A control apparatus of an internal combustion engine having an injector which directly injects fuel into a combustion chamber of a cylinder and a spark plug which ignites an air-fuel mixture containing the fuel injected by the injector includes an air-fuel ratio acquisition unit acquiring an air-fuel ratio of the air-fuel mixture in the combustion chamber, a nitrogen oxide concentration acquisition unit acquiring a concentration of nitrogen oxide in a combustion gas exhausted from the internal combustion engine, and a stratification level estimation unit estimating a level of stratification as a measure of level of distribution of the air-fuel mixture at a predetermined air-fuel ratio or below in a vicinity of the spark plug. The stratification level estimation unit estimates the level of stratification according to the air-fuel ratio acquired by the air-fuel ratio acquisition unit and the concentration of nitrogen oxide acquired by the nitrogen oxide concentration acquisition unit.

An internal combustion engine control device includes an engine state estimation unit, a wall surface temperature estimation unit, and an operation amount calculation unit. The engine state estimation unit calculates the energy transfer amount from the gas to the wall surface based on the parameter related to the operating condition, the parameter related to the chemical condition of combustion, and the parameter related to an operation status. The wall surface temperature estimation unit estimates the wall surface temperature on the basis of the energy transfer amount from the gas to the wall surface. The operation amount calculation unit calculates an operation amount of an actuator provided in the internal combustion engine on the basis of the wall surface temperature estimated by the wall surface temperature estimation unit.

A system and method of providing real-time calculation of heat flow in an engine. A piston is disposed in a cylinder of an engine block and movable relative to the cylinder in response to combustion inside the cylinder. A temperature of the combustion inside the cylinder, an average temperature of the wall of the cylinder, and a surface area of the wall of the cylinder based on timing of combustion are determined. An estimated temperature of the piston is derived from calculating a heat fraction to the piston in real-time, via a controller, based on the determined temperature of the combustion, the determined average temperature of the wall of the cylinder, and the determined surface area of the wall of the cylinder. A state of the engine is controlled based on the estimated temperature of the piston as derived from the real-time calculation of the heat fraction to the piston.

An engine system incorporating an engine, one or more sensors, and a controller. The controller may be connected to the one or more sensors and the engine. The one or more sensors may be configured to sense one or more parameters related to operation of the engine. The controller may incorporate an air-path state estimator configured to estimate one or more air-path state parameters in the engine based on values of one or more parameters sensed by the sensors. The controller may have an on-line and an off-line portion, where the on-line portion may incorporate the air-path state estimator and the off-line portion may configure and/or calibrate a model for the air-path state estimator.

An engine system is provided, including a controller which controls devices of an engine at a given engine speed so that, when a demanded engine load is a first load, a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel is a first G/F and mixture gas inside the cylinder combusts by flame-propagation, when the demanded load is a second load (<the first load), the G/F is a second G/F (>the first G/F) and an injection center-of-gravity is at a timing such that the entire mixture gas combusts by CI combustion, and when the demanded load is between the first and second loads, the G/F is at a third G/F (between the first and second G/Fs) and the injection center-of-gravity is at a later timing such that at least part of the mixture gas combusts by the CI combustion.

Methods and systems are provided for an engine for adjusting cylinder parameter settings to optimize engine output during a transient mode. In one example, a method may include adjusting cylinder parameter settings, including a cam timing setting, a spark timing setting, and a fuel injection timing setting based on a chamber temperature in response to a rate of fuel injection acceleration being greater than a positive threshold, thus indicating the engine is in the transient mode.

Systems and methods regarding a ducted fuel injection (DFI) combustion system for an internal combustion engine can control an injection timing of a fuel injector to output fuel injections through at least one duct and into a combustion chamber of the internal combustion engine. The injection timing can include one or more pilot injections according to a predetermined range before top dead center (BTDC) for a combustion cycle; and a main injection into the combustion chamber for the combustion cycle after all of the one or more pilot injections. A first amount of the fuel injected for the main injection can be greater than a second amount of fuel injected for the one or more pilot injections. The predetermined range before top dead center (BTDC) of the one or more pilot injections can be from 85 to 40 degrees BTDC.

A method of controlling an engine is provided, which includes setting, by a controller, a target torque of the engine in a specific cycle in the future by a given delay time from the present time based on a present accelerator opening. The method includes selecting beforehand, by the controller, combustion in the specific cycle according to the target torque, from flame propagation combustion and compressed self-ignition combustion. The method includes outputting, by the controller, a control signal to a property adjusting device before the specific cycle so that a property inside the cylinder in the specific cycle becomes a property corresponding to the selected combustion. The method includes estimating, by the controller, the property at a timing when an intake valve is closed in the specific cycle. The method includes outputting, by the controller, a control signal corresponding to the estimated property to a spark plug or an injector.

An engine system is provided, which includes a vehicle-mounted engine having an injector, a spark plug, an intake valve operating mechanism, and an exhaust valve operating mechanism, an accelerator opening sensor, and a controller. The engine is configured to execute flame propagation combustion and compressed self-ignition combustion. The controller performs a combustion control so that a target torque set based on an accelerator opening is realized in a specific cycle in the future from a present time by a given delay time. The controller sets beforehand the combustion mode based on a target load, estimates an in-cylinder property when the intake valve is closed in the present cycle, sets a target in-cylinder property so that the set combustion mode is realized in the specific cycle, and sets a target operating amount of each of the intake and exhaust valve operating mechanisms based on the set target in-cylinder property.

An engine system is provided, which includes a vehicle-mounted engine having an injector, a spark plug, an intake valve operating mechanism, and an exhaust valve operating mechanism, an accelerator opening sensor, and a controller. The controller sets beforehand a combustion mode so that a target torque set based on an accelerator opening is realized in a specific cycle in the future from a present time by a given delay time, sets an in-cylinder property when an intake valve is closed in the specific cycle so that the set combustion mode is realized in the specific cycle, estimates the actual in-cylinder property when the intake valve is closed in the specific cycle, when the delay time passes and the cycle becomes the specific cycle, and adjusts an operating amount of at least one of the injector and the spark plug, when the estimated in-cylinder property deviates from the target in-cylinder property.