Model predictive control based on mathematical model of humidity deficit in greenhouses by system identification method

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06332
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41040:Agricultural environmental engineering and agricultural information engineering-related
• Research Institution: Kochi National College of Technology
• Principal Investigator: Nakayama Shin 高知工業高等専門学校, ソーシャルデザイン工学科, 准教授 (40445846)
• Co-Investigator(Kenkyū-buntansha): 木村 竜士 高知工業高等専門学校, ソーシャルデザイン工学科, 准教授 (90571810)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ビニールハウス / 飽差 / 気温 / モデル予測制御 / システム同定

Outline of Final Research Achievements

In general greenhouses, when the windows are opened by temperature control during the winter season when the outside air is dry, the humidity deficit becomes more than 6 g/m3 and the plant stomata close, adversely affecting plant growth. In this study, we developed the inside humidity deficit and temperature greenhouse numerical model using the system identification method from measured data set as 'control output: inside humidity deficit and inside air temperature', 'control input: window opening degree' and 'disturbance input: outside humidity deficit, outside temperature and inside illumination'. The model predictive control window opener using this model was shown to be able to maintain the air temperature in the greenhouse at the target value of 27°C, while controlling the inside himidity deficit within the upper limit of 6 g/m3, approaching the target value of 4.5 g/m3.

Free Research Field

制御工学

Academic Significance and Societal Importance of the Research Achievements

学術的意義は，システム同定法による具体的なビニールハウス内の飽差気温モデルの作成手法と，モデル予測制御の実践方法を示し，その効果を証明した点である．社会的意義は，ハウス内外に温湿度・照度・窓開度のセンサを設置すれば，既設の窓開閉装置を利用して，ハウス内飽差気温のモデルベース制御がどのハウスでも利用できるようになることを示した点である．