Engine misfire detector
First Claim
1. A system for determining the occurrence of a misfire in an internal combustion engine including oscillating means for producing an oscillating signal, means coupled to the oscillating means for comparing an engine ignition timing signal with the oscillating signal and for generating a phase error signal from the comparison, means coupled to the means for comparing for producing a tracking signal which tracks changes in engine speed, the oscillating means being coupled to the means for producing the tracking signal and responsive to the tracking signal therefrom for generating the oscillating signal whose frequency changes in relation to changes in the tracking signal, said means for comparing being connected to said means for producing the oscillating signal for comparing the oscillating signal to the engine ignition timing signal, and means coupled to the means for comparing for receiving said error signal and responsive to changes in the error signal indicative of engine cylinder misfire and non-responsive to changes in the error signal associated with normal engine operation and for producing a cylinder misfire signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for determining the occurrence of a misfire in an internal combustion engine includes an oscillator, a phase detector coupled to receive an engine timing signal and the oscillating signal from the oscillator for producing an error signal functionally relating to phase difference between the signals. A loop filter is coupled to the phase detector for producing a tracking signal for producing the oscillating signal functionally related to the tracking signal. A phase error accumulator is coupled to receive the error signal and is operative to produce an output signal when the magnitude of at least one of the duration and magnitude of the error signal exceeds a predetermined value.
-
Citations
43 Claims
- 1. A system for determining the occurrence of a misfire in an internal combustion engine including oscillating means for producing an oscillating signal, means coupled to the oscillating means for comparing an engine ignition timing signal with the oscillating signal and for generating a phase error signal from the comparison, means coupled to the means for comparing for producing a tracking signal which tracks changes in engine speed, the oscillating means being coupled to the means for producing the tracking signal and responsive to the tracking signal therefrom for generating the oscillating signal whose frequency changes in relation to changes in the tracking signal, said means for comparing being connected to said means for producing the oscillating signal for comparing the oscillating signal to the engine ignition timing signal, and means coupled to the means for comparing for receiving said error signal and responsive to changes in the error signal indicative of engine cylinder misfire and non-responsive to changes in the error signal associated with normal engine operation and for producing a cylinder misfire signal.
- 13. A system for determining the occurrence of a misfire in an internal combustion engine including oscillating means for producing an oscillating signal, phase detecting means coupled to receive an engine timing signal and the oscillating signal and for producing an error signal functionally relating to phase difference between said signals, loop filter means coupled to said phase detecting means for receiving said error signal and for producing a tracking signal which tracks engine acceleration and deceleration, said oscillating means being coupled to receive the output signal from the loop filter and for producing an oscillating signal functionally related thereto, phase error signal responsive means coupled to receive the error signal from said phase detector and for producing a cylinder misfire signal when the magnitude of at least one of the duration and magnitude of the error signal exceeds a predetermined value.
- 16. A method for determining the occurrence of a misfire in an internal combustion engine including the steps of generating an oscillating signal, comparing an engine ignition timing signal from the engine with the oscillating signal, generating a phase error signal from the comparison of the engine timing signal and the oscillating signal, generating a tracking signal in response to the error signal which tracks changes in engine speed, modifying the oscillating signal as a function of the tracking signal, sensing the occurrence of a transient deceleration of the engine speed from at least one of the amplitude and duration of the error signal indicative of engine misfires, and rejecting changes in error signal associated with linear acceleration and deceleration, and counting said occurrences.
- 23. A system for determining the occurrence of a misfire in an internal combustion engine including phase locked loop means coupled to received an engine timing signal from an internal combustion engine, said phase locked loop means including means for generating an oscillating signal locked to the engine timing signal and means for comparing the engine timing signal to the oscillating signal and for producing an error signal in response to deviations therebetween, and means for producing a cylinder misfire signal when the error signal exceeds a reference value.
-
25. A system for determining the occurrence of a misfire in an internal combustion engine including oscillating means for producing an oscillating signal, means coupled to the oscillating means for comparing an engine ignition timing signal with the oscillating signal and for generating an error signal from the comparison, said error signal having an alternating component and a DC error component upon the occurrence of rapid engine deceleration incident to a cylinder misfire, means coupled to the means for comparing for producing a tracking signal which tracks changes in engine speed, the oscillating means being coupled to the means for producing the tracking signal and responsive to the tracking signal therefrom for generating the oscillating signal whose frequency changes in relation to changes in the tracking signal, said means for comparing being connected to said means for producing the oscillating signal for comparing the oscillating signal to the engine ignition timing signal, and means coupled to the means for comparing for receiving said error signal and responsive to changes in the error signal indicative of engine cylinder misfire and non-responsive to changes in the error signal associated with normal engine operation and for producing a cylinder misfire signal.
-
26. A system for determining the occurrence of a misfire in an internal combustion engine including oscillating means for producing an oscillating signal, means coupled to the oscillating means for comparing an engine ignition timing signal with the oscillating signal and for generating an error signal from the comparison, loop filter means coupled to the means for comparing for producing a tracking signal which tracks changes in engine speed, means coupled to the loop filter means and responsive to the engine timing signal for controlling the response of the loop filter means, the oscillating means being coupled to the means for producing the tracking signal and responsive to the tracking signal therefrom for generating the oscillating signal whose frequency changes in relation to changes in the tracking signal, said means for comparing being connected to said means for producing the oscillating signal for comparing the oscillating signal to the engine ignition timing signal, and means coupled to the means for comparing for receiving said error signal and responsive to changes in the error signal indicative of engine cylinder misfire and non-responsive to changes in the error signal associated with normal engine operation and for producing a cylinder misfire signal.
-
27. A system for determining the occurrence of a misfire in an internal combustion engine including oscillating means for producing an oscillating signal, means coupled to the oscillating means for comparing an engine ignition timing signal with the oscillating signal and for generating an error signal from the comparison, loop filter means coupled to the means for comparing for producing a tracking signal which tracks changes in engine speed, means coupled to the loop filter means and responsive to engine revolutions per unit time for controlling the response of the loop filter means, the oscillating means being coupled to the means for producing the tracking signal and responsive to the tracking signal therefrom for generating the oscillating signal whose frequency changes in relation to changes in the tracking signal, said means for comparing being connected to said means for producing the oscillating signal for comparing the oscillating signal to the engine ignition timing signal, and means coupled to the means for comparing for receiving said error signal and responsive to changes in the error signal indicative of engine cylinder misfire and non-responsive to changes in the error signal associated with normal engine operation and for producing a cylinder misfire signal.
-
28. A method for determining the occurrence of a misfire in an internal combustion engine including the steps of generating an oscillating signal, comparing an engine ignition timing signal from the engine with the oscillating signal, generating an error signal from the comparison of the engine timing signal and the oscillating signal, generating a tracking signal in response to the error signal which tracks changes in engine speed, generating the oscillating signal as a function of the tracking signal, sensing the occurrence of a transient deceleration of the engine speed from at least one of the amplitude and duration of the error signal indicative of engine misfires, sensing changes in throttle position and rejecting changes in error signal associated with linear acceleration and deceleration resulting from rapid changes in throttle position, and counting said occurrences.
-
29. A method for determining the occurrence of a misfire in an internal combustion engine including the steps of generating an oscillating input signal, comparing an engine ignition timing signal from the engine with the oscillating signal, generating an error signal from the comparison of the engine timing signal and the oscillating signal, generating an oscillator input signal which tracks changes in the error signal incident to engine acceleration and deceleration, controlling the oscillating signal in relation to changes in the oscillator input signal, generating a tracking signal in response to the error signal which tracks changes in engine speed, generating the oscillating signal as a function of the tracking signal, sensing the occurrence of a transient deceleration of the engine speed from at east one of the amplitude and duration of the error signal indicative of engine misfires, sensing changes in throttle position and rejecting changes in error signal associated with linear acceleration and deceleration resulting from rapid changes in throttle position, and counting said occurrences.
-
30. A system for determining the occurrence of misfire in an internal combustion engine having a rotatable shaft, said system comprising:
means for monitoring an engine parameter functionally related to the rotational position of the engine shaft and for generating a signal functionally related to said engine parameter, means coupled to said monitoring means for generating a tracking signal which tracks the engine parameter, means for generating a phase error signal comprising the difference in phase between the monitored engine parameter and the tracking signal, and correcting means coupled to the phase error signal generating means and responsive to the phase error signal for correcting the tracking signal, whereby significant changes in the magnitude of the phase error signal indicates the occurrence of engine misfire. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37)
- 38. A method for determining the occurrence of a misfire in an internal combustion engine having a rotatable shaft and including the steps of, monitoring an engine parameter functionally related to the rotational position of the engine shaft and generating a signal indicative of the engine parameter, generating a tracking signal which tracks the engine parameter, generating a phase error signal comprising the difference in phase between the monitored engine parameter and the tracking signal and correcting the tracking signal in response to the phase error signal whereby a sufficiently substantial change in the magnitude of the phase error signal indicates the occurrence of engine misfire.
Specification