Xiang Kui, Wang Wen, Chen Zichen
Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou 310027, China.
School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
Micromachines (Basel). 2022 Jan 29;13(2):221. doi: 10.3390/mi13020221.
As a key indicator reflecting the working accuracy of rotary functional units, the error motions of the precision shafting are very necessary to be measured. In this paper, the main error sources for the error motion measurement of a precision shafting using a T-type capacitive sensor were investigated. The theoretical modeling error due to the approximate simplification for the output capacitance expressions was firstly analyzed. By means of the 3D-FEA method, the influence of fringe effects was subsequently investigated. Finally, the analysis of electrode installation errors was emphasized on the tilt error of the cylindrical electrode and coaxiality error of the fan-shaped electrode by establishing mathematical models and numerical simulation. Based on the theoretical analysis and simulation results, the methods of decreasing the approximate error and the nonlinear error caused by fringe effects were subsequently proposed; for the installation errors, the tilt error of cylindrical electrode only makes the solution of phase angle have a certain deviation and has almost no effect on solving the radial displacement, especially for the measurement range less than 0.1 mm; the measurement of the rotor tilt displacement was basically not affected by the coaxiality error of the fan-shaped electrode.
作为反映旋转功能部件工作精度的关键指标，精密轴系的误差运动测量非常必要。本文研究了采用T型电容传感器测量精密轴系误差运动的主要误差源。首先分析了由于输出电容表达式的近似简化而产生的理论建模误差。随后通过三维有限元分析方法研究了边缘效应的影响。最后，通过建立数学模型和数值模拟，重点分析了电极安装误差，即圆柱电极的倾斜误差和扇形电极的同轴度误差。基于理论分析和仿真结果，提出了减小近似误差和边缘效应引起的非线性误差的方法；对于安装误差，圆柱电极的倾斜误差仅使相角的求解有一定偏差，对径向位移的求解几乎没有影响，特别是对于测量范围小于0.1mm的情况；转子倾斜位移的测量基本不受扇形电极同轴度误差的影响。
