Generalised formulation of composite filters and their application to earthquake engineering test systems

Abstract

Summary This paper addresses the problem of generating unmeasured kinetic data—and/or providing improvements in existing data—for the enhancement of performance characteristics of earthquake engineering test systems, such as shaking tables, reaction walls and other custom‐made test rigs. The approach relies upon the use of composite filters (CF), a method of data fusion that was originally conceived via transfer function formulation. The current work generalises the CF concept and extends its formulation into the state‐space domain, thereby providing a wider basis for application to test systems and their controllers, including those of a multivariable (coupled, multi‐axis) nature. Comparative simulation studies of shaking table control are presented that demonstrate the design techniques for state‐space CF and also their effectiveness for signal synthesis, noise suppression and performance improvement. Specific examples include the use of CF for displacement demand signal generation, velocity feedback generation and acceleration control. In each case, the essential principles behind CF—output signals with zero bias and zero drift—are consistently upheld. Copyright © 2017 John Wiley & Sons, Ltd.

A Two-Loop Control Method for Shaking Table Tests Combining Model Reference Adaptive Control and Three-Variable Control

“…Enokida and Stoten (Stoten, 2017a) compared these schemes via test, with a prime focus on the effect of pure time delays. Later, Stoten (2017b) carried out a unification of two methods for controlling dynamically substructured systems. However, the frequency response characteristic of the shaking table system will change with change of payload, and the applicability of the aforementioned methods is limited without consideration being given to the specimen and variation of the payload.…”