Design of Robust Optimal Controller for Nano Stage using Sliding-mode Control

나노 스테이지에 대한 슬라이딩-모드 제어 기반의 강인 최적 제어기 설계

In this paper. we design a robust optimal controller for ultra-precision positioning system. Generally, it is hard to control the nanometric scale positioning system because of the parameter uncertainties and external disturbances. To solve this problem. we suggest a control algorithm based on the modified sliding-mode control and the LQ control in an augmented system. The augmented system is composed of additional state variables: state estimates and control input in the nominal system. Through comparison with LQ optimal control, it is verified that the proposed control algorithm is more robust to the unexpected parameter variations and external noises.