In one embodiment, a method is provided. The method includes receiving a plurality of signals representative of an engine noise transmitted via a plurality of noise sensors, wherein the noise sensors are disposed in a grid about an engine. The method further includes receiving a knock sensor signal representative of an engine noise transmitted via a knock sensor. The method additionally includes deriving a combustion event based on the knock sensor signal, and deriving an engine condition based on the plurality of signals and the combustion event. The method also includes communicating the engine condition.

A control system for a vehicle includes an electronic control unit. The electronic control unit is configured to i) calculate a target supercharging pressure of an intake air such that, when an internal combustion engine is operated through the homogeneous charge compression ignition, the internal combustion engine achieves a required output while satisfying a predetermined requirement, ii) control an output of the internal combustion engine such that the output approaches the required output in accordance with an actual supercharging pressure in process of changing the actual supercharging pressure to the target supercharging pressure that is achieved by a supercharger, and iii) control a rotary machine such that an output of the rotary machine compensates for part or all of a differential output between the required output and the output in process of changing the actual supercharging pressure to the target supercharging pressure.

A control apparatus for an internal combustion engine, includes circuitry. The circuitry is configured to control a ratio of an amount of low octane number fuel to be supplied to a cylinder to a total amount of the low octane number fuel and a high octane number fuel to be supplied to the cylinder in order to control an overall octane number of fuel to be supplied to the cylinder. The high octane number fuel has a second octane number higher than a first octane number of the low octane number fuel. The circuitry is configured to calculate a maximum octane number of the fuel to be supplied into the cylinder. The circuitry is configured to restrict a power generated by the internal combustion engine based on the maximum octane number.

A method for engine combustion noise feedback control includes calculating an engine combustion noise target value by a controller. A cylinder pressure is measured after combustion of fuel according to a main injection timing and an amount of pilot fuel based on the calculated engine combustion noise target value. A combustion noise index (CNI) is calculated by converting the measured cylinder pressure into a cylinder pressure level. The feedback pilot injection is controlled in which the CNI is applied to injection variable control while controlling the main injection timing and the amount of pilot fuel.

At least some embodiments of the present disclosure are directed to systems and methods for controlling a cylinder deactivation (CDA) operation for an electrified powertrain, the electrified powertrain comprising an engine and an additional power source, the engine having a plurality of cylinders. The method includes the step of: operating the electrified powertrain in a CDA mode and deactivating one or more selected cylinders of the plurality of cylinders; receiving measurement data indicative of operating conditions of the electrified powertrain; analyzing the measurement data to determine whether a predetermined operating condition is met; and adjusting the CDA operation by adjusting the duration of the CDA operation or changing a number of deactivated cylinders.

A system according to the principles of the present disclosure includes a cylinder activation module and a spark timing module. The cylinder activation module selectively deactivates and reactivates a cylinder of an engine based on a driver torque request. When the cylinder is deactivated, the spark timing module selectively increases an amount by which spark timing of at least one active cylinder of the engine is retarded based on noise and vibration generated by the engine when the cylinder is deactivated.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, estimates of engine fuel consumption for operating the engine with a plurality of cylinder modes or patterns while a transmission is engaged in different gears are determined and are used as a basis for deactivating engine cylinders.

An engine is equipped with a first injection valve that injects fuel into an intake passage, and a second injection valve that injects fuel into a cylinder. The engine is provided with a fuel supply system having a first supply path for the first injection valve and a second supply path for the second injection valve. Moreover, an electronic control unit of the engine executes a unilateral injection process for causing fuel to be injected from one of the first injection valve and the second injection valve and prohibiting fuel injection from the other injection valve, when it is determined that there is a deviation between a property of fuel in the first supply path and a property of fuel in the second supply path.

A method for operating a fuel injector having at least one injection orifice that is controlled by an injector needle, in which pressure variations during the opening and/or closing of the injector needle are ascertained with the aid of a sensor. In order to determine the opening/closing instant of the injector needle, a variable that characterizes the velocity of sound of a pressure wave by the opening and/or closing is measured, and the wave propagation time, by which the needle or valve opening/closing instant is corrected, is inferred therefrom.

A fault diagnostic system of a vehicle includes a noise module that determines a noise value based on a plurality of differences between samples of a pressure signal generated by a pressure sensor located in a positive crankcase ventilation (PCV) system of an engine. A signal module determines a signal value based on the samples of the pressure signal generated by the pressure sensor located in the PCV system of the engine. A diagnostic value module determines a diagnostic value based on one of: (i) a product of the noise value and the signal value; and (ii) a sum based on the noise value and the signal value. A fault module selectively diagnoses a fault in the PCV system based on the diagnostic value and generates a malfunction indicator within a passenger cabin of the vehicle in response to the diagnosis of the fault in the PCV system.