Apparatus For and Method of Controlling Variable Valve Timing Mechanism

A method of controlling a variable valve timing mechanism that varies valve timing of an engine valve, comprising the steps of:

• calculating target valve timing;
• calculating a first manipulated variable based on the target valve timing,
• calculating a second manipulated variable by which a variation speed of valve timing is maximized;
• estimating valve timing of when the second manipulated variable is output to the variable valve timing mechanism;
• comparing an estimated valve timing with the target valve timing;
• determining timing at which the second manipulated variable is switched to the first manipulated variable based on a result of the comparison;
• outputting the second manipulated variable to the variable valve timing mechanism in a period after a start of an engine and before it is determined to be the switching timing;
• and
• outputting the first manipulated variable to the variable valve timing mechanism in a period after it is determined to be the switching timing.

An apparatus of controlling of a variable valve timing mechanism that varies valve timing of an engine valve, comprising:

• target calculation means for calculating target valve timing;
• first calculation means for calculating a first manipulated variable based on the target valve timing;
• second calculation means for calculating a second manipulated variable by which a variation speed of valve timing is maximized;
• estimation means for estimating valve timing of when the second manipulated variable is output to the variable valve timing mechanism;
• determination means for determining timing at which the second manipulated variable is switched to the first manipulated variable based on a comparison of the estimated valve timing with the target valve timing;
• and
• operation means for outputting the second manipulated variable to the variable valve timing mechanism in a period after a start of an engine and before it is determined to be the switching timing, and outputting the first manipulated variable to the variable valve timing mechanism in a period after it is determined to be the switching timing.