Method and system for diagnosing and reporting failure of a vehicle emission test

• US 5,729,452 A
• Filed: 03/31/1995
• Issued: 03/17/1998
• Est. Priority Date: 03/31/1995
• Status: Expired due to Fees

• Current Assignee: Envirotest Acquisition Co.
• Original Assignee: Envirotest Acquisition Co.
• Inventors: Smith, Mary V., Frost, Mark D.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US08/414,925
• Time in Patent Office: 1,082 Days
• Field of Search: 364/424.03, 364/424.02, 364/550.1, 364/552, 364/570, 364/571.01, 364/574.04, 364/579, 364/581, 364/148, 364/149, 364/151, 364/152, 395/10, 395/20, 395/23, 395/165, 395/905, 395/913, 395/161, 395/600
• US Class Current: 701/29
• CPC Class Codes: G01M 15/102 by monitoring exhaust gases

Abstract

A system and method which systematically diagnoses emissions test failure by applying the rules of a knowledge base to predict the cause of vehicle emissions failures. Classifiers are used to form predictions. The classifier is the data structure used in the automobile emission testing inspection lane by the lane diagnostic subsystem to provide a diagnosis for a particular vehicle. Its output is the likelihood that a vehicle suffers from a given failure based on the values of characteristics such as its emissions test results and the vehicle'"'"'s description. The classifier predictions are then used to prepare a failure report that is given to the motorist for use by his or her repair technician. In another feature of this invention, the classifiers are continuously updated in a learning process based on new repair records. The learning processes periodically analyzes the data and updates the knowledge base to include new or revised classifiers.

Claims

1. A method for generating a diagnosis of a vehicle'"'"'s cause of failure of an emissions test, wherein data is obtained relating to a plurality of vehicles which had failing emissions tests results and for which a prediction report was generated and wherein each of said plurality of vehicles has particular vehicle characteristics and also has passing emissions test results and a repair report, comprising the steps of:

in a storage media, storing a classifier table composed of a set of rules;

in an emissions testing facility, receiving and storing vehicle characteristics signals;

in said emissions testing facility, sampling emissions of said vehicle to create emission test results to generate a series of emission test signals;

transmitting to a processor said emissions test signals;

transmitting to said processor said vehicle characteristics signal; and

comparing said emission test signals and said vehicle characteristics signals to said classifier table'"'"'s set of rules in a manner in which forms said diagnoses of said vehicle'"'"'s cause of failure and generating a prediction report thereof;

receiving said vehicle characteristics signals, said failing emission test signals and said passing emission test signals of said plurality of vehicles;

dividing said vehicle characteristics signals and said failing and passing emission test signals of said plurality of vehicles to generate a training dataset and a testing dataset; and

correlating said plurality of repair reports with said training dataset to form new rules; and

from said new rules, forming new classifiers.

2. A method as recited in claim 1 further comprising the step of matching said prediction report with a failure frequency distribution file to generate a diagnostic assessment report including failure probabilities.

3. A method as recited in claim 2 further comprising the step of transmitting said diagnostic assessment report to a host computer where said diagnostic assessment report is stored.

4. A method as recited in claim 1 further comprising the step of periodically updating said classifier table.

5. A method as recited in claim 1 wherein prior to said dividing step, said method further comprising the steps of:

filtering said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles to remove certain data;

formatting said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles; and

weighting said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles.

6. A method as recited in claim 1 further comprising the steps of:

processing said testing dataset and said classifier table to form first output;

processing new classifiers to form second output;

comparing first output with said second output to generate a set of updated classifier rules;

forming an updated classifier table from said updated classifier rules.

7. A system for generating a diagnosis of a vehicle'"'"'s cause of failure of an emissions test, said vehicle having vehicle characteristics which form input to said system in the form of a vehicle characteristic signal, wherein data is obtained relating to a plurality of vehicles which had failing emissions test results and for which a prediction report was generated and wherein each of said plurality of vehicles has passing emissions test results and a repair report, comprising of:

stored in a storage media, a classifier table composed of a set of rules;

in an emissions testing facility, a receiving component for receiving said vehicle characteristics signal;

in said emissions testing facility, an emissions sampling apparatus to sample the emissions of said vehicle to create emission test results and which generates a series of emission test signals;

a transmitter for transmitting to a processor said emissions test signals;

a transmitter for transmitting to said processor said vehicle characteristics signal;

a comparator for comparing said emission test signals and said vehicle characteristics signal to said classifier table'"'"'s set of rules in a manner in which forms said diagnosis of said vehicle'"'"'s cause of failure and generating a prediction report thereof;

a receiver which receives said vehicle characteristics signals, said failing emission test signals and said passing emission test signals of said plurality of vehicles;

a division component which divides said vehicle characteristics signals and said failing and passing emission test signals of said plurality of vehicles to generate a training dataset and a testing dataset; and

a correlation component which correlates said plurality of repair reports with said training dataset to form new rules and therefrom, new classifiers.

8. A system as recited in claim 7 wherein said system also stores a frequency distribution file, said system further comprising:

a matching component which matches said prediction report with said failure frequency distribution file to generate a diagnostic assessment report including failure probabilities.

9. A system as recited in claim 8 further comprising a transmitter for transmitting said diagnostic assessment report to a host computer where it is stored.

10. A system as recited in claim 7 wherein said classifier table is periodically updated.

11. A system as recited in claim 7 further comprising:

a filter which filters said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles so that said signals meet selection criteria;

a formatting component which formats said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles to be acceptable to said correlation component; and

a weight component which weights said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles so that each of signal is appropriated scaled.

12. A system as recited in claim 7 further comprising:

a processor which processes said testing dataset and said classifier table to form first output;

a processor which processes new classifiers to form second output; and

a comparator which compares first output with said second output to generate a set of updated classifier rules to form an updated classifier table.

13. A method for improving a classifier table which correlates vehicle emission test failures with diagnostic assessments of the causes of the failure, said method including utilizing data derived from a plurality of vehicles which had failing emissions tests results and whose owners received a prediction report and wherein each of said plurality of vehicles has particular vehicle characteristics and also has passing emissions test results and a repair report, said method further comprising the steps of:

receiving said vehicle characteristics signals, said failing emission test signals and said passing emission test signals of said plurality of vehicles;

dividing said vehicle characteristics signals and said failing and passing emission test signals of said plurality of vehicles to generate a training dataset and a testing dataset; and

correlating said plurality of repair reports with said training dataset to form new rules;

from said new rules, forming new classifiers.

14. A method as recited in claim 13 wherein prior to said dividing step, said method further comprising the steps of:

filtering said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles for errors;

formatting said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles to be acceptable input for said correlating step; and

weighting said vehicle characteristics signals and failing and passing emission test signals of said plurality of vehicles so that each signal is appropriately scaled.

15. A method as recited in claim 13 further comprising the steps of:

processing said testing dataset and said classifier table to form first output;

processing new classifiers to form second output;

comparing first output with said second output to generate a set of updated classifier rules;

forming an updated classifier table.

16. A method as recited in claim 13 further comprising steps for generating a diagnosis of a vehicle'"'"'s cause of failure of an emissions test:

in a storage media, storing said classifier table composed of a set of rules;

in an emissions testing facility, receiving and storing vehicle characteristics signals;

in said emissions testing facility, sampling emissions of said vehicle to create emission test results to generate a series of emission test signals;

transmitting to a processor said emissions test signals;

transmitting to said processor said vehicle characteristics signal; and

comparing said emission test signals and said vehicle characteristics signals to said classifier table'"'"'s set of rules in a manner in which forms said diagnosis of said vehicle'"'"'s cause of failure and generating a prediction report thereof.

17. A method as recited in claim 16 further comprising the step of matching said prediction report with a failure frequency distribution file to generate a diagnostic assessment report including failure probabilities.

18. A method as recited in claim 16 further comprising the step of transmitting said diagnostic assessment report to a host computer where it is stored.