Methods and systems are provided for adjusting an ignition timing of an internal combustion engine responsive to a biasing force of a pressure-reactive piston. In one example, an engine may include a pressure-reactive piston having a top wall biased away from a piston base by a pressure of gas contained within the base. An ignition timing of a combustion chamber including the piston is adjusted responsive to an estimated biasing force of the gas against the top wall.

Methods and systems are provided for monitoring knock in a variable displacement engine. During fuel-cut operation, an engine cylinder may be heated. Upon fuel reactivation, a crankshaft sensor profile may be relearned responsive to lack of knock in the heated cylinder. In this way, erroneous identification of a knocking cylinder due to inaccurate crankshaft position data may be determined and mitigated by re-learning the crankshaft sensor profile.

The present disclosure relates to an engine provided with cylinder deactivation (CDA) apparatuses for at least some engine cylinders and provided with a water pump, and a method for controlling the same. The method for controlling the engine includes a controller: determining, based on output signals from vehicle driving information sensors, whether or not a current vehicle driving state corresponds to a CDA driving region; operating CDA apparatuses of some of the cylinders when the current vehicle driving state corresponds to the CDA driving region; determining whether or not detonation border lines (DBLs) of respective cylinders the CDA apparatuses of which are not operated precede a minimum spark advance for best torque (MBT); and, when the DBLs precede the MBT, operating corresponding water injecting nozzles so as to inject water into the respective cylinders.

The invention relates to a method for operating an internal combustion engine, in which the internal combustion engine has at least one first combustion chamber, in which combustion processes take place during fired operation of the first combustion chamber, at least one second combustion chamber, in which combustion processes take place during a fired operation of the second combustion chamber, a first knock sensor assigned to the first combustion chamber, by means of which irregular combustions in the first combustion chamber can be detected, and a second knock sensor assigned to the second combustion chamber, by means of which irregular combustions in the second combustion chamber can be detected. The internal combustion engine is operated in a first operating state in which channel switching is carried out. A switch is made from the first operating state to a second operating state in which channel switching does not take place.

To provide an internal combustion engine control device (100) in which a control unit (107b) controls an operating condition of an internal combustion engine (1) based on a difference TCC between a first temperature TCC corresponding to the temperature of a first portion in a wall defining a combustion chamber of the internal combustion engine (1), and a second temperature TE corresponding to the temperature of a second portion on an outer wall surface side than the first portion in the wall.

A knocking control method in a power generation system (1) which includes a gas engine (20) including a plurality of air cylinders (21) and a knocking detection unit (51) configured to detect knocking in each of the air cylinders (21). The knocking control method includes a first control step of delaying an ignition timing for at least one of the air cylinders (21) when the knocking detection unit (51) has detected knocking; a second control step of reducing an amount of gas supplied to at least one of the air cylinders (21) when the knocking has not been eliminated by the first control step; and a third control step of shutting off supply of a gas to any of the air cylinders (21) in which the knocking has occurred.

A multicylinder engine includes a plurality of intake ports, a plurality of in-cylinder injectors, and an electronic control unit. The electronic control unit is configured to initially set a value of a control parameter of the multicylinder engine, individually for each of the cylinders, such that there is a common regularity between a distribution among the cylinders, of a difference of the value of the control parameter of each of the cylinders from the value of the control parameter of a reference cylinder, and a distribution among the cylinders, of a difference of the distance of a narrowed portion of each of the cylinders from the distance of the narrowed portion of a reference cylinder. The control parameter is a parameter that determines an air-fuel ratio of an air-fuel mixture around an ignition plug at a time of ignition in stratified charge combustion operation.

Methods and systems are provided for adjusting an ignition timing of an internal combustion engine responsive to a biasing force of a pressure-reactive piston. In one example, an engine may include a pressure-reactive piston having a top wall biased away from a piston base by a pressure of gas contained within the base. An ignition timing of a combustion chamber including the piston is adjusted responsive to an estimated biasing force of the gas against the top wall.

Methods and systems are provided for coordinating cylinder deactivation adjustments with changes to individual cylinder piston displacement. In doing do, the benefits of variable displacement and variable compression ratio may be synergized. An engine can be operated with some cylinders deactivated while active cylinders operate with knock addressed while spark timing is at MBT for a longer duration.

A control device for an internal combustion engine includes an in-cylinder pressure sensor, a crank angle sensor, and an electronic control unit. The electronic control unit is configured to calculate a correlation index value showing a degree of a correlation between a actually measured data of a combustion mass ratio and reference data of the combustion mass ratio based on an operating condition of the internal combustion engine. The electronic control unit is configured to, in a case where the correlation index value is lower than a determination value, prohibit the actually measured value of the specific ratio combustion point pertaining to a combustion cycle in which the correlation index value is calculated from being reflected in the engine control or reduce a degree of the reflection in the engine control compared to a case where the correlation index value is equal to or higher than the determination value.