Online Identification of Stochastic Continuous-Time Wiener Models Using Sampled Data
This work addresses identification challenges for stochastic continuous-time Wiener models, offering a robust and simpler alternative to complex methods, though it appears incremental in improving existing techniques.
The paper tackles the problem of asymptotically biased estimators in stochastic Wiener model identification by developing a simple recursive online estimation algorithm based on an output-error predictor, which is robust to assumptions on disturbance spectrum as shown in numerical simulations.
It is well known that ignoring the presence of stochastic disturbances in the identification of stochastic Wiener models leads to asymptotically biased estimators. On the other hand, optimal statistical identification, via likelihood-based methods, is sensitive to the assumptions on the data distribution and is usually based on relatively complex sequential Monte Carlo algorithms. We develop a simple recursive online estimation algorithm based on an output-error predictor, for the identification of continuous-time stochastic parametric Wiener models through stochastic approximation. The method is applicable to generic model parameterizations and, as demonstrated in the numerical simulation examples, it is robust with respect to the assumptions on the spectrum of the disturbance process.