Speed change control apparatus for automatic transmission

A speed change control apparatus for an automatic transmission configured to selectively switch between a plurality of speed change modes including an automatic speed change mode in which an automatic speed change is executed on a basis of a predetermined speed change characteristic and a manual speed change mode in which a manual speed change is executed on a basis of a shifting operation performed by a driver of a vehicle, the speed change control apparatus comprising:

• a shifting operation unit configured to receive the shifting operation performed by the driver while the manual speed change mode is being selected;
• a speed change controller configured to change a speed ratio of the automatic transmission on a basis of the shifting operation received by the shifting operation unit;
• a deceleration detector configured to detect a deceleration rate of the vehicle;
• an allowable revolution number setting unit configured to set high-speed downshift allowable revolution number on a basis of the deceleration rate of the vehicle in a case where the shifting operation unit receives the shifting operation that requests downshifting during deceleration of the vehicle, the high-speed downshift allowable revolution number comprising engine revolution number at which the downshifting is allowed to be executed during the deceleration of the vehicle;
• and
• a state transition determining unit configured to determine, on a basis of a driving state of the vehicle, whether the vehicle is making a transition from a deceleration state to an acceleration state, wherein
• the speed change controller is configured to
• execute the downshifting in a case where:
• the shifting operation unit receives the shifting operation that requests the downshifting during the deceleration of the vehicle;
• and the engine revolution number becomes equal to or smaller than the high-speed downshift allowable revolution number, and
• cancel the downshifting being executed in a case where the state transition determining unit determines that the transition from the deceleration state to the acceleration state is made during execution of the downshifting.

A speed change control apparatus for an automatic transmission configured to selectively switch between a plurality of speed change modes including an automatic speed change mode in which an automatic speed change is executed on a basis of a predetermined speed change characteristic and a manual speed change mode in which a manual speed change is executed on a basis of a shifting operation performed by a driver of a vehicle, the speed change control apparatus comprising:

• a shifting operation unit configured to receive the shifting operation performed by the driver while the manual speed change mode is being selected;
• a deceleration detector configured to detect a deceleration rate of the vehicle;
• and
• circuitry configured to
• change a speed ratio of the automatic transmission on a basis of the shifting operation received by the shifting operation unit,
• acquire a gradient of a road surface of a road on which the vehicle is traveling,
• set high-speed downshift allowable revolution number on a basis of the deceleration rate of the vehicle and the gradient of the road surface in a case where the shifting operation unit receives the shifting operation that requests downshifting during deceleration of the vehicle, the high-speed downshift allowable revolution number comprising engine revolution number at which the downshifting is allowed to be executed during the deceleration of the vehicle, and
• execute the downshifting in a case where:
• the shifting operation unit receives the shifting operation that requests the downshifting during the deceleration of the vehicle;
• and the engine revolution number becomes equal to or smaller than the high-speed downshift allowable revolution number.

A speed change control apparatus for an automatic transmission configured to selectively switch between a plurality of speed change modes including an automatic speed change mode in which an automatic speed change is executed on a basis of a predetermined speed change characteristic and a manual speed change mode in which a manual speed change is executed on a basis of a shifting operation performed by a driver of a vehicle, the speed change control apparatus comprising:

• a shifting operation unit configured to receive the shifting operation performed by the driver while the manual speed change mode is being selected;
• a deceleration detector configured to detect a deceleration rate of the vehicle;
• and
• circuitry configured to
• change a speed ratio of the automatic transmission on a basis of the shifting operation received by the shifting operation unit,
• set high-speed downshift allowable revolution number on a basis of the deceleration rate of the vehicle in a case where the shifting operation unit receives the shifting operation that requests downshifting during deceleration of the vehicle, the high-speed downshift allowable revolution number comprising engine revolution number at which the downshifting is allowed to be executed during the deceleration of the vehicle,
• determine, on a basis of a driving state of the vehicle, whether the vehicle is making a transition from a deceleration state to an acceleration state,
• execute the downshifting in a case where:
• the shifting operation unit receives the shifting operation that requests the downshifting during the deceleration of the vehicle;
• and the engine revolution number becomes equal to or smaller than the high-speed downshift allowable revolution number, and
• cancel the downshifting being executed in a case where it is determined that the transition from the deceleration state to the acceleration state is made during execution of the downshifting.