基于云模型推理的施肥机pH值和电导率解耦控制

摘要

施肥机肥水pH值和电导率(EC)调节过程中,由于水分蒸发、植物对水分和营养物质的吸收等,调节过程存在非线性、时滞性、时变性、不确定性等特点,较难建立精确的数学模型.为实现施肥机pH值和EC值的稳定调节,提出一种基于云模型推理的施肥机pH值和EC值解耦控制方法.采用正态云模型描述调节误差语言值,基于一维正态云模型规则推理设计出云模型控制器,对pH值和EC值进行解耦控制并在线修正.利用阳台蔬菜机进行施肥控制试验,结果表明,提出的云模型控制器能够满足施肥机pH值和EC值精确配比以及施肥的要求,有效提高肥水利用率.%Due to evaporation, plants absorption of water and nutrients, and other factors, the adjustment process of pH and electric conductivity (EC) value of fertilizer and water of fertilizer applicator existed problems such as nonlinear, time-lag, time-varying and uncertainty.Therefore, it was difficult to establish accurate mathematical model.In order to realize the stable adjustment of pH and EC value, an EC and pH decoupling control method for fertilizer applicator was proposed based on cloud model reasoning.In this method, normal cloud model was adopted to describe adjust error language value, and a cloud model controller was designed based on one-dimensional normal cloud model rule reasoning to realize the decoupling control of pH and EC value and online correction.Experimental test showed that the proposed cloud model controller could meet the requirement of precision of pH and EC value, and improve the utilization rate of fertilizer and water.