This study presents Active Wheel Damper (AWD) unit which can be fixed on the flexible structures such as cantilever beam with ease. The AWD uses a gyro sensor to measure the absolute angular velocity due to the vibration of deflection of the structure directly, and can construct sky-hook control with no difficulty by direct feedback of the angular velocity. In this study, Sky-hook With Adaptive Disturbance Cancellation (SWADC) control, which is constructed as a combined control system of sky-hook control and adaptive disturbance cancellation control, is also proposed to enhance the performance of vibration suppression of AWD unit. Adaptive algorithm, which can estimate the frequency of the vibration of the structure in real-time, is derived based on adaptive notch filter algorithm, and estimated frequency is used for the model of disturbance observer which estimates harmonic disturbance. Performance of vibration suppression of the AWD is shown by simulation and experiment in this study.