SYSTEM AND METHOD FOR OPERATING AN ENGINE

• US 20180058391A1
• Filed: 08/25/2016
• Published: 03/01/2018
• Est. Priority Date: 08/25/2016
• Status: Active Application

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Gibson, Alexander O`Connor, Short, Christopher M., Jentz, Robert Roy, Rollinger, John Eric
• Granted Patent: US 10,288,016 B2
• Time in Patent Office: Days
• CPC Class Codes: F02B 37/183 Arrangements of bypass valves or actuators therefor
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/08 Exhaust gas treatment apparatus parameters
• CPC Class Codes: F02D 2200/703 Atmospheric pressure
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/0072 Estimating, calculating or determining the EGR rate, amount or flow sensors in EGR systems F02M26/45
• CPC Class Codes: F02D 41/0077 Control of the EGR valve or actuator, e.g. duty cycle, closed loop control of position EGR valve position sensor F02M26/48
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor
• CPC Class Codes: F02M 26/49 Detecting, diagnosing or indicating an abnormal function of the EGR system
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Methods and systems for operating an engine including an external exhaust gas recirculation (EGR) system are presented. In one non-limiting example, output of a differential pressure sensor and output of an intake manifold pressure sensor are used as a basis for determining whether or not EGR system degradation is present while an engine is operating at conditions other than engine idle conditions.

Claims

1. A method for operating an engine, comprising:

receiving a differential pressure sensor output and intake manifold pressure sensor output to a controller;

judging whether or not exhaust gas recirculation system degradation is present responsive to the differential pressure sensor output and the intake manifold pressure sensor output while operating an engine with intake manifold pressure greater than atmospheric pressure via the controller; and

adjusting an actuator via the controller responsive to the judgment.

2. The method of claim 1, where the actuator is a waste gate.

3. The method of claim 1, further comprising converting the differential pressure sensor output to a differential pressure, and where the judgement is based on the differential pressure exceeding a second threshold.

4. The method of claim 3, further comprising converting the intake manifold pressure sensor output to an intake manifold pressure, and where the judgement is also based on the intake manifold pressure minus a barometric pressure exceeding a first threshold.

5. The method of claim 1, further comprising converting the differential pressure sensor output to a differential pressure, and where the judgement is based on an absolute value of the differential pressure exceeding an eighth threshold.

6. The method of claim 5, further comprising converting the intake manifold pressure sensor output to an intake manifold pressure, and where the judgement is also based on the intake manifold pressure minus a barometric pressure exceeding a seventh threshold.

7. The method of claim 1, further comprising closing an exhaust gas recirculation valve while operating the engine with intake manifold pressure greater than atmospheric pressure.

8. A method for operating an engine, comprising:

receiving a differential pressure measurement and a second measurement to a controller;

judging presence of EGR system degradation upstream of a differential pressure sensor in response to an absolute value of the differential pressure measurement being greater than an eighth threshold and engine intake manifold pressure minus the second measurement being greater than a seventh threshold; and

adjusting an actuator via the controller responsive to the judgment.

9. The method of claim 8, further comprising judging presence of EGR system degradation downstream of a differential pressure sensor in response to the differential pressure measurement being greater than a second threshold and engine intake manifold pressure minus the second measurement being greater than a first threshold.

10. The method of claim 8, where the second measurement is a measurement of barometric pressure.

11. The method of claim 8, where the second measurement is a measurement of exhaust manifold pressure.

12. The method of claim 8, further comprising judging presence of EGR system degradation downstream of a differential pressure sensor in response to an absolute value of the differential pressure measurement being greater than a sixth threshold and an absolute value of engine intake manifold pressure minus the second measurement being greater than a fifth threshold.

13. The method of claim 8, further comprising judging presence of EGR system degradation upstream of a differential pressure sensor in response to the differential pressure measurement being greater than a fourth threshold and an absolute value of engine intake manifold pressure minus the second measurement being greater than an third threshold.

14. The method of claim 8, where the engine is operating with a positive intake manifold pressure while the controller receives the differential pressure measurement and the second measurement.

15. A vehicle system, comprising:

an engine including an intake manifold and an exhaust manifold;

an exhaust gas recirculation system including a conduit coupling the intake manifold to the exhaust manifold, a differential pressure sensor located along the conduit, and an intake manifold pressure sensor;

a barometric pressure sensor; and

a controller including executable instructions stored in non-transitory memory to adjust a state of an actuator in response to an indication of exhaust gas recirculation system degradation based on an absolute value of an output of the differential pressure sensor being greater than a sixth threshold and an absolute value of an output of the engine intake manifold pressure sensor minus an output of the barometric pressure sensor being greater than a fifth threshold.

16. The vehicle system of claim 15, where the actuator is a fuel injector.

17. The vehicle system of claim 15, where the actuator is a throttle.

18. The vehicle system of claim 15, where the actuator is an ignition system.

19. The vehicle system of claim 15, further comprising additional instructions to adjust the actuator in response to an indication of exhaust gas recirculation system degradation based on an output of the differential pressure sensor being greater than a fourth threshold and an absolute value of an output of the engine intake manifold pressure sensor minus an output of the barometric pressure sensor being greater than a third threshold.

20. The vehicle system of claim 15, where the executable instructions are executed when the engine is not idling.