Abstract: An engine control system includes an engine calibration module that sets fuel injection timing based on one of N cetane number (CN) values, wherein N is an integer greater than one. A combustion noise module generates a combustion noise signal based on cylinder pressure in a compression ignition (CI) engine during combustion. A fuel quality determination module compares the combustion noise signal to N predetermined combustion noise levels corresponding to the N CN values, and that selects the one of the N CN values based on the comparison.

Abstract: A method for controlling combustion in a direct injection internal combustion engine operable in a lean combustion mode includes monitoring in-cylinder pressure, utilizing a time-based filter to calculate an actual combustion noise based upon the monitored in-cylinder pressure, monitoring combustion control parameters utilized by the engine, determining an expected combustion noise based upon the monitored combustion control parameters, comparing the actual combustion noise to the expected combustion noise, and adjusting the combustion control parameters based upon the comparing.

Abstract: Combustion pressure in a diesel combustion chamber is monitored to determine a combustion parameter as a function of the monitored pressure. A cetane number of the fuel combusted is determined as a function of a predetermined correlation between the combustion parameter and the cetane number.

Abstract: A method for adjusting fuel injection timing in an internal combustion engine including a cylinder and configured to operate multiple fuel injections in the cylinder per combustion cycle includes monitoring in-cylinder pressure through a first combustion cycle, determining actual combustion phasing metrics based upon the in-cylinder pressure, monitoring a baseline fuel injection timing comprising a first injection timing and a second injection timing, providing expected combustion phasing metrics based upon the baseline fuel injection timing, comparing the actual combustion phasing metrics to the expected combustion phasing metrics, and adjusting the baseline fuel injection timing in a second combustion cycle based upon the comparing.

Abstract: A direct-injection, compression-ignition internal combustion engine control adapts nominal minimum pulsewidth parameters controlling the fuel injectors to minimize pilot fuel delivered to the cylinders required to initiate a preliminary combustion event.

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 pressure readings in the plurality of combustion chambers across engine crank angles, estimating a mass fraction burn percentage for each pressure reading, determining respective crank angles corresponding to a predetermined mass burn percentage for each combustion chamber, comparing said determined crank angles for sequential ones of the plurality of combustion chambers, and indicating an abnormal combustion event if compared crank angles differ by a predetermined angle.

Abstract: A method for correcting main fuel injection quantities in an internal combustion engine in a plurality of cylinders of the engine includes monitoring a desired fuel injection quantity for the plurality of cylinders, monitoring an in-cylinder pressure for each of the cylinders, determining a burnt fuel mass resulting from a main fuel injection for each of the cylinders based upon the in-cylinder pressures, determining a fuel injection quantity correction for each of the cylinders based upon the burnt fuel masses, and controlling fuel injections into the plurality of cylinders based upon the desired fuel injection quantity and the fuel injection quantity correction for each of the cylinders.

Abstract: Systems and methods useful for detecting a combustion fault in a combustion engine include determining cylinder power density values for cylinders present on the engine during its operation and determining cylinder imbalance parameters for the cylinders, based on the cylinder power density values. The cylinder imbalance parameters are compared with a provided diagnostic threshold value.

Abstract: A method for adjusting fuel injection quantities in an internal combustion engine configured to operate multi-pulse fuel injections in a cylinder of the engine includes monitoring in-cylinder pressure, determining a burnt fuel mass for main combustion based upon the in-cylinder pressure, determining a burnt fuel mass for post combustion based upon the in-cylinder pressure, determining a main fuel quantity offset based upon the burnt fuel mass for main combustion, determining a post fuel quantity offset based upon the burnt fuel mass for post combustion, and controlling fuel injections into the cylinder based upon the main fuel quantity offset and the post fuel quantity offset.

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 controlling combustion in a direct injection internal combustion engine operable in a lean combustion mode includes monitoring in-cylinder pressure, utilizing a time-based filter to calculate an actual combustion noise based upon the monitored in-cylinder pressure, monitoring combustion control parameters utilized by the engine, determining an expected combustion noise based upon the monitored combustion control parameters, comparing the actual combustion noise to the expected combustion noise, and adjusting the combustion control parameters based upon the comparing.

Abstract: A method for adjusting fuel injection timing in an internal combustion engine including a cylinder and configured to operate multiple fuel injections in the cylinder per combustion cycle includes monitoring in-cylinder pressure through a first combustion cycle, determining actual combustion phasing metrics based upon the in-cylinder pressure, monitoring a baseline fuel injection timing comprising a first injection timing and a second injection timing, providing expected combustion phasing metrics based upon the baseline fuel injection timing, comparing the actual combustion phasing metrics to the expected combustion phasing metrics, and adjusting the baseline fuel injection timing in a second combustion cycle based upon the comparing.

Abstract: Combustion pressure in a diesel combustion chamber is monitored to determine a combustion parameter as a function of the monitored pressure. A cetane number of the fuel combusted is determined as a function of a predetermined correlation between the combustion parameter and the cetane number.

Abstract: A method for adjusting fuel injection quantities in an internal combustion engine configured to operate multi-pulse fuel injections in a cylinder of the engine includes monitoring in-cylinder pressure, determining a burnt fuel mass for main combustion based upon the in-cylinder pressure, determining a burnt fuel mass for post combustion based upon the in-cylinder pressure, determining a main fuel quantity offset based upon the burnt fuel mass for main combustion, determining a post fuel quantity offset based upon the burnt fuel mass for post combustion, and controlling fuel injections into the cylinder based upon the main fuel quantity offset and the post fuel quantity offset.

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: 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 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: Systems and methods useful for detecting a combustion fault in a combustion engine include determining cylinder power density values for cylinders present on the engine during its operation and determining cylinder imbalance parameters for the cylinders, based on the cylinder power density values. The cylinder imbalance parameters are compared with a provided diagnostic threshold value.

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 a direct-injection, internal combustion engine including a plurality of combustion chambers and operative lean of stoichiometry includes monitoring pressure readings in the plurality of combustion chambers across engine crank angles, estimating a mass fraction burn percentage for each pressure reading, determining respective crank angles corresponding to a predetermined mass burn percentage for each combustion chamber, comparing said determined crank angles for sequential ones of the plurality of combustion chambers, and indicating an abnormal combustion event if compared crank angles differ by a predetermined angle.