Exhaust aftertreatment system diagnostic and conditioning

• US 9,708,960 B2
• Filed: 05/06/2014
• Issued: 07/18/2017
• Est. Priority Date: 05/08/2013
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Hall, Tony J., Charlton, Stephen J., McGuire, Michael J.
• Primary Examiner(s): Kirkland, III, Freddie
• Application Number:
  US14/270,907
• Publication Number:
  US 20140331752A1
• Time in Patent Office: 1,169 Days
• CPC Class Codes: B01D 53/9418 for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 11/002 the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
• CPC Class Codes: F01N 2550/00 Monitoring or diagnosing the deterioration of exhaust systems
• CPC Class Codes: F01N 2550/02 Catalytic activity of catalytic converters
• CPC Class Codes: F01N 2550/04 Filtering activity of particulate filters
• CPC Class Codes: F01N 2550/05 Systems for adding substances into exhaust
• CPC Class Codes: F01N 2900/0414 using a state observer
• CPC Class Codes: F01N 2900/1402 Exhaust gas composition
• CPC Class Codes: F01N 2900/1406 Exhaust gas pressure
• CPC Class Codes: F01N 3/029 by adding non-fuel substances to exhaust
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 9/002 of filter regeneration, e.g. detection of clogging
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2200/0811 NOx storage efficiency
• CPC Class Codes: F02D 2200/0812 Particle filter loading
• CPC Class Codes: F02D 41/0235 in relation with the state of the exhaust gas treating apparatus control of exhaust gas treating apparatus per se F01N
• CPC Class Codes: F02D 41/024 to increase temperature of the exhaust gas treating apparatus
• CPC Class Codes: F02D 41/029 the exhaust gas treating apparatus being a particulate filter
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02D 41/1441 : Plural sensors
• CPC Class Codes: F02D 41/1446 : the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/146 : the characteristics being an NOx content or concentration
• CPC Class Codes: F02D 41/22 : Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/222 : relating to the failure of sensors or parameter detection devices
• CPC Class Codes: F02D 41/2432 : Methods of calibration
• CPC Class Codes: G01M 15/102 : by monitoring exhaust gases
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 : Engine management systems

Abstract

An engine diagnostic tool includes a diagnostic engine calibration module structured to include a plurality of diagnostic processes for operating an internal combustion engine system of an immobilized vehicle. One or more of the plurality of diagnostic processes are structured to be an intrusive diagnostic process for the internal combustion engine system, wherein the intrusive diagnostic process causes the internal combustion engine system to operate outside of one or more calibration parameters. The diagnostic engine module is further structured to control the order and timing of each diagnostic process in the plurality of diagnostic processes.

Claims

1. A method for diagnosing and conditioning a system of a vehicle, comprising:

immobilizing the vehicle in a controlled environment;

removing a production engine calibration program from an electronic control unit of the internal combustion engine system;

uploading a diagnostic engine calibration program to the electronic control unit;

running the diagnostic engine calibration program while the vehicle is immobilized in the controlled environment without user intervention, the diagnostic engine calibration including a plurality of diagnostic processes for operating an immobilized vehicle, wherein the plurality of diagnostic processes includes a high NOx sensor rationality test that includes disabling a DEF dosing event, providing an amount of engine out NOx at or above a predefined high NOx concentration threshold, operating an engine at or above a high speed threshold, determining a NOx concentration across a SCR system, and comparing the determined NOx concentration against a predetermined fault threshold to diagnose a NOx sensor;

removing the diagnostic engine calibration program from the electronic control unit after completion of the plurality of diagnostic processes; and

uploading the production engine calibration program to the electronic control unit;

wherein one or more of the plurality of diagnostic processes cause the internal combustion engine system to operate outside of one or more calibration parameters.

2. The method of claim 1, further comprising controlling the order and timing of each diagnostic process in the plurality of diagnostic processes.

3. The method of claim 1, wherein the diagnostic processes include a SCR performance test before an SCR regeneration event, wherein the SCR performance test before an SCR regeneration event includes substantially maximizing an exhaust gas flow rate, and monitoring a NOx conversion efficiency at various DEF dosing rates.

4. The method of claim 1, wherein the diagnostic processes include a SCR performance test with an SCR regeneration event, wherein the SCR performance test with an SCR regeneration event includes elevating an exhaust gas temperature and reducing an engine speed for a predetermined amount of time followed by substantially maximizing an exhaust gas flow rate, and monitoring a NOx conversion efficiency at various DEF dosing rates.

5. The method of claim 1, wherein the plurality of diagnostic processes includes a low NOx sensor rationality test, wherein the low NOx sensor rationality test includes disabling a DEF dosing event, providing about 75 ppm to 100 ppm NOx out of the engine, and determining a NOx concentration across the SCR system, wherein the determined NOx concentration is compared against a predetermined fault threshold.

6. The method of claim 1, wherein the plurality of diagnostic processes includes a DOC and DPF temperature sensor rationality test, wherein the DOC and DPF temperature sensor rationality test includes comparing DOC and DPF temperature sensor readings to each other after an engine has run at an idle speed for a predetermined amount of time after running the engine at a relatively higher speed for another predetermined amount of time.

7. The method of claim 1, wherein the plurality of diagnostic processes includes a SCR temperature sensor rationality test, wherein the SCR temperature sensor rationality test includes comparing SCR temperature sensor readings to each other after an engine has run at an idle speed for a predetermined amount of time after running the engine at a relatively higher speed for another predetermined amount of time.