Virtual reference feedback tuning using closed-loop step response data in frequency domain

The paper gives a controller tuning method using a Virtual Feedback Tuning (VRFT) approach in the frequency domain. While the original VRFT uses a data-driven performance index based on input/output data directly, the proposed one derives a frequency domain performance index based on the Fourier transformation of one-shot experimental input-output data. The frequency domain performance index makes the optimal pre-filter be straightforwardly designed without using the spectral density of the collected input signal. Hence, the proposed ones outperforms the original ones when the input and output data is collected from the closed loop step response. The effectiveness of the proposed method is illustrated through a numerical example.