基于流量调节阀和神经网络的植保机械在线混药装置

On-line Mixing Pesticide Device Based on Flow Control Valve and Neural Network

农药的小流量、高精度实时动态测控是在线混药装置急需解决的一个关键问题。流过调节阀的流量与阀前后压差、流体密度、阀开度有关，通过建立流量与这3个变量间的关系表达式，即可利用调节阀对药液流量进行实时检测和控制。设计了利用流量计和调节阀分别对水和农药原液进行计量的在线混药装置，在提出调节阀相应标定方法的基础上，建立了调节阀的流量关系表达式，并在室内进行了测试。结果表明，农药流量在24—240mL／min范围内时，混药装置的药液流量相对偏差均小于4％。

Small flow high precision real-time dynamic detection and control of pesticide is a key problem which need to solve urgently for on-line mixing device. Flow rate passing the flow regulating valve is related to differential pressure between the upstream and downstream of the valve, fluid density and the valve opening. By developing the relation expression between flow rate and these three variables, real- time detection and control for pesticide flow rate can be implemented using the control valve. In order to meter and control the flow rate of water and pesticide by using flow meter and control valve respectively, the online mixing pesticide device is designed. The calibration method of control valve is proposed and the flow rate relation expressions are developed. The experiments are conducted for the designed mixing device. The experimental results show that the relative error of the pesticide flow rate is less than 4% as the pesticide flow rate is between 24 mL/min and 240 mL/min.