INTEGRAL CONSTRAINTS AND PERFORMANCE LIMITS ON COMPLEMENTARY SENSITIVITY: DISCRETE-TIME SYSTEMS

摘要

We study performance limitation issues for multivariable discrete-time feedback systems. The complementary sensitivity function is employed as a performance measure, and Bode and Poisson type integral inequalities and H{sub}∞ type performancelimits are derived. The results exhibit frequency-dependent constraints as well as best achievable limits on the complementary sensitivity function, which are shown to be constrained by nonminimum phase zeros and unstable poles. In particular, thedirections of such zeros and poles are seen to play a central role to this effect.