Experiment design for improved frequency domain subspace system identification of continuous-time systems
Paper in proceeding, 2015

A widely used approach for identification of linear, time-invariant, MIMO (multi-input/multi output) systems from continuous-time frequency response data is to solve it in discrete-time domain using subspace based identification algorithm incorporated with a bilinear transformation. However, the bilinear transformation maps the distribution of the frequency lines from continuous-time domain to discrete-time domain in a non-linear fashion which may make identification algorithm to be ill-conditioned. In this paper we propose a solution to get around this problem by designing a dedicated frequency sampling strategy. Promising results are obtained when the algorithm is applied to synthetic data from a 6DOF mass-spring model.

Frequency responses

System identification

Subspace methods

Frequency sampling strategy

Bias reduction


Majid Khorsand Vakilzadeh


Vahid Yaghoubi Nasrabadi


Tomas McKelvey

Chalmers, Signals and Systems, Signal Processing and Biomedical Engineering, Signal Processing

Thomas Abrahamsson


Lennart Ljung

Linköping University


24058963 (eISSN)

Vol. 48 28 886-891

17th IFAC Symposium on System Identification SYSID 2015
Beijing, China,

Subject Categories

Mechanical Engineering



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