Decentralized control of sound radiation using a high-authority/low-authority control strategy with anisotropic actuators

This paper describes a combined control strategy designed to reduce sound radiation from stiffened aircraft‐style panels. In particular, the control approach uses robust active damping in addition to high‐authority LQG control. Active damping is achieved using direct velocity feedback with triangularly shaped strain actuators and point velocity sensors [P. Gardonio and S.J. Elliott, JASA 117(4), 2046‐2064 (2005)]. However unlike previous work, anisotropic actuators are used since they outperform traditional isotropic actuators in this application. While active damping is simple and robust, stability is guaranteed at the expense of performance. Therefore, this approach is often referred to as low‐authority control. In contrast, LQG control strategies can achieve substantial reductions in sound radiation. Unfortunately, the unmodeled interaction between neighboring control units can destabilize decentralized control systems. Numerical simulations show that combining active damping and decentralized LQG cont...