| 摘要 |
<p>PURPOSE:To enhance the accuracy for measuring a flow rate by providing the upper limit or the lower limit on a correction value derived from a deviation of a first and a second arithmetic values, and correcting an output of a flow rate sensor. CONSTITUTION:An explanation is made with regard to a fuel injector of an engine. In a signal processor 9, by a value obtained by bringing an output voltage of an air flow rate sensor 1 to A/D conversion 91, the corresponding flow rate is derived, based on a flow rate characteristic measured in advance. Subsequently, when an interruption signal by a crank angle sensor 8 is inputted, an average air flow rate Q is calculated. Next, data to the flow rate Q at the time when the sensor 1 is in a stationary state is derived by referring to a table set in advance. Also, from a second arithmetic value and a first arithmetic value calculated by a processing routine, a correction factor C is derived. In such a case, when the factor C is larger than the prescribed upper limit value, the factor C is set to the upper limit value, and when the factor C is smaller than the lower limit value, the factor C is set to the lower limit value. In such a way, by multiplying the factor C by the flow rate Q, a substantial air flow rate is calculated.</p> |
