Active Control of Rotor Vibrations by Two Feedforward Control Algorithms

Kari Tammi (Corresponding Author)

    Research output: Contribution to journalArticleScientificpeer-review

    13 Citations (Scopus)


    Resonance vibrations (critical speeds) play a significant role in rotor vibration control. Active vibration control methods for rotors are studied to develop solutions to enhance machines’ dynamic behavior, durability, and operating range. This paper reports rotor vibration attenuation with a supplementary electromagnetic actuator located outside the rotor bearing span. Feedback and feedforward control system design are shown, and comparative experiments on two active vibration control methods for mass unbalance compensation are reported. The methods compared are adaptive FIR filter with the least mean squares (LMS) algorithm and convergent control (CC) method with a frequency-domain adaptation algorithm. The methods were experimentally validated on the rotor test rig (rotor weight 2.7 kg, length 560 mm, and first critical speed about 50 Hz). The feedback system provided wideband damping in the sub- and supercritical regions. The feedforward systems attenuated vibratory responses at the speed of rotation and its harmonic. The attenuation achieved was about 20 dB depending on the rotor speed. Also, discrete-time CC algorithm is shown to have a feedback equivalent circuit. The significance of feedback control lies in making the system phase-characteristics sufficiently smooth for feedforward control methods. Then, feedforward algorithms provided a good vibration damping performance over the operating range. CC was found to be a more effective and simpler algorithm for the purpose than the adaptive FIR filter with the LMS algorithm. The equivalent feedback circuit derived for CC, and systems similar to CC, facilitates their stability and robustness analysis.
    Original languageEnglish
    Number of pages10
    JournalJournal of Dynamic Systems, Measurement and Control
    Issue number5
    Publication statusPublished - 2009
    MoE publication typeA1 Journal article-refereed


    • adaptive control
    • compensation
    • control system synthesis
    • damping
    • durability
    • electromagnetic actuators
    • feedforward
    • FIR filters
    • frequency-domain analysis
    • machine bearings
    • resonance
    • rotors
    • vibration control


    Dive into the research topics of 'Active Control of Rotor Vibrations by Two Feedforward Control Algorithms'. Together they form a unique fingerprint.

    Cite this