基于PLC的液压无级调速变量施肥控制系统的研究

Study on Hydraulic Stepless Speed Control System Based on PLC of the Variable Rate Fertilizer

设计了以PLC为控制核心、液压马达为执行机构的变量施肥控制系统。该系统由PLC控制器、信号采集单元、液压传动控制组成,通过使用step7-Mico/win32 V3.2编程软件实现了手动控制、GPS导航定位和无GPS定位三种变量施肥工作模式,并对其进行了控制精度试验。试验表明:在机具速度为6km/h,施肥量为300~1280kg/ha范围内时,马达转速的系统控制误差≤8%。

A set of control system with a PLC as a control core and a hydraulic motor as executing unit was designed to realize the variable rate fertilization.This system was made of a PLC controller,a signal collecting unit,a hydraulic steering controller.By using step7-Mico/win32 V3.2 software,three kinds of working patterns for variable rate fertilization,e.g.,manual control,GPS navigation and non-GPS guidance were developed.The control accuracy test was carried out.The test results showed that the control accuracy of the motor’s speed was less than 8% when the fertilizer dosage is 300 kg/ha^1280 kg/ha and ground speed at 6 km/h.