LTI approximations of slightly nonlinear systems [Elektronisk resurs] some intriguing examples / Martin Enqvist, Lennart Ljung.

• Approximations of slightly nonlinear systems with linear time-invariant (LTI) models are often used in applications. Here, LTI models that are optimal approximations in the mean-square error sense are studied. It is shown that these models can be very sensitive to small nonlinearities. Furthermore, the significance of the distribution of the input process is discussed. From the examples studied here, it seems that LTI approximations for inputs with distributions that are Gaussian or almost Gaussian are less sensitive to small nonlinearities. 

Indexterm och SAB-rubrik

System identification

Nonlinear systems

Linearization