The present invention relates to a method of controlling a positive-ignition internal combustion engine, in which the ignition advance is controlled (CON) by means of an estimation (EST) of the distribution of the knock measurements (MEAS). This estimation (EST) makes it possible to determine, for these measurements (MEAS), a confidence interval (q.sub.min, q.sub.max) of a predetermined quantile of the distribution of the knock measurements (MEAS).

An engine device including an intake manifold (67) configured to supply air into a cylinder (36), a gas injector (98) configured to mix fuel gas with air supplied from the intake manifold (67), and supply mixed gas to the cylinder (36), and an igniter (79) configured to ignite, in the cylinder (36) premixed fuel obtained by pre-mixing the fuel gas with the air, the engine device further including a controlling unit (73) configured to determine an air amount in the premixed fuel in the cylinder (36). The controlling unit (73) performs in multiple steps retard control of ignition timing by the igniter (79), when the air amount is insufficient, and performs in multiple steps advance control of the ignition timing, when the air amount is sufficient.

An ignition timing control apparatus for an internal combustion engine includes an electronic control unit configured to i) perform determination as to whether knocking has occurred in the engine; ii) update a first learning value and a second learning value such that the ignition timing is retarded when determining that knocking has occurred; and iii) derive, as a required ignition timing, a timing obtained by retarding a base ignition timing based on the first and second learning values. The electronic control unit is configured to update the second learning value within a range in which an update amount of the second learning value within a prescribed period set in advance does not exceed a prescribed amount, when updating the second learning value.

A control device for an internal combustion engine includes an electronic control unit configured to determine whether or not cylinder-specific air-fuel ratio processing is being executed in which an air-fuel ratio of at least one of a plurality of cylinders is controlled to be a rich air-fuel ratio and an air-fuel ratio of at least one of the other cylinders is controlled to be a lean air-fuel ratio. The electronic control unit updates a first learning value in which a result of comparison between a knock strength of the internal combustion engine and a first determination value is reflected when the cylinder-specific air-fuel ratio processing is not being executed. The electronic control unit prohibits updating of the first learning value and calculates a target ignition timing of the internal combustion engine based on the first learning value when the cylinder-specific air-fuel ratio processing is being executed.

In a catalyst warming-up control, a first time injection is performed by an injector in an intake stroke. A second time injection is performed with an amount smaller than the first time injection in an expansion stroke after a compression top dead center. In the catalyst warming-up control, an interval from the start of the ignition period of an spark plug to the completion of the second time injection is controlled by the ECU so that the initial flame generated from an air-fuel mixture containing the fuel spray injected by the first time injection is brought into contact with the fuel spray injected by the second time injection.

An engine device including an intake manifold (67) configured to supply air into a cylinder (36) a gas injector (98) configured to mix fuel gas with air supplied from the intake manifold (67) and supply mixed gas to the cylinder (36) and an igniter (79) configured to ignite, in the cylinder (36) premixed fuel obtained by pre-mixing the fuel gas with the air, the engine device further including a controlling unit (73) configured to determine an air amount in the premixed fuel in the cylinder (36) The controlling unit (73) performs in multiple steps retard control of ignition timing by the igniter (79), when the air amount is insufficient, and performs in multiple steps advance control of the ignition timing, when the air amount is.

An ignition timing control device has a knocking detection unit and an ignition timing adjustment unit. In a condition that the operation state of the internal combustion engine is suitable for adjustment of the ignition timing, the ignition timing control device outputs to an igniter an adjusted ignition signal as adjusted (corrected) by an adjusted ignition timing determination process. The ignition timing control device outputs to the igniter a reference ignition signal as it is outputted from an internal combustion engine control unit without adjustment (correction) in a condition that the operation state of the internal combustion engine is not suitable for adjustment of the ignition timing.

A method for knock control of an internal combustion engine capable of being operated using a water injection system, in which at least one parameter of the knock control is determined as a function of a variable connected to the water injection system, in particular the water content.

A knocking detector is to detect knocking in the internal combustion engine in which a low-octane fuel is injected into a cylinder and a high-octane fuel whose octane number higher than an octane number of the low-octane fuel is injected into an inlet port. A knocking suppressor includes a first knocking suppressor and a second knocking suppressor. The first knocking suppressor is to increase a high-octane fuel ratio of an injection quantity of the high-octane fuel to a sum of an injection quantity of the low-octane fuel and the injection quantity of the high-octane fuel in order to suppress knocking in the internal combustion engine when the knocking detector detects the knocking. The second knocking suppressor is to suppress knocking of the internal combustion engine at a beginning of a period while the first knocking suppressor increases the high-octane fuel ratio.

A method of controlling knocking of an internal combustion engine has, when knocking having a knock judgment threshold value or more is detected, retard-correcting an ignition timing at a predetermined retardation speed, while the knocking is not detected, gradually advancing the ignition timing at a predetermined advance speed so as to approach an MBT point, performing an ignition timing correction for aiming for a first trace-knock state, and when an accelerator opening is a full-open-equivalent opening or more and also for a delay period until a predetermined catalyst protection increasing control is started, performing an ignition timing correction for aiming for a second trace-knock state in which the ignition timing is controlled to a relatively advance side as compared with that in the first trace-knock state.