An engine control device includes a model that, based on engine operating condition and first-type operation amount, reproduces at least one index from among various indexes of combustion state of engine, and a processor that executes a process including deciding on second-type operation amount, by optimization using the model so as to treat at least one of the indexes, which are reproduced by the model, as estimated value of control amount, and ensure that the estimated value of the control amount follows control target value, associating the second-type operation amount with the control target value and the engine operating condition, rewriting a learning control table in which operation amount corresponding to the control target value and the engine operating condition is registered, and calculating operation amount according to the learning control table based on the control target value and the engine operating condition.

A piston engine is provided; the piston engine has a cylinder, a main piston and an auxiliary piston; a combustion chamber is formed between the main piston and the auxiliary piston within the cylinder; the main piston has an crankpin offset L0, the auxiliary piston and the main piston move in different frequencies, an extended constant V≈Vc of the combustion chamber is formed from θ to >10° CA; when at a=θ=arc sin[L0/(L+R)] the main piston is at its top dead center; at a=arc sin(L0/R) the side force on the main piston is 0; when peak pressure of combustion is located at PPmax by choosing ignition timing, the most effective torque can be obtained; the torque is controlled by the amount of fuel injected; engine knocking can be prevented by retarded ignition at a>θ.

To provide a controller and a control method for internal combustion engine which can set appropriately an angle interval for estimating the combustion state in accordance with change of a burning angle interval, and can reduce calculation processing load for estimation of the combustion state. A controller for internal combustion engine changes the estimation crank angle interval based on an operating condition of the internal combustion engine; calculates an increment of gas pressure torque by burning at each crank angle of the estimation crank angle interval; and estimates the combustion state of the internal combustion engine, based on the increment of gas pressure torque by burning in the estimation crank angle interval.

Methods and systems are provided for adjusting a substitution ratio based on water in a combustion mixture of a multi-fuel engine. In one example, a method includes adjusting a substitution ratio in response to an amount of water provided to a multi-fuel engine configured to combust a first fuel and a second fuel, the second fuel different than the first fuel.

A method for detecting a cylinder-specific combustion profile parameter value for an internal combustion engine is described. The method includes the following: (a) detecting a toothed encoder signal, (b) determining a cylinder-specific tooth time interval on the basis of the toothed encoder signal, (c) determining a cylinder-specific phase value on the basis of a Fourier transformation of a part of the toothed encoder signal corresponding to the cylinder-specific tooth time interval, (d) determining the combustion profile parameter value on the basis of the cylinder-specific phase value and a stored transfer function which represents a relationship between the combustion profile parameter and the phase value.

A dual fuel system includes a liquid pilot fuel supply, a liquid main fuel supply, and a fuel injection apparatus. The dual fuel system further includes a fueling control unit coupled with a cylinder pressure sensor and a NOx sensor, and structured to vary, via outputting a fueling control command to a main fuel injection control valve, fuel delivery parameters each on the basis of at least one of a cylinder pressure parameter or a NOx parameter. The fueling control unit compensates via the varying fuel delivery parameters for a change to a liquid main fuel composition such as a change from a first alcohol fuel or blend to a second alcohol fuel or blend.

An asymmetry cylinder de-activation (CDA) engine provided with a first, a second, a third and a fourth cylinder of which CDA apparatuses are mounted thereto respectively may include a crankshaft connected with pistons of each cylinder through a first, a second, a third and a fourth cranking journal respectively, and a controller configured to control operations of the CDA apparatuses, in which phase differences between cranking journals according to firing order may include 90±10 degrees and 270±10 degrees.

To provide a controller for internal combustion engine which can improve the estimation accuracy of the period in the chipped tooth section, even if the period is suddenly varied in the chipped tooth section. A controller for internal combustion engine detects a period when the tooth passes, based on an output signal of the crank angle sensor; determines a period corresponding to the chipped tooth section; determines a crank angle corresponding to the passed tooth; and estimates a period of a virtual unit angle interval when assuming that the tooth is provided at the unit angle interval in the chipped tooth section, based on the period of the chipped tooth section, the period before the chipped tooth section, and the period after the chipped tooth section.

A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a target combustion condition. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition via a feedback control with a gain. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to determine the gain so as to increase as the fuel ratio decreases.

A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to calculate a target combustion condition according to the fuel ratio. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition.