Initial estimates for Wiener–Hammerstein models using phase-coupled multisines

摘要: Block-oriented models are often used to model nonlinear systems. These consist of linear dynamic (L) and static (N) sub-blocks. This paper addresses the generation initial estimates for a Wiener-Hammerstein (LNL cascade). While it is easy measure product two blocks using Gaussian excitation identification methods, difficult split global dynamics over individual blocks. first proposes well-designed multisine with pairwise coupled random phases. Next, modified best approximation estimated on shifted frequency grid. It shown that this procedure creates shift input known offset, while output do not shift. The resulting transfer function, which has complex coefficients due shift, domain estimation method. identified poles zeros can be assigned either or dynamics. Once done, in literature remaining initialization problem solved much easier than original one. method illustrated experimental data obtained from benchmark system.