Engine event-based correction of engine speed fluctuations
AssigneeChrysler Group LLC
InventorsKenneth P. DeGroot, Jeffrey P. Wuttke, Gerald Lee Kennie, Dennis W. Fett
Life of this patent
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Abstract
Ignition timing for a combustion engine may be controlled by determining the roughness of current engine operation, comparing the determined roughness with a control roughness to determine if the determined roughness is within a threshold limit of the control roughness, and changing the ignition timing in a subsequent fuel delivery event as a function of the difference between the determined roughness and the control roughness. Preferably, the ignition timing is changed at least when the determined roughness is not within the threshold limit, although other factors may be taken into account when changing the ignition timing.
Claims17
A method of controlling ignition timing for a combustion engine, comprising:
- determining roughness of current engine operation;
- comparing the determined roughness with a predetermined control roughness to determine if the determined roughness is within a threshold limit of the control roughness;
- changing ignition timing of the engine for a subsequent ignition event as a function of the difference between the determined roughness and the control roughness at least when the determined roughness is not within said threshold limit;
- wherein the roughness of current engine operation is determined as a function of changes in engine speed associated with combustion in individual cylinders of the engine;
- and
- wherein the engine speed after a selected combustion event in one engine cylinder is compared to the engine speed after a subsequent combustion event in a different engine cylinder.
A method of controlling combustion in an internal combustion engine, comprising:
- sensing engine speed for each expected firing of individual cylinders of the internal combustion engine;
- determining a difference in engine speed for a selected cylinder firing and a cylinder firing occurring prior to the selected cylinder firing, said difference in engine speed providing an acceleration estimate value;
- determining a difference between a current acceleration estimate value and a preceding acceleration estimate value to provide an acceleration difference value;
- determining roughness of current engine operation as a function of the acceleration difference value;
- comparing the determined roughness with a control roughness to determine if the determined roughness is within a threshold limit of the control roughness;
- and
- controlling combustion of the internal combustion engine as a function of the difference between the determined roughness and the control roughness at least when the determined roughness is not within said threshold limit.
A method of controlling combustion for a combustion engine, comprising:
- determining roughness of current engine operation;
- comparing the determined roughness with a control roughness to determine if the determined roughness is within a threshold limit of the control roughness;
- changing ignition timing and fuel delivery to the engine for a subsequent ignition event as a function of the difference between the determined roughness and the control roughness at least when the determined roughness is not within said threshold limit;
- and
- wherein the determined roughness is determined Using an acceleration estimate value based on engine combustion events in two different cylinders.
Dependencies are inferred from the claim text.