摘要
针对土壤含水率电容传感器检测精度低,标定模型对盐渍土壤的适用性不高等问题,提出基于电导率对相对介电常数补偿的含水率电容传感器标定法。在标准溶液中建立相对介电常数与传感器输出电压关系对数模型(R^(2)=0.983),进一步基于二元二次回归分析法,建立标准溶液电导率对相对介电常数补偿的相对介电常数与传感器输出电压及电导率的回归标定模型(R^(2)=0.979)。对传感器进行土壤含水率标定,建立土壤体积含水率与相对介电常数关系的三阶多项式标定模型(R^(2)=0.996)。对两步标定模型进行实测,结果表明:土壤电导率为0~2 dS/m时,体积含水率检测最大误差从未电导率补偿时0.0383 m^(3)/m^(3)降至电导率补偿后0.0127m^(3)/m^(3),最大相对误差从12.0200%降至6.2241%。结果表明,在不同电导率的同类土壤中,使用基于电导率对相对介电常数补偿的含水率传感器标定法能明显提高土壤含水率检测精度和对不同电导率土壤(黄土)的适用性。
Soil moisture capacitive sensors exhibited issues with low detection accuracy and limited applicability of calibration models to saline soils.In order to solve these problems,a calibration method for moisture capacitive sensors based on conductivity compensation of the relative permittivity was proposed.Firstly,a logarithmic model between soil relative permittivity and sensor output was established in the standard solution,and the R^(2)of the model was 0.983.Furthermore,a regression calibration model of dielectric constant compensation for standard solution conductivity was established through the binary quadratic regression analysis,and the R^(2)of the model was 0.979.The calibration model was about relative permittirity,the output voltage and conductivity.Secondly,the third-order polynomial calibration model of the relationship between soil volume water content and relative permittivity was established according to the special calibration of soil sensor in soil sample,and the R^(2)of the model was 0.996.Finally,the above two-step calibration equation was verified by soil measurement.When the soil conductivity ranged between 0 dS/m and 2 dS/m,the detection error range of soil volumetric moisture content was reduced from 0.0383 m^(3)/m^(3)to 0.0127 m^(3)/m^(3),and the maximum relative error was reduced from 12.0200%to 6.2241%.The results indicated that,in similar soils with different conductivities,using the calibration method for moisture sensors based on conductivity compensation of the relative permittivity can significantly improve the accuracy of soil moisture detection and the applicability to loess soils with different conductivities.
作者
张西良
谢飞洋
盛庆元
倪梦瑶
张家祺
徐云峰
ZHANG Xiliang;XIE Feiyang;SHENG Qingyuan;NI Mengyao;ZHANG Jiaqi;XU Yunfeng(School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,China;School of Mechanical and Electrical Engineering and Transportation,Shaoxing Vocational and Technical College,Shaoxing 312000,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2024年第8期344-351,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(32071900)。
关键词
土壤含水率
含水率电容传感器
传感器标定
二元回归分析法
电导率补偿
soil moisture
moisture capacitance sensor
sensor calibration
binary regression analysis
conductivity compensation
