A system and method for detecting and mitigating automatic ignition in a cylinder of an internal combustion engine. The method includes providing a first sensor for sensing and determining a crank angle of a crankshaft of the engine. A second sensor is provided for detecting a change in an engine vibration frequency caused by Auto Ignition (AI). The engine vibration signal of the second sensor is processed into a knock intensity signal. The knock intensity signal is indicative of the cylinder pressure and is acquired when the crank angle is between a first predetermined crank angle and a second predetermined crank angle. At least one characteristic of the knock intensity signal is determined and the at least one characteristic of the knock intensity signal is compared to at least one predetermined characteristic threshold. If the at least one characteristic of the knock intensity signal is determined to exceed the at least one predetermined characteristic threshold, then at least one auto ignition mitigating action is performed to mitigate the auto ignition event.

A diagnostic system for a vehicle includes a difference module, a Fourier module, and a fault module. The difference module determines pressure differences for a camshaft revolution based on differences between: first pressures within first chambers of a camshaft phaser measured during the camshaft revolution, wherein the first pressures within the first chamber control advancement of the camshaft relative to a crankshaft of an engine; and second pressures within second chambers of the camshaft phaser measured during the camshaft revolution, wherein the second pressures within the second chamber control retardation of the camshaft relative to the crankshaft of the engine. The Fourier module performs a Fourier Transform (FT) based on the pressure differences to produce FT data. The fault module, based on the FT data, selectively indicates that a fault is present in a variable valve lift mechanism that is actuated by the camshaft.

The present invention suppresses the worsening of stability due to a variation in EGR amounts between cylinders in a spark ignition engine. An engine control device for controlling a spark ignition engine equipped with an EGR means for recirculating exhaust gas in a combustion chamber and an air-fuel-ratio detection means for detecting the air-fuel ratio in each cylinder, the engine control device being characterized by being equipped with a means for changing the parameters for ignition control of a rich cylinder, when the air-fuel ratio of cylinders varies and there are richer cylinders and leaner cylinders relative to a prescribed air-fuel ratio during the execution of exhaust gas recirculation by the EGR means.

The purpose of the present invention is to provide an engine control device with which it is possible to minimize decreases in combustion speed even when the EGR rate has been increased. The present invention is an engine control device for: controlling an engine provided with an injector for injecting fuel directly into a cylinder, an ignition device for igniting the injected fuel, and an EGR means capable of recycling combustion gas and varying the EGR rate of the recycling combustion gas; and commanding the injector to perform multiple injections during one cycle, wherein a command is given to perform a control for increasing the injection quantity per compression stroke relative to the total injection quantity in one cycle so that the injection quantity per compression stroke is greater when the EGR rate is high than when the EGR rate is low, and/or a control for increasing the number of injections per compression stroke relative to the total number of injections in one cycle so that the number of injections per compression stroke is greater when the EGR rate is high than when the EGR rate is low.

Systems are provided for detecting a change in performance of an engine component. In one example, a system includes a first pressure sensor of a first exhaust manifold coupled to a first subset of cylinders of an engine, a second pressure sensor of a second exhaust manifold coupled to a second subset of cylinders of the engine, a passage coupling the first exhaust manifold to an intake manifold, and a controller configured to detect a change in performance of any cylinder of the engine based on frequency content from the first pressure sensor and from the second pressure sensor during both a first mode where no exhaust gas from the first exhaust manifold is provided to the intake manifold, and during a second mode where all exhaust gas from the first exhaust manifold is provided to the intake manifold, and adjust an operating parameter responsive to the change in performance.

A method for controlling an engine includes, with a fuel injector, injecting a quantity of fuel into a cylinder of the engine for combustion. The method further includes calculating a torsional power level for the cylinder in response to the combustion of the injected quantity of fuel, mapping the torsional power level to an injected fuel mass, and comparing the injected fuel mass to a reference fuel mass to determine a fuel mass offset. The engine may be controlled based on the determined fuel mass offset.

A system includes a controller configured to receive a signal acquired by the at least one knock sensor coupled to a reciprocating device, to sample the received signal, to analyze the sampled signal, and to utilize standard quality control (SQC) techniques to perform real-time diagnostics on the reciprocating device based on the analyzed signal.

A control apparatus for an internal combustion engine (i) acquires a rotational speed signal correlated with a rotational speed of the internal combustion engine, (ii) extracts, from the acquired rotational speed signal, at least first-order and lower-order than the first-order components of the rotational speed signal, (iii) extracts, from the acquired rotational speed signal, at least an n-th-order component of the rotational speed signal, (iv) determines that no disturbance has occurred when a first-order parameter regarding a magnitude of an amplitude of the extracted first-order and lower-order than the first-order components is smaller than a first threshold, and (v) determines that a disturbance has occurred when the first-order parameter is equal to or larger than the first threshold and an n-th-order parameter regarding an amplitude of the extracted n-th-order component is equal to or larger than a second threshold.

A mechanical diagnosis method for combustion abnormality using engine noise includes: calculating an Energy K and a Loudness standard deviation index (N.sub.STD) with Kurtosis analysis by a diagnosis controller 30 from noise data measured together with a signal component by rotation excitation of an engine 10; calculating a plurality of order frequency peak order component values by a Modulation Frequency Transform; and distinguishing a cylinder where abnormal combustion occurs from a cylinder where normal combustion occurs by applying a predetermined threshold to these calculated values, thereby classifying, by Modulation Frequency analysis, problem samples of the rotation excitation and combustion excitation influence of the engine in which the abnormality state determination of the engine has been difficult only with energy distribution while overcoming the limitation of Kurtosis analysis.

A system and method for providing feedback for an aircraft-bladed rotor about a longitudinal axis and having an adjustable blade pitch angle. At least one position marker is provided at the rotor, extends along an axial direction, from a first end to a second end, and has varying magnetic permeability from the first end to the second end. At least one sensor is coupled to the rotor and configured for producing, as the rotor rotates about the longitudinal axis, at least one sensor signal in response to detecting passage of the at least one position marker. A control unit is communicatively coupled to the at least one sensor and configured to generate a feedback signal indicative of the blade pitch angle in response to the at least one sensor signal received from the at least one sensor.