A method for calculating a degradation degree of a damper clutch of an automatic transmission of a vehicle includes: filtering, by a controller, a vibration signal of the vehicle according to driving of the vehicle in order to remove a vibration signal of the vehicle corresponding to a natural frequency of an engine of the vehicle from the vibration signal of the vehicle according to the driving of the vehicle; converting, by the controller, the filtered vibration signal into a signal including a sinusoidal wave having a natural frequency of the automatic transmission based on a gear stage of the automatic transmission of the vehicle by using a frequency analysis method; and calculating, by the controller, a degradation degree of the damper clutch included in a torque converter of the automatic transmission based on a magnitude of the sinusoidal wave having the natural frequency of the automatic transmission.

A hybrid vehicle control device has: a determining portion determining, during idle engine operation, whether a meshing state is achieved in which the lock member is meshed with the parking gear, or a non-meshing state is achieved in which the lock member is not meshed with the parking gear; and a control portion providing a control of applying the running electric motor torque to the rotary member to eliminate a gap in a meshing portion between gears in the power transmission system and a gap in a meshing portion between the parking gear and the lock member when it is determined that the meshing state is achieved, and providing a control of applying a torque of the differential electric motor to the rotary member to eliminate a gap in the meshing portion between gears in the power transmission system when it is determined that the non-meshing state is achieved.

A hybrid vehicle control device has: a determining portion determining, during idle engine operation, whether a meshing state is achieved in which the lock member is meshed with the parking gear, or a non-meshing state is achieved in which the lock member is not meshed with the parking gear; and a control portion providing a control of applying the running electric motor torque to the rotary member to eliminate a gap in a meshing portion between gears in the power transmission system and a gap in a meshing portion between the parking gear and the lock member when it is determined that the meshing state is achieved, and providing a control of applying a torque of the differential electric motor to the rotary member to eliminate a gap in the meshing portion between gears in the power transmission system when it is determined that the non-meshing state is achieved.