| 摘要 |
PROBLEM TO BE SOLVED: To suppress the variation of the calculated value of the rotational speed of an engine when the rotational speed of the engine is calculated based on the output signal of a cam angle sensor if the crank angle sensor of the engine fails.SOLUTION: If the crank angle sensor 24 fails, a pseudo startup timing is generated by the output timing of a cam angle signal output from the cam angle sensor 27, and in a period from a time when a cam angle signal is output to a time immediately before a next cam angle signal is output, a pseudo startup timing is generated at time intervals obtained by equally dividing the time interval of the output timing of the cam angle signal which has been already. Though the rotational speed of the engine is calculated based on the cumulative value of the time intervals of the pseudo startup timing, the rotational speed of the engine can be calculated without being affected by the variation of the time intervals of the pseudo startup timing during the output of the cam angle signal by eliminating the time intervals of the pseudo startup timing during the output of the cam angle signal (time intervals between the pseudo startup timing during the output of the cam angle signal and the pseudo startup timing immediately before that pseudo startup timing). |
