Nonlinear modification of positive-real LQG compensators for enhanced disturbance rejection and energy dissipation

A general framework for the feedback interconnection of passive nonlinear systems is used to investigate the effectiveness of modifying positive-real LQG compensators with nonlinearities to enhance disturbance rejection and energy dissipation. The primary purpose of the nonlinear modifications is to spread the spectrum of the compensator states, and thereby enhance the energy flow from the plant to the compensator. This framework is also used as a basis for the active emulation of vibration absorbers