The residual based extended least squares identification method for dual-rate systems

In this paper, we focus on a class of dual-rate sampled-data systems in which all the inputs u(t) are available at each instant while only scarce outputs y(qt) can be measured (q being an integer more than unity). To estimate the parameters of such dual-rate systems, we derive a mathematical model by using the polynomial transformation technique, and apply the extended least squares algorithm to identify the dual-rate systems directly from the available input–output data {u(t),y(qt)}. Then, we study the convergence properties of the algorithm in details. Finally, we give an example to test and illustrate the algorithm involved.