| 摘要 |
PROBLEM TO BE SOLVED: To reduce or suppress the occurrence of the overshoot or undershoot of a rail pressure when a vehicle operating state suddenly changes and to improve the stability and reliability of the rail pressure control.SOLUTION: An integral gain of an integration term for a PID control is corrected using an integration correction factor and the changed integral gain is used for the PID control. If a necessary passage flow rate that is a quantity of fuel necessary to pass through a high-pressure pump 7 is out of a prescribed appropriate range, or if the necessary passage flow rate is within the prescribed appropriate range and a change rate of the necessary passage flow rate per unit time is out of a prescribed change range, the integration correction factor is initialized in either case so as to forcibly stop the integration term from functioning. On the other hand, if the change rate of the necessary passage flow is within the prescribed change range, the integration correction factor is calculated on the basis of a preset correlation in response to an increase of the change rate to enable the integration term to function.SELECTED DRAWING: Figure 2 |
