Artificial Damping for Spacecraft Structures Based on LQG Controller and Kalman Observer
- Paper number
IAC-05-C2.2.04
- Author
Dr. Anton Grillenbeck, Industrieanlagen-Betriebsgesellschaft mbH (IABG), Germany
- Coauthor
Dr. Ahmed Abou-El-Ela, Industrieanlagen-Betriebsgesellschaft mbH (IABG), Germany
- Coauthor
Mr. Mark Wagner, Industrieanlagen-Betriebsgesellschaft mbH (IABG), Germany
- Year
2005
- Abstract
An active damping based on piezo-active elements in combination with an LQG controller and a Kalman observer was applied to a spacecraft representative truss testbed. This paper reports on the design, the simulation and the hardware implementation of such a control strategy. Finally, a verifying experiment was performed which demonstrated the ability of such an approach to achieve considerable vibration suppression in a predefined frequency bandwidth. The basic requirement to this investigation was to use standard, off the shelf controller hard- and software components. As spacecraft representative testbed, a truss structure of the size 1.5 m x 2.8 m x 2 m was used. This non-symmetric structure had a non-uniform mass distribution and was equipped with appendages simulating platforms for scientific payloads. The main modes of vibration of this testbed were in the frequency bandwith of 20 Hz to 70 Hz. The main objective of the designed control strategy was to suppress the major modes of one selected payload appendage with respect to any (unkown) excitation. Therefore, one platform interface was equipped with four piezoelectric-actuators. The Kalman observer was based on a modal model which was extracted from an experimentally verified and updated finite element model. The LQG controller was designed and simulated using the MatLab / Simulink software. The final implementation was done by using a common dSpace controller hard- and software package. Finally, the control strategy was realized on the testbed. Six input channels and twelve additional channels to observe the structural behaviour and four output channels to drive the piezo- actuators were used. This setup enabled the LQG controller to achieve active vibration suppression in the frequency range of 20 Hz to 70 Hz. Besides that this investigation has shown the feasibility of such a controller design to considerably increase the structural damping, the main benefit was to realise a practicable and straight-forward process to develop a complex control system for an active vibration suppression. This process easily may be adapted to further applications in the field of active damping and vibration suppression.
- Abstract document
- Manuscript document
IAC-05-C2.2.04.pdf (🔒 authorized access only).
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