| Title |
Robust Linear Quadratic Gaussian Controller Design for Oil Coolers Based on a State Space Model |
| Authors |
Seok Kwon Jeong ; Tae Eun Kwon |
| DOI |
http://dx.doi.org/10.6110/KJACR.2019.31.3.130 |
| Keywords |
강인한 LQG 제어기 ; 오일쿨러 ; 상태공간 모델 ; 칼만필터 ; 최적제어 Robust LQG controller ; Oil cooler ; State space model ; Kalman filter ; Optimum control |
| Abstract |
This paper presents a robust LQG controller design method by a state space model to improve control performance of a refrigeration cycle under process and measurement noise. First, a state-space model of an oil cooler is derived as a 4th order system equation using several governed equations based on a moving boundary model. Next, the LQG controller which uses the Kalman filter is designed using linear quadratic regulator (LQR) gain and the Kalman gain to minimize an evaluation function and the individual influence of noise. We can independently determine the two gains of LQR and Kalman by the Riccati equation using the separation theorem. If the weighted matrices of the evaluation function are designed to satisfy the desired control performance and energy condition input, the designer conclusively determines LQR gain. Finally, the validity of the proposed design method is validated by computer simulations and real experiments in several cases. The results of some of the simulation and experiments showed that the proposed method can be implemented as a robust control. |