Design of sliding mode controllers for linear uncertain systems based on first order approximation filters

The focus of this paper is on the synthesis of first order filters which generate approximations for upper bounds of the norm of signals needed in the modulation function of some sliding mode control laws. The design of output-feedback sliding mode controllers for uncertain multivariable linear systems in regular form is considered. Optimization methods are applied to reduce the amplitude of the control signals. The model-reference control of a mechanical system with uncertain parameters and uncertain order illustrates the design method