Online frequency estimation with applications to engine and generator sets

Manngård, Mikael; Böling, Jari M.

doi:10.1016/j.ymssp.2016.12.043

Cited by 5 publications

(7 citation statements)

References 29 publications

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“…For a sequence {x(n)}n=0 n=N-1, Fourier transform can be stated as follows (Manngård and Böling, 2017) where X k is called k th DFT coefficient as follows …”

Section: External Frequency Estimationmentioning

confidence: 99%

“…This Fourier coefficient provides information about frequency ωk=2πkN for k = 0,…, N−1. The amplitude A k and phase ϕk for frequency ωk are as follows (Manngård and Böling, 2017) …”

Section: External Frequency Estimationmentioning

confidence: 99%

“…DFT coefficients are given by X k = y k (N). The following steps are used to find the DFT coefficients (Manngård and Böling, 2017) Compute θk(n),forn=0,1,…,N-1 Compute Xk=ei2πkNθk(N-1)-θk(N-2) …”

Section: External Frequency Estimationmentioning

confidence: 99%

“…To rectify this problem, a windowing operation is required. By considering Hanning and Hamming windows as follows, the leakage can be rectified (Manngård and Böling, 2017) …”

Section: External Frequency Estimationmentioning

confidence: 99%

“…There is no need to calculate all the DFT coefficients. Selective estimations of DFT coefficients can be efficiently done using the Goertzel filter (GF) (Manngård and Böling, 2017). However, finding the frequency by using the GF is more computationally demanding as compared to ANF for the online case.…”

Section: Introductionmentioning

confidence: 99%

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Adaptive hybrid control of unbalanced vibrations of a rotor/active magnetic bearing system with coupling misalignment using low cost instrumentation

Vashisht

Peng

2019

Journal of Vibration and Control

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An adaptive hybrid controller is proposed for reducing the unbalanced vibration response of a flexible rotor/active magnetic bearing system. It is observed that conventional adaptive feedforward controller (AFFC) normally used in the active noise control is very sensitive in performance for changes in rotor spin frequencies. Although frequency updating is a part of its architecture, a small practical variation in the rotor spin frequency can reduce its effectiveness drastically. A smart combination of adaptive notch filter and Goertzel filter is proposed for the frequency estimation. During changes of the rotor spin frequency, fundamental harmonics of the flexible rotor are excited. By using hybrid controllers that combine feedback control and AFFC, the amplitude of these fundamental harmonics is reduced significantly. By applying the multi-harmonic hybrid control, the multiple harmonics generated due to coupling misalignment are compensated efficiently. Fourier transform of the control signal is further used to detect the presence of the coupling misalignment.

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“…For a sequence {x(n)}n=0 n=N-1, Fourier transform can be stated as follows (Manngård and Böling, 2017) where X k is called k th DFT coefficient as follows …”

Section: External Frequency Estimationmentioning

confidence: 99%

Section: External Frequency Estimationmentioning

confidence: 99%

Section: External Frequency Estimationmentioning

confidence: 99%

“…To rectify this problem, a windowing operation is required. By considering Hanning and Hamming windows as follows, the leakage can be rectified (Manngård and Böling, 2017) …”

Section: External Frequency Estimationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations