| 摘要 |
Disclosed is a shift control for an automatic transmission adapted to shift speed ranges by coupling or decoupling of the friction coupling elements (20-27) mounted on the transmission mechanism (10). The coupling force of the friction coupling elements (20-27) is subjected to feed-forward control during a preset period after a signal of instruction for shifting was given. A control value for the feed-forward control is determined in accordance with control value characteristics which vary from a given initial value at a constant change rate. After the preset period, coupling force of the friction coupling element is feedback controlled by actual revolutions of an input shaft (1) of the transmission mechanism (10). A final control value for the feedback control is determined by determining a target change rate in the feedback control by an amount of change in revolutions number of the input shaft (1) of the transmission mechanism (10) estimated by shifting and a set time for the feed-back control. With the target change rate, a target number of revolutions for each of plural control cycles obtainable by dividing the set time into portions is determined. For each of the control cycles, the final control value is determined by comparing the actual number of revolutions of the input shaft (1) and the target number of revolutions. |
