基于归一化植被指数的变量施肥控制系统研究

Research on control system of variable rate fertilizer applicator in precision agriculture based on NDVI

研究表明,归一化植被指数(NDVI)可以很好地预测潜在产量和判断当时作物氮的吸收情况并最终预测最优施氮量。本系统是一个集成光学传感和施肥控制装置的实时自动变量施肥系统,它根据实时监测的作物光谱信息和施肥机具的实际前进速度调节施肥量。系统采用无损测试技术和模糊控制算法,实际操作时通过光传感器实时获取归一化植被指数,并使用施氮优化算法(NFOA)计算潜在产量和施氮量,结合施肥机具行进速度调节实施机构中水用电磁阀的开闭,实现实时变量施肥。

The normalized difference vegetative index can be availably used in predicting potential yield, judging crop absorption of N fertilizer of the time and finally determining the most effective quantity of N fertilizer. This system is a fertilizer application system with automatic vaiables which integrated optical sensing with application, which adjusts applying quantity of N fertilizer by real-time measuring spectrum data of crop and the speed of the tractor. The system employs a kind of measuring technology without damaging effect and adopts fuzzy control algorithm. It acquires the real-time value of Normalized Difference Vegetative Index by optical sensors, and accordingly calculates potential yield and applying quantity of N fertilizer using Nitrogen Fertilizer Optimization Algorithm, and simultaneously considers the speed of the tractor of the time to determine open or close of electromagnetic valves to variably apply fertilizer in real-time.