ℋ∞ design of switching surfaces for sliding-mode control with nonmatching disturbances

An XFI,-normg uaranteed cost design for sliding surfaces in variable structure controllers is presented. This procedure is suitable for approximate rejection of nonmatching disturbances. Both unstructured signal disturbances and structured convex-bounded model uncertainties are considered. A state-space convex optimisation approach, via linear matrix inequalities, is employed in the surface design.