프로세스 제어 시스템의 PID 게인 자동 튜닝을 통한 강인한 제어

다국어 초록 (Multilingual Abstract)

Proportional-Integral-Derivative (PID) controllers are extensively utilized in industrial process control due to their simplistic design and exceptional control performance. Typically, PID gains are devised based on transfer function models of plants. However, deriving a low-dimensional linear approximation model for a variable speed refrigeration system (VSRS) becomes highly challenging due to its inherent nonlinearity and high-order dynamic characteristics. While there are fuzzy control and AI methods that do not rely on models, their control logic is extensive, necessitating expensive microprocessors and relying heavily on expertise and experience, thus making maintenance very difficult. Furthermore, model-independent PID gain tuning methods are cumbersome, making it difficult to achieve the desired control performance and apply them to real systems. Therefore, robust auto-tuning and PID control of VSRS, which is multi-variable system with strong inherent nonlinearity, are described in this paper. This method is a simple tuning method through ON/OFF operation, and it is an integrated system that automatically switches to PID control after tuning is completed. In addition, this method was applied to the actual system to conduct simulations and experiments, and the tuning method was modified and proposed due to the influence of heat noise and disturbance during the experiment. Moreover, in the case of a multi-variable system, the operating conditions of the remaining variables were clearly revealed when auto-tuning one variable. Experimental validation corroborates the efficacy of the proposed method. Stability and reproducibility are confirmed through analyses involving the pole position of the closed-loop control system and the bode diagram of the open-loop control system. additionally applied to the EHP air handling unit, and the validity of the proposed method is verified through simulation and experiment. These results substantiate the effectiveness of the proposed approach in ensuring stable control despite the inherent complexities of the system, thereby solidifying its potential for real-world applications.

목차 (Table of Contents)

• 제1장 서 론 1
• 1.1 연구 배경 및 목적 1
• 1.2 연구 범위 및 내용 4
• 제2장 프로세스 제어 시스템의 동적 모델링 6
• 2.1 VSRS의 구성 및 장치 사양 6
• 2.2 동특성 실험을 통한 전달함수 모델링 10
• 제3장 PID 게인 자동 튜닝을 통한 PID 제어기 설계 12
• 3.1 PID 피드백 제어계와 제어기 설계 12
• 3.2 ON/OFF 운전을 통한 PID 게인 자동 튜닝 13
• 3.3 MATLAB 기반 PID 게인 자동 튜닝 및 제어 시스템 설계 16
• 3.4 MATLAB 기반 시뮬레이션 18
• 3.5 시뮬레이션 결과 및 고찰 19
• 제4장 실험 결과 및 고찰 21
• 4.1 기존 자동 튜닝 방법의 실험 결과 및 고찰 21
• 4.2 열잡음과 외란을 고려한 수정된 자동 튜닝 방법 제안 23
• 4.3 수정 제안한 자동 튜닝 방법의 실험 결과 및 고찰 26
• 4.4 OCS의 오일출구온도와 과열도 PID 게인 자동 튜닝 및 제어 27
• 4.5 제안한 튜닝 방법의 제어 응답 재현성과 안정성 평가 29
• 제5장 EHP 공조기의 급기 팬 회전수 제어 적용 31
• 5.1 EHP 공조기의 구성 31
• 5.2 동특성 및 자동 튜닝 실험을 위한 실험 조건 34
• 5.3 동특성 실험을 통한 전달함수 모델링 36
• 5.4 시뮬레이션 결과 및 고찰 38
• 5.5 실험 결과 및 고찰 41
• 제6장 결 론 44
• 참고문헌 46
• Appendix 48
• 학술지 게재 논문 및 학술대회 발표 논문 목록 54
• 감사의 글 55