A control system of an internal combustion engine which performs diffusion combustion by compression autoignition on fuel injected in a main injection in at least a partial operating range and which performs stratified combustion by spark ignition using a spark plug on fuel injected prior to the main injection. The control system determines whether or not the diffusion combustion occurs and performs combustion by spark ignition using the spark plug on the fuel injected in the main injection when it is determined that the diffusion combustion does not occur.

An internal combustion engine is configured to operate in a homogeneous-charge compression-ignition combustion mode. Operation of the engine includes determining a combustion pressure parameter for each cylinder. Fueling for each cylinder is controlled responsive to a target state for the combustion pressure parameter for the corresponding cylinder. An end-of-injection timing and a corresponding spark ignition timing for each cylinder are controlled responsive to a target mass-burn-fraction point for an engine operating point.

A method for operating an internal combustion engine includes operating at least one cylinder pre-chamber in a homogeneous charge compression ignition (HCCI) combustion mode by providing an air/fuel mixture in the pre-chamber that is fluidly connected to the at least one engine cylinder, creating H and OH radicals in the pre-chamber to achieve an ignition in the at least one pre-chamber, determining whether an ignition timing is advanced or delayed relative to a desired timing, and delaying the ignition when the ignition is advanced relative to the desired timing by cooling the pre-chamber and the at least one engine cylinder.

Methods and systems are provided for adjusting spark and/or fuel injection to a cylinder based on late combustion, partial burn, or misfire in a neighboring cylinder. In one example, a method may include deactivating spark and fuel injection to a second cylinder receiving exhaust residuals from combustion in a first cylinder, the first cylinder experiencing a misfire or late combustion event. Mitigating actions are performed in the second cylinder before the occurrence of a pre-ignition event.

Variable compression ratio engines and methods for homogeneous charge, compression ignition operation. The engines effectively premix the fuel and air well before compression ignition. Various embodiments are disclosed including embodiments that include two stages of compression to obtain compression ratios well above the mechanical compression ratio of the engine cylinders for compression ignition of difficult to ignite fuels, and a controllable combustion chamber volume for limiting the maximum temperature during combustion. Energy storage with energy management are also disclosed.

An illustrative example method of controlling an engine of a vehicle, includes determining a target pressure curve for a cylinder of the engine for a first combustion cycle, determining a heat release model for the cylinder for the first combustion cycle, determining a mass flow of fuel from the heat release model to achieve the target pressure curve during the first combustion cycle, and automatically controlling opening of an injector of the cylinder of the engine during the first combustion cycle to provide the determined mass flow of fuel to the cylinder. The method includes determining a real pressure curve during the first combustion cycle and automatically adjusting at least one of the heat release model or the mass flow for a second, subsequent combustion cycle based on a difference between the target pressure curve and the real pressure curve.

An illustrative example method of controlling an engine of a vehicle, includes determining a target pressure curve for a cylinder of the engine, determining a heat release model for the cylinder, determining a mass flow of fuel from the heat release model to achieve the target pressure curve, and automatically controlling opening of an injector of the cylinder of the engine to provide the determined mass flow of fuel to the cylinder.

When only smoke is generated, the sensor sensitivity is not substantially changed from the initial value. When both smoke and unburned HC are generated, the number of times the sensor sensitivity becomes lower than the initial value is increased. From these results, it can be understood that a deposit is formed in the presence of unburned HC and smoke existing simultaneously. The degree of reduction in sensor sensitivity becomes higher if the smoke concentration is increased when the unburned HC concentration condition is fixed. From this result, it can also be understood that while the coexistence of smoke and unburned HC is a prerequisite, unburned HC contributes largely to the formation of a deposit.

A glow plug including a substantially cylindrical housing extending in an axial direction; a rod-shaped heater unit having a front end protruding from the front end of the housing and movable in the axial direction; a connecting member connecting the heater unit to the housing within the housing and allowing the heater unit to move in the axial direction; and a pressure sensor that detects pressure received by the heater unit. The heater unit has a large-diameter portion at the rear end thereof and a small-diameter portion frontward of the large-diameter portion and having a diameter smaller than the diameter of the large-diameter portion. The connecting member connects the small-diameter portion of the heater unit to the housing within the housing.

The invention relates to a control device for an internal combustion engine using the center-of-gravity position of a heat generation rate for combustion control. This control device controls the center-of-gravity position of a heat generation rate to correspond to a reference position in a case where an engine cooling water temperature is equal to or higher than a reference cooling water temperature and controls the center-of-gravity position of a heat generation rate to correspond to a crank angle further on an advance side than the reference position in a case where the engine cooling water temperature is lower than the reference cooling water temperature.