Linear quadratic problems (On “linear” approaches in nonlinear system theory)

Abstract

The term “linear quadratic problem” refers to the problems of dynamics where linear controlled systems are associated with a certain quadratic functional of performance. “Linear” approaches are the approaches that are usually applied to linear systems, e.g. the methods of the integral transforms (Laplace, Fourier), the linear functional analysis and the frequency domain methods. The paper considers some cases where these approaches are applied to nonlinear systems.