Abstract: A dual injection type internal combustion engine including an injector for in-cylinder injection and an injector for intake manifold injection includes a learning device for learning a background noise level based on an output signal of a knock sensor, and a knocking suppression control device for performing, while learning the background noise level, knocking suppression control by controlling fuel injection of the injector for in-cylinder injection or the injector for intake manifold injection. Alternatively, the engine includes a fixing device for fixing, while learning the background noise level, a start timing or end timing of fuel injection by the injector for in-cylinder injection at a basic timing determined by an operating state of the engine.

Abstract: Systems and methods useful for detecting a combustion fault in a combustion engine include determining cylinder power density values for cylinders present on the engine during its operation and determining cylinder imbalance parameters for the cylinders, based on the cylinder power density values. The cylinder imbalance parameters are compared with a provided diagnostic threshold value.

Abstract: An internal combustion engine has a plurality of cylinders and an exhaust tract into which a mixture which is situated in the respective cylinder is introduced in the respective discharge strokes. A combustion misfire rate is determined as a function of at least one operating variable of the internal combustion engine. A temperature in the exhaust tract is determined as a function of the combustion misfire rate.

Abstract: An ignition timing control system for an internal combustion engine, which is capable of properly carrying out ignition timing control over a wide control range, thereby making it possible to improve fuel economy, and is capable of suppressing combustion fluctuation, thereby making it possible to improve drivability. Ignition timing is calculated, when the engine is determined to be in an intense combustion mode, such that a largest in-cylinder pressure angle at which in-cylinder pressure becomes largest converges to a target angle, whereas when the engine is determined to be in a weak combustion mode, the same is calculated by feedback, based on the target angle and combustion state parameters indicative of a combustion state in the cylinder.

Abstract: A vibration reducing system for an engine is disclosed. The vibration reducing system includes at least one pumping member movable through a plurality of pumping strokes during an engine cycle. The vibration reducing system also includes a controller in communication with the at least one pumping member, the controller being configured to identify a vibration characteristic of the engine. The controller also is configured to adjust the displacement of fuel during at least one of the plurality of pumping strokes based on the vibration characteristic.

Abstract: The invention is directed toward a device for controlling an internal combustion engine. An aspect of the invention is determining a polytropic exponent according to at least two measured values of the pressure in a combustion chamber of a cylinder of an internal combustion engine during the working stroke of the cylinder once an air/fuel mixture of a cylinder has been burned and before the gas discharge valve is opened. A first exhaust gas temperature is determined and a second temperature of the exhaust gas is determined in accordance with the first exhaust gas temperature. The pressure associated in the combustion chamber, the pressure prevailing in the combustion chamber after closing the gas discharge valve, and the polytropic exponent are determined. An actuation signal for controlling an actuating member of the internal combustion engine is generated according to the second temperature of the exhaust gas.

Abstract: An engine ECU executes a program including a step of setting a search range of the crank angle of a peak value P that is the largest integrated value in a vibration waveform of an engine detected by calculating integrated values that are integrals of output voltage values of a knock sensor for every five degrees of a crank angle such that the search range may include the crank angle increasing with increase in engine speed NE, and a step of detecting the crank angle of the largest integrated value in the search range, and setting the detected crank angle as the crank angle of peak value P in the vibration waveform. At the crank angle based on the crank angle of peak value P, the vibration waveform is compared with a knock waveform model.

Abstract: A method for estimating the cylinder interior pressure of an internal combustion engine from a cylinder pressure model having at least the input variables load, speed of rotation, and crank angle (Ppressure model), which forms the cylinder interior pressure (Pgas) to be determined, corrected by a pressure correction value (?Pgas). The pressure correction value (?Pgas) is determined from an observation of the alternating moments at the crankshaft. The modeled value of the cylinder interior pressure from the pressure model is obtained as a pre-control value, and corrected with a correction value formed from the measured value of the non-uniformity of rotation.

Abstract: When a revolution speed of the engine (crankshaft) changes faster or slower, the vibration from the engine is propagated to an occupant in the vehicle, and the occupant may feel a sense of discomfort. For this reason, the present invention provides an active vibration isolating support apparatus and method for controlling the same to suppress the propagation of the vibration from the engine to the vehicle body so that the occupant may feel less sense of discomfort even if the revolution speed of the engine changes.

Abstract: A hybrid propulsion system for a vehicle and method of operation are provided. As one example, the system comprises an engine including at least one combustion chamber, a motor configured to selectively propel the vehicle via the drive wheel, a fuel system configured to deliver a first substance and a second substance to the combustion chamber in varying relative amounts, wherein the first substance includes a fuel and the second substance includes a greater concentration of a knock suppressing substance than the first substance; and a control system configured to operate the fuel system to vary the relative amounts of the first substance and the second substance delivered to the combustion chamber in response to an operating condition while operating the motor to propel the vehicle.

Abstract: Control apparatus performs knocking suppression control in an internal combustion engine provided with a variable valve mechanism that is capable of varying a closing timing IVC of an inlet valve. The control apparatus, in a case in which an alcohol concentration and octane number of a fuel are low and knocking is likely to occur, controls the variable valve mechanism and retards the closing timing of the inlet valve from the bottom dead center TDC. Thereby, the effective compression ratio is reduced and knocking occurrence is consequently suppressed.

Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, and an electrical circuit configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within a combustion chamber. The engine includes a controller configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a spark crank angle timing of the IC engine where the incipient knock occurs, and adjust the spark timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond an incipient knock set point.

Abstract: Identifying fires by: measuring pressure pulses from the exhaust; generating a waveform from the measured pressure pulses; dividing the waveform into segments, one for each engine cylinder; associating each segment with the cylinder which generated the pulse; and examining each segment for features which indicate a misfire. The method further includes: generating a trigger signal; associating the trigger signal with ignition in a cylinder; measuring the time between this signal and the next trigger signal; dividing the time between these trigger signals into cylinder boxes, one for each cylinder; and shifting each of the boxes relative to the associated segment such that the peak and a portion of the rising edge and/or the falling edge falls within the box. For each box the peak, rising edge and falling edge is compared with threshold values. Each box in which at least two of the thresholds are exceeded is flagged.

Abstract: An engine control system includes an engine calibration module that sets fuel injection timing based on one of N cetane number (CN) values, wherein N is an integer greater than one. A combustion noise module generates a combustion noise signal based on cylinder pressure in a compression ignition (CI) engine during combustion. A fuel quality determination module compares the combustion noise signal to N predetermined combustion noise levels corresponding to the N CN values, and that selects the one of the N CN values based on the comparison.

Abstract: A method for controlling an internal combustion engine having a common rail system together with individual accumulators. A rotational speed-control deviation (dn) is determined from a target rotational speed (nSL) that represents the set point for an outer control loop to control the rotational speed, as well as from an actual rotational speed (nIST). A target torque (MSL) is determined from the rotational speed-control deviation (dn) via a rotational speed controller as a master controller. A target injection duration (SD(SOLL)) is determined from the target torque (MSL). The target duration injection (SD(SOLL)) represents the set point for an inner control loop for controlling cylinder-specific injection duration. An injection duration deviation is determined from the target injection duration (SD(SOLL)) and from an actual injection duration.

Abstract: Provided is a control apparatus for an internal combustion engine with which temporal and frequency resolutions necessary for analysis of a frequency of knock by digital signal processing are ensured with limited amounts of processing and memory. The control apparatus includes a lowpass filter for eliminating a high frequency component of an output signal from a knock sensor or a cylinder internal pressure sensor, an A/D conversion unit for performing A/D conversion on the output signal from the filter, and DFT processing units for performing digital signal processing on data obtained by the A/D conversion as knock detection units, each of the DFT processing units includes observation interval setting units for dividing the A/D-converted data to set observation intervals each containing a predetermined number of samples, and a multi-frequency simultaneous analysis unit for simultaneously analyzing multiple frequencies by a discrete Fourier transform for each of the set observation intervals.

Abstract: A vehicle stability control system uses a physical quantity corresponding to a driver accelerator input to control engine power produced by an engine and to controllably drive an engine load device for regulating the engine power to produce a desired drive force. The vehicle stability control system includes a vibration detector and a corrector. The vibration detector determines a vibration that occurs during running of the vehicle to disturb the stability of the vehicle. The corrector drives the engine load device to suppress the vibration in response to the vibration determined by the vibration detector.

Abstract: In a method of monitoring for a misfire event in an internal combustion engine signals representative of engine speed are monitored for successive engine revolutions subsequent to each firing event. The monitored signals are stored (e.g., in a buffer) and processed to detect changes in the monitored speed signals. Changes in monitored speed signals that are indicative of an actual misfire event are detected and a misfire count is changed in response thereto.

Abstract: An engine control system includes a digital signal processing (DSP) module that generates a fast Fourier transform (FFT) of an engine knock signal generated by an engine knock sensor. An intensity determination module determines an engine knock intensity based on one of a maximum of and an average of the FFT. A status determination module determines a status of the engine knock sensor based on the engine knock intensity, a plurality of predetermined knock intensity thresholds, and a rotational speed of an engine crankshaft.

Abstract: A system includes a fuel detection module, a misfire detection module, and a fuel control module. The fuel detection module detects when a fuel supplied to an engine having C cylinders has a high drivability index (HIDI), where C is an integer greater than 1. The misfire detection module detects whether M of the C cylinders misfire when the fuel has the HIDI, where M is an integer, and 1?M<C. The fuel control module injects a first amount of the fuel into the M of the C cylinders when M is less than or equal to D, where D is an integer less than C, and where the first amount is greater than a first predetermined amount.

Abstract: A method for distinguishing between combustion issues and sensor faults within an engine includes monitoring pressure sensor data from a cylinder within the engine, monitoring engine data describing combustion health from a source other than a pressure sensor, analyzing the pressure sensor data to diagnose an anomalous combustion event, comparing the anomalous combustion event to analysis of the engine data, and indicating a pressure sensor fault warning if the comparison diagnoses a pressure sensor fault.

Abstract: A knock control apparatus includes: a knock sensor for detecting knock of an internal combustion engine; a signal processing section for calculating a knock intensity; and knock determination level setting sections: for calculating an average value of the knock intensity; for calculating, based on the average value, an overall variance of the knock intensity of an entirety of a frequency distribution, a higher variance of the knock intensity above the average value, and a lower variance of the knock intensity below the average value; for calculating a standard deviation of the knock intensity from the overall variance; for presetting a value allowing the frequency distribution of the knock intensity to be a predetermined confidence interval as a confidence coefficient; and for setting a sum of the average value and a value obtained by multiplying the standard deviation by the corrected confidence coefficient as a knock determination level.

Abstract: An active engine mount assembly for counteracting resultant forces in active fuel management systems, wherein resultant forces are transmitted to a frame of a motorized vehicle generated by the deactivation of at least one cylinder in an internal combustion engine. The active engine mount assembly is fluidly connected to a hydraulic circuit. The hydraulic circuit is operatively connected to an engine crankshaft and operable to actively generate pressure pulses having frequencies self-synchronized with the rotational speed of the crankshaft.

Abstract: This invention relates to a method for knock detection in a combustion engine, in which combustion is controlled by a control unit (2), which comprises the steps of, a) obtaining at least one sensor signal (4, 4?) carrying information of knock intensity related within a combustion chamber of the combustion engine (1); (b) processing the sensor signal (4, 4?) to obtain a knock intensity related detection variable (z1), (c) using said detection variable (z1) in said control unit (2) arranged to avoid a knocking condition in said combustion engine (1), if the value (z1) of said detection variable indicates knock when compared with a threshold value (T) wherein using two different computations/processes for said processing (5, 6) of the at least one sensor signal (4, 4?) to obtain two separate sub-values (y1, y2), and thereafter combining said sub-values (y1, y2) to obtain said detection variable (z1).

Abstract: An engine control system includes a digital signal processing (DSP) module that generates a fast Fourier transform (FFT) of an engine knock signal generated by an engine knock sensor. An intensity determination module determines an engine knock intensity based on one of a maximum of and an average of the FFT. A status determination module determines a status of the engine knock sensor based on the engine knock intensity, a plurality of predetermined knock intensity thresholds, and a rotational speed of an engine crankshaft.

Abstract: A control method and a control device of an engine are introduced. During the process of the engine controlling, the control unit does the adaptive learning for the actual target value of the feedback of different aims, and following the dynamic spectrogram generation strategy optimizing compares the adaptively learning parameter of the same working status and the same time with the basic spectrogram parameter. If the compared result doesn't meet the condition, then keep the basic spectrogram parameter. And if it meets the condition, then the engine generates the dynamic spectrogram parameter. Based on the dynamic spectrogram combination strategy, the engine combines the basic spectrogram parameter and the dynamic spectrogram parameter generated to the combined spectrogram parameter instead of the basic spectrogram parameter.

Abstract: The invention relates to a method having application to combustion control of an internal-combustion engine for real-time estimation of engine combustion parameters from vibratory signals. A vibratory signal representative of the engine vibrations is continuously acquired as a function of the crank angle, from a vibration detector. Real-time filtering of this vibratory signal and real-time estimation of the Fourier decomposition coefficients for the acquired vibratory signal is carried out by inverting the dynamics of the filter which is used. Finally, real-time estimation of combustion parameters allowing the combustion to be qualified is carried out from these coefficients.

Abstract: A control system is provided. This system generally includes a table datastore that stores data in a table format wherein the table format includes a plurality of zones. A data storage module stores learned data to one or more of the plurality of zones. A data access module generates a table output by retrieving the learned data from one or more of the plurality of zones and interpolating between the learned data.

Abstract: A method and system for controlling an engine includes a spark ignition (SI) control module operating the engine in a spark ignition mode in a high lift valve state and a pre-HCCI control module entering a matching state when homogeneous charge compression ignition (HCCI) mode conditions are met. When a matching condition is met, the pre-HCCI control module enters a pre-homogeneous charge compression ignition mode and performs spark retardation, stratified operation or lean operation and commands a low lift valve state. The system also includes an HCCI control module entering an HCCI mode and when in the low lift valve state.

Abstract: In hybrid electric vehicle control, when an engine is cranked by the torque of a first motor-generator to start the engine, the torque of the first motor-generator is corrected according to the crankshaft angle of the engine to prevent the amount of increase in engine rotation speed from fluctuating. Fluctuation in inertia torque is reduced through this control of the torque of the first motor-generator to reduce fluctuation in the cranking reaction force torque exerted on a drive axle. Further, the torque of a second motor-generator is so controlled to cancel out this cranking reaction force torque. Thus, the cranking reaction force torque exerted on the drive axle is accurately canceled out through control of the torque of the second motor-generator to suppress fluctuation in the torque of the drive axle.

Abstract: In a V6 engine that can switch between a first running state and a second running state which differ in the number of cylinders that are permitted to operate, when switching from L3 selective cylinder operation to V4 selective cylinder operation is determined to be required, control of an active vibration isolation support system corresponding to L3 selective cylinder operation is normally continued for one cycle. However, in this case of switching from L3 selective cylinder operation to V4 selective cylinder operation, a vibration pattern of L3 selective cylinder operation continues for longer than usual, that is, for a period greater than one cycle. Therefore, control of the active vibration isolation support system corresponding to the vibration pattern of L3 selective cylinder operation is continued for two cycles of the vibration pattern, thereby further effectively improve a vibrational state when switching between running states from L3 selective cylinder operation to V4 selective cylinder operation.

Abstract: A split-cycle variable capacity rotary spark ignition engine system having at least a first rotary configuration (C1) including repetitively volume variable working chambers [60, 61, 62] for carrying out the combustion-expansion and exhaust phases and at least a second rotary configuration (C2) including repetitively volume variable working chambers (70, 71, 72) for carrying out the intake and compression phases of a four phase engine cycle. Dividing seal means (73, 74 of C1, 75, 76 of C2) for periodically dividing each of successive working chambers into a volume enlarging leading portion and a volume contracting trailing portion. Discharge valve means for varying compression chamber capacity through discharging fraction of trapped intake gas from compression chambers. A first phase altering arrangement is provided for varying the phase relation between the first rotary configuration (C1) and the second rotary configuration (C2).

Abstract: A fuel management system for using water for on-board vehicular separation of ethanol from ethanol-gasoline blends is described. Water or a water-alcohol mixture from a secondary tank is mixed with the ethanol-gasoline blend resulting in separation of the ethanol. By using on-board vehicular separation, the consumption of the externally supplied liquid from a secondary tank can be decreased to less than 1% of the gasoline consumption. This allows for long refilling periods for the externally supplied fluid. In another embodiment, a water-based fluid is directly injected into the cylinders of a spark ignition engine to eliminate knocking without causing misfire. In a further embodiment, an alcohol-based fluid is also used in those circumstances where injection of the water-based fluid may cause misfire.

Abstract: The engine misfire detection process according to one aspect of the invention first makes tentative detection on the occurrence or the non-occurrence of an engine misfire in execution of both vibration control and rotation speed control. In response to the tentative detection of an engine misfire, the engine misfire detection process subsequently makes final detection on the occurrence or the non-occurrence of an engine misfire. In the event of no final detection of an engine misfire, the engine misfire detection process makes tentative detection and final detection on the occurrence or the non-occurrence of an engine misfire in prohibition of the vibration control. In the event of still no final detection of an engine misfire, the engine misfire detection process makes tentative detection and final detection on the occurrence or the non-occurrence of an engine misfire in further prohibition of the rotation speed control.

Abstract: When knocking occurs, a control apparatus for an internal combustion engine increases the rotational speed of a pump to increase the flow rate of a coolant supplied to an area near a combustion chamber wall surface, and controls an actual mechanical compression ratio to a low mechanical compression ratio lower than a mechanical compression ratio set based on the load of the engine. Thus, the pressure of end gas is decreased, and occurrence of knocking is suppressed. Then, the actual mechanical compression ratio is returned to the mechanical compression ratio at a time point at which the temperature of the combustion chamber wall surface has been sufficiently decreased due to the increase in the rotational speed. Thus, occurrence of knocking is suppressed while avoiding the situation where the actual mechanical compression ratio continues to be controlled to the low mechanical compression ratio that is lower than the mechanical compression ratio.

Abstract: A method of controlling an internal combustion engine having at least one cylinder defining a variable-volume combustion chamber; and a rotating crankshaft powered by a piston sliding inside the cylinder; the control method including the steps of: determining a recording window expressed in engine angle degrees and having a start engine angle and a stop engine angle; acquiring and memorizing the intensity of sound pressure waves, generated by the internal combustion engine as a function of an engine angle, by means of at least one sound pressure sensor and within the recording window; and estimating the value of at least one operating parameter of a part of the internal combustion engine by analysing the intensity of the sound pressure waves in the recording window.

Abstract: A device dedicated to processing analog knock signals delivered by a sensor of an internal combustion engine coupled to an engine monitoring unit, includes processing elements for converting values of the analog signals acquired by the sensor at known instants into representative digital samples, then for temporarily storing the samples whose acquisition instants are contained in a chosen time window, and for applying chosen digital processing operations to these stored samples so as to deliver a digital output signal representative of the knock of the engine during this time window. The processing elements are responsible i) for applying a chosen digital preprocessing operation to the stored samples whose acquisition instants coincide with instants of occurrence, and ii) for adapting at least one of the digital processing operations according to the number of stored samples that are the subjects of a coincidence.

Abstract: A vibration controller includes a map controller, an adaptive controller, a set-up frequency judge/switcher, and an actuator. The map controller includes a data map storage for storing data on control signals determined in advance for a vibration insulator, and a signal generator for selecting one of the data, depending on a frequency of a cyclically pulsating signal emitted from a vibration generating source of a vehicle, from the data map storage and generating a control signal. The adaptive controller generates the control signal with respect to the cyclically pulsating signal using an adaptive control method. The set-up frequency judge/switcher switches from the map controller to the adaptive controller or vice versa based on the frequency of the cyclically pulsating signal. The actuator actuates an actuator of the vibration insulator based on the control signal generated by the map controller or the adaptive controller, whereby inhibiting the vehicle from vibrating.

Abstract: The invention is an abnormal combustion detection method for spark-ignition internal-combustion engines. For each engine cycle, a parameter characterizing a distribution of N combustion indicator values, CA10 for example, acquired over N cycles preceding the cycle in progress, is determined while ignoring extreme values. A threshold is defined from this parameter for the combustion indicator. The start of an abnormal combustion is then detected by comparing the combustion indicator with this threshold and the course of the abnormal combustion detected in the combustion chamber is controlled.

Abstract: An ECU of an internal combustion engine estimates an anticipated air amount in response to a demand for the internal combustion engine and causes an injector to inject an initial amount of fuel determined in accordance with the anticipated air amount so that an air-fuel ratio of a mixture in a combustion chamber is lower than a target value, and thereafter, calculates an amount of intake air aspired into the combustion chamber based on an in-cylinder pressure in the combustion chamber at a given timing during a compression stroke and before ignition, and causes the injector to inject a correction amount of fuel determined based on the calculated amount of the intake air and the initial amount of the fuel so that the air-fuel ratio of the mixture in the combustion chamber corresponds to the target value.

Abstract: A method for detection of abnormal combustion for internal combustion engines is disclosed. A physical model is chosen that describes, as a function of the angle a of rotation of the engine crankshaft, the development of pressure in the cylinder during combustion without any pre-ignition phenomenon. The cylinder pressure Pe(?) is estimated using this model and the intake pressure is measured. The beginning of abnormal combustion is detected by comparing a first value of a variable calculated using the measurement of the cylinder pressure, to a second value of the variable calculated using the estimation of the cylinder pressure. The amplitude of the pre-ignition is determined by repeating these steps for a defined number of crankshaft angles. Then the progress of the abnormal combustion detected in the combustion chamber is controlled as a function of the amplitude of the pre-ignition phenomenon.

Abstract: There is provided a method and a control scheme to control an internal combustion engine operating in an auto-ignition mode by selectively activating a control scheme for controlling fuel injector operation based upon engine combustion parameters, e.g., IMEP or NMEP. The method comprises operating the engine in the auto-ignition combustion mode, and monitoring combustion in each of the cylinders. The fuel correction is selectively enabled only when either one of a partial burn and a misfire of a cylinder charge in one of the cylinders has been detected.

Abstract: Apparatus and method for air/fuel ratio control for smoothening variation of air/fuel ratio among a plurality of cylinders of an internal combustion engine including a sensor for measuring output of the internal combustion engine. A device calculates a correlation function of each cylinder by taking cross-correlation of values measured by the sensor and a reference signal for each cylinder. A device then calculates a smoothing target value which is common for all of the cylinders. Cylinder controllers produce control input to the respective cylinders such that the correlation function converges to the smoothing target value.

Abstract: The invention relates to a method for controlling the operating mode of an internal combustion engine (1) comprising several cylinders (3) and an injection system (4) with one injection unit (5) per cylinder (3). According to said method: a digital measuring signal, which characterizes the combustion of fuel (6) in the internal combustion engine (1), is first determined; said digital measuring signal is then transformed into a frequency range; a misfiring of the ignition is detected using the amplitude information of the transformed measuring signal and if a misfiring has occurred, the injection of the individual cylinders (3) is deactivated sequentially for a predefined period and for each cylinder the corresponding digital measuring signal that characterizes said cylinder is determined and transformed into the frequency range and a misfiring cylinder (3) is identified during the evaluation of the transformed measuring signal using the amplitude information.

Abstract: Engine management system for operation of a direct injection spark ignition gasoline engine. The system includes a gasoline engine, a source of gasoline and a source of an anti-knock agent. Gasoline and anti-knock agent are introduced into a proportioning valve that delivers a selected mixture of gasoline/anti-knock agent to a high pressure pump. At least one injector receives the selected mixture from the high pressure pump and delivers the mixture into a cylinder of the engine. The engine management system provides a rapidly variable mixture of directly injected anti-knock agent and gasoline which prevents knock as the engine torque increases.

Abstract: A hybrid propulsion system for a vehicle and method of operation are provided. As one example, the system comprises an engine including at least one combustion chamber, a motor configured to selectively propel the vehicle via the drive wheel, a fuel system configured to deliver a first substance and a second substance to the combustion chamber in varying relative amounts, wherein the first substance includes a fuel and the second substance includes a greater concentration of a knock suppressing substance than the first substance; and a control system configured to operate the fuel system to vary the relative amounts of the first substance and the second substance delivered to the combustion chamber in response to an operating condition while operating the motor to propel the vehicle.

Abstract: The duration of a knock detection window over which a filtered knock signal is single-point DFT-processed for engine knock detection is user adjustable. The knock detection window is defined by at least two overlapping identical duration sub-windows, and the extent of the sub-window overlap is changed to adjust the duration of the knock detection window. The DFT processing is performed over each sub-window and the processing results are combined for knock detection.

Abstract: A system and method for operating an engine having ionization signal sensing include detecting plug fouling and controlling the engine using progressively more aggressive control strategies if the fouling condition persists. A first control strategy may be used when the number of engine starts or running time are below corresponding thresholds and a second strategy otherwise. The first strategy may employ progressively more aggressive control procedures to eliminate spark plug deposits that may include repetitive sparking, exhaust cycle sparking, increasing engine loading, advancing spark timing, increasing air/fuel ratio, and increasing idle speed, for example. The second strategy may include similar corrective actions employed in a different order and/or to a lesser degree in an attempt to eliminate plug fouling without any noticeable change in engine operation or performance as perceived by the vehicle operator.

Abstract: An internal combustion engine includes a piston reciprocable within a cylinder, a phase controllable valvetrain configured to alter the effective compression ratio of the engine, and a knock sensor. A method for controlling the engine includes controlling the valvetrain to a first effective compression ratio whereat knock is detectable by the knock sensor and thereafter controlling the valvetrain to reduce the effective compression ratio to a point whereat knock is no longer detectable.

Abstract: An engine ECU runs a program that detects the speed of an engine, a depression amount of an accelerator (ACC) and a vehicle speed, and determines that the vehicle being started from an idle state, if the ACC is more than an ACC threshold value or if the a time differential value (DACC) of the depression amount of the accelerator is more than a DACC threshold value. In addition, the program also detects an intake air temperature (TA), and if the TA is more than a TA threshold value, calculates an air flow guard from a map, which is defined to largely limit the amount of intake air as a KCS learning value is large to a retard side or as the TA is high.