Patent ID: 8229635

Claim:
A control device of an automatic transmission, including an automatic transmission having a clutch for transmitting a power from an engine to a gear change mechanism part, gear change control unit that controls a gear change of said automatic transmission, and a motor that changes a gear range of said automatic transmission based on a gear change command from said gear change control unit, the control device of an automatic transmission comprising: a gear change end determination unit that determines that a gear change of said automatic transmission is ended; a motor stop determination unit that determines that said motor is stopped; and a coil resistance estimation unit that estimates a coil resistance of said motor in which a state of application of a predetermined voltage to the motor during a stopped state before the start of the gear change and a state of no application thereof are alternately repeated at regular intervals, wherein in the case that the motor is determined to be stopped by said gear change end determination unit and said motor stop determination unit, during the stoppage of the motor before the start of a gear change, an initial value of a command voltage to be applied to said motor after the start of the gear change is corrected in a predetermined time period in accordance with a coil resistance value having been calculated by said coil resistance estimation unit.