%0 Report %9 Technical Report %A Laurain, Vincent %A Tóth, Roland %A Piga, Dario %C The Netherlands %D 2013 %F eprints:2429 %I University of Technology, Eindhoven %N 001 %T An instrumental Least Squares Support Vector Machine for nonlinear system identification: enforcing zero-centering constraints %U http://eprints.imtlucca.it/2429/ %X Least-Squares Support Vector Machines (LS-SVM's), originating from Stochastic Learning theory, represent a promising approach to identify nonlinear systems via nonparametric es- timation of nonlinearities in a computationally and stochastically attractive way. However, application of LS-SVM's in the identification context is formulated as a linear regression aim- ing at the minimization of the ℓ2 loss in terms of the prediction error. This formulation corresponds to a prejudice of an auto-regressive noise structure, which, especially in the non- linear context, is often found to be too restrictive in practical applications. In [1], a novel Instrumental Variable (IV) based estimation is integrated into the LS-SVM approach provid- ing, under minor conditions, a consistent identification of nonlinear systems in case of a noise modeling error. It is shown how the cost function of the LS-SVM is modified to achieve an IV-based solution. In this technical report, a detailed derivation of the results presented in Section 5.2 of [1] is given as a supplement material for interested readers. %Z TUE-CS-2013-001