Linearly Parameterised Controller Design


A new approach for robust fixed-order H∞ controller design by convex optimization is proposed. Linear time-invariant single-input single-output systems represented by nonparametric models in the frequency domain are considered. It is shown that the H∞ robust performance condition can be represented by a set of linear or convex constraints with respect to the parameters of a linearly parameterized controller in the Nyquist diagram. Systems with time-delay and with multimodel and frequency-domain uncertainty can be considered straightforwardly in the proposed approach. The proposed method is compared with the standard H∞ control problem by a simulation example on an unstable system.

Main Publications:

Fixed-order H∞ controller design for nonparametric models by convex optimization, A Karimi, G Galdos, Automatica 46 (8), 1388-1394, 2010.

A data-driven approach to mixed-sensitivity control with application to an active suspension system, S Formentin, A Karimi, IEEE Transactions on Industrial Informatics, 9(4), 2293-2300, 2013.

H∞ gain-scheduled controller design for rejection of time-varying narrow-band disturbances applied to a benchmark problem, A Karimi, Z Emedi, European Journal of Control 19 (4), 279-288, 2013.

Robust controller design by linear programming with application to a double-axis positioning system, A Karimi, M Kunze, R Longchamp, Control Engineering Practice 15 (2), 197-208, 2007.