A CPU advances ignition timing within a range in which knocking can be suppressed by feedback control based on an output signal of a knocking sensor. The CPU sets the igniting timing based on a feedback adjustment amount and a learning value. The CPU limits timing advancing update of the learning value when an exhaust pressure is higher than or equal to a threshold.

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 internal-combustion-engine control unit and control method are provided that can prevent an excessive ignition-timing retard while occurrences of knocking are suppressed. An internal-combustion-engine control unit that controls an internal-combustion engine, the internal-combustion-engine control unit including: a knock-occurrence-frequency sensing section that senses a knock occurrence-frequency of a cylinder; and a cylinder-wall-temperature computing section that computes a wall temperature of the cylinder on a basis of the knock occurrence-frequency sensed at the knock-occurrence-frequency sensing section.

A control device for an engine is provided, which includes a knock intensity sensor configured to detect a knock intensity, an output adjustment mechanism configured to adjust an engine output torque, and a controller configured to control the output adjustment mechanism based on the knock intensity. The controller executes a first control in which the output adjustment mechanism is controlled to reduce the knock intensity when the number of strong knocks that is the number of times the knock intensity becomes a second determination intensity or greater is a given determination number or less and when the knock intensity is greater than a first determination intensity, and executes a second control in which the output adjustment mechanism is controlled to reduce the maximum torque more than when the number of strong knocks is the determination number or less, when the number of strong knocks is greater than the determination number.

A CPU advances ignition timing within a range in which knocking can be suppressed by feedback control based on an output signal of a knocking sensor. The CPU sets the igniting timing based on a feedback adjustment amount and a learning value. The CPU limits timing advancing update of the learning value when an exhaust pressure is higher than or equal to a threshold.

An engine control system comprises a balancing arrangement together with a knock mitigation controller configured to implement a knock mitigation procedure wherein an offset input value (V.sub.I) is applied to the balancing algorithm. The offset input value (V.sub.I) may cause the balancing algorithm to adjust the control output (O.sub.1) for the respective one of the combustion chambers to progressively vary the fuel supply or ignition timing for the affected cylinder to mitigate the knock condition. Alternatively, the controller may generate an offset output value (V.sub.O) to more rapidly vary the fuel supply or ignition timing, with the offset input value (V.sub.I) being selected for example to compensate for the resulting change in the control input (I.sub.1) from the cylinder to the balancing algorithm, or to provide additional, more gradual adjustment to further mitigate the knock condition.

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 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.

Methods and systems are provided for improving fuel usage while addressing knock by adjusting the use of spark retard and direct injection of a knock control fluid based on engine operating conditions and the composition of the injected fluid. One or more engine parameters, such as EGR, VCT, boost, throttle position, and CMCV, are coordinated with the direct injection to reduce torque and EGR transients.

A control device for an internal combustion engine includes a knock control system, a cooling system, and an electronic control unit. The knock control system is configured to ignite a spark plug an ignition crank angle obtained by retarding the ignition crank angle in response to an occurrence of the knocking. The electronic control unit is configured to supply a command value corresponding to a target value of a cooling parameter to the cooling system such that the cooling system performs cooling of the internal combustion engine according to the command value. The electronic control unit is configured to correct the command value based on a KCS learned value such that as the KCS learned value increases, a correction amount for correcting the command value increases in correction amount in a direction in which a cooling capacity of the cooling system increases.