| 摘要 |
<P>PROBLEM TO BE SOLVED: To secure stable operation of an actuator without making gas flow rate zero by stop of power supply to an actuator even if quantity of power supplied to the actuator of a valve element reaches an upper limit value in an exhaust gas recirculation control device. <P>SOLUTION: ECU divides a numerical value range which duty value can take into a permissible range and a nonpermissible range determined from a point of view of stable operation of the actuator, stores a first threshold value dividing the permissible range and the nonpermissible range, and limits duty value to a second threshold value and moves the same to the permissible range not to make gas flow rate zero when difference between a target valve position and an actual valve position gets to a predetermined value or less and duty value moves to the first threshold value or the nonpermissible range from the permissible range. Consequently, duty value changes mostly in the permissible range even if the same temporarily moves in the nonpermissible range. Thus stable operation of the actuator can be secured without making gas flow rate zero. <P>COPYRIGHT: (C)2007,JPO&INPIT |
