Mathematical Problems in Engineering
Volume 2009 (2009), Article ID 387317, 14 pages
Research Article

Trajectory Sensitivity Method and Master-Slave Synchronization to Estimate Parameters of Nonlinear Systems

Departamento de Engenharia Elétrica da Escola de Engenharia de São Carlos, Universidade de São Paulo 13566-590, São Carlos, SP, Brazil

Received 1 February 2009; Revised 21 May 2009; Accepted 12 June 2009

Academic Editor: Elbert E. Neher Macau

Copyright © 2009 Elmer P. T. Cari 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.


A combination of trajectory sensitivity method and master-slave synchronization was proposed to parameter estimation of nonlinear systems. It was shown that master-slave coupling increases the robustness of the trajectory sensitivity algorithm with respect to the initial guess of parameters. Since synchronization is not a guarantee that the estimation process converges to the correct parameters, a conditional test that guarantees that the new combined methodology estimates the true values of parameters was proposed. This conditional test was successfully applied to Lorenz's and Chua's systems, and the proposed parameter estimation algorithm has shown to be very robust with respect to parameter initial guesses and measurement noise for these examples.