This paper proposes the adaptive parallel observer system (APOS), a multirate estimation technique for discrete time systems, to compensate for output measurements that are available only periodically and for systems whose frequency content is beyond that of the Nyquist frequency. The APOS provides the controller with stable state and system parameter estimates, which allow for the extraction of the system damping ratio and resonant frequency despite the presence of aliasing. A stability proof and error bounds are provided. The APOS is applied to the actuator dynamics of an IBM Head/Disk Assembly (HDA) System, and the APOS parameter estimates are used to extract values of the system damping ratio and aliased resonant frequency via a trained neural network.

Issue Section:
Technical Papers
Keywords:
observers, parameter estimation, discrete time systems, multivariable systems, Nyquist stability, adaptive systems
Topics:
Damping, Discrete time systems, Disks, Errors, Manufacturing, Resonance, Stability, Uncertainty, Artificial neural networks, Dynamics (Mechanics), Actuators
1.
Lu
,
W.
, and
Fisher
,
D. G.
,
1992
, “
Multirate Adaptive Inferential Estimation
,”
IEE Proc.-D: Control Theory Appl.
,
139
, pp.
181
–
189
.
2.
Ramachandran, P., Young, G. E., and Misawa, E. A., 1996, “Intersample Output Estimation With Multirate Sampling,” in Proceedings of the IEEE Conference on Control Applications, pp. 576–581.
3.
Kando
,
H.
,
Aoyama
,
T.
, and
Iwazumi
,
T.
,
1989
, “
Multirate Observer Design via Singular Perturbation Theory
,”
Int. J. Control
,
50
, pp.
2005
–
2023
.
4.
Shousse
,
K. R.
, and
Taylor
,
D. G.
,
1995
, “
Discrete-Time Observers for Singularly Perturbed Continuous-Time Systems
,”
IEEE Trans. Autom. Control
,
40
, pp.
224
–
235
.
5.
Phillips, A. M., and Tomizuka, M., 1996, “Multirate Estimation and Control Under Time-Varying Data Sampling With Application to Information Storage Devices,” in Proceedings of the American Control Conference, pp. 4151–4155.
6.
Hara, T., and Tomizuka, M., 1998, “Multi-Rate Controller for Hard Disk Drive With Redesign of State Estimator,” in Proceedings of the American Control Conference, pp. 3033–3037.
7.
Thein, M. L., and Misawa, E. A., 1999, “A Parallel Observer System for Multirate State Estimation,” in Proceedings of the American Control Conference, pp. 3885–3889.
8.
Thein, M. L., and Misawa, E. A., 2003, “A Parallel Observer System for Non-Deterministic Multirate Systems,” accepted for publication to the ASME J. Dyn. Syst., Meas., Control.
9.
Suzuki
,
T.
,
Nakamura
,
T.
, and
Koga
,
M.
,
1980
, “
Discrete Adaptive Observer With Fast Convergence
,”
Int. J. Control
,
31
, pp.
1107
–
1119
.
10.
Cooper, E. S., 1993, “Minimum Time Control With Minimum Vibration and With Power Limiting, With Application to the Magnetic Disk File,” Ph.D. thesis, Santa Clara University.
11.
Lyle, T. R., and Rendon, T., 1998, “A Technical Report on a General Disk Drive Model,” Technical Memorandum ACL-98-009, Advanced Controls Laboratory, School of Mechanical & Aerospace Engineering, Oklahoma State University, Stillwater, OK.
12.
Thein, M. L., Rendon, T., and Misawa, E. A., 1999, “A Genetic Algorithm for the Tuning of a Discrete Adaptive Observer Implemented on an IBM Head/Disk Assemby,” in Proceedings of the IEEE Conference on Control Applications, pp. 164–169.
Copyright © 2003
 by ASME
You do not currently have access to this content.