差动平行极板变极距电容式传感器的误差校正方法  

Method of Error Correction for Differential Parallel Plate Variable Distance Capacitive Sensor

作　　者：蒲明辉[1,2] 罗祺 张金皓 艾振军 苏飞 黄伟[1,2] PU Ming-hui;LUO Qi;ZHANG Jin-hao;AI Zhen-jun;SU Fei;HUANG Wei(School of Mechanical Engineering,Guangxi University,Nanning 530004,China;Guangxi Key Lab of Manufacturing System&Advanced Manufacturing Technology,Guangxi University,Nanning 530004,China;Intelligent Manufacturing Institute,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]广西大学机械工程学院,广西南宁530004 [2]广西制造系统与先进制造技术重点实验室,广西大学,广西南宁530004 [3]湖南科技大学智能制造研究院,湖南湘潭411201

出　　处：《仪表技术与传感器》2022年第3期33-39,共7页Instrument Technique and Sensor

基　　金：广西制造系统与先进制造技术重点实验室基金项目(20-065-40S001);广告科技重大专项项目(桂科AA18242033)。

摘　　要：差动式平行极板变极距电容式传感器应用广泛,但由于其存在差动电容器极板初始极距不同的问题,导致差动电容值非线性误差增大,影响了其测量精度。首先,基于差动式平行极板变极距电容器的工作原理,分析了误差产生机理;采用最小二乘法建立了误差分析模型,引入差动加权系数构建误差校正表达式,然后,利用线性拟合和残差平方和分析法求解差动加权系数的数值,进而对电容测量数据进行误差校正。仿真分析证明了误差校正方法的准确性和可行性。实验结果表明:使用该误差校正方法的非线性误差为2.79%,与直接差动法的非线性误差9.80%相比,非线性误差降低了71.53%,验证了该误差校正方法的有效性。The differential parallel plate variable distance capacitance sensor is widely used, but due to the different initial distance between the differential capacitor plates, the nonlinear error of the differential capacitance value increases, which affects its measurement accuracy.First, based on the working principle of differential parallel plate variable distance capacitor, the error generation mechanism was analyzed.The least square method was used to establish the error analysis model as well as the differential weighting coefficient was introduced to establish the error correction model, and then linear fitting and residual analysis were used to solve the numerical value of the differential weighting coefficient.Then the error correction of capacitance measurement data was carried out.Simulation analysis proved the accuracy and feasibility of the error correction method.Experiments show that the nonlinear error of the error correction method is 2.79%.Compared with the nonlinear error 9.80% of the direct differential method, the nonlinear error is reduced by 71.53%,which verifies the effectiveness of the error correction method.

关 键 词：差动电容 非线性误差 误差校正 最小二乘法 电容式传感器 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TH73[自动化与计算机技术—控制科学与工程]