Robust sampled data eigenstructure assignment using the delta operator

Abstract

Eigenstructure assignment is considered for a linear time-invariant plant that is represented by the so-called unified delta model, which is valid both for continuous time and sampled data operation of the plant. We show that the eigenvectors of the delta model are identical to the eigenvectors of the continuous time plant and an expression is derived for the eigenstructure assignment feedback gain matrix for the delta model. We extend a sufficient condition for robust stability to the delta model of the plant. A robust sampled data design is computed for the Extended Medium Range Air-to-Air Technology missile by minimizing the integral of the roll rate with constraints on selected eigenvalues, actuator deflection rates, and the sufficient condition for robust stability. The robust design exhibits a significantly improved sideslip gust response as compared to an orthogonal projection eigenstructure assignment design.