System and method for impulse noise suppression for integrator-based ion current signal processor
AssigneeDelphi Technologies, Inc.
InventorsRonald J. Kiess, Robert W. Koseluk, Raymond O. Butler JR., Philip Allen Karau, Jerral A. Long
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Abstract
An impulse noise suppression circuit for an integrator-based ion current signal processing system includes a one-shot circuit activated by a trigger signal that is produced when a noise transient in a bandpass filtered ion current signal exceeds a predetermined threshold. The output pulse of the one-shot circuit is selected to have a pulse width configured to mask a substantial portion of the noise transient without masking the remaining filtered ion current signal during the remainder of a knock window in which knock is detected.
Claims19
An apparatus comprising:
- an ion current detection circuit configured to bias a spark plug in an engine cylinder for producing an ion current signal indicative of an ion current through the spark plug;
- and
- a processing circuit including (i) a blanking circuit configured to suppress noise transients in said ion current signal and (ii) an integrator for integrating said ion current signal to produce an output signal.
An apparatus comprising:
- an ion current detection circuit configured to bias a spark plug in an engine cylinder after a spark during a combustion event for producing an ion current signal indicative of an ion current through the spark plug;
- and
- a processing circuit including (i) a bandpass filter configured to filter said ion current signal;
- (ii) a blanking circuit responsive to a trigger signal configured to suppress noise transients in said filtered, ion current signal during a knock window, said trigger signal being produced when said noise transients exceeds a predetermined threshold;
- and (iii) an integrator for integrating said filtered, ion current signal to produce an output signal.
A method of determining a knock condition comprising the steps of:
- (A) generating an ion current signal;
- (B) filtering said ion current signal to extract knock components;
- (C) suppressing a first noise transient in the filtered ion current signal to produce a conditioned signal;
- and
- (D) integrating said conditioned signal to produce an output signal indicative of the knock condition.
Dependencies are inferred from the claim text.