Abstract: Combustion noise in a compression-ignition engine is controlled by measuring in-cylinder pressure of a cylinder of the compression-ignition engine, determining a combustion noise level based on the in-cylinder pressure measurement, and modifying a combustion control parameter based on the combustion noise level.

Abstract: A method for distinguishing between combustion issues and sensor faults within an engine includes monitoring pressure sensor data from a cylinder within the engine, monitoring engine data describing combustion health from a source other than a pressure sensor, analyzing the pressure sensor data to diagnose an anomalous combustion event, comparing the anomalous combustion event to analysis of the engine data, and indicating a pressure sensor fault warning if the comparison diagnoses a pressure sensor fault.

Abstract: Combustion within an internal combustion engine is diagnosed and includes monitoring crankshaft angular velocity and generating a combustion phasing value for a combustion chamber based on the crankshaft angular velocity. The combustion phasing value is compared to an expected combustion phasing value based on a predetermined start of injection crank angle and combustion phasing differences greater than an allowable combustion phasing difference are identified based on the comparison.

Abstract: A method for diagnosing combustion within an engine includes monitoring pressure cylinder pressure and generating a measured combustion phasing value for the cylinder at a predetermined metric selected to index the combustion cycle. The measured combustion phasing value is calculated through a Fast Fourier Transform and compared to an expected combustion phasing value.

Abstract: An engine control system comprises a fuel diagnostic module and a fuel control module. The fuel diagnostic module determines a pressure-ratio difference average (PRDA) based on a pressure in at least one cylinder and determines a cetane number (CN) of a fuel based on the PRDA. The fuel control module actuates fuel injectors based on the CN.

Abstract: A method for diagnosing combustion within a direct-injection, internal combustion engine including a plurality of combustion chambers and operative lean of stoichiometry includes monitoring combustion in the combustion chambers and estimating mass fraction burn therein. Mass fraction burn of sequential ones of the plurality of combustion chambers are compared and combustion phasing differences between sequential ones of the plurality of combustion chambers based on said mass fraction burn comparisons are identified.

Abstract: A system and method comprises operating an engine during a first cycle to drive a piston in a cylinder without energizing a fuel injector of the cylinder; acquiring first pressure data of the cylinder for a predetermined crank angle window during the first cycle; energizing the fuel injector for an energizing time during a second cycle; acquiring second pressure data of the cylinder for the predetermined crank angle window during the second cycle; calculating a pressure ratio difference average (PRDA) from the first pressure data and the second pressure data; and modifying the operation of the fuel injector based on the PRDA value.

Abstract: A method for controlling operation of an internal combustion engine operating lean of stoichiometry is described. The engine is a multi-cylinder direct-injection engine operative in repetitive cycles each cycle including intake, compression, expansion, and exhaust strokes. The method includes adapting a plurality of fuel injectors to directly inject a first and a second mass of fuel into the cylinders during each cycle. Pressure sensing devices monitor in-cylinder pressure in the cylinders during ongoing operation. The first mass of fuel is injected into one of the cylinders. A cylinder pressure ratio is determined in the cylinder subsequent to injecting the first mass of fuel based upon the monitored pressure. The first mass of fuel injected is adjusted during a subsequent cycle based upon the cylinder pressure ratio.

Abstract: A method for accurate estimation of a gas temperature at transient conditions includes measuring temperature sensor readings in a gas flow and estimating the gas temperature by equating the specific heat properties of the temperature sensor to the sum of conductive heat, convective heat, and radiative heat acting upon the temperature sensor and solving for the gas temperature.

Abstract: The invention comprises a method to operate a direct-injection engine operative at various air/fuel ratios. The method comprises monitoring in-cylinder pressure, along with a corresponding engine crank position to periodically to determine instantaneous in-cylinder pressure states corresponding to the engine crank position during compression and expansion. Pressure ratios are determined based upon the instantaneous in-cylinder pressure states. A combustion heat release is determined based upon the pressure ratios. An aspect of the invention comprises extending the operation to diesel, diesel premixed and to HCCI engines.

Abstract: A method for controlling operation of an internal combustion engine operating lean of stoichiometry is described. The engine comprises a multi-cylinder direct-injection engine, the engine operative in repetitive cycles each cycle comprising intake, compression, expansion, and exhaust strokes. The method comprises adapting a plurality of fuel injectors to directly inject a first and a second mass of fuel into the cylinders during each cycle. Pressure sensing devices monitor in-cylinder pressure in the cylinders during ongoing operation. The first mass of fuel is injected into one of the cylinders. A cylinder pressure ratio is determined in the cylinder subsequent to injecting the first mass of fuel based upon the monitored pressure. The first mass of fuel injected is adjusted during a subsequent cycle based upon the cylinder pressure ratio.

Abstract: The invention comprises a method to operate a direct-injection engine operative at various air/fuel ratios. The method comprises monitoring in-cylinder pressure, along with a corresponding engine crank position to periodically to determine instantaneous in-cylinder pressure states corresponding to the engine crank position during compression and expansion. Pressure ratios are determined based upon the instantaneous in-cylinder pressure states. A combustion heat release is determined based upon the pressure ratios. An aspect of the invention comprises extending the operation to diesel, diesel premixed and to HCCI engines.

Abstract: The invention comprises a method to determine a position of a piston in a cylinder of an engine during ongoing operation, comprising adapting pressure sensing devices to monitor in-cylinder pressure, and, operating the engine. In-cylinder pressure is monitored along with a corresponding engine crank position. The engine is operated in a motoring mode and in a cylinder firing mode, and a plurality of instantaneous in-cylinder pressure states are determined during compression and expansion strokes. Pressure ratios are determined based upon the instantaneous in-cylinder pressure states, which are used to determine an engine crank angle and compression ratio error and, adjust the monitored engine crank position based upon the crank angle error and readjust engine operation according to these sensed errors.

Abstract: An internal combustion engine is configured with combustion chamber pressure sensing and exhaust gas recirculation apparatus. Exhaust gas recirculation control includes closed-loop controlling exhaust gas recirculation apparatus in accordance with a predetermined control target. Adjustments to the control target are made based on combustion chamber pressure information.

Abstract: An internal combustion engine is configured with combustion chamber pressure sensing and exhaust gas recirculation apparatus. Fuel injection timing is adjusted based on combustion phasing and exhaust gas recirculation is controlled based on average fuel injection timing adjustments.