基于PLC的药液配比系统设计与试验研究

Design and research of pesticide-liquid mixing system based on PLC

针对当前农药配比存在的利用效率低、多余农药无法回收、人与农药接触机会多、环境污染等问题,设计一种基于西门子PLC S7—200可编程控制器作为核心控制单元的药液配比系统。本设计采用柴油机作为柱塞泵的动力源,中间采用流量传感器与电流发生器作为信号源,最后通过步进电机控制蠕动泵,达到控制浓度的目的。试验证明该系统实现浓度随时可调,误差范围在0.02%内,满足实际喷药浓度要求。

In view of the current existing problems of pesticide ratio,such as the low use efficiency,unable to recycle the excess pesticide,the high opportunities of people contacting pesticide,environmental pollution,this paper designed a pesticide-liquid mixing system based on Siemens PLC S-200 programmable controller as the core control unit.This design used the diesel engine as a power source of the plunger pump,and took flow sensor and current generator as the source of signal.To adopted the stepper motor to control the peristaltic pump for achieving to the purpose of control concentration.This experiment proved that the system has realized the concentration can be adjusted at any time,within the error range was in 0.02%,satisfies the requirement of the actual concentration of spraying.