测量条干均匀度的平行板式电容传感器优化设计

Optimal Design of Parallel-plate Capacitance Sensors for Measuring Yarn Evenness

摘要:

条干均匀度一般是指纱线沿轴向粗细变化的均匀程度；检测纱线的微小变化对仪器灵敏度等指标提出了很高的要求,因此对电容传感器的结构尺寸进行优化设计是很有必要的；文章对平行板电容传感器检测纱线的原理进行了研究,并利用电磁场有限元分析软件ANSYS,构建了平行板式电容传感器三维模型,分析了传感器极板尺寸参数的变化对灵敏度和线性度两个优化指标的影响,提出多组传感器分段检测法,完成对电容传感器尺寸的优化；另外,针对平行板电容边缘发散电场对检测结果产生干扰的问题,提出等电位保护环法,并仿真验证其对电容传感器边缘效应的抑制作用；研究结果为平行板式电容传感器优化设计提供了依据。

Abstract:

Evenness refers to the uniformity of yarn in the axial direction. It is necessary to optimize the size of capacitive sensors, so as to detect little changes of yarn. The article studies the principle of detecting the quantity of yarn with parallel plate capacitance sensor, then constructs three-dimensional model using finite element analysis software to analyze the influence of size on sensitivity and linearity of sensors. Finally the optimal size is obtained with the method of muti-segmented detection. In addition, equipotential protection ring is proposed to restrain the interference caused by diverging electric field, and the method has been verified by ANSYS. The research results provide the basis for the optimal design of the parallel plate capacitance sensor.