Core Concepts
Efficient model order reduction techniques are used to create reduced-order structural models of large adaptive mirrors, enabling high-fidelity simulations of the full adaptive mirror system with reasonable computational resources.
Abstract
The paper presents a framework for performing high-fidelity adaptive mirror simulations using reduced-order structural models. The key points are:
The physical modeling of the adaptive mirror system involves a multiphysics description, including the deformable mirror, reference structure, air gap, actuators, and supporting structure.
The structural dynamics of the system are described using high-order finite element models, which are computationally expensive to simulate directly.
Model order reduction techniques are applied in two steps:
First, modal truncation is used to reduce the model to a predefined frequency range of interest.
Second, advanced model reduction methods such as balanced truncation, rational Krylov subspace methods, and the Loewner framework are used to further reduce the model size.
The reduced-order structural models are then combined with the remaining system components (fluid dynamics, control system) to enable efficient simulation of the full adaptive mirror system.
The framework is validated through numerical simulations of the GMT P72 prototype adaptive mirror, comparing the performance of different model reduction methods.
The reduced-order models preserve key system properties such as stability and input-output behavior, enabling high-fidelity simulations with reasonable computational resources.
Stats
The GMT P72 prototype adaptive mirror has 72 actuators and a diameter of 354 mm.
The finite element model of the GMT P72 has a state matrix of dimension 1672 × 1672.
Quotes
"The capability to perform the simulations with an acceptable amount of time and computational resources is highly dependent on finding appropriate methods to reduce the size of the resulting dynamic models."
"The reduced dynamic model is then combined with the remaining system components allowing to simulate the full adaptive mirror in a computationally efficient way."