Abstract: Aiming at the problem of lacking effect moisture detection method for large grain pile, it proposes a new method using electromagnetic wave detection to overcome the shortcomings of traditional methods such as poor precision, complexity and so on. Based on the principles of reflection and refraction of electromagnetic wave on different media interface, it obtains the dielectric constant of grain surface, according to the law of reflection and refraction, it uses the surface dielectric constant to infer the distribution of dielectric constant in other grain lays, and based on a permittivity-moisture model, it transforms the permittivity distribution into the moisture distribution, thus, to simulate a whole grain pile moisture distribution. This method has the advantages such as high precision, quick detection and so on, which helps to improve the level of moisture detection for large grain pile.

Key words: electromagnetic wave detection, dielectric constant, reflection, refraction, permittivity-moisture model

摘要： 针对现有粮库缺乏有效的储粮水分检测技术的问题，研究一种利用甚高频电磁波快速检测大型粮堆内部水分的方法，用于克服传统抽样法和传感器法带来的测量精度差、代表性不足等缺陷。利用电磁波在粮堆中不同深度的反射和折射原理，获取粮堆表层介电常数，利用表层介电常数，根据菲涅尔公式，反演出粮堆其他层介电常数分布。根据一个介电-水分经验模型，将粮堆各层的介电常数分布转换为水分分布，从而模拟出整个粮堆三维立体水分分布图。实验结果表明，该方法具有检测精度高、速度快的优点，与传统方法相比，更适用于大范围的检测。

关键词: 电磁波探测, 介电常数, 反射, 折射, 介电-水分模型