Control apparatus for automatic transmission

1. An apparatus for controlling an automatic transmission configured to change speed of driving rotation of a power source mounted on a vehicle and transmit the speed of driving rotation to an output shaft of the transmission, comprising:

an up-shift instructing unit configured to be operated by a driver of the vehicle to output an up-shift command for a gear position of the transmission;

a down-shift instructing unit separated from the up-shift instructing unit and configured to be operated by the driver to output a down-shift command for the gear position of the transmission;

a mode switching unit configured to switch a gear-shift mode between an automatic gear-shift mode for automatically selecting the gear position based on a driving condition of the vehicle and a manual gear-shift mode for selecting the gear position based on an output of the up-shift instructing unit or the down-shift instructing unit; and

a mode maintaining unit configured to maintain the manual gear-shift mode for a predetermined time period when the up-shift instructing unit or the down-shift instructing unit is operated by the driver,

wherein the mode maintaining unit sets the predetermined time period when the up-shift instructing unit is operated, to be shorter than the predetermined time period when the down-shift instructing unit is operated, when the gear position is at or higher than a first gear position, and

the mode maintaining unit sets the predetermined time period when the up-shift instructing unit or the down-shift instructing unit is operated in a case that the gear position is at or higher than a second gear position higher than the first gear position, to be equal to or shorter than the predetermined time period when the up-shift instructing unit or the down-shift instructing unit is operated in the case that the gear position is at or higher than the first gear position and lower than the second gear position.

2. The apparatus according to claim 1 , wherein the mode maintaining unit sets the predetermined time period when the up-shift instructing unit or the down-shift instructing unit is operated in a case that the gear position is lower than the first gear position, to be equal to or shorter than the predetermined time period when the up-shift instructing unit or the down-shift instructing unit is operated in a case that the gear position is equal to or higher than the first gear position.

3. The apparatus according to claim 1 , wherein the mode maintaining unit changes the predetermined time period to be equal to or shorter than the predetermined time period set when the up-shift instructing unit or the down-shift instructing unit is operated by the driver for the first time in the manual gear-shift mode, when operation of the up-shift instructing unit or the down-shift instructing unit is repeated by the driver.

4. The apparatus according to claim 1 , further comprising:

a steering angle detecting unit configured to detect a steering angle of a steering wheel operated by the driver,

wherein the mode maintaining unit stops counting of the predetermined time period when the up-shift instructing unit or the down-shift instructing unit is operated while the steering angle detected by the steering angle detecting unit is equal to or greater than a predetermined value.

5. The apparatus according to claim 1 , wherein the up-shift instructing unit and the down-shift instructing unit are provided on a back surface of a steering wheel operated by the driver.

6. The apparatus according to claim 1 , further comprising:

an acceleration/deceleration demand outputting unit configured to output a demand for acceleration or deceleration of the vehicle based on an operation by the driver,

wherein the mode maintaining unit prohibits switching from the manual gear-shift mode to the automatic gear-shift mode by the mode switching unit when the demand for acceleration or deceleration is outputted by the acceleration/deceleration demand outputting unit.