance information, or from past experience of experts concerning preventive maintenance work,

wherein said inference apparatus comprises;

a parts degradation analyzing unit for calculating a first remaining lifetime (L₁) of parts by using the parts degradation characteristic data or parts failure data;

an apparatus performance analyzing unit for calculating a second remaining lifetime (L₂) of the parts by using the function test data,

a relativity analyzing unit for calculating a third remaining lifetime (L₃) of the parts from a relative relation between the parts degradation characteristic data and the function test data, and

a remaining lifetime evaluating unit for calculating the remaining lifetime (L) from said first, second and third remaining lifetimes (L₁, L₂, L₃) and for selecting the apparatus to be inspected.