This paper will discuss the experimental evaluation of a structural control system designed using a combination of Frequency Weighted LQG and Maximum Entropy. The experimental implementation was performed on an experimental truss structure, the Sandia Truss, which is described in the paper. The control design model was obtained via experimental system identification using the eigensystem realization algorithm with data correlation. The control design used frequency weighting to stabilize the unstructured uncertainty of the system due to low signal-to-noise and uncertain system dynamics in various frequency ranges. Maximum entropy is used to provided robustness for structured uncertain system dynamics within the controller bandwidth. The experimental implementation of the controllers designed with this approach show the ability to design controllers with a specified bandwidth, gain stabilization of unstructured uncertainty, and robustness to structured uncertainty within the controller bandwidth.

Issue Section:
Technical Papers
Topics:
Control equipment, Design, Entropy, Trusses (Building), Uncertainty, Dynamics (Mechanics), Robustness, Uncertain systems, Algorithms, Control systems, Eigenvalues, Signal to noise ratio
1.
Allen, J. J., Lauffer, J. P., Marek, E. L., 1990, “The Sandia Structural Control Experiments,” Proceedings of the First Joint U.S./Japan Conference on Adaptive Structures, Maui, HI, Nov.
2.
Bendat, J. S., and Piersol, A. G., 1986, Random Data, Wiley-Interscience, New York.
3.
Bernstein
D. S.
, and
Greeley
S. W.
,
1986
, “
Robust Controller Synthesis Using the Maximum Entropy Design Equations
,”
IEEE Transactions on Automatic Control
, Vol.
AC-31
, Apr., pp.
362
–
364
.
4.
Collins, E. G., Jr., Phillips, D. J., and Hyland, D. C., 1991, “Robust Decentralized Control Laws for the ACES Structure,” IEEE Control Systems, Apr., pp. 62–70.
5.
Collins
E. G.
,
Davis
L. D.
,
Richter
S.
,
1994
, “
Homotopy Algorithms for Maximum Entropy Design
,”
Journal of Guidance, Control and Dynamics
, Vol.
17
, No.
2
, Mar.–Apr., pp.
311
–
321
.
6.
Collins
E. G.
,
King
I. A.
,
Phillips
D. J.
, and
Hyland
D. C.
,
1992
, “
High Performance, Accelerometer-Based Control of the Mini-MAST Structure
,”
Journal of Guidance, Control and Dynamics
, Vol.
15
, No.
4
, July–Aug., pp.
885
–
892
.
7.
Doyle
J. C.
, “
Guaranteed Margins for LQG regulators
,”
1978
,
IEEE Transactions on Automatic Control
, Vol.
AC-23
, No.
4
, Aug., pp.
756
–
757
.
8.
Gupta, N. K., 1980, “Frequency-Shaped Cost Functionals: Extension of Linear-Quadratic-Gaussian Design Methods,” J. Guidance, Control and Dynamics, Vol. 3, No. 6, Nov.–Dec.
9.
Hyland, D. C., Junkins, J. L., Longman, R. W., 1993, “Active Control Technology for Large Space Structures,” Journal of Guidance, Control and Dynamics, Vol. 16, No. 5, Sept.–Oct.
10.
Juang
J. N.
,
Cooper
J. E.
, and
Wright
J. R.
,
1988
, “
An Eigensystem Realization Algorithm Using Data Correlations (ERA/DC) for Modal Parameter Identification
,”
Journal of Control Theory and Advanced Technology
, Vol.
4
, No.
1
, Mar., pp.
5
–
14
.
11.
Juang, J. N., Horta, L. G., Phan, M. Lew, J. S. Chen, C. W., 1991, “Observer/System Realization Tool Box,” NASA Langley Research Center, Aug. 21.
12.
Maciejowski, J. M., 1989, Multivariable Feedback Design, Addison-Wesley.
13.
Moore, B., 1981, “Principal Component Analysis in Linear Systems: Controllability, Observability, and Model Reduction,” EEE Trans. Automat. Contr., AC-26, Feb.
14.
Opdenacker, Ph. C, et al., 1990, “Reduced-Order Compensator Design for a Flexible Structure,” J. Guidance and Control, Vol. 13, No. 1, Jan.–Feb.
15.
Rocklin, G., Crowley, J., Void, H., 1985, “A Comparison of H1, H2, and Hv Frequency Response Function,” Proceedings of the 3rd International Modal Analysis Conference, Orlando, Florida, Jan.
16.
Safonov
M. G.
,
1981
, “
Feedback Properties of Multivariable Systems: The Role and Use of the Return Difference Matrix
,”
IEEE Trans. Automat. Contr.
,
AC-26
, No.
1
, Feb., pp.
47
–
65
.
17.
Shih, C. Y., Tsuei, Y. G., Allemang, R. J., and Brown, D. I., 1989, “Complex Mode Indication Function and its Applications,” Proceedings of the 7th International Modal Analysis Conference, Las Vegas, Nevada, pp. 533–540.
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