ROBUST STABILITY AND SENSITIVITY OF INPUT OUTPUT SYSTEMS OVER EXTENDED SPACES .2. SENSITIVITY

This paper is the second part of [6] which is concerned with the sensitivity of general input-output systems over extended spaces. It is assumed that such systems, which need not be of feedback type, are governed by nonlinear operator equations relating the input, the state, and the output. These equations depend on a parameter A that can vary in a neighborhood of a nominal value A0. Essentially, a system is called insensitive if any truncation of its output depends continuously on A provided the input is fixed. The theorems derived provide sufficient conditions for insensitivity. A control system of a feedback-feedforward type and a dynamical system described by a linear vector differential equation on [0, infinity) are discussed as examples.