Method of adaptively controlling a motor vehicle engine system
AssigneeFord Global Technologies, LLC
InventorsMark Ustel, Mohammad Farid
Life of this patent
Estimating the term…
Abstract
A method is disclosed for adaptively controlling an engine system of a motor vehicle comprising the steps of evaluating the outputs from angular position sensors associated with inlet and exhaust camshafts of an engine of the engine system to establish whether differences between the currently measured positions and previously saved positions are the result of elongation of an endless drive used to drive the camshafts or due to some other reason. If it is confirmed that the differences are due to elongation of the endless drive then the measured values of angular position are used in the control of a number of engine functions.
Claims20
A method of adaptively controlling a motor vehicle engine system comprising an engine having a crankshaft, first and second camshafts driven by an endless drive system including an endless drive from the crankshaft of the engine, and an electronic controller, the electronic controller including a processor and a memory for storage of instructions to be executed, wherein the method comprises:
- measuring an angular position for one other of the first and second camshafts when the crankshaft is in a reference position and using the measured angular position to produce a value of change in angular position for one of the first and second camshafts;
- measuring an angular position for the other of the first and second camshafts when the crankshaft is in the reference position and using the measured angular position to produce a value of change in angular position for the other of the first and second camshafts;
- a first establishing step of establishing whether a change in angular position for one of the first and second camshafts is in a retarded direction and whether a corresponding change in angular position for the other of the first and second camshafts is in the retarded direction;
- a second establishing step of establishing whether changes in angular position of the first and second camshafts are gradual changes;
- a third establishing step of establishing whether a ratio of change of angular position of one of the first and second camshafts with respect to the other of the first and second camshafts is substantially equal to a predefined fixed ratio based upon a geometry of the endless drive system;
- and
- if results of the first, second, and third establishing steps indicate that a change in angular position for both the first and second camshafts is in the retarded direction and changes in angular position are gradual changes and the ratio of change in angular position of one of the first and second camshafts with respect to the other of the first and second camshafts is substantially equal to the predefined fixed ratio based upon the geometry of the endless drive system, the method further comprises confirming that a current change in angular position of the first and second camshafts is a result of elongation of the endless drive, and using the measured angular positions of the first and second camshafts to control one or more operational functions of the engine.
A motor vehicle engine system comprising an engine having first and second camshafts driven by an endless drive system including an endless drive from a crankshaft of the engine, a crankshaft sensor to sense a rotational position of the crankshaft, and first and second camshaft sensors to sense rotational positions of the first and second camshafts respectively when the crankshaft is in a reference position;
- and an electronic controller to process an output from the crankshaft sensor and outputs from the first and second camshaft sensors, the electronic controller including a processor and a memory for storage of instructions to be executed, wherein the electronic controller is operable to:
- a first use step of using the outputs from the first and second camshaft sensors to establish whether a change in angular position for one camshaft of the first and second camshafts is in a retarded direction and whether a corresponding change in angular position for the other of the first and second camshafts is in the retarded direction;
- a second use step of using the outputs from the first and second camshaft sensors to establish whether changes in angular position of the first and second camshafts are gradual changes;
- a third use step of using the outputs from the first and second camshaft sensors to establish whether a ratio of change of angular position of one of the first and second camshafts with respect to the other of the first and second camshafts is substantially equal to a predefined fixed ratio based upon a geometry of the endless drive system;
- and
- if results of the first, second, and third use steps indicate that a change in angular position is in the retarded direction for both the first and second camshafts and the changes in angular position of the first and second camshafts are gradual changes and the ratio of change in angular position of one of the first and second camshafts with respect to the other of the first and second camshafts is substantially equal to the predefined fixed ratio based upon the geometry of the endless drive system, the electronic controller is operable to confirm that a current change in angular position of the first and second camshafts is a result of elongation of the endless drive, and is further operable to use measured angular positions of the first and second camshafts to control one or more operational functions of the engine.
Dependencies are inferred from the claim text.