Making astatism in variable structure servosystems

There is considered the principle of designing variable structure servo-systems obtaining the high-order astatism (reproducing with a zero static error a broad class of control actions $g(t)$) without enlarging a number of integration elements in the regulator.
Reproduction of the liner function $g(t)=\alpha t$ (при $t\leq0$, $g(t)=0$) by the variable structure system having one integrating unit in the regulator is analyzed.