# Mechanical Modeling of an Actuated Platform for Precision Pointing Control - Via Finite-element Analysis and Normal Mode Analysis

### Eric U. Diaz, Gerardo Zarate, Helen Boussalis, Khosrow Rad

#### Abstract

A large, segmented space telescope requires high precision and accuracy in its mirror shape to obtain clear images. The Structures, Propulsion, and Control Engineering (SPACE) telescope testbed at the NASA sponsored University Research Center of excellence must maintain a pointing control accuracy of 2 arc seconds. A Peripheral Pointing Architecture (PPA) has been designed to demonstrate the Testbed’s pointing accuracy. A Finite Element Analysis (FEA) model of the PPA is developed. Normal mode analysis is performed to establish the PPA’s natural frequencies, mode shapes, and the mass and stiffness matrices. Utilizing the H-infinity controllers developed to achieve figure maintenance, the pointing control of the Testbed structure is achieved.

#### References

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#### Paper Citation

#### in Harvard Style

U. Diaz E., Zarate G., Boussalis H. and Rad K. (2012). **Mechanical Modeling of an Actuated Platform for Precision Pointing Control - Via Finite-element Analysis and Normal Mode Analysis** . In *Proceedings of the 9th International Conference on Informatics in Control, Automation and Robotics - Volume 1: ICINCO,* ISBN 978-989-8565-21-1, pages 595-599. DOI: 10.5220/0004030305950599

#### in Bibtex Style

@conference{icinco12,

author={Eric U. Diaz and Gerardo Zarate and Helen Boussalis and Khosrow Rad},

title={Mechanical Modeling of an Actuated Platform for Precision Pointing Control - Via Finite-element Analysis and Normal Mode Analysis},

booktitle={Proceedings of the 9th International Conference on Informatics in Control, Automation and Robotics - Volume 1: ICINCO,},

year={2012},

pages={595-599},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0004030305950599},

isbn={978-989-8565-21-1},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the 9th International Conference on Informatics in Control, Automation and Robotics - Volume 1: ICINCO,

TI - Mechanical Modeling of an Actuated Platform for Precision Pointing Control - Via Finite-element Analysis and Normal Mode Analysis

SN - 978-989-8565-21-1

AU - U. Diaz E.

AU - Zarate G.

AU - Boussalis H.

AU - Rad K.

PY - 2012

SP - 595

EP - 599

DO - 10.5220/0004030305950599