Patent ID: 8166843

Claim:
A shift transmission control device of a vehicle, comprising: a transmission configured to transmit a rotational drive force generated by a power source to a drive wheel at a predetermined change gear ratio; a clutch configured to connect and disconnect the power source and the drive wheel in order to and not to transmit the rotational drive force; a shift transmission controller configured to control the transmission and the clutch; a shift inhibition state detector configured to detect based on a running state of the vehicle that a predetermined shift inhibition condition is satisfied; a front wheel rotational speed sensor configured to detect a rotational speed of a front wheel of the vehicle; and a rear wheel rotational speed sensor configured to detect a rotational speed of a rear wheel of the vehicle, wherein the transmission is capable of providing a preliminary change gear ratio while the predetermined change gear ratio at which the rotational drive force is transmitted to the drive wheel is maintained, wherein the shift transmission controller is configured to control the transmission to inhibit a change of the predetermined change gear ratio at which the rotational drive force is transmitted to the drive wheel and to provide the preliminary change gear ratio in response to the running state of the vehicle when the shift inhibition condition is satisfied, and wherein the shift inhibition state detector is configured to determine that the shift inhibition condition is satisfied when at least one of a slip ratio of the front wheel and the rear wheel, rotational speed difference between the front wheel and the rear wheel, and deceleration of the front wheel and the rear wheel which are calculated based on detection values detected by the front wheel rotational speed sensor and the rear wheel rotational speed sensor becomes to be equal to or larger than a predetermined value.