This paper presents experimental results for the real-time adaptive identification and control of a flexible, slewing beam. A frequency domain identification algorithm incorporating non-parametric transfer function estimation and least squares parametric estimation is used to reconstruct an accurate parametric model of the system, capable of accurately tracking changing plant dynamics in real time. This model is subsequently used to produce an LQG compensator which actively damps beam vibration caused by rapid slewing manoeuvres with large payload changes. Non-persistent excitation is addressed in the context of identification during nominal motion. It is shown that after a short duration learning period, the proposed identification scheme will yield a model which is sufficiently accurate for controller synthesis.

1.
Balas, M. J., 1977, “Active Control of Flexible System,” Proc. Dynamics and Control of Large Flexible Spacecraft, Blacksburg, VA, June 13–15, pp. 217–236.
2.
Bayard
D. S.
,
Hadaegh
F. Y.
,
Scheid
R. E.
,
Mettler
E.
and
Milman
M. H.
,
1991
, “
Automated On-Orbit Frequency Domain Identification for large Space Structures
,”
Automatica
, Vol.
27
.
6
, pp.
931
946
.
3.
Chait
Y.
and
Radcliffe
C. J.
,
1989
, “
Control of Flexible Structures with Spillover Using an Augmented Observer
,”
Journal of Guidance, Control, and Dynamics
, Vol.
12
, No.
2
, Mar.-Apr., pp.
155
161
.
4.
Franklin, G. F., Powell, J. D., and Workman, M. L., 1990, Digital Control of Dynamic Systems, Addison-Wesley, U.S.A.
5.
Garcia
E.
, and
Inman
D. J.
,
1991
, “
Modeling of the Slewing Control of a Flexible Structure
,”
Journal of Guidance, Control, and Dynamics
, Vol.
14
, No.
4
, July-Aug., pp.
736
742
.
6.
Juang
Jer-Nan
and
Horta
L. G.
, and
Robertshaw
H.
,
1986
, “
A Slewing Control Experiment for Flexible Structures
,”
Journal of Guidance, Control, and Dynamics
, Vol.
9
, No.
5
, Sept.-Oct pp.
599
607
.
7.
Ljung, L., 1987, System Identification Theory for the User, Prentice-Hall, NJ.
8.
Milford, R. I., Asokanthan, S. F. and Gilmore, D. B., 1993, “Experimental On-Line Identification of an Elastic Robot Manipulator,” Journal of Electrical and Electronic Engineering Australia, No. 4, Dec., pp. 321–327.
9.
Rovner, D. M., 1990, “Experiments in Adaptive Control of a Very Flexible One Link Manipulator,” Department of Aeronautics and Astronautics, Stanford University, Ph.D. Thesis.
10.
Sanathanan, C. K., and Koerner, J., 1963, “Transfer Function Synthesis as a Ratio of Two Complex Polynomials,” IEEE Transactions on Automatic Control, Jan., pp. 56–58.
11.
Schmitz, E., 1985, “Experiments on the End-Point Position Control of a Very Flexible One-Link Manipulator,” Department of Aeronautics and Astronautics, Stanford University, Ph.D. Thesis.
12.
Smith, J. O., 1983, “Methods for System identification and Digital Filter Design with Application to the Violin,” Department of Electrical Engineering, Stanford University, pp. 50–60.
13.
Tzes
A. P.
, and
Yurkovich
S.
,
1990
, “
A Frequency Domain Identification Scheme for Flexible Structure Control
,”
ASME JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL
, Vol.
112
,
427
434
.
14.
Tzes
A. P.
, and
Yurkovich
,
1991
, “
Application and Comparison of On-Line Identification Methods for Flexible Manipulator Control
,”
The International Journal of Robotics Research
, Vol.
10
, No.
5
, Oct., pp.
515
527
.
15.
Widrow, B. and Stearns, S. D., 1991, “Adaptive Signal Processing,” Prentice-Hall, NJ.
16.
Widrow, B., Titchner, P. F., and Gooch, R. P., 1981, “Adaptive Design of Digital Filters,” Proc. IEEE Conf. Acoust., Speech, Signal Processing, pp. 243–246.
17.
Wong
E. C.
,
1986
, “
In-Flight Identification of the Galileo Spacecraft Flexible Mode Characteristics
,”
Journal of Guidance, Control, and Dynamics
, Vol.
9
, No.
1
, Jan-Feb., pp.
92
98
.
18.
Yurkovich
S.
and
Pacheco
F. E.
,
1989
, “
On Controller Tuning for a Flexible-Link Manipulator with Varying Payload
,”
Journal of Robotic Systems
, Vol.
6
, No.
3
, pp.
233
254
.
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