Diagnostic system for an engine employing collection of exhaust gases

• US 5,572,424 A
• Filed: 05/23/1994
• Issued: 11/05/1996
• Est. Priority Date: 05/23/1994
• Status: Expired due to Fees

• Current Assignee: Automotive Information Systems, Inc. (Michigan) (Cox Enterprises Incorporated)
• Original Assignee: Automotive Information Systems
• Inventors: Kellogg, Robert L., Hislop, Jeffrey K., Norman, Kenneth S., Pillai, Sushil L.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): Fiul, Dan
• Application Number:
  US08/247,542
• Time in Patent Office: 897 Days
• Field of Search: 364/424.03, 364/496, 73/23.31, 73/863.01, 73/117, 73/117.3, 340/439, 356/51
• US Class Current: 701/29
• CPC Class Codes: G01M 15/102 by monitoring exhaust gases

Abstract

A computer implemented method for providing a diagnosis for automotive engine malfunctions using collected vehicle emissions data. The concentration levels of gases within exhaust emitted from a vehicle engine being determined and compared to a plurality of predetermined concentration level data sets stored in a database to find a matching data set. Each predetermined concentration level data set having corresponding engine diagnosis data for identifying engine malfunction. The engine diagnosis and concentration level data being printed on a testing diagnosis form to be filled out by mechanics upon repair of the malfunctioning engine. Upon return of a previously tested vehicle that has been repaired, the same test is performed on the vehicle and the newly collected concentration level data is compared with the prior failing concentration level data to determine the accuracy of the repair performed. The database within the computer is updated with a new diagnosis and concentration level data set when the repair performed is different than that recommended by the diagnosis or when the new concentration level data set generated is not found within the database. This provides the closed loop learning system in which new failure concentration level data sets and an associated diagnosis are stored for addition to the database.

Claims

1. A computer implemented method for providing a diagnosis for automotive engine malfunctions using collected vehicle emissions data, comprising the steps of:

(a) generating a concentration level subset for each individual gas of a group of gases within said vehicle emissions data collected forming a plurality of concentration level subsets;

(b) comparing each of said concentration level subsets with predetermined normative concentration break point value data sets to determine relative correspondence between each of said concentration level subsets and said predetermined normative concentration break point values;

(c) generating relative correspondence data patterns representative of said relative correspondence between each of said concentration level subsets and said predetermined normative concentration break point values; and

(d) comparing said relative correspondence data patterns with a plurality of predetermined relative correspondence data patterns for finding a match, wherein each said predetermined relative correspondence data patterns are each associated with a failure signature code, whereby said failure signature code is used to diagnose said engine malfunctions.

2. A computer implemented method for providing a diagnosis to automotive engine malfunctions comprising the following steps:

(a) determining automatically an engine type for a vehicle being tested;

(b) searching a computer database for predetermined normative gas characteristics associated with said engine type;

(c) loading said predetermined normative gas characteristics into a memory location in the computer, said predetermined normative gas characteristics including failure patterns, normative concentration break point values, causes and reasons for abnormal gas concentrations and correlation information;

(d) generating vehicle emissions for use in determining the engine malfunction, said vehicle emissions being generated by operating said engine at varying loads, said loads defined by emission testing standards;

(e) collecting said vehicle emissions for use in generating a concentration level subset for each individual gas of a group of gases within said vehicle emissions collected;

(f) comparing each said concentration level subset with said concentration break point values of said predetermined normative characteristics to determine a relative correspondence between each said concentration level subset and said normative concentration break point values, said relative correspondence being represented as a bitmap pattern;

(g) comparing said bitmap pattern of said relative correspondence against a plurality of predetermined relative correspondence bitmap patterns for determining an engine condition associated with each gas, wherein each of said predetermined relative correspondence bitmap patterns is associated with a failure signature code for use in diagnosing said engine malfunction; and

(h) diagnosing said engine malfunction using said failure signature codes.

3. The computer implemented method of claim 2 including the step of:

(a) updating said plurality of predetermined relative correspondence bitmap patterns to include said bitmap patterns of said relative correspondence when a match for said bitmap patterns of said relative correspondence is not within said plurality of predetermined relative correspondence bitmap patterns.

4. The computer implemented method of claim 2 wherein said failure signature codes used in diagnosing said engine malfunction are keys into causes within a cause information table and reasons within a reason information table, said cause information table having descriptive information about said gas behaviors, said reason information table containing a matrix of associated engine malfunctions, said cause information table being updated with information received for repairs preformed.

5. The computer implemented method of claim 2 wherein said group of gases including NOx, CO2, CO, and HC.

6. The computer implemented method of claim 2 wherein said method further includes performing a correlation comparison analysis on said emissions testing data when one of said relative correspondence bitmap patterns is not identically matched with one of said predetermined relative correspondence bitmap patterns, said correlation comparison analysis including the following steps:

(a) concatenating said failure signature codes associated with each of said predetermined relative correspondence bitmap patterns causing a testing data correlation pattern to be generated;

(b) comparing each said testing data correlation pattern against a plurality of predetermined correlation patterns for locating an identical pattern match, wherein each of said predetermined correlation patterns is associated with a correlation failure signature code for use in diagnosing said engine malfunction; and

(c) diagnosing said engine malfunction using said correlation failure signature code.

7. The computer implemented method of claim 2 wherein said method further analyzes said emissions testing data by performing a correlation comparison analysis including the following steps:

(a) concatenating said failure signature associated with each said predetermined failure bitmap pattern causing a testing data correlation pattern to be generated;

(b) comparing each said testing data correlation pattern against a plurality of predetermined correlation patterns for locating an identical pattern match, wherein each of said predetermined correlation patterns is associated with a correlation failure signature code for use in diagnosing said engine malfunction; and

(c) diagnosing said engine malfunction using said correlation failure signature code.

8. The computer implemented method of claim 2 wherein said method further includes performing an inference engine analysis on said emissions testing data when more than one of said emission concentration level bitmap patterns is not identically matched with one of said predetermined failure bitmap patterns, said inference engine analysis including the following steps:

(a) receiving said raw emissions testing data and said break point values of said predetermined normative gas characteristics for use in creating a solution index value;

(b) creating a solution index value;

(c) comparing said solution index value to a rule set table, said rule set table having an array of solution values, wherein one of said solution values matches said solution index value, wherein a theoretical solution is associated with each said solution value; and

(d) diagnosing said engine malfunction using said theoretical solution.

9. The computer implemented method of claim 2 wherein said method further includes performing an inference engine analysis on said emissions testing data when a correlation comparison analysis does not determine a cause and reason for said engine malfunction, said inference engine analysis including the following steps:

(a) receiving said vehicle emissions collected and said normative concentration break point values of said predetermined normative gas characteristics for use in creating a solution index value;

(b) generating a solution index value;

(c) comparing said solution index value to a rule set table, said rule set table having an array of solution values, wherein one of said solution values matches said solution index value, wherein a theoretical pattern identification is associated with each said solution value; and

(d) diagnosing said engine malfunction using said theoretical pattern identification.

10. The method of claim 9 wherein said inference engine analysis includes performing supplemental processing to generate said theoretical pattern identification for use in diagnosing said engine malfunction when said solution value identified indicates that supplemental processing needs to be performed.

11. A computer implemented method of refining diagnosis provided to a vehicle owner for automotive engine malfunctions detected during an emissions test comprising the following steps:

(a) repeating the emissions test following repair of the engine malfunction for determining whether retested engine emissions collected are within an acceptable concentration range;

(b) comparing a first test engine emissions and said retested engine emissions for determining the efficiency of said repair performed; and

(c) updating a database within the computer with said repair performed, when said repair performed is different from the diagnosis provided and said retested engine emissions collected are more normative than said first test engine emissions, for replacing the diagnosis provided and generating a new diagnosis for association with the engine malfunction.

12. A computer implemented system for diagnosing automotive engine malfunctions using collected vehicle emissions data, comprising:

(a) a means for generating a concentration level subset for each individual gas of a group of gases within said vehicle emissions data collected forming a plurality of concentration level subsets;

(b) a means for comparing each of said concentration level subsets with predetermined normative concentration break point values to determine a relative correspondence between each of said concentration level subsets and said normative concentration break point values; and

(c) a means for comparing said relative correspondence with a plurality of predetermined relative correspondence data readings for finding a match, wherein each said predetermined relative correspondence data reading is associated with a failure signature code, whereby said failure signature code is used to diagnose said engine malfunctions.

13. A computer implemented system for diagnosing automotive engine malfunctions comprising:

(a) a means for automatically determining an engine type for a vehicle being tested;

(b) a means for searching a computer database for predetermined normative gas characteristics associated with said engine type;

(c) a means for loading said predetermined normative gas characteristics into a memory location in the computer, said predetermined normative gas characteristics including failure patterns, normative concentration break point values, causes and reasons for abnormal gas concentrations and correlation information;

(d) a means for generating vehicle emissions for use in determining the engine malfunction, said vehicle emissions being generated by operating said engine at varying loads, said loads defined by emission testing standards;

(e) a means for collecting said vehicle emissions for use in generating a concentration level subset for each individual gas of a group of gases within said vehicle emissions collected;

(f) a means for comparing each said concentration level subset with said concentration break point values of said predetermined normative characteristics to determine a relative correspondence between each said concentration level subset and said normative concentration break point values, said relative correspondence being represented as a bitmap pattern;

(g) a means for comparing said bitmap pattern of said relative correspondence against a plurality of predetermined relative correspondence bitmap patterns for determining an engine condition associated with each gas, wherein each of said plurality of predetermined relative correspondence bitmap patterns is associated with a failure signature code for use in diagnosing said engine malfunction; and

(h) a means for diagnosing said engine malfunction using said failure signature codes.

14. The computer implemented system of claim 13 including:

(a) a means for updating said plurality of predetermined relative correspondence bitmap patterns to include said bitmap patterns of said relative correspondence when a match for said bitmap patterns of said relative correspondence is not within said plurality of predetermined relative correspondence bitmap patterns.

15. The computer implemented system of claim 13 wherein said failure signature codes used in diagnosing said engine malfunction are keys into causes and reasons within cause and reason information tables, said cause information table having descriptive information about said gas behaviors, said reason information table containing a matrix of associated engine malfunctions, said cause table being updated with information received for repairs performed.