基于数字 PI 算法的精准施肥控制系统设计及仿真

摘要

In order to make the rate of fertilization consistent with the speed of the machine, this paper presents a closed loop fertilization system based on the digital PI algorithm. It mainly consists of sensor, PLC, pulse width modulation mo-tor driver( PWM driver) , GPRS module and DC brushless motor. According to the speed of the tractor and the outer groove wheel, PLC makes PWM driver to control the speed of the external groove wheel by the input decisions, so as to realize the precision fertilization. The simulation and the experimental results show that the closed loop control system of the digital PI algorithm can improve the precision and speed of fertilization. The whole set of equipment is simple in operation and stable in the field.%为了使施肥速度与机器行进速度同步，提出了一种基于数字 PI 算法的闭环施肥系统，主要由传感器、PLC、脉宽调制电机驱动器( PWM 驱动器)、GPRS 模块及直流无刷电机组成。通过检测拖拉机的速度信号及外槽轮转速， PLC 根据所输入决策经 PWM 驱动器对外槽轮下料速度进行闭环控制，从而实现精准施肥。仿真实验结果表明：基于数字 PI 算法的闭环控制系统提高了施肥精度和响应速度，机具操作简单，在田间工作性能稳定。