Determination device and determination method

A determination device configured to determine damage imparted to a synchronization device, in a power transmission system including:

• a clutch device configured to switch between a connection state in which power from a driving force source is transmitted and a disconnection state in which power transmission is interrupted;
• and a transmission configured to transmit, by gear shifting at a predetermined gear ratio, power from the clutch device to a driving wheel by synchronously coupling a transmission gear to a shaft by the synchronization device, the determination device comprising:
• a synchronization start determination unit configured to determine synchronization start of the synchronization device;
• a half-clutch determination unit configured to determine whether the clutch device is in a half-clutch state in which the clutch device is not switched from the connection state to the disconnection state;
• and
• a damage determination unit configured to determine that damage due to differential rotation between power transmitted from the driving force source via the clutch device and power transmitted from the driving wheel is imparted to the synchronization device when the synchronization start determination unit determines the synchronization start and the half-clutch determination unit determines that the clutch device is in the half-clutch state.