Diagnostic techniques for a surge valve of a turbocharged engine

Patent metadata

Field	Value
Publication number	US-10690081-B2
Application number	US-201815959864-A
Country	US
Kind code	B2
Filing date	Apr 23, 2018
Priority date	Apr 23, 2018
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

Diagnostic systems and methods for a surge valve that selectively bypasses a compressor of a turbocharger of an engine involve receiving, by a controller, a barometric pressure signal indicative of a barometric pressure external to the engine, receiving, by the controller, a throttle inlet pressure (TIP) signal indicative of an air pressure at an inlet of a throttle valve of the engine and downstream from the surge valve and the compressor, and performing, by the controller, a diagnostic technique on the surge valve, the diagnostic technique comprising generating a pressure ratio signal that is a ratio of the TIP signal to the barometric pressure signal, applying a high-pass filter to the pressure ratio signal to obtain a filtered pressure ratio signal, and based on a quantity of detected pulses in the filtered pressure ratio signal that exceed the diagnostic threshold, detecting a malfunction of the surge valve.

First claim

What is claimed is:

1. A diagnostic system for a surge valve that selectively bypasses a compressor of a turbocharger of an engine, the system comprising:
a barometric pressure sensor configured to generate a barometric pressure signal indicative of a barometric pressure external to the engine;
a throttle inlet pressure (TIP) sensor disposed downstream from the surge valve and the compressor and being configured to output a TIP signal indicative of an air pressure at an inlet of a throttle valve of the engine; and
a controller configured to perform a diagnostic technique on the surge valve, the diagnostic technique comprising:
generating a pressure ratio signal that is a ratio of the TIP signal to the barometric pressure signal;
applying a high-pass filter to the pressure ratio signal to obtain a filtered pressure ratio signal;
detecting any pulses in the filtered pressure ratio signal that exceed a diagnostic threshold; and
based on a quantity of detected pulses exceeding the diagnostic threshold, detecting a malfunction of the surge valve.

2. The system of claim 1 , wherein the controller is configured to detect a set of preconditions for performing the diagnostic technique.

3. The system of claim 2 , wherein the set of preconditions comprises (i) a current request to open the surge valve, (ii) a recent tip-in to tip-out transition of an accelerator device of the engine, and (iii) the throttle valve being closed.

4. The system of claim 3 , wherein the set of preconditions further comprises engine speed and requested turbocharger boost being within predetermined ranges.

5. The system of claim 3 , wherein a count corresponding to the quantity of detected pulses resets to zero when the surge valve is no longer requested to open.

6. The system of claim 1 , wherein the malfunction indicates that the surge valve is stuck closed.

7. The system of claim 6 , wherein the controller is further configured to activate a malfunction indicator lamp (MIL) indicating a need to replace the surge valve.

8. The system of claim 1 , wherein the diagnostic technique is non-intrusive in that the controller does not temporarily alter operation of the engine as part of the diagnostic technique.

9. A diagnostic method for a surge valve that selectively bypasses a compressor of a turbocharger of an engine, the method comprising:
receiving, by a controller and from a barometric pressure sensor, a barometric pressure signal indicative of a barometric pressure external to the engine;
receiving, by the controller and from a throttle inlet pressure (TIP) sensor disposed downstream from the surge valve and the compressor, a TIP signal indicative of an air pressure at an inlet of a throttle valve of the engine; and
performing, by the controller, a diagnostic technique on the surge valve, the diagnostic technique comprising:
generating a pressure ratio signal that is a ratio of the TIP signal to the barometric pressure signal;
applying a high-pass filter to the pressure ratio signal to obtain a filtered pressure ratio signal;
detecting any pulses in the filtered pressure ratio signal that exceed a diagnostic threshold; and
based on a quantity of detected pulses exceeding the diagnostic threshold, detecting a malfunction of the surge valve.

10. The method of claim 9 , further comprising detecting, by the controller, a set of preconditions for performing the diagnostic technique.

11. The method of claim 10 , wherein the set of preconditions comprises (i) a current request to open the surge valve, (ii) a recent tip-in to tip-out transition of an accelerator device of the engine, and (iii) the throttle valve being closed.

12. The method of claim 11 , wherein the set of preconditions further comprises engine speed and requested turbocharger boost being within predetermined ranges.

13. The method of claim 11 , wherein a count corresponding to the quantity of detected pulses resets to zero when the surge valve is no longer requested to open.

14. The method of claim 9 , wherein the malfunction indicates that the surge valve is stuck closed.

15. The method of claim 14 , further comprising activating, by the controller, a malfunction indicator lamp (MIL) indicating a need to replace the surge valve.

16. The method of claim 9 , wherein the diagnostic technique is non-intrusive in that the controller does not temporarily alter operation of the engine as part of the diagnostic technique.

Assignees

• Henson Scott E
• Sahota Amarjeet Singh
• Shah Dhaval D
• Fca Us Llc

Inventors

• Henson Scott E
• Sahota Amarjeet Singh
• Shah Dhaval D

Classifications

• Y02T10/40

  Engine management systems · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• G01L23/24

  {specially adapted} for measuring pressure in inlet or exhaust ducts of internal-combustion engines · CPC title

• F02B37/16 Primary

  by bypassing charging air · CPC title

• F02D2200/703

  Atmospheric pressure · CPC title