| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an injection waveform arithmetic unit capable of highly accurately extracting an injection waveform of expressing a fuel pressure change caused by injection from an injection time sensor waveform detected by a fuel pressure sensor corresponding to an injection cylinder. <P>SOLUTION: One uninjected fuel pressure sensor is selected from uninjected time sensors existing in a plurality, an uninjected time sensor waveform output from the selected uninjected time sensor and an injection time sensor waveform output from an injection time sensor are detected in the same timing (a detection means), the detected uninjected time sensor waveform is corrected for an ignition timing advance so that a phase of its waveform advances in the ignition timing (an ignition timing advance correction means), the uninjected time sensor waveform corrected for the ignition timing advance is subtracted from the injection time sensor waveform, and the injection waveform of expressing the fuel pressure change caused by the injection in the injection cylinder is extracted (an injection waveform extraction means). The detection means selects the uninjected time sensor so that the fuel passage lengths La and Lb up to reaching the injection time sensor from the selected uninjected time sensor, become the same even when any of a plurality of cylinders becomes the injection cylinder. <P>COPYRIGHT: (C)2012,JPO&INPIT |
