喷杆式施药机对行喷雾控制系统设计与试验

针对现有大田喷杆式施药机喷雾过程中喷头无法精准对行喷施造成农药浪费的问题,基于机器视觉技术设计了喷杆式施药机对行喷雾控制系统。该系统包括作物行中心线位置提取上位机软件和电动喷杆控制系统,利用工业相机获取作物行RGB图像,采用G-RTG-BT算法及形态学处理实现作物行分割,基于改进的垂直投影法获取作物行中心线,利用坐标系转换实现将作物行中心线位置信息转化为喷杆横向偏移量,并经RS2 3 2串口传输至ATMega1 6控制器,控制推杆电机带动喷杆在滑轨上左右移动,借助位移传感器实时监测喷杆移动距离,以实现作物行追踪和对行喷雾控制。实验室和田间试验表明:改进的作物行中心线提取算法平均耗时12.51ms,喷杆横向偏移量计算误差小于0.44cm;电动喷杆右移最大误差0.3cm,左移最大误差0.5cm;小车速度为0.26m/s时,对倾角为5°、10°、15°模拟作物行的最大对行误差分别为3.22、2.86、2.51cm;小车速度为0.2 4 m/s,最大偏移1 4.0 2 cm时,对田间玉米幼苗的对行喷雾最大误差为4.8 6 cm,为实现作物行追踪和对行喷雾控制提供了一种有效的解决方案。

Design and Experiment of Row-follow Control System for Boom Sprayer

Spraying in fields using a boom sprayer whose nozzles couldn't follow crop rows precisely always causes environmental pollution and much waste of pesticides.In order to solve that problem, a row-follow control system for boom sprayer was designed based on machine vision, which included a upper computer software for crop rows centerline position extracting and an electric boom control system.Crop rows RGB images acquired by a CCD camera were analyzed by G-R>T&G-B>T algorithm, morphology processing and centerline extracting based on a modified vertical projection method.Then the line of the crop row was obtained, and the electric boom adjustment parameters were calculated by means of axes transfer.An ATMega16 controller received the parameters through an RS232 serial port form upper computer, and adjusted the electric boom to the left or right with movement monitoring by a displacement sensor.Experiments were conducted in the lab and field.The results showed that the modified algorithm of crop row centerline extracting cost 12.51ms in average with calculation errors of 0.44 cm.The electric boom adjustment error was less than 0.3 cm when shifting right, and less than 0.5 when shifting left.The row-follow control error was less than 3.22cm, 2.86cm and 2.51cm under the speed of 0.26m/s, when following simulated crop rows with obliquity of 5°, 10° and 15°, while less than 4.86cm when following the rows of corn seedings with the speed of 0.24m/s and the shifting of 14.02cm.It provided an effective solution for crop rows tracting and row-follow spraying.