温室环境现场层监控系统控制策略研究

Research on Control Tactic of Field Level Monitoring System for Greenhouse Environment

根据温室环境非线性、大延时、强耦合等特点,选用模糊控制方法作为系统的控制策略。通过对模糊控制理论的分析以及温室环境系统特点的研究,选择系统的温湿度偏差以及偏差变化率作为系统的输入输出量并进行模糊化,设计了温室环境监控系统的模糊控制器。得出温室动态模型,并进行了仿真实验,与实测数据进行比较,验证了模型的准确性和控制方法的可行性。最后对PID控制和模糊控制进行了比较,表明模糊控制方法超调量小,调整时间短,控制效果优于PID。

Based on the nonlinear, more lingering and strong coupling characteristics, fuzzy control method was selected as the control strategy for the system. According to the analysis and research about fuzzy control theory and greenhouse environment, temperature-humidity warp and warp change rate were selected as I/O variables which were fuzzed for the system,and a fuzzy controller was designed for the greenhouse environment monitoring system. After that, a dynamic greenhouse environment model was constructed and simulations were carried out. The results got a good agreement with the experiment data, which proved the accuracy of the model and the validity of the control strategy. In the end, the outcome of fuzzy control was compared with that of PID control. It was confirmed that the fuzzy control with a smaller overhoot and adjusting time constant is superior to the PID control.