Methodology for Real-time State Estimation at Unobserved Locations for Structures Experiencing High-rate Dynamics

Abstract

Real-time monitoring, condition assessment, and control of structural systems that experience high-rate dynamics are challenging due to these structures operating at timescales below 10ms. Examples of structures that may experience high-rate dynamics include hypersonic vehicles, space crafts, and barriers with active blast mitigation. The realtime monitoring systems used on these structures could greatly benefit from a robust and effective high-rate state estimation methodology that would enable the state of the structure at any unobserved location to be estimated. Any methodology designed for these high-rate systems must account for the challenges associated with data measurement and processing at the considered timescale. This work presents and experimentally validates a methodology for enabling the real-time state estimation at unmonitored locations on a dynamic system that undergoes system level changes (i.e. damage). In this work, the DROPBEAR experimental test bed at the Air Force Research Laboratory is used to validate the proposed methodology for a one-degree-of-freedom system excited with an impact load where a system level change is realized through the dropping of a magnetically attached mass during testing. Results show that the proposed methodology is capable of accurately estimating the levels of acceleration experienced at two unobserved locations in real-time both before and after the mass is detached. A time interval between state estimations of 7.1 ms was achieved during testing.