Abstract: An engine system includes a combustion chamber including a cylinder, a fuel supply that supplies fuel including gasoline into the combustion chamber, circuitry configured to predict a knock will occur in the combustion chamber, and a fluid injector that injects a fluid into the combustion chamber. Further, there is circuitry configured to suppress a knock by instructing the fluid injector, when the knock is predicted to occur by the circuitry configured to predict, to inject the fluid into the combustion chamber within a period before a burned mass fraction reaches 50% after a start of combustion.

Abstract: A control device for a compression-ignition (CI) engine in which partial CI combustion including spark ignition (SI) combustion performed by combusting a portion of mixture gas inside a cylinder by spark ignition followed by CI combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an engine operating range, is provided, including an EGR (exhaust gas recirculation) controller configured to change an EGR ratio, and a combustion controller configured to control the EGR controller during the partial compression-ignition combustion to switch a combustion mode between first and second modes in which the EGR ratio is higher than the first mode. After the first mode is switched to the second mode, if a condition is satisfied, the combustion controller causes the resumption to the first mode after a given period of time has elapsed from the switching.

Abstract: A control device for a compression-ignition engine is provided, in which partial compression-ignition combustion including spark ignition (SI) combustion performed by combusting a portion of mixture gas inside a cylinder by spark-ignition followed by compression ignition (CI) combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an operating range of the engine. The device includes a detector configured to detect a parameter related to noise caused by the combustion inside the cylinder, an EGR (exhaust gas recirculation) controller configured to change an EGR ratio being a ratio of exhaust gas introduced into the cylinder, and a combustion controller configured to control the EGR controller to increase the EGR ratio when a noise index value specified based on the detected parameter of the detector is confirmed to exceed a given threshold during the partial compression-ignition combustion.

Abstract: A control device for a compression-ignition engine in which partial compression-ignition combustion including spark ignition (SI) combustion performed by combusting a portion of a mixture gas inside a cylinder by spark-ignition followed by compression ignition (CI) combustion performed by causing the remaining mixture gas to self-ignite is executed at least within a part of an engine operating range is provided, which includes a detector configured to detect a given parameter that changes as combustion progresses inside the cylinder, an A/F (air-fuel ratio) controller configured to change an air-fuel ratio of air to fuel introduced into the cylinder, and a combustion controller configured to determine combustion stability based on the detected parameter of the detector and control the A/F controller to reduce the air-fuel ratio when it is confirmed that during the partial compression-ignition combustion the combustion stability is low.

Abstract: A compression self-ignition engine performs a SI combustion in which an air-fuel mixture is combusted due to flame propagation triggered by spark ignition, and a CI combustion in which the air-fuel mixture is combusted due to self-ignition induced by the flame propagation. An ECU comprises a first control means for controlling a SI ratio serving as an index relating to a ratio of a heat amount generated in the SI combustion with respect to a total heat amount generated in the SI and CI combustions or a heat amount generated in the CI combustion; and a second control means for controlling an in-cylinder temperature before the SI combustion. The ECU is configured to change a combustion state of each of the SI and CI combustions by both the first and second control means according to the operating state of the engine.

Abstract: A control device for an engine in which partial compression-ignition combustion including SI combustion performed by forcibly combusting a portion of mixture gas inside a cylinder followed by CI combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an operating range of the engine, is provided. The device includes a detector configured to detect a parameter related to noise caused by the combustion inside the cylinder, a memory configured to store a characteristic defining a relationship between a start timing of the CI combustion and a combustion noise index, and a processor configured to specify a given combustion noise index value based on the detection value of the detector, and control the start timing of the CI combustion.

Abstract: A control apparatus that is applied to a gasoline engine including cylinders is provided, which includes a controller for controlling the engine to perform a compression self-ignition operation within a first operating range, and perform a forced-ignition operation within a second operating range. Within a third operating range where an engine load is above the first range and below the second range, the controller executes a combined operation control in which a first cylinder performs the compression self-ignition operation and a second cylinder performs the forced-ignition operation, and the controller causes a change rate of a torque from the first cylinder to be lower than that of a torque from the second cylinder, the rates being taken in relation to a change of a requested load of the engine, the first cylinder being one or some of the cylinders, the second cylinder being the rest of the cylinders.

Abstract: A control apparatus that is applied to a gasoline engine including cylinders is provided. The apparatus includes a controller for controlling the engine to perform a compression self-ignition operation within a first operating range, and perform a forced-ignition operation within a second operating range. Within a third operating range where the engine load is above the first range and below the second range, the controller executes a combined operation control in which a first cylinder performs the compression self-ignition operation and a second cylinder performs the forced-ignition operation, and the controller causes the first cylinder to generate a torque that is the same or lower than a torque before the control, and causes the second cylinder to generate a torque that is higher than a torque before the control, the first cylinder being one or some of the cylinders, the second cylinder being the rest of the cylinders.