Extension
to Nonlinear Time Varying Uncertainty
qSuppose D Î DN is a structured Nonlinear (Time-varying) Uncertainty and suppose D is constant scaling matrix
such that DDD-1 Î DN . (Note that we do not require DD=DD.)
Then a sufficient stability condition for all D Î DN with ||D||¥< 1, is (by small gain theorem)
||D-1G(s)D||¥ £ 1
