A method for detecting knocking of an engine includes receiving a knock signal indicating a vibration level in a cylinder of the engine and a crank angle signal indicating a crank angle by which a knocking window and an end of injection (EOI) of an injector of the engine are expressed, determining whether the knocking window and the EOI overlap, based on the crank angle signal, setting a second reference value for an overlapping range within the knocking window overlapping the EOI by reflecting a predetermined level on a first reference value for a non-overlapping range within the knocking window non-overlapping the EOI depending on the determination, integrating the knock signal in the knocking window, determining whether an integrated value of the knock signal exceeds the first reference value in the non-overlapping range or the second reference value in the overlapping range, and retarding an ignition timing of the engine as a knocking avoidance logic depending on the determination.

There is provided a pressure detection device including: a pressure detection element which receives pressure so as to output a detection signal corresponding to the pressure P; and a processing circuit which processes and outputs the detection signal output from the pressure detection element, where the processing circuit includes: a voltage transformation circuit which only transforms a power supply voltage fed from an external power supply so as to obtain a first reference voltage with a predetermined voltage value; an integrator circuit which uses the first reference voltage as an operation reference to perform integral processing on the detection signal so as to convert the detection signal into a voltage waveform; and at least one or more amplifier circuits which use a second reference voltage with a predetermined voltage value as an operation reference to perform amplification processing on an output signal from the integrator circuit.

A specific sound having a higher frequency than an operation sound of an engine is generated in synchronization with timing of a top dead center of a specific cylinder of the engine. Thus, timing of a noise of the engine is estimated by using, for example, a deviation in time between timing of generation of a specific sound and timing at which a noise occurs in the engine, based on a sound collected from around the engine without directly using a signal of a crank angle of the engine.

An apparatus includes a base assembly, a gasket and a housing assembly. The base assembly may have a locking feature and a bearing feature. The locking feature may have a first passage in communication with an exterior of the apparatus. The gasket may be disposed on the base assembly and may have (i) a base portion, (ii) a column portion and (iii) a second passage in communication with the first passage. The housing assembly may have a sealing feature and may be configured to hold a sensor. The sealing feature (a) may mate with the bearing feature and (b) may compress the base portion of the gasket. The sensor (a) may seal to the column portion of the gasket and (b) may be in communication with the exterior of the apparatus through the first passage and the second passage.

A method and a device for knock control of an internal combustion engine, a knock signal of a cylinder of the internal combustion engine being measured by a knock sensor and, on the basis thereof, a knock intensity is generated. The knock intensity is compared to a reference level in order to classify a combustion as a knocking or non-knocking combustion. Moreover, an arrangement is provided, which takes the level of the knock intensity into account for the determination of the reference level.

To provide a control device, of an internal combustion engine, that accurately identifies the combustion state through ion current detection in a wide operation range of the internal combustion engine, without impairing the reliability and the durability of the control device of the internal combustion engine. This internal combustion engine control device includes: an ignition plug having a center electrode and a ground electrode opposed to each other with a gap therebetween; a circulation device for short-circuiting a primary winding to cause a circulation route to enter a conduction state, thereby stopping spark discharge; and an ion-current-detection bias voltage control device for controlling bias voltage for ion current detection. The potential of the center electrode in an ion current detection period is controlled by adjusting the value of the bias voltage and the changing speed of the bias voltage.

Methods and systems are disclosed for operating an engine that includes a knock control system that may determine contributions of individual noise sources to an engine background noise level. The contributions of the individual noise sources may be the basis for establishing the presence or absence of knock in one or more engine cylinders. The contributions of individual noise sources may be determined when engine cylinders are deactivated.

Methods and systems are disclosed for operating an engine that includes a knock control system that may determine contributions of individual noise sources to an engine background noise level. The contributions of the individual noise sources may be the basis for establishing the presence or absence of knock in one or more engine cylinders. The contributions of individual noise sources may be determined when engine cylinders are deactivated.

A control device includes a processor configured to: calculate an estimated value of a contribution of a disturbance in a transition of an internal state of a dynamic power unit, based on a last internal state and a last control input by which the internal state is controlled; determine the control input so as to minimize a difference from a reference value of the control input by which the internal state becomes a predetermined internal state, under a condition that a sum of the estimated value of the contribution and a value of the constraint condition expression when there is not the disturbance at the current time is equal to or more than a value resulting from reducing a last value of the constraint condition expression by a predetermined ratio; and control the dynamic power unit in accordance with the determined control input.

To provide a control device, of an internal combustion engine, that accurately identifies the combustion state through ion current detection in a wide operation range of the internal combustion engine, without impairing the reliability and the durability of the control device of the internal combustion engine. This internal combustion engine control device includes: an ignition plug having a center electrode and a ground electrode opposed to each other with a gap therebetween; a circulation device for short-circuiting a primary winding to cause a circulation route to enter a conduction state, thereby stopping spark discharge; and an ion-current-detection bias voltage control device for controlling bias voltage for ion current detection. The potential of the center electrode in an ion current detection period is controlled by adjusting the value of the bias voltage and the changing speed of the bias voltage.