亞熱帶溫室微氣候最佳化控制之模擬與分析－萵苣栽培為例

Simulation and analysis of microclimate optimal control in subtropical greenhouse-lettuce cultivation as example

楊清富(Yang, C. F.) ； 林聖泉(T. C. Lin)

《臺南區農業改良場研究彙報》 72期 (2018/12) Pp. 63-75

摘要

近年來臺灣陸續建造許多溫室來栽培作物。由於地處亞熱帶，高溫及潮濕的氣候對溫室環控形成更嚴苛的挑戰，特別是夏季的高溫，更是影響亞熱帶溫室作物能否周年生產的關鍵。為了降低環境控制的成本及栽培需求，亞熱帶溫室需著重於降溫的規劃與設計。藉由適當的環境控制，可在溫室中創造更合宜的微氣候，從而改善作物生長條件。然而人工環境控制衍生出能源耗用的問題，而能源過度消耗向來是溫室最為人所詬病的議題。因此，無論國內、外對溫室環境控制的研究從不間斷，並持續受到關注。近年來有許多國外溫室環境控制系統被引進臺灣，然而由於這些地區與臺灣的氣候環境有極大差異，致使這些系統在臺灣無法發揮其預期的功效，對經濟效益的提升並無太大的助益。透過數學模型對溫室在不同氣候條件下進行模擬，進而找到最佳的設計方案已成為研究溫室環境控制的趨勢。本研究以亞熱帶氣候條件，建立了一個包含植株乾物重、CO_2濃度、溫度及濕度等狀態的動態模型。臺灣的設施農業正在蓬勃發展，除了硬體技術不斷的提升，以環境控制技術改善環境逆境的意識逐漸受到重視。但過多環境控制的投入對經濟效益有負面的影響，因此藉由權衡控制支出與收益才能獲得最大的經濟效益。本研究以溫室生產萵苣的最大化淨收益作為主要評估的性能指標。利用作物生長模型、歷史氣候數據，應用最佳化控制理論來推算最佳化控制策略，並與現有的環境控制策略進行比較。本研究推導的控制策略可以使萵苣生產的淨收益增加約8%。現有技術：溫室環境控制通常以能量平衡及作物生長需求作為控制參考。創新內容：導入最佳化控制理論，推算亞熱帶溫室最佳化控制策略。對產業影響：溫室微氣候最佳化控制，可作為未來溫室生產最大化淨收益生產模式之方法。

關鍵字

亞熱帶 ； 溫室 ； 微氣候 ； 最佳化控制 ； 模擬

並列摘要

In recent years, many greenhouses had been built in Taiwan to cultivate crops. Ventilation and cooling must be designed carefully in greenhouses to reduce the cost of environmental control. By employing an adequate environmental control, a better microclimate can be achieved in the greenhouse, to improve the crop growth conditions. Therefore, environmental control in greenhouses has continually won considerable research attentions. In recent years, many foreign environmental control systems have been introduced to Taiwan. However, there the climate and environment are different between these regions and Taiwan, these systems did not perform well as expected, and the promotion of economic benefits was limited. Through the mathematical model of the greenhouse under different climatic conditions of simulation, and then developing the best design has become the trend of research on greenhouse environment control. Taiwan's facility agriculture is booming. Using environment control technology to improve the environment and adversity has gradually been paid more attention. However, too much investment in environmental control may cause a negative impact on economic benefits. In this study, a dynamic model containing plant dry matter weight, CO_2 concentration, temperature and humidity was established based on subtropical climatic conditions. The maximum net income from lettuce production in greenhouse was defined as the main performance index. We applied the theory of optimal control to estimate the best control strategy. A comparison was performed with an existing environmental control strategy. The results showed that the proposed control strategy could increase the net income of lettuce production by approximately 8%. What is already known on this subject? Greenhouse environmental control is usually connerned by energy balance and crop growth requirements. What are the new findings? Introduce optimization control theory and calculate subtropical greenhouse optimization control strategy. What is the expected impact on this field? Greenhouse microclimate optimization control can be used as a method to maximize net income production model in the future.

並列關鍵字

Subtropical ； Greenhouse ； Microclimate ； Optimal control ； Simulation