Diagnostic method for a compressor recirculation valve

• US 9,702,298 B2
• Filed: 12/09/2014
• Issued: 07/11/2017
• Est. Priority Date: 12/09/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Ossareh, Hamid-Reza, Banker, Adam Nathan, Xiao, Baitao
• Primary Examiner(s): Trieu, Thai Ba
• Application Number:
  US14/565,150
• Publication Number:
  US 20160160747A1
• Time in Patent Office: 945 Days
• Field of Search: 60611, 701101-104, 7311431, 7311433
• CPC Class Codes: F02B 37/007 with exhaust-driven pumps arranged in parallel , e.g. at least one pump supplying alternatively
• CPC Class Codes: F02B 37/16 by bypassing charging air
• 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 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: F02D 41/222 relating to the failure of sensors or parameter detection devices
• CPC Class Codes: G01L 23/24 specially adapted for measuring pressure in inlet or exhaust ducts of internal-combustion engines
• CPC Class Codes: G01L 27/007 Malfunction diagnosis, i.e. diagnosing a sensor defect
• CPC Class Codes: G01M 15/08 by monitoring pressure in cylinders
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Methods are provided for identifying degradation in components of a compressor bypass valve (CBV). One method comprises commanding a periodic signal to the CBV and indicating degradation of a throttle of the CBV based on changes in pressure at an inlet of an intake throttle in response to the periodic signal.

Claims

1. A method for a boosted engine, comprising:

sending, via an electronic controller, a periodic signal command to a compressor recirculation valve (CRV) comprising a square waveform;

distinguishing between degradation of a position sensor of the CRV and a throttle of the CRV based on changes in pressure at an inlet of an intake throttle in response to the square waveform periodic signal command; and

in response to the degradation of the throttle of the CRV, adjusting a position of a wastegate valve.

2. The method of claim 1, wherein the periodic signal command has a period slower than a response time of a turbocharger in the boosted engine, and wherein the throttle of the CRV is determined to be degraded when the changes in pressure at the inlet of the intake throttle in response to the periodic signal command do not correspond to a periodicity of the periodic signal command.

3. The method of claim 2, wherein the position sensor of the CRV is determined to be degraded when the changes in pressure at the inlet of the intake throttle correspond to the periodicity of the periodic signal command to the CRV, and when a second signal commanding a change in a position of the throttle of the CRV does not produce a corresponding change in a response of the position sensor, the second signal being distinct from the periodic signal command.

4. A method for operating a boosted engine, comprising:

sending, with an electronic controller, a periodic actuator signal to a compressor bypass valve (CBV) actuator;

indicating degradation of a throttle of a CBV by activating a diagnostic code stored in memory of the electronic controller based on changes in pressure at an inlet of an intake throttle in response to the periodic actuator signal;

deactivating the CBV with the electronic controller in response to an indication of degradation of a position sensor of the CBV; and

adjusting a position of a wastegate valve in response to the degradation of the throttle of the CBV.

5. The method of claim 4, wherein pressure at the inlet of the intake throttle is measured by a sensor coupled to an intake passage and located upstream of the intake throttle and downstream of an intake compressor of the boosted engine.

6. The method of claim 5, wherein the periodic actuator signal is sent based on an operator input.

7. The method of claim 6, wherein the periodic actuator signal includes a square waveform.

8. The method of claim 5, wherein the periodic actuator signal has a periodicity based on response time of a turbocharger of the boosted engine.

9. The method of claim 8, further comprising indicating degradation of the throttle of the CBV when changes in pressure at the inlet of the intake throttle do not correspond to the periodicity of the periodic actuator signal to the CBV, including a determination of whether changes in throttle inlet pressure result in shifts in position of the CBV throttle.

10. The method of claim 8, further comprising indicating degradation of the position sensor of the CBV when changes in pressure at the inlet of the intake throttle correspond to the periodicity of the periodic actuator signal, and when sending a second actuator signal commanding a change in a position of the throttle of the CBV does not produce a corresponding change in a response of the position sensor.

11. The method of claim 10, wherein the second actuator signal is not a periodic signal.

12. The method of claim 4, further comprising adjusting the intake throttle responsive to the deactivating of the CBV.

13. The method of claim 4, wherein the CBV is a continuously variable compressor bypass valve.

14. A system, comprising;

an engine;

a turbocharger for providing a boosted aircharge to the engine, the turbocharger including an exhaust turbine and an intake compressor;

an intake throttle positioned in an intake passage downstream of the intake compressor;

a wastegate coupled across the exhaust turbine;

a continuously variable recirculation valve (CCRV) coupled across the intake compressor, the CCRV including a CCRV throttle and a CCRV position sensor;

a throttle inlet pressure (TIP) sensor coupled to the intake passage upstream of the intake throttle and downstream of the intake compressor; and

a control system with computer-readable instructions stored on non-transitory memory for;

commanding a periodic signal to the CCRV;

measuring changes in pressure at an inlet of the intake throttle via the TIP sensor; and

if the changes in pressure at the inlet of the intake throttle in response to the commanded periodic signal do not correspond to a frequency of the commanded periodic signal,

indicating degradation of the CCRV throttle and adjusting a position of a wastegate valve in response to the degradation of the CCRV throttle.

15. The system of dam 14, wherein the control system includes further instructions for, if the changes in pressure at the inlet of the intake throttle in response to the commanded periodic signal correspond to the frequency of the commanded periodic signal, not indicating degradation of the CCRV throttle.

16. The system of claim 15, wherein the control system includes additional instructions for indicating degradation of the CCRV position sensor based on a first determination of degradation of the CCRV, and the changes in pressure at the inlet of the intake throttle in response to the commanded periodic signal corresponding to the frequency of the commanded periodic signal.

17. The system of claim 16, wherein the first determination of degradation of the CCRV includes a lack of change in an output of the CCRV position sensor responsive to a first commanded change in position of the CCRV, the first commanded change being distinct from the periodic signal.

18. The system of claim 17, wherein the periodic signal includes a square waveform with a period based on response time of the turbocharger.

19. The system of claim 18, wherein the control system includes further instructions for, deactivating the CCRV and adjusting, a position of the intake throttle in response to deactivating the CCRV.