A control apparatus for a vehicle automatic transmission includes a downshift determining unit that determines whether downshift of a gear shift stage is to be performed based on at least one of a history of lateral accelerations and a history of variations of a vehicle speed. A lateral acceleration history acquiring unit or a vehicle speed variation history acquiring unit returns at least one of the history of the lateral accelerations and the history of the variations of the vehicle speed to an initial value when a shift control mode determined by a shift control mode determining unit is switched. At least one of the initial value of the history of the lateral accelerations and the initial value of the history of the variations of the vehicle speed is a value that is set for each shift control mode determined by the shift control mode determining unit.

A control apparatus for a vehicle automatic transmission includes a downshift determining unit that determines whether downshift of a gear shift stage is to be performed based on at least one of a history of lateral accelerations and a history of variations of a vehicle speed. A lateral acceleration history acquiring unit or a vehicle speed variation history acquiring unit returns at least one of the history of the lateral accelerations and the history of the variations of the vehicle speed to an initial value when a shift control mode determined by a shift control mode determining unit is switched. At least one of the initial value of the history of the lateral accelerations and the initial value of the history of the variations of the vehicle speed is a value that is set for each shift control mode determined by the shift control mode determining unit.

A method for training an automatic gear unit of a two-wheeled vehicle and/or a device, as well as a two-wheeled vehicle having such a device modifies an existing characteristic map for the control of the gear unit based on the individual user information. Optionally, it is also possible to set up a characteristic map for the control of the gear unit with the aid of the method in that the user information is recorded during gear-change operations and utilized for further automatic gear-change operations.

A vehicle transmission control apparatus including a manual shift instructing portion outputting a manual shift instruction for upshifting or downshifting a transmission, and an electric control unit including a microprocessor and a memory to control a shift operation. The microprocessor controls the shift operation in accordance with a first shift chart stored in the memory based on vehicle information before the manual shift instruction is output, controls the shift operation in accordance with the manual shift instruction when the manual shift instruction is output, and controls the shift operation in accordance with a second shift chart stored in the memory based on the vehicle information when a predetermined mode switch condition is established after the manual shift instruction is output.

A differential assembly with at least a first gear ratio and a second gear ratio that can be integrated with an automatic transmission system thereby increasing the total number of available gear ratios is presented. A method of shifting to improve engine efficiency is also provided.

A control apparatus for a vehicle automatic transmission includes a downshift determining unit that determines whether downshift of a gear shift stage is to be performed based on at least one of a history of lateral accelerations and a history of variations of a vehicle speed. A lateral acceleration history acquiring unit or a vehicle speed variation history acquiring unit returns at least one of the history of the lateral accelerations and the history of the variations of the vehicle speed to an initial value when a shift control mode determined by a shift control mode determining unit is switched. At least one of the initial value of the history of the lateral accelerations and the initial value of the history of the variations of the vehicle speed is a value that is set for each shift control mode determined by the shift control mode determining unit.

A control apparatus for a vehicle automatic transmission includes a downshift determining unit that determines whether downshift of a gear shift stage is to be performed based on at least one of a history of lateral accelerations and a history of variations of a vehicle speed. A lateral acceleration history acquiring unit or a vehicle speed variation history acquiring unit returns at least one of the history of the lateral accelerations and the history of the variations of the vehicle speed to an initial value when a shift control mode determined by a shift control mode determining unit is switched. At least one of the initial value of the history of the lateral accelerations and the initial value of the history of the variations of the vehicle speed is a value that is set for each shift control mode determined by the shift control mode determining unit.