Robust broadband control of acoustic duct

Robust controller design methodology is presented for broadband control of a 1D acoustic duct using passivity-based techniques. The controller design is shown to be robust to unmodeled dynamics and parametric uncertainties. A finite dimensional mathematical model is used as the design model. It is shown that the theoretical model agrees very well with the experimentally identified system model. The acoustic duct model being inherently non-passive, passification techniques are used to render the open-loop system passive. The control design methodology exploits inherent robustness of passivity-based controllers and selective mode attenuation capability of resonant mode controllers. The resulting controller is low-order, robust, broadband, easy to implement being output feedback, and has guaranteed stability.