The Best Linear Approximation of MIMO Systems: First Results on Simplified Nonlinearity Assessment
Many mechanical structures are nonlinear and there is no unique solution for modeling nonlinear systems. When a single-input, single-output system is excited by special signals, it is easily possible to decide whether the linear framework is still accurate enough to be used, or a nonlinear framework must be used. However, for multiple-input, multiple-output (MIMO) systems, the design of experiment is not a trivial question since the input and output channels are not mutually independent. This paper shows the first results of an ongoing research project and it addresses the questions related to the user-friendly processing of MIMO measurements with respect to the design of experiment and the analysis of the measured data.
When the proposed framework is used, it is easily possible (a) to decide, if the underlying system is linear or not, (b) to decide if the linear framework is still accurate (safe) enough to be used, and (c) to tell the unexperienced user how much it can be gained using an advanced nonlinear framework. The proposed nonparametric industrial framework is illustrated on a ground vibration testing of an electrical airplane.
KeywordsMIMO systems Nonlinearity Nonparametric estimation System identification Ground vibration testing
This work was funded by the VLAIO Innovation Mandate project number HBC.2016.0235.
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