Modelling and control of suspensions as used in interferometric gravitational wave detectors

Palmer, David Andrew (2001) Modelling and control of suspensions as used in interferometric gravitational wave detectors. PhD thesis, University of Glasgow.

Abstract

In this thesis the bond graph modelling of multi-stage pendula is presented. The models are abstractions of the real physical pendula as used in the GEO 600 gravitational wave detector. In addition, Model Based Observers (MBO) for the control of these real physical pendula, are presented. The bond graph domain is utilised because it is an energy based methodology which facilitates the creation of unambiguous hierarchical models. This hierarchical property is fully exploited to produce a library of components which can be used to create complex multistage pendula in a modular fasshion. Included in these models are hierarchical wire models which can model forces due to linear extension, bending dynamics and transverse modes of vibration. Components have been validated against a real physical system and as such alternatively configured system models can be created with confidence. Bond graph pendulum models are incorporated in the design of Model Based Observer controllers. Model Based Observers are designed in the "physical domain" of bond graphs and as such provide an intuitive approach to controller design, and a unified approach to both system modelling and controller synthesis. As a case study, a Model Based Observer has been designed and successfully implemented on a real physical pendulum system. This controller damps the resonant motion of a real double pendulum. A more sophisticated Model Based Observer, incorporating a split feedback topology, which is designed to control the position of a multi-stage pendula has also been investigated.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Astrophysics.
• Colleges/Schools: College of Science and Engineering
• Supervisor's Name: Gawthrop, Professor Peter
• Date of Award: 2001
• Depositing User: Enlighten Team
• Unique ID: glathesis:2001-73236
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 01 Sep 2022 14:17
• Thesis DOI: 10.5525/gla.thesis.73236
• URI: https://theses.gla.ac.uk/id/eprint/73236