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For a multivariable Hammerstein controlled autoregressive moving average system (CARMA) system, the identification difficulty is hard to parameterize the system into an quasi auto-regression form to which the standard least square method can apply. By using an interactive maximum likelihood (IML) estimation method, this paper interactively maximizes the logarithmic likelihood function over multiple parameter vectors in a more general model, respectively. The details include: (1) reframe the system into a sum of some bilinear functions about the parameter vectors of the nonlinear part and the linear part; (2) interactively maximize the logarithmic likelihood function over each parameter vector to get their estimates; (3) when updating one parameter vector, substitute other parameter vectors or unknown information vectors by their estimates. The advantage of the IML algorithm is that it overcomes the limit on an autoregressive model form with one parameter vector. The IML method is simple to understand and easy to implement. Numerical simulations indicate that the explored IML algorithm is capable of generating accurate parameter estimates, and easy to implement on-line. [ABSTRACT FROM AUTHOR]

Mathematical models are basic for designing controller and system identification is the theory and methods for establishing the mathematical models of practical systems. This paper considers the parameter identification for Hammerstein controlled autoregressive systems. Using the key term separation technique to express the system output as a linear combination of the system parameters, the system is decomposed into several subsystems with fewer variables, and then a hierarchical least squares (HLS) algorithm is developed for estimating all parameters involving in the subsystems. The HLS algorithm requires less computation than the recursive least squares algorithm. The computational efficiency comparison and simulation results both confirm the effectiveness of the proposed algorithms. [ABSTRACT FROM AUTHOR]

Maximum likelihood methods are significant for parameter estimation and system modeling. This paper gives the input-output representation of a bilinear system through eliminating the state variables in it, and derives a maximum likelihood least squares based iterative for identifying the parameters of bilinear systems with colored noises by using the maximum likelihood principle. A least squares based iterative (LSI) algorithm is presented for comparison. It is proved that the maximum of the likelihood function is equivalent to minimize the least squares cost function. The simulation results indicate that the proposed algorithm is effective for identifying bilinear systems and the maximum likelihood LSI algorithm is more accurate than the LSI algorithm. [ABSTRACT FROM AUTHOR]

This paper concentrates on the identification problems of pseudo-linear autoregressive moving average systems. A least squares based iterative (LSI) algorithm is proposed using the data filtering technique and an LSI algorithm is developed for comparisons. The basic idea is to use a linear filter to filter the input–output data, to decompose a pseudo-linear autoregressive moving average system into a system model and a noise model. Finally, two examples are given to confirm the effectiveness of the proposed algorithms. [ABSTRACT FROM AUTHOR]