To preliminarily estimate a natural vibration frequency of a vehicle during idle operation of the vehicle mounted with an internal combustion engine with a variable compression ratio mechanism that varies a mechanical compression ratio by relatively moving a cylinder block with respect to a crankcase to prevent the vehicle from causing resonance during idle operation.
The natural vibration frequency of the vehicle during the idle operation on this time is preliminarily calculated (step 106) based on a whole vehicle weight (step 102) and a spring constant (step 105) of the vehicle that is preset relative to a mechanical compression ratio during idle operation (step 104) which is estimated before the idling on this time, and an idle-rotation speed is controlled (step 109) for the idle operation on this time so as not to fall within a resonance rotation speed range (step 107) that causes resonance relative to the calculated natural vibration frequency.
NAKASAKA YUKIHIRO
KAWASAKI TAKASHI
| JP2009114964A | 2009-05-28 | |||
| JP2010247727A | 2010-11-04 | |||
| JP2009215958A | 2009-09-24 |
Jun Tsuruta
Tetsuro Shimada
Shinji Mitsuhashi
Koichi Ito
Tatsuki Sone