Adaptive Observers for Structural Health Monitoring of High-Rate, Time-Varying Dynamic Systems

Abstract

<p><p id="x-x-Par1">Safe and reliable operation of hypersonic aircraft, space structures, advanced weapon systems, and other high-rate dynamic systems depends on advances in state estimators and damage detection algorithms. High-rate dynamic systems have rapidly changing input forces, rate-dependent and time-varying structural parameters, and uncertainties in material and structural properties. While current structural health monitoring (SHM) techniques can assess damage on the order of seconds to minutes, complex high-rate structures require SHM methods that detect, locate, and quantify damage or changes in the structure’s configuration on the microsecond timescale. <p id="x-x-Par2">This paper discusses the importance of microsecond structural health monitoring (μSHM) and some of the challenges that occur in development and implementation. Two model-based parameter estimators are examined for estimating the states and parameters of an example time-varying system consisting of a two degree of freedom system with a sudden change in a stiffness value that simulates structural damage. The ability of these estimators to track this stiffness change, the role of measurement noise, and the need for persistent excitation are examined.</p>