| 摘要 |
<p>In a transition process from a gear ratio Gx in a speed change stage before speed change to a gear ratio in a target speed change stage, an actual speed change time is measured using, as speed-change starting, earlier one of a time point when the current gear ratio G decreases a specified number N of times continuously at a unit gear ratio of DELTA G or above and a time point when a first gear ratio G1 set lower by a specified value than the gear ratio Gx is reached. Start of speed change can be detected at time ts1 when the first gear ratio is reached for a quick variation of gear ratio and at time ts4 when the gear ratio decreases continuously for a slow variation of gear ratio. In any case, start of speed change is detected at an early time close to an actual speed change start time ts. Start of speed change can also be detected in an early state even during idling by starting speed change when a second gear ratio set higher by a specified value than the gear ratio Gx is reached. Speed change time is determined with high accuracy in a speed change time learning control for controlling the working oil pressure of an automatic transmission.</p> |
