Knowledge based diagnostic advisory system and method for an air separation plant

• US 5,557,549 A
• Filed: 03/28/1995
• Issued: 09/17/1996
• Est. Priority Date: 09/28/1992
• Status: Expired due to Fees

• Current Assignee: Praxair Technology Incorporated (Linde Plc)
• Original Assignee: Praxair Technology Incorporated (Linde Plc)
• Inventors: Chang, Ching M.
• Primary Examiner(s): Weinhardt, Robert A.
• Assistant Examiner(s): Thomas, Joseph
• Application Number:
  US08/411,917
• Time in Patent Office: 539 Days
• Field of Search: 395/12, 395/50, 395/54, 395/157, 395/158, 395/160, 395/161, 395/911, 395/914, 395/915, 364/402, 364/188, 364/551.01
• US Class Current: 702/183
• CPC Class Codes: F25J 2205/24 using regenerators, cold accumulators or reversible heat exchangers
• CPC Class Codes: F25J 3/04848 Control strategy, e.g. advanced process control or dynamic modeling
• CPC Class Codes: G05B 23/0248 Causal models, e.g. fault tree; digraphs; qualitative physics
• CPC Class Codes: G05B 23/027 Alarm generation, e.g. communication protocol; Forms of alarm
• CPC Class Codes: Y10S 706/914 Process plant
• CPC Class Codes: Y10S 715/965 for process control and configuration

Abstract

This invention is a method and system for troubleshooting a breakdown or malfunction in an industrial plant facility identified by alarm or shutdown signals based upon forming a knowledge base of knowledge elements for providing advice and guidance to the technician. Each fault condition has a set of knowledge elements arranged in a sequence having an ordered hierarchy corresponding to different levels of information. The subordinate knowledge elements are linked to permit selection for display on a computer monitor in a specified manner and in a predetermined cascade arrangement relative to each higher level knowledge element to which it is linked.

Claims

1. A diagnostic advisory system for troubleshooting an abnormal condition in the production of at least one gas in an air separation plant identified by one or more alarm or shutdown signals triggered by a different fault condition affecting the normal production of said at least one gas with said diagnostic advisory system comprising:

a programmed computer including memory means for storing a knowledge base of an air separation plant composed of a hierarchy of knowledge elements containing textual, graphical and/or video material for providing advice and guidance to an operator to enable the operator to monitor and to determine the cause of a fault condition of at least one gas and what action to take to correct such fault with the knowledge elements arranged in a sequence having an ordered priority corresponding to different levels of information with the highest priority knowledge element for the identified fault condition providing a preset number of diagnostic strategies with each strategy incorporating one or more subordinate knowledge elements in ranked order to the higher knowledge elements and to one another in accordance with the priority given to each level of information;

means for interactively linking subordinate knowledge element(s) to their higher priority knowledge element(s);

means responsive to a fault indicating signal for displaying each of said knowledge elements with each subordinate knowledge element displayed in a cascade formation relative to all higher ranking knowledge elements to which it is linked for said fault indicated signal; and

means for successively displaying one or more lower ranking knowledge elements within the linkage chain of knowledge elements to indicate what remedial action should be taken to correct the fault condition; and

means for returning to any higher knowledge element from which the displayed lower knowledge element depends.

2. A diagnostic advisory system as defined in claim 1 wherein said means for returning to any higher knowledge element operates to sequentially return the display to each higher knowledge element in the chain of selected knowledge elements.

3. A diagnostic advisory system as defined in claim 2 further comprising means for jumping out of the knowledge base to access external software programs and for returning to the knowledge base exactly at the location in the knowledge base from where the knowledge base was exited.

4. A diagnostic advisory system as defined in claim 1 further comprising means for conducting an index search for providing an alphabetical listing of all knowledge elements in the knowledge base at a location on said display showing the linkage to the knowledge element at the outset of said index search.

5. A diagnostic advisory system as defined in claim 1 further comprising means for conducting a word search which will access all knowledge elements corresponding to the matched words which are not directly linked to the knowledge element under diagnosis.

6. A diagnostic advisory system as defined in claim 1 further comprising means for performing a pattern search for specific word patterns within a given knowledge element.

7. A diagnostic advisory system as defined in claim 1 further comprising means for accessing an external text editing or word processing software program to write notes and comments to an electronic file in connection with the diagnostic procedure relative to a given knowledge element and for returning to the position in the knowledge element under diagnosis at the location when the external file was accessed.

8. A diagnostic method for troubleshooting an abnormal condition of an air separation plant identified by one or more alarm or shutdown signals corresponding to different fault conditions affecting the normal production of at least one gas comprising the steps of:

forming a knowledge base of an air separation plant in which air is decomposed into purified constituents selected from the group of gases comprising nitrogen, oxygen, argon and said knowledge base composed of a hierarchy of knowledge elements for providing advice and guidance to an operator to enable the operator to monitor and to determine the cause of a fault condition in at least one gas and what action to take to correct such fault with each identified fault condition having a set of knowledge elements for providing textual, graphical and/or video material and arranged in a sequence having an ordered priority corresponding to different levels of information with the highest priority knowledge element for the identified fault condition providing a preset number of diagnostic strategies with each strategy incorporating one or more subordinate knowledge elements in ranked order to the higher knowledge elements and to one another in accordance with the priority given to each level of information;

storing in a computer said knowledge base of the air separation plant and along with means for monitoring the production of at least one gas in the air separation plant;

detecting a fault condition in the industrial air separation plant by one or more signals;

actuating the signal in the computer to display the highest priority knowledge element corresponding to the existing fault condition;

displaying the selected highest priority knowledge element on a monitor connected to said computer;

selecting a subordinate knowledge element identified within the selected highest priority knowledge element with said subordinate knowledge element containing a list of action steps to be taken by the user to relate the fault condition to a specific device, component or process known to cause such default and outlining one or more appropriate remedial action steps to correct such device, component or process;

displaying the selected subordinate knowledge element on said monitor in a cascade fashion relative to its higher ranking knowledge element;

highlighting in succession each action step in said subordinate knowledge element to be taken by the user;

linking each highlighted action step in each subordinate knowledge element to other knowledge elements of lower ranking to provide the user with access to additional information and advice relating to each action step; and

displaying each linked lower ranking knowledge element in succession and in a cascade fashion partially superimposed over each higher ranking knowledge element to provide further information to the user to facilitate remedial action to correct the fault condition with the operator knowing at all times the position of the knowledge element displayed relative to all linked higher ranking knowledge elements.

9. A diagnostic method as defined in claim 8 wherein each subordinate knowledge element containing action steps includes a brief statement of the overall function of said knowledge element and is linked to a knowledge element displaying a logic decision tree for the subordinate knowledge element containing said action steps.

10. A diagnostic method as defined in claim 9 wherein said brief statement contains reference to at least one other knowledge element providing a definition and/or explanation of the operation of the knowledge element under diagnosis.