Frequency domain approach to sliding mode control

Frequency shaping linked with linear quadratic optimal and sliding mode control is a technique for controlling systems with uncertainties. In this paper we propose a new method for designing sliding mode control when the LQ weighting functions are not constant for all frequencies. Furthermore, we introduce conditions for which the spectrum of the original reduced system is a subset of the spectrum of the augmented system, and develop an iterative optimal construction procedure for the sliding mode.