| 摘要 |
PURPOSE: To attain a downshift by high quality closed throttle by monitoring input speed and output speed so as to balance the application of an on-operation clutch and the release of an off-operation clutch, in an electronic control system. CONSTITUTION: A clutch/clutch closed throttle/downshift is controlled by filling an on-operation clutch at a maximum pressure command for a prescribed period, commanding off-operation clutch pressure to a low value and releasing off- operation before the end of a filling period. When the filling period is expired, on-operation pressure is set to an initial value, and next, on-operation pressure is ramped up till turbine speed is stopped due to slippage of the on-operation clutch. Next, a closed loop/profile control period is started and slippage of the on-operation clutch is controlled. When synchronization of the on-operation clutch is detected, maximum pressure is commanded. If the off-operation still has pressure when a throttle is opened during the downshift, the state is returned to a calculation of a powered downshift. If the off-operation clutch is released, the state is returned to a closed loop/ramp control of the on-operation clutch. |
