基于多频率交流阻抗测量的肉类水分检测方法

Meat moisture detection method based on multiple frequency measurement of AC impedance

为减小肉类生物组织在不同频率激励信号作用下等效阻抗稳定性的差异对水分测量精度的影响,提出一种基于多频率交流阻抗测量的肉类水分检测方法。依据Cole定律建立生物电阻抗数学模型,并利用模型数据仿真论证高频等效阻抗的稳定性。利用FIR数字滤波器以及软件滤波算法去除信号中的干扰信号,提高阻抗测量的精度。在此基础上采用最小二乘法原理通过对肉类生物组织Cole圆弧曲线的拟合和逼近,求解阻抗模型参数中的高频等效阻抗并以此表征肉类生物组织的水分含量。为验证该文肉类水分检测方法的优越性,对猪肉样本进行阻抗检测实验和水分测量实验。实验结果表明:采用该文方法可以对肉类生物体水分含量准确测量,最大测量误差<1%。

In order to reduce the impact of stability of biological tissue equivalent impedance under different-frequency excitation signal on the accuracy of the moisture detection, a meat moisture detection method based on multiple frequency measurement of AC impedance is proposed.The law of Cole is used as a foundation to establish the mathematical model of biological impedance. Data from the simulation model is adopted to analyze the stability of high frequency equivalent impedance. FIR digital filter and software filter algorithm are used to remove the interference signal with the purpose of improving the accuracy of the impedance measurement. The Cole circular curve of meat biological tissue is fitted and approximated by least square method to forecast the high frequency equivalent impedance in impedance model parameters to represent the moisture content in meat biological tissue. Impedance test and moisture measurement of pork are carried to verify the superiority of the meat moisture detection method in this paper. Experimental results show that the method can measure the moisture content in meat biological tissue accurately and the maximum measurement error is less than 1%.