Combustion balancing control strategy using normalized instantaneous heat release in HCCI engines

Abstract

The invention relates to a combustion balancing control strategy using normalized instantaneous heat release in HCCI engines. A method for controlling combustion in a multi-cylinder internal combustion engine operating in a controlled auto-ignition mode includes providing combustion control parameters, determining peak cylinder pressures and crank angle location of the peak cylinder pressures. Cylinder volumes at the peak cylinder pressures and at intake valve closings are determined and cylinder pressures at intake valve closings are determined. A combustion parameter for each cylinder is calculated based upon the peak cylinder pressure, the cylinder pressure at the intake valve closing, the crank angle location of the peak cylinder pressure, the cylinder volume coincident with the peak cylinder pressure, and the cylinder volume at the intake valve closing. A target combustion parameter is determined and the calculated combustion parameter for each cylinder is compared to the target combustion parameter. The provided combustion control parameters for each cylinder are adjusted to balance the combustion parameter across all cylinders based on the comparison. The engine is controlled based on the adjusted provided combustion control parameters.

Description

technical field [0001] The present invention relates to the operation and control of homogeneous charge compression ignition (HCCI) engines. Background technique [0002] The descriptions in this section merely provide background information related to the present disclosure and may not constitute prior art. [0003] Internal combustion engines, especially motor vehicle internal combustion engines, generally fall into one of two analogies: spark ignition and compression ignition. A spark ignition engine, such as a gasoline engine, introduces an air / fuel mixture into a combustion cylinder where it is compressed during the compression stroke and ignited by a spark plug. Compression ignition engines, such as diesel engines, inject pressurized fuel into the combustion cylinder near top dead center (TDC) of the compression stroke, which ignites upon injection. Combustion in both gasoline and diesel engines involves premixed or diffuse flames controlled by fluid mechanics. Each...

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Problems solved by technology

However, for a multi-cylinder engine, the throttle and EGR valve positions have a wide influence on the combustion phasing of all cylinders, thus, such combustion control parameters cannot be used for individual combustion phasing control

Similarly, a multi-cylinder engine equipped only with a conventional mechanical cam phasing system results in the same NVO being applied to all cylinders, and the ability for individual cylinder NVO control to be used for combustion phasing is not feasible

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