Reconstructing the states and parameters of Chua's system based on successive integrations of the output

In this Letter we describe an efficient method to reveal some parameters and states of Chua's system by means of the knowledge of a well-chosen (measurable variable) output. First, it is shown that the system is constructible. This, allows us to obtain an integral output parametrization of the remaining states. Based on this integral parametrization we construct an iterative integral equation of the output. The parameter reconstruction process is accomplished in a very short time, depending on the system's order and the sampling time. Besides, only one output is needed and no input is required. A numerical implementation of the method can be easily achieved employing electronic integrators, avoiding the calculations of the derivatives. (C) 2003 Elsevier B.V. All rights reserved.