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 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 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: 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 combustion control system for a vehicle comprises a pressure ratio (PR) module, a pressure ratio difference (PRD) module, and a pressure ratio difference rate (PRDR) module. The PR module determines fired PR values and measured motored PR values based on cylinder pressures measured by a cylinder pressure sensor when a cylinder of an engine is fired and motored, respectively. The PRD module determines PRD values for predetermined crankshaft angles, wherein each of the PRD values is determined based on one of the fired PR values and one of the measured motored PR values at one of the predetermined crankshaft angles. The PRDR module determines and outputs a PRDR value based on a rate of change of the PRD values over a range of the predetermined crankshaft angles.

Abstract: A combustion control system for a vehicle comprises a pressure ratio (PR) module, a pressure ratio difference (PRD) module, and a pressure ratio difference rate (PRDR) module. The PR module determines fired PR values and measured motored PR values based on cylinder pressures measured by a cylinder pressure sensor when a cylinder of an engine is fired and motored, respectively. The PRD module determines PRD values for predetermined crankshaft angles, wherein each of the PRD values is determined based on one of the fired PR values and one of the measured motored PR values at one of the predetermined crankshaft angles. The PRDR module determines and outputs a PRDR value based on a rate of change of the PRD values over a range of the predetermined crankshaft angles.

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.