Frequency domain based real-time performance optimization of Lur'e systems

•Frequency domain based performance assessment of nonlinear systems in practice.•Performance based on output measurements only, requiring no dynamical models.•Application of extremum seeking control for real-time performance optimization.•Application of the proposed methodology in both simulation and experiment.

Nonlinear effects can lead to performance degradation in (controlled) dynamical systems. This paper provides a practical method to optimally compensate performance degrading nonlinear effects in Lur'e-type systems in an automated way. Using novel frequency domain based techniques, a well defined performance measure is derived and real-time performance optimization is achieved by application of extremum seeking algorithm. This yields a new method for real-time compensation of performance degrading nonlinear effects, which is successfully demonstrated in both simulation and experiment.