Group Delay in Digital Filter Induced Instability of a Two-Dimensional Airfoil Active Flutter Suppression System

Abstract:

The presented paper deals with the group delay in the digital filter induced instability of a two dimensional airfoil section active flutter suppression system. Firstly, the aeroelastic model of the airfoil with an ultrasonic motor actuated control surface is set up; secondly, both H_∞ and μ robust controllers are designed; and then, the group delay induced instability in wind tunnel test is presented; finally, through a combined theoretical and numerical study, the test phenomenon is well explained. Wind tunnel experiments and numerical simulations demonstrate that long enough group delay in digital filter can induce instability of flutter control system, the flutter under control will decrease first, and then become another flutter of lower frequency and moderated amplitude, and μ controller works better than H_∞ controller on the same condition.

• Periodical: Applied Mechanics and Materials (Volumes 226-228)
• Pages: 64-69
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.226-228.64
• Online since: November 2012
• Authors: Ming Li Yu
• Keywords: Active Flutter Suppression, Digital-Filter, Group Delay, Stability, Time Delay

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