| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect cylinder internal pressure, by correcting a temperature drift of a pressure sensor. SOLUTION: Output of the pressure sensor 11 is amplified by a charge amplifier 28, and then, is inputted to a sensor output correcting part 29. A pyroelectric quantity calculating part 30 calculates a pyroelectric quantity PE per one degree of a crank angle, and eliminates an output drift of the pressure sensor 11 by correcting output of the charge amplifier 28. A set timing detecting part 31 discriminates an expected crank angle of an intake stroke on the basis of output of a crank angle sensor 17. When becoming the expected crank angle, the output of the charge amplifier 28 is reset to zero by outputting a reset signal. When inputting the reset signal, an output signal of the charge amplifier 28 just before inputting the reset signal, is held in a pyroelectric quantity calculating part 30 as a drift quantity in one cycle. The pyroelectric quantity calculating part 30 calculates the pyroelectric quantity PE per one angle of the crank angle by this drift, and supplies the pyroelectric quantity to the sensor output correcting part 29. COPYRIGHT: (C)2008,JPO&INPIT
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