| Title |
H-infinity Controller Design for Robust Control of Variable Speed Refrigeration System with Disturbance and Model Uncertainty |
| Authors |
Dong Geun Kim ; Seok Kwon Jeong |
| DOI |
https://doi.org/10.6110/KJACR.2021.33.10.520 |
| Keywords |
가변속 냉동시스템; H-infinity 제어; 모델 불확실성; 강인 제어; 혼합감도 문제 Variable speed refrigeration system; H-infinity control; Model uncertainty; Robust control; Mixed sensitivity problem |
| Abstract |
This paper describes the design of H-infinity controller for robust control of a variable speed refrigeration system. The suggested controller can ensure robustness against disturbance and model uncertainty by minimizing H-infinity norm of the transfer function from exogenous input to performance output and applying the small gain theorem. In particular, the controller was designed to simultaneously reduce the effects of disturbance and model uncertainty by formalizing these problems as a mixed sensitivity problem. In addition, an integrator was included to the controller to prevent the occurrence of steady state error. The validity of the proposed controller was demonstrated by computer simulations and real experiments. Moreover, the effectiveness of the proposed controller was confirmed by comparing its performance to the PI controller, which was tested under the same experimental conditions as the H-infinity controller. |