Mathematical Problems in Engineering
Volume 2012 (2012), Article ID 296701, 13 pages
http://dx.doi.org/10.1155/2012/296701
Research Article

D-Optimal Design for Parameter Estimation in Discrete-Time Nonlinear Dynamic Systems

Yu Liu,1 Hamid Reza Karimi,2 and Zhiwei Yu1

1The Control Science and Engineering Department, Harbin Institute of Technology, Harbin 150001, China
2The Department of Engineering, Faculty of Engineering and Science, University of Agder, 4898 Grimstad, Norway

Received 21 June 2012; Accepted 7 August 2012

Academic Editor: Bo Shen

Copyright © 2012 Yu Liu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

An optimal input design method for parameter estimation in a discrete-time nonlinear system is presented in the paper to improve the observability and identification precision of model parameters. Determinant of the information matrix is used as the criterion function which is generally a nonconvex function about the input signals to be designed. To avoid the locally optimizing problem, a randomized design method is proposed by which a globally optimizing test plan other than input signals may be obtained. Then the randomized design can be approximated by a nonrandomized design about optimal inputs. An iterative algorithm integrated with dynamic programming is given and verified by a numerical example on experimental design for self-calibration tests of ISP system.