| 摘要 |
A downshift control method for an automatic transmission, which transmission is normally downshifted, to increase a gear ratio, when a vehicle throttle is opened more than a preset value. The method includes a step of selecting a slip-determining threshold on the basis of an instantaneous steering angle of a vehicle. The method also includes steps of detecting a perceived rear wheel speed Vs, and averaging a number of rear wheel speeds Vs to derive an average vehicle speed Va. The normal downshift procedure is overridden, and the automatic transmission is prevented from downshifting, if a difference between the perceived rear wheel speed and the average vehicle speed exceeds the slip-determining threshold T, and the rear wheels are determined to be slipping. |
