Method of determining air charging system deficient state of health during part load operation

Patent metadata

Field	Value
Publication number	US-10400686-B2
Application number	US-201615292739-A
Country	US
Kind code	B2
Filing date	Oct 13, 2016
Priority date	Oct 13, 2016
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A method to diagnose post air charger compressor icing obstructions without the addition of a post compressor pressure sensor. The method detects when conditions exists for icing to occur and performs at least one icing mitigation strategy when the icing conditions exceed a predetermined icing condition threshold.

First claim

What is claimed is:

1. A method of determining an air charger system deficient state of health condition during engine part load operation comprising:
an engine;
an intake line;
a compressor positioned in the intake line and configured to provide compressed air to the engine;
a charge air cooler provided in the intake line downstream of the compressor and upstream of the engine;
a charge air cooler pressure sensor; and
a controller, wherein the controller is configured to perform the steps of:
detecting if the engine is operating at a steady state condition;
detecting if the air charger system deficient state of health condition exists when the engine is operating at a steady state condition;
calculating a charge air cooler pressure based on engine speed, intake manifold pressure and barometric pressure when the air charger deficient state of health condition exists;
measuring a charge air cooler pressure of the charge air cooler via the charge air cooler sensor;
comparing the calculated charge air cooler pressure to the measured charge air cooler pressure;
starting a deficient state of health condition timer when a difference between the calculated charge air cooler pressure and the measured charge air cooler pressure is greater than a predetermined charge air cooler pressure difference threshold; and
performing at least one mitigation strategy when the deficient state of health condition timer indicates that a period of time has elapsed which is greater than a predetermined timer threshold.

2. The method of claim 1 wherein the air charger system deficient state of health condition is caused by icing.

3. The method of claim 1 wherein detecting the air charger system deficient state of health condition further comprises detecting that a positive crankcase ventilation gas flows into the intake line via a positive crankcase ventilation line.

4. The method of claim 3 wherein the positive crankcase ventilation pas flows into the intake line via the positive crankcase ventilation line when engine manifold air pressure (MAP) is greater than a predetermined MAP pressure threshold.

5. The method of claim 4 wherein the positive crankcase ventilation line comprises a valve to selectively admit positive crankcase ventilation gas into the intake line.

6. The method of claim 1 wherein the step of calculating the charge air cooler pressure is further based on an outlet air pressure of the compressor.

7. The method of claim 1 wherein the step of calculating the charge air cooler pressure is further based on the engine speed from a crankshaft position sensor signal.

8. The method of claim 1 wherein the step of calculating the charge air cooler pressure is further based on the intake manifold pressure from a MAP sensor signal.

9. The method of claim 1 wherein the step of calculating the charge air cooler pressure is further based on the barometric pressure from a barometric sensor signal.

10. The method of claim 1 wherein the step of performing the at least one mitigation strategy further comprises changing a current gear state to a lower gear state.

11. The method of claim 10 wherein the step of changing the current gear to the lower gear state further comprises reducing a throttle body opening.

12. The method of claim 4 wherein the air charger system deficient state of health condition is caused by icing.

13. The method of claim 4 wherein the positive crankcase ventilation line comprises a valve to selectively admit positive crankcase ventilation gas into the intake line.

14. The method of claim 4 wherein the step of calculating the charge air cooler pressure is based on an outlet air pressure of the compressor.

15. The method of claim 4 wherein the step of performing the at least one mitigation strategy further comprises changing a current gear state to a lower gear state.

16. The method of claim 4 wherein the step of changing the current gear state to the lower gear state further comprises reducing a throttle body opening.

17. The method of claim 4 wherein the step of calculating the charge air cooler pressure is further based on the barometric pressure from a barometric sensor signal.

18. The method of claim 4 wherein the step of calculating the charge air cooler pressure is further based on the engine speed from a crankshaft position sensor signal.

19. A system comprising:
an engine;
an intake line;
a compressor positioned in the intake line and configured to provide compressed air to the engine;
a charge air cooler provided in the intake line downstream of the compressor and upstream of the engine;
a charge air cooler pressure sensor; and
a controller, wherein the controller is configured to perform the steps of:
detecting if the engine is operating at a steady state condition;
detecting if an air charger system deficient state of health condition exists when the engine is operating at a steady state condition;
calculating a charge air cooler pressure based on engine speed, intake manifold pressure and barometric pressure when the air charger deficient state of health condition exists;
measuring a charge air cooler pressure of the charge air cooler via the charge air cooler sensor;
comparing the calculated charge air cooler pressure to the measured charge air cooler pressure;
starting a deficient state of health condition timer when a difference between the calculated charge air cooler pressure and the measured charge air cooler pressure is greater than a predetermined charge air cooler pressure difference threshold; and
performing at least one mitigation strategy when the deficient state of health condition timer indicates that a period of time has elapsed which is greater than a predetermined timer threshold.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Dickson Steven G
• Weaver Jordan D

Classifications

• F02D41/0007 Primary

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02M35/1038

  for temperature or pressure · CPC title

• F02D41/0025

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title

• F02D41/1444 Primary

  characterised by the characteristics of the combustion gases · CPC title

• F02D41/023

  in relation with the gear ratio shifting (conjoint control for improving gear change B60W30/19) · CPC title