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 to control an exhaust gas recirculation and a manifold air pressure in an engine includes utilizing a decoupling matrix within a multiple input and multiple output controller to determine an exhaust gas recirculation command and a manifold air pressure command, wherein the decoupling matrix is configured based upon a diagonally dominant model of the engine compensated by the determined exhaust gas recirculation command and the manifold air pressure command. The exhaust gas recirculation and manifold air pressure are controlled based upon the determined exhaust gas recirculation command and the determined manifold air pressure command.

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: 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 to control an exhaust gas recirculation and a manifold air pressure in an engine includes utilizing a decoupling matrix within a multiple input and multiple output controller to determine an exhaust gas recirculation command and a manifold air pressure command, wherein the decoupling matrix is configured based upon a diagonally dominant model of the engine compensated by the determined exhaust gas recirculation command and the manifold air pressure command. The exhaust gas recirculation and manifold air pressure are controlled based upon the determined exhaust gas recirculation command and the determined manifold air pressure command.

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 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: 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: 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 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.