Control apparatus and control method of engine

A control apparatus of an engine comprising:

• throttle valve control means for controlling an opening degree of a throttle valve;
• target torque calculating means for calculating a target engine torque using an operation amount of an accelerator;
• first opening area calculating means for converting said target engine torque into a first opening area of said throttle valve;
• idling required air amount calculating means for calculating a required air amount at the time of idling;
• second opening area calculating means for converting said required air amount into a second opening area of said throttle valve;
• total opening area calculating means for adding said first opening area of said throttle valve and said second opening area of said throttle valve to calculate a target total opening area of said throttle valve;
• target opening degree calculating means for calculating a target opening degree of said throttle valve in correspondence to said target total opening area;
• and
• output means for outputting said target opening degree to said throttle valve control means;
• wherein said second opening area calculating means converts said required air amount into said second opening area of said throttle valve in a sonic region.

A control method of an engine comprising:

• calculating a target engine torque using an operation amount of an accelerator;
• converting said target engine torque into a first opening area of a throttle valve;
• calculating a required air amount at the time of idling;
• converting said required air amount into a second opening area of said throttle valve;
• calculating a target total opening area of said throttle valve by adding said first opening area of said throttle valve and said second opening area of said throttle valve;
• calculating a target opening degree of said throttle valve in correspondence to said target total opening area;
• and
• controlling said throttle valve based on said target opening degree of said throttle valve;
• wherein said first opening area of said throttle valve is obtained by calculating a reference intake amount ratio corresponding to said target engine torque, calculating a normalized opening area corresponding to said reference intake amount ratio, and multiplying said normalized opening area by an engine speed and an exhaust amount.