Design of model reduction and robust controller for underwater echo cancellation

Abstract

This paper presents the design and development of a simple and robust control system for structural acoustics based on state space control theory. The controller was developed using model Hankel singular value (MHSV)-based model reduction, and analog controllers are fabricated. MHSV is developed for a model coordinate system describing vibrating structures, and analog controllers were designed from transfer functions of controllers, which have great advantage over digital controllers in terms of simplicity and cost. This controller design for structural acoustics is applied for controlling sound transmission and reflection. MHSV shows good model reduction of finite-element-based structure models. The feasibility of this controller for the underwater active reflection cancellation is also studied. 1-3 piezocomposite material is used as a transducer that generates the acoustic signal. Its electroacoustic model is developed using the Mason circuit and the control parameters are directly derived. The controller has been designed accordingly and its performance is evaluated using pulse tube. The simulation and measurement show the possibility of achieving a very good reflection reduction in a desired frequency band.