We present an observer for parameter estimation in nonlinear oscillating systems (periodic, quasiperiodic or chaotic). The observer requires measurements of generalized displacements. It estimates generalized velocities on a fast time scale and unknown parameters on a slow time scale, with time scale separation specified by a small parameter ε. Parameter estimates converge asymptotically like eεt where t is time, provided the data is such that a certain averaged coefficient matrix is positive definite. The method is robust: small model errors and noise cause small estimation errors. The effects of zero mean, high frequency noise can be reduced by faster sampling. Several numerical examples show the effectiveness of the method.

1.
Chatterjee, A., and Cusumano, J. P., 1999, “Parameter Estimation in a Nonlinear Vibrating System Using an Observer for an Extended System,” ASME Paper No. DETC99/VIB-8067 (available on CDROM).
2.
Bard, Y., 1974, Nonlinear Parameter Estimation, Academic Press, Orlando, FL.
3.
Jezequel, L., and Lamarque, C. H., (eds), 1992, Euromech 280, Proc. of Int. Symp. on Identification of Nonlinear Mechanical Systems from Dynamic Tests, Ecully, France, 1991, A. A. Balkema, Rotterdam, Netherlands.
4.
Srinath, M. D., Rajasekaran, P. K., and Viswanathan, R., 1996, Introduction to Statistical Signal Processing With Applications, Prentice-Hall, NJ (Indian Reprint published by Prentice-Hall of India, New Delhi, 1999).
5.
Masri
,
S. F.
, and
Caughey
,
T. K.
,
1979
, “
A Nonparametric Identification Technique for Nonlinear Dynamic Problems
,”
ASME J. Appl. Mech.
,
46
, pp.
433
447
.
6.
Masri
,
S. F.
,
Miller
,
R. K.
,
Saud
,
A. F.
, and
Caughey
,
T. K.
,
1987
, “
Identification of Nonlinear Vibrating Structures: Part I-Formulation
,”
ASME J. Appl. Mech.
,
54
, pp.
918
922
.
7.
Masri
,
S. F.
,
Miller
,
R. K.
,
Saud
,
A. F.
, and
Caughey
,
T. K.
,
1987
, “
Identification of Nonlinear Vibrating Structures: Part II-Applications
,”
ASME J. Appl. Mech.
,
54
, pp.
923
929
.
8.
Mohammad
,
K. S.
,
Worden
,
K.
, and
Tomlinson
,
G. R.
,
1992
, “
Direct Parameter Estimation for Linear and Non-Linear Structures
,”
J. Sound Vib.
,
152
(
3
), pp.
471
499
.
9.
Feeny, B. F., and Yuan, C. M., 1999, “Parametric Identification of an Experimental Two-Well Oscillator,” Proc. of 1999 ASME Design Engineering and Technical Conf., Las Vegas, Nevada, ASME Paper, No. DETC99/VIB-8361.
10.
Tadi
,
M.
, and
Rabitz
,
H.
,
1997
, “
Explicit Method for Parameter Identification
,”
J. Guid. Control Dyn.
,
20
(
3
), pp.
486
491
.
11.
Mook
,
D. J.
,
1989
, “
Estimation and Identification of Nonlinear Dynamic Systems
,”
AIAA J.
,
27
(
7
), pp.
968
974
.
12.
Yasuda
,
K.
, and
Kamiya
,
K.
,
1999
, “
Experimental Identification Technique of Nonlinear Beams in Time Domain.
Nonlinear Dyn.
,
18
, pp.
185
202
.
13.
Eykhoff, P., 1974, System Identification: Parameter and State Estimation, John Wiley & Sons, London, (Reprinted 1977.) Chap. 13.
14.
Rajamani
,
R.
, and
Cho
,
Y. M.
,
1998
, “
Existence and Design of Observers for Nonlinear Systems: Relation to Distance to Unobservability
,”
Int. J. Control
,
69
(
5
), pp.
717
731
.
15.
Chang
,
P. H.
,
Lee
,
J. W.
, and
Park
,
S. H.
,
1997
, “
Time Delay Observer: A Robust Observer for Nonlinear Plants
,”
ASME J. Dyn. Syst., Meas., Control
,
119
, pp.
521
527
.
16.
Bernard
,
O.
,
Sallet
,
G.
, and
Sciandra
,
A.
,
1998
, “
Nonlinear Observers for a Class of Biological Systems: Application to Validation of a Phytoplanktonic Growth Model
,”
IEEE Trans. Autom. Control
,
43
(
8
), pp.
1056
1065
.
17.
Farza
,
M.
,
Busawon
,
K.
, and
Hammouri
,
H.
,
1998
, “
Simple Nonlinear Observers for On-line Estimation of Kinetic Rates in Bioreactors
,”
Automatica
,
34
(
3
), pp.
301
318
.
18.
Maybhate
,
A.
, and
Amritkar
,
R. E.
,
2000
, “
Dynamics Algorithm for Parameter Estimation and its Applications
,”
Phys. Rev. E
,
61
(
6
), pp.
6461
6470
.
19.
Ahmed
,
J.
,
Coppola
,
V. T.
, and
Bernstein
,
D. S.
,
1998
, “
Adaptive Asymptotic Tracking of Spacecraft Attitude Motion With Inertia Matrix Identification.
J. Guid. Control Dyn.
,
21
(
5
), pp.
684
691
.
20.
Sanders, J. A., and Verhulst, F., 1985, Averaging Methods in Nonlinear Dynamical Systems, Applied Mathematical Sciences 59, Springer-Verlag, New York.
21.
Golub, G. H., and Van Loan, C. F., 1989, Matrix Computations, Second Edition, John Hopkins University Press, Baltimore, MD.
22.
Press, W. H., Flannery, B. P., Teukolsky, S. A., and Vetterling, W. T., 1986, Numerical Recipes: The Art of Scientific Computing, Cambridge University Press, Cambridge.
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