On estimation of the stability defect of the sets with piecewise smooth border

Nonlinear control system and connected differential inclusion on a finite time interval is considered. A game problem of approaching for a control system with a compact target set is studied. Some questions about weak invariance property of compact target set with respect to differential inclusion are considered. Also questions about estimation and calculation of stability defect of the sets with piecewise smooth border are considered. Formula of a stability defect for the sets with piecewise smooth border common case under conditions proving correct conception of weak invariance defect are obtained. A modeling example of a two dimensions control system is calculated.