基于视觉传感器的大田甘蓝对靶变量喷雾系统设计与试验

Design and Test of Vision Sensor-based Targeted Variable Spray System for Field Cabbage

摘要:

为改善甘蓝等高密度田间作物的机械化病虫害防治效果，解决传统的大田高地隙喷雾机农药用量大、作业效率低及存在的药液浪费等问题，本研究结合大田甘蓝的农艺特性，设计了一套基于视觉传感器识别的高地隙变量施药系统。利用Gemini 335型深度相机实时探测作物靶标，并融合脉宽调制技术（Pulse Width Modulation, PWM）实现农药的精准对靶变量喷洒。提出一种改进YOLO v8n的目标检测模型，通过田间试验测试，其检测精确率可达90.2%，提高1.5个百分点；检测速度提高7.6f/s，模型的检测精度得以改善，可满足甘蓝田间防治精度需求。设计电磁阀占空比的流量开闭测试模型，进行不同占空比测试，不同喷雾压力拟合决定系数R2均大于0.9，相关性显著。对整个系统集成并进行田间试验，变量喷雾模式，对靶变量喷洒的靶心雾滴沉积密度明显高于常量喷雾，平均雾滴密度增量为21.53个/cm2，甘蓝靶心区域覆盖率可达23.8%，且沉积均匀性高，变异系数仅0.4%。相比常量喷雾模式下，甘蓝表面整体覆盖率提升5.2个百分点，能够实现按需对靶变量施药且满足甘蓝的病虫害防治要求，整套系统作业性能稳定。研究结果可为高密度蔬菜等作物的田间管理与病虫害治理提供方法和思路，为高地隙精准施药防治技术植保应用提供参考。

Abstract:

Aiming to enhance the mechanized pest control effectiveness for high-density field crops like cabbage and address issues with conventional high-clearance sprayers that consume excessive pesticides, have low operational efficiency, and cause significant waste of pesticide solution. Based on the agronomic characteristics and pest control needs of field cabbage, a high gap variable application system was designed based on visual sensor identification. The Gemini 335 depth camera was used to detect the crop target in real time, and the PWM pulse width modulation technology was used to achieve the precise spraying of pesticides on the target variable. An improved YOLO v8n object detection model was proposed, which demonstrated 90.2% accuracy in field cabbage trials. The detection accuracy of the model was improved by 1.5 percentage points, and the frame rate (FPS) was increased by 7.6 frames per second. The detection accuracy of the model was improved to meet the precision requirements of field control of cabbage. An electromagnetic valve duty cycle flow control test model was designed and experiments were conducted with different duty cycles. The fitting decision coefficients R2 for various spray pressures were all above 0.9 with strong linear correlation. The integrated system underwent field testing to validate its performance. Field trials demonstrated that variable-rate spraying (VRS) achieved significantly higher target droplet deposition density in cabbage fields compared with conventional fixed-rate spraying. The VRS system showed an average droplet density increase of 21.53 particles/cm2, achieving 23.8% coverage with a minimal error margin of 0.4%. Compared with fixed-rate spraying, VRS enhanced overall cabbage surface coverage by 5.2 percentage points, enabling precise application tailored to pest and disease control needs while maintaining stable operational performance. This approach improved pesticide utilization efficiency and reduced waste. The research result can provide innovative methods for precision management of high-density vegetable crops and offer valuable references for precision application technologies in high-precision spray systems.