| 摘要 |
PURPOSE:To prevent output loss by computing an upper limit value of octane estimation value on the basis of an operational state, determining a final estimation value according to an estimation value when the estimation value is smaller than an upper limit value and according to an upper limit value when it is larger and thus computing an ignition timing correction quantity and so determining a final ignition timing. CONSTITUTION:When knocking occurs an octane estimation value KRO is compared with an octane value estimation learning value KRREF. When thus an estimation value exceeds a learning value, a learning value is taken as an estimation value. Then, an estimation learning value and an upper limit value KRMBT by obtained MBT are compared. When a learning value is smaller than an upper limit value, an estimation value is compared with an estimation learning value. Then, when an estimation value is larger than a learning value, a learning value is taken as an estimation final value. When an estimation value is smaller than a learning value, an estimation value is taken as a final value. When a learning value is larger than an upper limit value, an estimation value is compared with an upper limit value. When it is thus larger, an upper limit value is taken as estimation final value. The treatment so far, becomes equivalent to the ignition timing exceeding MBT in angle advance direction, so that unnecessary engine output loss can be evaded. |
