An engine control unit of a multi-fuel is provided. The engine consumes a mixture of a first combustion fuel and a second combustion fuel. The engine control unit includes hardware circuitry that includes one or more processors configured to calculate an autoignition delay of the mixture of the air and the second combustion fuel based on current operating conditions of the multi-fuel engine. The one or more processors also are configured to calculate an upper limit on an amount of the second combustion fuel that is supplied to the multi-fuel engine based on the autoignition delay that is calculated.

A sensor failure diagnostic apparatus includes a first estimation unit to estimate a mixing ratio of each type of a molecular structure included in a fuel, based on combustion parameters when a combustion of an internal combustion engine is executed in different combustion conditions, among the combustion parameters sensed by a combustion sensor, a second estimation unit to estimate the mixing ratio, based on characteristic parameters sensed by a characteristic sensor, a combustion sensor diagnostic unit to determine whether a failure of the combustion sensor exists, based on a sensed value of the combustion sensor when the combustion is not executed, and a characteristic sensor diagnostic unit to determine whether a failure of the characteristic sensor exists, by comparing the mixing ratio estimated by the first estimation unit with the mixing ratio estimated by the second estimation unit when the combustion sensor diagnostic unit determines the combustion sensor is normal.

To provide a controller and a control method for an internal combustion engine capable of performing automatic adaptation of the optimal ignition timing or the optimal control value of the combustion operation mechanism during operating. A controller and a control method for an internal combustion engine changes setting values of a torque characteristics function so that an output torque calculated using the torque characteristics function approaches an output torque calculated based on an actual value of internal cylinder pressure; calculates a plurality of output torques corresponding to respective plurality of combustion control states using the torque characteristics function; and changes setting values of a combustion control target setting function so that a target value of combustion control state calculated using the combustion control target setting function approaches a maximum torque combustion control state where the output torque becomes the maximum.

A control device for a compression self-ignition engine includes a fuel injection system and an injection controller. While the engine is operated by CI combustion under a given first condition, a first injection is carried out in which fuel is injected at a first timing in a compression stroke and at which the fuel goes toward a part radially outward of a cavity formed in a crown surface of a piston, and a second injection is suspended. While the engine is operated by the CI combustion under a second condition in which a temperature inside a combustion chamber at a close timing of an intake valve becomes lower than the first condition, at least the second injection is carried out in which the fuel is injected at a second timing later than the first timing in the compression stroke and at which the fuel goes toward the cavity.

A method of controlling combustion in an internal combustion engine includes measuring parameters of combustion in a cylinder of the engine during a combustion phase of the cylinder, after igniting an air/fuel charge in the cylinder, and calculating the heat release of combustion in the cylinder based on the measured parameters. An auto-ignition event of the air/fuel charge is identified based on the calculated heat release, and, based at least in part on the identified auto-ignition event, at least one of ignition timing in the cylinder for the next combustion phase of the cylinder or an amount of exhaust gas supplied to the cylinder for the next combustion phase of the cylinder is controlled to cause an auto-ignition event of the air/fuel charge in the next combustion phase to shift toward a specified crank angle.

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 fuel quality rating testing system and related methodology. The system comprises a data acquisition system, comprising: (i) circuitry for receiving a time-varying signal from a pickup, the pickup for coupling to a test engine; and (ii) circuitry for determining a fuel rating in response to the time-varying signal. The fuel quality rating testing system also comprises a communications path coupled to the fuel quality rating testing system and a calibrator.

A method of controlling combustion in an internal combustion engine includes measuring parameters of combustion in a cylinder of the engine during a combustion phase of the cylinder, after igniting an air/fuel charge in the cylinder, and calculating the heat release of combustion in the cylinder based on the measured parameters. An auto-ignition event of the air/fuel charge is identified based on the calculated heat release, and, based at least in part on the identified auto-ignition event, at least one of ignition timing in the cylinder for the next combustion phase of the cylinder or an amount of exhaust gas supplied to the cylinder for the next combustion phase of the cylinder is controlled to cause an auto-ignition event of the air/fuel charge in the next combustion phase to shift toward a specified crank angle.

An engine control device is provided. A fuel injection valve performs a pre-injection and a main injection on a retarding side of the pre-injection so that pressure waves resulting from combustions caused by the injections cancel each other out. The control device secures a fuel injection amount to be supplied to a combustion chamber in one cycle by at least the pre-injection, the main injection, and a middle injection. The control device causes the fuel injection valve to perform the pre-injection at a timing when a piston is located at an advancing side of compression top dead center for premix combustion, to start the main injection during a combustion period of the fuel injected by the pre-injection for diffuse combustion, and to perform the middle injection at a timing between the other two injections with a fuel injection amount less than the other injections.

A control system for controlling pilot fuel injection in a dual fuel engine is disclosed. The control system may determine, using measurements from one or more sensors, one or more combustion parameters associated with the dual fuel engine during operation of the dual fuel engine. The control system may determine an estimated nitrogen oxides (NOx) emissions level based on the one or more combustion parameters, and may determine a NOx error based on a comparison between the estimated NOx emissions level and a desired NOx emissions level. The control system may control a quantity of pilot fuel injected into the dual fuel engine based on the NOx error.