Apparatus and method for controlling a cam
AssigneeVitesco Technologies GmbH
InventorsYoungMo Lee, HaMyeong Song, JaeWon Choi
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Abstract
Various embodiments of the teachings herein include a method for controlling a cam using an ECU (electronic control unit) comprising: learning a holding region in which linearity is not ensured by increasing or decreasing a PWM signal while the cam maintains a holding state; based on the results of the learning, generating a final PWM signal; and transmitting the final PWM signal to an oil control valve. The final PWM signal comprises a sum of a minimum PWM signal for the cam to leave the holding region and a control PWM signal for the cam to reach a desired position.
Claims8
A method for controlling a cam using an ECU (electronic control unit), the method comprising:
- learning a holding region in which linearity is not ensured by increasing or decreasing a pulse width modulation (PWM) signal while the cam maintains a holding state;
- based on the holding region, generating a final PWM signal;
- wherein the final PWM signal comprises a sum of a minimum PWM signal for the cam to leave the holding region and a control PWM signal for the cam to reach a desired position;
- and
- transmitting the final PWM signal to an oil control valve;
- wherein learning the holding region comprises:
- increasing the PWM signal if the cam is positioned in a target area;
- halting the increase of the PWM signal at an instant in which a position of the cam changes whilst increasing the PWM signal, and storing the PWM signal, the increase of which has been halted, as a holding advance region among a set of engine conditions;
- decreasing the PWM signal in the holding advance region;
- halting the decrease of the PWM signal at an instant the position of the cam changes whilst decreasing the PWM signal, and storing the PWM signal, the decrease of which has been halted, as a holding retard region among the set of engine conditions;
- and
- defining an average of the PWM signal in the holding advance region and the PWM signal in the holding retard region as a learned value of the holding region.
An apparatus for controlling a cam, the apparatus comprising:
- an electronic control unit (ECU) with a learning unit for learning a holding region in which linearity is not ensured by performing an operation of increasing or decreasing a pulse width modulation (PWM) signal while the cam maintains a holding state;
- and
- a control unit in the ECU which, based on the holding region, generates a final PWM signal;
- wherein the final PWM signal comprises a sum of a minimum PWM signal for the cam to leave the holding region and a control PWM signal for the cam to reach a desired position;
- and
- wherein the ECU transmits the final PWM signal to an oil control valve;
- wherein the learning unit:
- increases the PWM signal if the cam is positioned in a target area;
- halts the increase of the PWM signal at an instant a position of the cam changes whilst increasing the PWM signal, and stores the PWM signal, the increase of which has been halted, as a holding advance region among a set of engine conditions;
- decreases the PWM signal in the holding advance region;
- halts the decrease of the PWM signal at an instant the position of the cam changes whilst decreasing the PWM signal, and stores the PWM signal, the decrease of which has been halted, as a holding retard region among the set of engine conditions;
- and
- defines an average of the PWM signal in the holding advance region and the PWM signal in the holding retard region as a learned value of the holding region.
Dependencies are inferred from the claim text.