Abstract: An internal-combustion-engine combustion condition detection apparatus that can accurately comprehend a combustion condition is obtained. The internal-combustion-engine combustion condition detection apparatus includes an ion-current detection device (41) that detects an ion current generated during combustion and ignition devices including a first ignition device (21) having a first ignition plug (11) that causes main combustion in a combustion chamber (33) and a second ignition device (22) having a second ignition plug (12) disposed in the same combustion chamber (33) as and spaced apart from the first ignition plug (11) of the first ignition device (21); the ion-current detection device (41) detects a combustion ion current that is generated in the second ignition device (22) regardless of whether or not ignition is performed by the second ignition device (22), thereby detecting pre-ignition or a precursor phenomenon of pre-ignition.

Abstract: The present invention relates to a knocking detecting device for an internal combustion engine, for controlling a timing at which an ignition coil is actuated according to a knocking occurrence intensity, the knocking detecting device including the signal processing module for processing a signal attributable to knocking occurring in the operation of the internal combustion engine to determine a knocking occurrence intensity, in which the signal processing module includes: signal detecting means for detecting a signal attributable to knocking; frequency intensity calculating means for selecting a plurality of frequencies extracted from an output of the signal detecting means to calculate a frequency intensity; and knocking intensity determining means for finally determining that knocking occurs in a case where it is determined that at least two primary determination results of among a plurality of primary knocking determination results based on the outputs of the frequency intensity calculating means.

Abstract: An internal-combustion-engine combustion condition detection apparatus is provided with an ignition means that makes an ignition plug ignite a fuel; an ignition control means that controls the operation of the ignition means; an ion-current detection means that detects an ion current generated; an ion current detection range setting means that sets an ion-current detection range; a preignition detection means that detects preignition within a detection range to be set; a leakage current detection range setting means that sets a leakage-current detection range; and a leakage current determination means that determines whether or not a smolder exists, based on a current detected, within a detection range to be set, by the ion-current detection means. The ignition control means includes a non-combustion-stroke ignition control means; the leakage-current detection range set by the leakage current detection range setting means is set within the non-combustion stroke.

Abstract: A combustion state detection apparatus for an internal combustion engine, includes convexity detection means (30) for detecting that domain within the detection interval in which the change shape of the ionic current is upwardly convex, on the basis of the ionic current data extracted by data extraction means (20), and preignition decision means (40) including comparison setting means for setting a comparison value with which the upwardly convex domain is compared, and functioning to decide the occurrence of the preignition or the premonitory phenomenon thereof when the upwardly convex domain lies at a timing earlier than the comparison value, wherein the convexity detection means (30) includes leak current judgment means for judging the appearance of a leak current across electrodes, and it enables the detection of the upwardly convex domain when the appearance of the leak current has been judged.

Abstract: The internal-combustion-engine ignition diagnosis apparatus is configured in such a way that the first duration setting unit sets the first detection duration in a predetermined duration including a time instant when the spark discharge is generated, the second duration setting unit sets the second detection duration after the first detection duration, the diagnosis unit determines normality of the spark discharge, based on a signal state in the second detection duration, and regardless of the signal state in the second detection duration, determines abnormality of the spark discharge, based on a signal state in the first detection duration.

Abstract: An internal-combustion-engine combustion condition detection apparatus that can accurately comprehend a combustion condition is obtained. The internal-combustion-engine combustion condition detection apparatus includes an ion-current detection device (41) that detects an ion current generated during combustion and ignition devices including a first ignition device (21) having a first ignition plug (11) that causes main combustion in a combustion chamber (33) and a second ignition device (22) having a second ignition plug (12) disposed in the same combustion chamber (33) as and spaced apart from the first ignition plug (11) of the first ignition device (21); the ion-current detection device (41) detects a combustion ion current that is generated in the second ignition device (22) regardless of whether or not ignition is performed by the second ignition device (22), thereby detecting pre-ignition or a precursor phenomenon of pre-ignition.

Abstract: The present invention relates to a knocking detecting device for an internal combustion engine, for controlling a timing at which an ignition coil is actuated according to a knocking occurrence intensity, the knocking detecting device including the signal processing module for processing a signal attributable to knocking occurring in the operation of the internal combustion engine to determine a knocking occurrence intensity, in which the signal processing module includes: signal detecting means for detecting a signal attributable to knocking; frequency intensity calculating means for selecting a plurality of frequencies extracted from an output of the signal detecting means to calculate a frequency intensity; and knocking intensity determining means for finally determining that knocking occurs in a case where it is determined that at least two primary determination results of among a plurality of primary knocking determination results based on the outputs of the frequency intensity calculating means.

Abstract: A knock control apparatus for an internal combustion engine can avoid an incorrect knock determination thereby to prevent output power reduction and suppress knocks occurring in succession. A knock detection section outputs a knock detection signal based on an ionic current, and a threshold setting section sets a knock determination threshold. A knock determination section determines the occurrence of a knock based on the threshold and the knock detection signal. A required correction amount setting section sets a required correction amount for ignition timing based on a knock determination result, and a control parameter correction section corrects ignition timing based on the required correction amount. A noise determination section determines the occurrence of noise based on whether said knock detection signal or said control parameter correction amount is within a set level range, and a noise removal period setting section sets a noise removal period based on the noise determination result.

Abstract: A knock control apparatus for an internal combustion engine can avoid an incorrect knock determination thereby to prevent output power reduction and suppress knocks occurring in succession. A knock detection section outputs a knock detection signal based on an ionic current, and a threshold setting section sets a knock determination threshold. A knock determination section determines the occurrence of a knock based on the threshold and the knock detection signal. A required correction amount setting section sets a required correction amount for ignition timing based on a knock determination result, and a control parameter correction section corrects ignition timing based on the required correction amount. A noise determination section determines the occurrence of noise based on whether said knock detection signal or said control parameter correction amount is within a set level range, and a noise removal period setting section sets a noise removal period based on the noise determination result.

Abstract: A knock detection apparatus for an internal combustion engine can accurately detect the occurrence of a knock without an influence of a noise component even if the noise component having the same frequency as a knock vibration superposes on an ionic current signal. The apparatus includes an ionic current detection section, a knock signal detection section for detecting a knock signal based on an ionic current, a crank angle sensor for detecting a crank angle corresponding to a rotational position of the engine, a window setting section for setting a noise detection window, a noise component detection section for detecting a noise component in the window, and a knock determination section for determining the occurrence of a knock based on a relation between the noise component and the knock signal. The window setting section sets the window after a predetermined crank angle corresponding to an end of a combustion stroke of the engine.

Abstract: A knocking detection apparatus including: spark plugs disposed in cylinders of an internal combustion engine; an ion current detector for detecting ion currents flowing in the spark plugs; a time-frequency transformer for setting time intervals allowing one or more overlaps within a time from after ignition by the spark plugs to until the spark plug in the respective cylinder or in another cylinder next ignites and sampling ion currents in the respective time intervals to determine the time-frequency components of the ion current; a knocking detector for detecting knocking based on the time-frequency components; and a detection controller for inputting running status and controlling the time-frequency transformer and the knocking detector.

Abstract: A misfire detection apparatus of an internal combustion engine for detecting combustion or a misfire of an air fuel mixture in the internal combustion engine based on an ion current generated at the combustion time of the air fuel mixture. The misfire detection apparatus includes ion current detection means and misfire determination means. The ion current detection means detects the ion current responsive to the amount of ions occurring in a cylinder just after combustion of the air fuel mixture in the cylinder in the internal combustion engine. The misfire determination means calculates a predetermined function based on the ion current detection value and determines that the condition is combustion when the magnitude exceeds a threshold value.

Abstract: A control device for an internal combustion engine, including: an ion current detecting unit for detecting an ion current flowing between electrodes, via ions generated in a combustion chamber upon combustion, at a time when a voltage is applied to electrodes arranged in a combustion chamber of the internal combustion engine; a parameter extracting unit for extracting an ion current characteristics parameter correlating to an IMEP, from the ion current detected by the ion current detecting unit; an IMEP-related-information calculating unit for using the ion current characteristics parameter outputted from the parameter extracting unit, to calculate information relating to the IMEP of the internal combustion engine; and an internal combustion engine control unit for controlling operations of the internal combustion engine based on the output from the IMEP-related-information calculating unit.

Abstract: A misfire detection apparatus for an internal combustion engine is capable of detecting combustion when an ionic current generated upon combustion is superimposed on a leakage current, even if the ionic current does not contain an increased component. An ionic current detection part (1) detects an ionic current flowing between electrodes arranged in a combustion chamber of the internal combustion engine through ions generated upon combustion of an air fuel mixture therein by impressing a voltage on the electrodes. A tendency recognition part (4-7) recognizes a tendency of a change in the ionic current detected by the ionic current detection part. A threshold determination device (8) sets a threshold for an output of the tendency recognition part. A determination device (10) determines an occurrence of combustion or misfiring in the combustion chamber based on an output of the tendency recognition part and an output of the threshold determination device.

Abstract: A knocking detection apparatus including: spark plugs disposed in cylinders of an internal combustion engine; an ion current detector for detecting ion currents flowing in the spark plugs; a time-frequency transformer for setting time intervals allowing one or more overlaps within a time from after ignition by the spark plugs to until the spark plug in the respective cylinder or in another cylinder next ignites and sampling ion currents in the respective time intervals to determine the time-frequency components of the ion current; a knocking detector for detecting knocking based on the time-frequency components; and a detection controller for inputting running status and controlling the time-frequency transformer and the knocking detector.

Abstract: A control device for an internal combustion engine, including: an ion current detecting unit for detecting an ion current flowing between electrodes, via ions generated in a combustion chamber upon combustion, at a time when a voltage is applied to electrodes arranged in a combustion chamber of the internal combustion engine; a parameter extracting unit for extracting an ion current characteristics parameter correlating to an IMEP, from the ion current detected by the ion current detecting unit; an IMEP-related-information calculating unit for using the ion current characteristics parameter outputted from the parameter extracting unit, to calculate information relating to the IMEP of the internal combustion engine; and an internal combustion engine control unit for controlling operations of the internal combustion engine based on the output from the IMEP-related-information calculating unit.

Abstract: A knock detection apparatus for an internal combustion engine is provided which accurately distinguishes knock from noise even when noise having a frequency component identical to a knock frequency component is superposed on an ion current signal.

Abstract: A misfire detection apparatus for an internal combustion engine is capable of accurately determining an occurrence of combustion or misfiring in each cylinder of the engine even when an ionic current superposed on a leakage current decreases monotonously to provide no period or range in which the ionic current increases. An ionic current detector 3 detects an ionic current signal corresponding to an ionic current generated when an air fuel mixture in each combustion chamber of the engine is combusted. A gradient detector 6, 7, 8 detects, after firing of the air fuel mixture, a first gradient of the ionic current signal at first detection intervals and a second gradient of the ionic current signal at second detection intervals longer than the first detection intervals. A determination of combustion or misfiring in each combustion chamber is made based on the first and second gradients.

Abstract: A knock control apparatus normalizes a knock frequency magnitude and a background noise level to substantially the same levels in all the engine operating conditions in consideration of a variation in an ionic current level due to an environment, the number of revolutions per minute of the engine, an engine load, etc.

Abstract: A knock detection apparatus for an internal combustion engine is provided which accurately distinguishes knock from noise even when noise having a frequency component identical to a knock frequency component is superposed on an ion current signal.