Powertrain control module spark duration diagnostic system

• US 20060030993A1
• Filed: 08/06/2004
• Published: 02/09/2006
• Est. Priority Date: 08/06/2004
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Goodell, Kirk R., McCoy, James D.
• Granted Patent: US 7,124,019 B2
• Time in Patent Office: Days
• US Class Current: 701/114
• CPC Class Codes: F02P 17/12 Testing characteristics of the spark, ignition voltage or current testing of sparking plugs H01T13/60
• CPC Class Codes: F02P 3/02 having inductive energy storage, e.g. arrangements of induction coils ignition coils structurally combined with sparking plugs F02P13/00; constructional details of ignition coils H01F38/12

Abstract

A system and method for diagnosing ignition system performance of an internal combustion engine. The method operates an engine control unit to produce a sequence of spark ignition current pulses through primary windings of a plurality of ignition coils. The current pulses produce voltage pulses across electrodes of the spark plugs. The voltage pulses produce flyback voltages across the primary windings. Output pulses are produced in response to the flyback voltages having time durations related to the time durations of the sparks produced by the spark plugs. Digital signal are produced in response to each one of the output pulses representative of the spark time duration of a corresponding one of the sparks. A comparison of the digital signals determines whether the spark time duration of one of the spark plugs is substantially different from the spark time durations of the other ones of the plurality of spark plugs.

Claims

1. A system for diagnosing ignition system performance of an internal combustion engine, comprising:

a spark plug;

an ignition coil having a secondary winding coupled to the spark plug and a primary winding;

an engine control unit for producing a spark ignition current pulse through the primary winding, such current pulse producing a voltage pulse across electrodes of the spark plug, such voltage pulse producing a spark across the electrodes of the spark plug and a flyback voltage across the primary winding, such engine control unit producing, in response to the flyback voltage, a digital signal representative of the time duration between the rise of the initial breakdown voltage, through the sustaining voltage to the falling edge of the sustaining voltage.

2. A system for diagnosing ignition system performance of an internal combustion engine, comprising:

an engine having a plurality of spark plugs;

a plurality of ignition coils, each one having a secondary winding coupled to a corresponding one of the plurality of spark plugs, each one of the plurality of ignition coils having a primary winding;

an engine control unit for producing a sequence of spark ignition current pulses through the primary winding of the plurality of ignition coils, such current pulses producing voltage pulses across electrodes of the spark plugs, such voltage pulses producing sparks across the electrodes of the spark plugs and flyback voltages across the primary windings, the engine control unit producing, in response to the flyback voltages, digital signals representative of the time durations between the rises of the initial breakdown voltages, through the sustaining voltages, to the falling edge of the sustaining voltages.

3. A method for diagnosing ignition system performance of an internal combustion engine having a plurality of spark plugs;

a plurality of ignition coils, each one having a secondary winding coupled to a corresponding one of the plurality of spark plugs, each one of the plurality of ignition coils having a primary winding; and

an engine control unit, such method comprising;

operating the engine control unit to produce a sequence of spark ignition current pulses through the primary winding of the plurality of ignition coils, such current pulses producing voltage pulses across electrodes of the spark plugs, such voltage pulses producing sparks across the electrodes of the spark plugs and flyback voltages across the primary windings;

producing, in response to the flyback voltages, digital signals representative of the time durations of the sparks; and

comparing the digital signals to determine whether the spark time duration of one of the spark plugs is substantially different from the spark time durations of the other ones of the plurality of spark plugs.

11. The method recited in claim 3 wherein the time duration is the time between the rise of the initial breakdown voltage, through the sustaining voltage, to the falling edge of the sustaining voltage.

4. A system for diagnosing ignition system performance of an internal combustion engine, comprising:

a spark plug;

an ignition coil having a secondary winding coupled to the spark plug and a primary winding;

an engine control unit comprising;

a microprocessor;

a spark time duration circuit; and

an ignition coil driver section;

wherein the microprocessor operates to produce a spark ignition current pulse through the primary winding, such current pulse producing a voltage pulse across electrodes of the spark plug, such voltage pulse producing a spark across the electrodes of the spark plug and a flyback voltage across the primary winding;

wherein the spark time duration circuit is responsive to the flyback voltage to produce an output pulse having a time duration related to the spark time duration of the spark produced across the electrodes of the spark plug, such time duration being between the rise of the initial breakdown voltage, through the sustaining voltage, to the falling edge of the sustaining voltage; and

wherein the microprocessor produces, in response to the output pulse, a digital signal representative of such time duration.

5. The system recited in claim 4 wherein the ignition coil driver section comprises a plurality of solid state switching devices each one being connected to both a corresponding one of the ignition coil primary windings and output control of the microprocessor.

6. The system recited in claim 5 wherein the spark time duration circuit comprises an attenuated/filter device coupled to the plurality of solid state switching devices, and a comparator fed by the attenuated/filter.

7. A system for diagnosing ignition system performance of an internal combustion engine, comprising:

an engine having a plurality of spark plugs;

a plurality of ignition coils, each one having a secondary winding coupled to a corresponding one of the plurality of spark plugs, each one of the plurality of ignition coils having a primary winding;

an engine control unit comprising;

a microprocessor,

a spark time duration circuit; and

an ignition coil driver section;

wherein the microprocessor operates to produce a sequence of spark ignition current pulses through the primary winding of the plurality of ignition coils, such current pulses producing voltage pulses across electrodes of the spark plugs, such voltage pulses producing sparks across the electrodes of the spark plugs and flyback voltages across the primary windings;

wherein the spark time duration circuit is responsive to the flyback voltages to produce output pulses having time durations related to the time durations of the sparks produced across the electrodes between the rises of the initial breakdown voltages, through the sustaining voltages, to the falling edge of the sustaining voltages; and

wherein the microprocessor produces, in response to each one of the output pulses a digital signal representative of the spark time duration of a corresponding one of the sparks produced across the electrodes of the corresponding one of the spark plugs.

8. A method for diagnosing ignition system performance of an internal combustion engine having a plurality of spark plugs;

a plurality of ignition coils, each one having a secondary winding coupled to a corresponding one of the plurality of spark plugs, each one of the plurality of ignition coils having a primary winding; and

an engine control unit, such method comprising;

operating the engine control unit to produce a sequence of spark ignition current pulses through the primary winding of the plurality of ignition coils, such current pulses producing voltage pulses across electrodes of the spark plugs, such voltage pulses producing sparks across the electrodes of the spark plugs and flyback voltages across the primary windings;

producing, in response to the flyback voltages, output pulses having time durations related to the time durations of the sparks produced across the electrodes of the spark plugs;

producing, in response to each one of the output pulses, a digital signal representative of the spark time duration of a corresponding one of the sparks produced across the electrodes of the corresponding one of the spark plugs; and

comparing the digital signals to determine whether the spark time duration of one of the spark plugs is substantially different from the spark time durations of the other ones of the plurality of spark plugs.

12. The method recited in claim 8 wherein the time duration is the time between the rise of the initial breakdown voltage, through the sustaining voltage, to the falling edge of the sustaining voltage.

9. An article of manufacture comprising:

a computer storage medium having a program encoded for diagnosing ignition system performance of an internal combustion engine having a plurality of spark plugs;

a plurality of ignition coils, each one having a secondary winding coupled to a corresponding one of the plurality of spark plugs, each one of the plurality of ignition coils having a primary winding; and

an engine control unit, such medium having;

code for operating the engine control unit to produce a sequence of spark ignition current pulses through the primary winding of the plurality of ignition coils, such current pulses producing voltage pulses across electrodes of the spark plugs, such voltage pulses producing sparks across the electrodes of the spark plugs and flyback voltages across the primary windings;

code for producing, in response to the flyback voltages, output pulses having time durations related to the time durations of the sparks produced across the electrodes of the spark plug, such time durations being between the rises of the initial breakdown voltages, through the sustaining voltages, to the falling edge of the sustaining voltages; and

code producing, in response to each one of the output pulses, a digital signal representative of the spark time duration of a corresponding one of the sparks produced across the electrodes of the corresponding one of the spark plugs.

10. The article of manufacture recited in claim 9 wherein the computer storage medium is a semiconductor chip.