The Modeling And Optimization Of PH Regulation In The Drop Irrigation And Fertilization Control System

The crops, such as vegetables in the greenhouse and flowers have a high demand for the circumstances. In order to improve the quantity and quality of the crops, appropriate water, fertilization and temperature is needed. The crops control systems in the irrigating and fertilization are imported in Tianjin in recent years and they have achieved better effects. However, the price of the control systems is so high and they are inconvenient to repair that they only can be used as a model. The study of the technology has begun since 2001,but the regulation quality of pH in dropping and fertilizing systems can not reach the standards of same products in other countries and it limit the development of the technology.The PH regulating is a complicated and colligated technology in the control system of the crop irrigating and fertilization. With the development of the production process of agriculture, new demands are required in precision and functions, etc of the process control. To accommodate technical requirements, and improvements have been made in the structures and functions of control system, forming many special control systems.Based on the study of dropping and fertilizing control systems, we should find the network model and its optimization method of the regulation of pH. The method using genetic algorithm and manual neural network is used to optimize the structure and coefficient of network. The optimal control makes use of the process model that can predict the frequency of opening PH valve by the disturbances that influence the PH parameter to build the dynamic feedforward correctional ratio of the regulation of pH and the PH fertilization system runs on the near optimal.The control optimal makes use of the process model that can predict the frequency of opening PH valve by the disturbances that influence the PH parameter and the are optimized in the training of the network in the regulation of pH.The main achievements in scientific research are described as follow:(1)the software in the found and optimization of network model has been achieved in regulation of pH in dropping and fertilizing systems.(2)using the control systems to the domestic dropping and fertilizing, it reach the control standards of same products in other countries, when the water flow fluctuates due to changed over the number of irrigating field valve, the control system can reach normal value in two regulation cycles and its tolerance is less than two percent .(3)the normal regular in the found and optimization of network model has been achieved and the dropping and fertilizing control system is perfected. (4)The result show: using genetic algorithm optimize weight and threshold of artificial neural network, not only can be putted into practice, but also has very appealing advantage.