Fractional-Order Negative Position Feedback for Vibration Attenuation

In this paper, a fractional-order extension of a negative position feedback (NPF) controller for active damping is proposed. The design of the controller is motivated by the frequency-domain loop shaping analysis, and the controller dynamics are defined to maintain the high-pass characteristics of an integer-order NPF. The proposed controller provides greater attenuation of a resonance peak of a flexible plant than the integer order equivalent with the same high-frequency gain. The stability and influence of tuning parameters on the behaviour of the proposed controller are analysed. The efficiency and feasibility of the fractional-order controller are demonstrated by implementing it on an experimental setup.