Systems and method for performing prognosis of fuel delivery systems using solenoid current feedback

Patent metadata

Field	Value
Publication number	US-10378501-B2
Application number	US-201715834099-A
Country	US
Kind code	B2
Filing date	Dec 7, 2017
Priority date	Dec 7, 2017
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

An engine fuel delivery system, prognosis system, and method of conducting a fuel pump solenoid prognosis are provided. The engine fuel delivery system includes a fuel pump having a pumping chamber, a closeable inlet valve (such as a fuel pump control solenoid), and a fuel rail to communicate pressurized fuel received from the fuel pump to at least one engine cylinder. The engine fuel delivery system, prognosis system, and method are configured to determine a solenoid current feedback of a fuel pump control solenoid and a variation in the feedback. The fuel delivery system, prognosis system, and method are further configured to indicate a potential solenoid electrical connection fault if the solenoid current feedback is less than a predetermined current threshold and less than a predetermined variation threshold, and to indicate a potential solenoid weakened electromagnetic field fault if the solenoid current feedback is greater than the predetermined variation threshold.

First claim

What is claimed is:

1. A method of conducting a fuel pump solenoid prognosis, the method comprising:
determining a solenoid current feedback of a fuel pump control solenoid;
determining whether the solenoid current feedback is less than a predetermined low current threshold;
determining a magnitude of variation of the solenoid current feedback;
determining whether the magnitude of variation of the solenoid current feedback exceeds a predetermined variation threshold;
indicating a potential solenoid electrical connection fault if the solenoid current feedback is less than the predetermined low current threshold and less than the predetermined variation threshold; and
indicating a potential solenoid weakened electromagnetic field fault if the solenoid current feedback is greater than the predetermined variation threshold.

2. The method of claim 1 , wherein the step of determining a solenoid current feedback includes determining a mean of the solenoid current feedback, the method further comprising:
determining whether the mean is greater than a predetermined high current threshold; and
indicating the potential solenoid weakened electromagnetic field fault if the mean is greater than the predetermined high current threshold.

3. The method of claim 2 , wherein the step of determining the solenoid current feedback includes measuring an amount of current flowing through the fuel pump control solenoid at a range of operating conditions and normalizing the amount of current flowing through the fuel pump control solenoid against the range of operating conditions.

4. The method of claim 3 , further comprising:
determining a plurality of control signal adjustment gain values applied to a control signal for controlling the fuel pump control solenoid at the range of operating conditions;
normalizing the plurality of control signal adjustment gain values against the range of operating conditions to define a set of normalized control signal adjustment gain values;
indicating a deviating control signal adjustment if any normalized control signal adjustment gain value of the set of normalized control signal adjustment gain values lies outside of a predetermined desired gain range;
indicating a normal control signal adjustment if the set of normalized control signal adjustment gain values lies inside of the predetermined desired gain range; and
indicating a potential bad current sensing fault if the normal control signal adjustment is indicated and at least one of the potential solenoid electrical connection fault and the potential solenoid weakened electromagnetic field fault is indicated.

5. The method of claim 4 , further comprising energizing the fuel pump control solenoid to hold the fuel pump control solenoid closed during a hold timeframe and deenergizing the fuel pump control solenoid to begin a solenoid off timeframe, wherein the step of determining the solenoid current feedback is performed at one of the following times: a) at the start of the solenoid off timeframe; and b) during the hold timeframe.

6. The method of claim 5 , further comprising:
issuing a potential solenoid electrical connection fault warning message if the potential solenoid electrical connection fault is indicated;
issuing a potential solenoid weakened electromagnetic field fault warning message if the potential solenoid weakened electromagnetic field fault is indicated; and
issuing a potential bad current sensing fault warning message if the potential bad current sensing fault is indicated.

7. A fuel delivery system comprising:
a fuel pump having a pumping chamber and a closeable inlet valve;
a fuel rail configured to communicate pressurized fuel received from the fuel pump to at least one engine cylinder; and
a control system comprising a memory and an instruction set, the instruction set executable to:
determine a current feedback of the closeable inlet valve;
determine whether the current feedback is less than a predetermined low current threshold;
determine a magnitude of variation of the current feedback;
determine whether the magnitude of variation of the current feedback exceeds a predetermined variation threshold;
indicate a potential valve electrical connection fault if the current feedback is less than the predetermined low current threshold and less than the predetermined variation threshold; and
indicate a potential valve weakened electromagnetic field fault if the current feedback is greater than the predetermined variation threshold.

8. The fuel delivery system of claim 7 , wherein the control system is further configured to:
determine a mean of the solenoid current feedback;
determine whether the mean is greater than a predetermined high current threshold; and
indicate the potential solenoid weakened electromagnetic field fault if the mean is greater than the predetermined high current threshold.

9. The fuel delivery system of claim 8 , wherein the control system is configured to determine the current feedback by determining an amount of current flowing through the closeable inlet valve at a range of operating conditions and normalizing the amount of current flowing through the closeable inlet valve against the range of operating conditions.

10. The fuel delivery system of claim 9 , the control system being configured to:
determine a plurality of control signal adjustment gain values applied to a control signal for controlling the closeable inlet valve at the range of operating conditions;
normalize the plurality of control signal adjustment gain values against the range of operating conditions to define a set of normalized control signal adjustment gain values;
indicate a deviating control signal adjustment if any normalized control signal adjustment gain value of the set of normalized control signal adjustment gain values lies outside of a predetermined desired gain range;
indicate a normal control signal adjustment if the set of normalized control signal adjustment gain values lies inside of the predetermined desired gain range; and
indicate a potential bad current sensing fault if the normal control signal adjustment is indicated and at least one of the potential solenoid electrical connection fault and the potential solenoid weakened electromagnetic field fault is indicated.

11. The fuel delivery system of claim 10 , wherein the control system is configured to determine the current feedback by calculating an average and a standard deviation of a difference between an actual current feedback signal and an expected current feedback signal.

12. The fuel delivery system of claim 10 , the control system being further configured to energize the closeable inlet valve to hold the closeable inlet valve closed during a hold timeframe and deenergize the closeable inlet valve to begin a solenoid off timeframe, wherein the control system is configured to determine the current feedback at one of the following times: a) at the start of the solenoid off timeframe; and b) during the hold timeframe.

13. The fuel delivery system of claim 12 , the control system being configured to: issue a potential solenoid electrical connection fault warning message if the potential solenoid electrical connection fault is indicated, issue a potential solenoid weakened electromagnetic field fault warning message if the potential solenoid weakened electromagnetic field fault is indicated, and issue a potential bad current sensing fault warning message if the potential bad current sensing fault is indicated.

14. The fuel delivery system of claim 13 , further comprising a low-pressure supply pump configured to provide fuel to the fuel pump.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Sarwar Azeem
• Sankavaram Chaitanya
• Lu Xiangxing
• Mehdi Syed B

Classifications

• F02D41/3082

  Control of electrical fuel pumps · CPC title

• F02M65/00 Primary

  Testing fuel-injection apparatus, e.g. testing injection timing {(testing of ignition F02P17/00; measuring fuel consumption G01F9/00); Cleaning of fuel-injection apparatus} · CPC title

• F02M59/466

  Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means · CPC title

• F02D2041/286

  comprising means for signal processing · CPC title

• F02M59/366

  Valves being actuated electrically · CPC title