System and method for controlling dual camshafts in a variable cam timing engine
AssigneeFord Global Technologies, LLC
InventorsMrdjan J. Jankovic, Stephen Lee Cooper, Stephen William Magner
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Abstract
A system and method for controlling first and second phase shiftable camshafts in a variable cam timing engine is provided. The method includes determining when the first camshaft is moving toward a first scheduled phase angle with respect to the crankshaft at a faster rate than the second camshaft is moving toward the first scheduled phase angle. Finally, the method includes slowing down the first camshaft so that the rate of movement of the first camshaft approaches a rate or movement of the second camshaft toward the first scheduled phase angle.
Claims12
A method for controlling first and second phase shiftable camshafts in a variable cam timing engine said first and second camshafts controlling air flow communicating with said first and second cylinders, respectively, of said engine, said engine further including a crankshaft being driven by first and second pistons within said first and second cylinders, respectively, said method comprising:
- determining when said first camshaft is moving toward a first scheduled phase angle with respect to said crankshaft at a faster rate than said second camshaft is moving toward said first scheduled phase angle;
- and,
- slowing down said first camshaft so that said rate of movement of said first camshaft approaches a rate of movement of said second camshaft toward said first scheduled phase angle.
A system for controlling first and second phase shiftable camshafts in a variable cam timing engine, said first and second camshafts controlling air flow communicating with first and second cylinders, respectively, of said engine, said engine further including a crankshaft being driven by first and second pistons within said first and second cylinders, respectively, said system comprising:
- a first sensor generating a first signal indicative of a position of said first camshaft;
- a second sensor generating a second signal indicative of a position of said second camshaft;
- a third sensor generating a third signal indicative of a position of said crankshaft;
- and,
- a controller operably connected to said first, second, and third sensors, said controller configured to determine when said first camshaft is moving toward a first scheduled phase angle with respect to said crankshaft at a faster rate than said second camshaft is moving toward said first scheduled phase angle based on said first, second, and third signals, said controller being further configured to slow down said first camshaft so that said rate of movement of said first camshaft approaches said rate of movement of said second camshaft toward said first scheduled phase angle.
An article of manufacture, comprising:
- a computer storage medium having a computer program encoded therein for controlling first and second phase shiftable camshafts in a variable cam timing engine, said first and second camshafts controlling air flow communicating with first and second cylinders, respectively, of said engine, said engine further including a crankshaft being driven by first and second pistons within said first and second cylinders, respectively, said computer storage medium comprising:
- code for determining when said first camshaft is moving toward a first scheduled phase angle with respect to said crankshaft at a faster rate than said second camshaft is moving toward said first scheduled phase angle;
- and,
- code for slowing down said first camshaft so that said rate of movement of said first camshaft approaches a rate of movement of said second camshaft toward said first scheduled phase angle.
Dependencies are inferred from the claim text.