SYSTEM FOR PARTICULATE MATTER SENSOR SIGNAL PROCESSING

• US 20070089399A1
• Filed: 10/21/2005
• Published: 04/26/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Honeywell International Inc.
• Inventors: Ma, Hongbin, Rhodes, Michael, Krafthefer, Brian, Kittleson, David
• Granted Patent: US 7,765,792 B2
• Time in Patent Office: Days
• US Class Current: 60/278
• 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 2550/04 Filtering activity of particulate filters
• CPC Class Codes: F01N 2560/02 the means being an exhaust gas sensor
• CPC Class Codes: F01N 2560/05 the means being a particulate sensor
• CPC Class Codes: F01N 2560/14 having more than one sensor of one kind
• CPC Class Codes: F01N 3/027 using electric or magnetic heating means
• CPC Class Codes: F01N 9/002 of filter regeneration, e.g. detection of clogging
• CPC Class Codes: F02D 2041/288 for performing a transformation into the frequency domain, e.g. Fourier transformation
• CPC Class Codes: F02D 2200/0812 Particle filter loading
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/029 the exhaust gas treating apparatus being a particulate filter
• CPC Class Codes: F02D 41/1441 Plural sensors
• CPC Class Codes: F02D 41/1466 the characteristics being a soot concentration or content
• CPC Class Codes: F02M 26/53 using electric actuators, e.g. solenoids
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system having a particulate matter sensor in an exhaust stream of an engine upstream from a particulate filter and another such sensor downstream from the filter. There may also be an exhaust gas recirculation (EGR) control on the engine. The amount of particulate matter in or loading of the filter may be determined by the upstream filter. The working condition of the filter may be determined by the downstream sensor. The filter may have a heater and control for providing operational and particulate matter burn-off temperatures to the filter. A processor may be connected to the sensors, the EGR control and the filter heater control.

Claims

1. A sensor system comprising:

a first particulate matter (PM) sensor situated in an exhaust conveyance device connected to an engine;

a particulate matter filter situated downstream from the first PM sensor in the exhaust conveyance device; and

a second PM sensor situated in the exhaust conveyance device downstream from the particulate matter filter; and

wherein;

the first PM sensor is for detecting particulate matter approaching the filter;

the second PM sensor is for detecting particulate matter leaving the filter;

the first PM sensor is for indicating an amount of loading of particulate matter in the filter; and

the second PM sensor is for indicating failure of the filter.

2. The system if claim 1, further comprising:

an exhaust gas recirculation (EGR) valve having an input connected to the exhaust conveyance device and being proximate to the first PM sensor, having an output connected to an input conveyance device of the engine; and

a processor connected to the first PM sensor and EGR valve; and

the processor is for adjusting the EGR valve at least partially in response to particulate matter detected by the first PM sensor.

3. The system of claim 2, wherein the processor is for adjusting the EGR valve to reduce an amount of particulate matter sensed by the first PM sensor.

4. The system of claim 1, wherein if the second PM sensor detects particulate matter, then the filter is regarded as having a failure.

5. A sensor system comprising:

a first particulate (PM) sensor situated in an exhaust gas conveyance device of an engine;

a particulate matter filter situated in the exhaust gas conveyance device downstream from the first PM sensor; and

a processor connected to the first PM sensor for determining the loading of particulate matter in the filter and for operating the particulate matter filter for cleaning.

6. The system of claim 5, further comprising:

a second PM sensor situated in the exhaust gas conveyance device downstream from the filter; and

wherein the second PM sensor is connected to the processor for determining whether the filter is operating appropriately.

7. The system of claim 5, further comprising:

an exhaust gas recirculation (EGR) mechanism connected to the exhaust gas conveyance device and to an intake device of the engine; and

wherein the EGR mechanism is connected to the processor for controlling a flow of exhaust gas to the intake device in order to reduce particulate matter as sensed by the first PM sensor.

8. The system of claim 5, further comprising:

a heater situated in the filter; and

wherein the heater is connected to the processor for controlling a temperature in the filter for operation and/or a burning off particulate matter.

9. A sensor system comprising:

a particulate matter filter situated in an exhaust gas system of an engine; and

a particulate matter (PM) sensor situated in the exhaust gas system downstream from the filter.

10. The system of claim 9, further comprising a processor connected to the PM sensor for indicating whether the filter is operating appropriately.

11. The system of claim 10, further comprising:

a heater situated in the filter; and

wherein;

the heater is connected to the processor; and

the processor is for turning on the heater for particulate matter burn-off if the filter is not operating appropriately due to an excessive amount of particulate matter in the filter.

12. A processing system for particulate matter sensing comprising:

a particulate matter (PM) sensor for being positioned in an exhaust stream;

a processor connected to the PM sensor; and

an engine crank angle input connected to the processor; and

wherein the processor comprises a program for providing analyzed profiles of individual engine cylinder behavior.

13. The system of claim 12, wherein the program comprises a combination of time-domain and/or frequency domain analysis algorithms.

14. The system of claim 13, wherein the profiles of individual cylinder behavior have pulses that are analyzed for baseline, peak height and/or integrated peak area.

15. The system of claim 14, wherein the processor is for conditioning sensor output signals to the engine to provide adjustments to cause the profiles of the individual cylinder behavior to be the same for all of the cylinders.

16. The system of claim 15, wherein the processor may provide an exhaust flow rate.

17. The system of claim 16, wherein the algorithms indicate compensation for cylinder-to-cylinder and cycle-to-cycle variability.

18. The system of claim 17, wherein the profiles of the individual cylinders are from direct measures of particulate matter emitted from an individual engine cylinder.

19. A processing system for determining engine parameters comprising:

a particulate matter transducer profile;

a charge amplifier having an input connected to the transducer profile;

a data extractor connected to the charge amplifier; and

a signal conditioner and a processor connected to the data extractor.

20. The system of claim 19, wherein the transducer probe comprises an electrode situated in an exhaust mechanism of an engine.

21. The system of claim 20, wherein the processor comprises a program for converting signals from the transducer probe into data about cylinders of an engine.

22. The system of claim 21, wherein:

the data about the cylinders of the engine provide information about individual cylinders; and

the information about the individual cylinders is compared and differences among the cylinders provided.

23. The system of claim 22, wherein the processor provides parameter adjustment signals for minimizing the differences among the cylinders.

24. The system of claim 23, wherein the program comprises a combination of time domain and/or frequency domain analysis algorithms.

25. The system of claim 24, wherein the algorithms are for providing profiles of individual cylinders from analyses of real-time exhaust particulate data from the transducer probe.

26. A method for analyzing particulate matter (PM) of an exhaust gas of an engine, comprising:

detecting particulate matter of an exhaust gas;

converting the detection of particulate matter of the exhaust gas into PM signals; and

processing the PM signals into information about each cylinder.

27. The method of claim 26, further comprising:

evaluating the information about each cylinder; and

providing signals to an engine control unit in response to the evaluating the information about each cylinder.

28. The method of claim 27, wherein the evaluating the information about each cylinder comprises comparing each cylinder to another cylinder and/or comparing one engine cycle to another engine cycle.

29. The method of claim 28, wherein the processing the PM signals comprises time-windowed and/or frequency domain analysis of the PM signals.

30. The method of claim 29, wherein the providing signals to the engine control unit is for reducing variations among the cylinders.

31. The method of claim 29, wherein the providing signals to the engine control unit is for reducing variations among the engine cycles.

32. A sensor system comprising:

a first particulate matter (PM) sensor situated in an exhaust conveyance device connected to an engine;

a second PM sensor situated in the exhaust conveyance device downstream from a diesel particulate filter (DPF);

a third PM device situated in the exhaust conveyance device downstream from the first PM sensor and upstream from the DPF filter; and

a processor connected to the first PM sensor, the second PM sensor, the third PM sensor and the DPF filter.

33. The system of claim 32, wherein the processor outputs signals having information comprising:

exhaust flow velocity;

amount of loading of the DPF filter;

failure indication of the DPF filter; and

/or

time to clean the DPF filter.

34. The system of claim 32, wherein the processor outputs signals having information comprising optimal exhaust gas recovery (EGR) operation.