$H_{\infty}$제어기법을 이용한 비선형 마찰 및 공진 효과가 존재하는 서보시스템의 램프추종 제어기 설계에 관한 연구

A study on the ramp tracking controller for the servo systems with nonlinear friction and resonance using $H_{\infty}$controller design method

Resonance effects and nonlinear frictions which generate many problems in control system exist in almost all the servo system. therefore, In this paper, the design procedure which employs $H_{\infty}$ control theory after augmenting with two integrators is proposed to track the ramp input. Limit cycles are unavoidable by the effect of interaction between two integrators and Coulomb friction in these system. The describing function is used to check the limit cycles and decide the coefficients of two integrators to minimize the effect of the limit cycles.