Patent ID: 7856305

Claim:
A control system for an internal combustion engine, comprising: an accelerator operation amount sensor that measures an operation amount of an accelerator, target throttle opening calculating means for calculating a target value of a throttle opening in accordance with the accelerator operation amount, a sudden operation detector that detects a sudden operation of the accelerator, an operating condition detector that detects at least one operating condition of the vehicle, and a throttle controller that sets a corrected target value obtained by correcting the target value in accordance with the at least one operating condition of the vehicle as an initial value when a sudden operation of the accelerator is detected, and gradually changing the throttle opening from the corrected target value as the initial value to the target value, wherein the throttle controller: measures or estimates an actual pressure in a surge tank, and measures or estimates a cylinder intake mass airflow as an amount of air drawn from the surge tank into cylinders of the engine; calculates a target pressure change in the surge tank according to the target value of the throttle opening, on the basis of the measured or estimated actual surge tank pressure and the cylinder intake mass airflow, using a relationship between the throttle opening and a pressure change in the surge tank in a virtual intake system model having a virtual surge tank volume, and sets the virtual surge tank volume in accordance with the at least one operating condition of the vehicle, wherein, upon detection of a sudden operation of the accelerator, the throttle controller controls the throttle opening in accordance with the measured or estimated surge tank pressure and the cylinder intake mass airflow, so as to provide the target pressure change in the surge tank under a condition of an actual volume of the surge tank, thereby to gradually change the throttle opening from the initial value determined depending on the virtual surge tank volume to the target value.