Error Analysis of a Spherical Capacitive Sensor for the Micro-Clearance Detection in Spherical Joints
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School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
2
School of Mechanical Engineering, Zhejiang University, Hangzhou 310027, China
3
State Key Lab of Fluid Power & Mechatronic Systems, Zhejiang University, Hangzhou 310027, China
*
Author to whom correspondence should be addressed.
Micromachines 2020, 11(9), 837; https://doi.org/10.3390/mi11090837
Received: 16 August 2020
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Revised: 30 August 2020
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Accepted: 1 September 2020
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Published: 3 September 2020
(This article belongs to the Special Issue Advances in Capacitive Sensors)
Spherical joints have attracted increasing interest in the engineering applications of machine tools, industrial robots, medical equipment, and so on. As one of the promising methods of detecting the micro-clearance in spherical joints, the measurement accuracy of a spherical capacitive sensor could be affected by imperfectness during the manufacturing and installation of the sensor. This work presents error analysis of a spherical capacitive sensor with a differential structure and explores the dependence of the differential capacitance on manufacturing and the installation imperfectness. Five error sources are examined: the shape of the ball and the capacitive plate, the axial and radial offset of the plate, and the inclined installation of the plate. The mathematical models for calculating the capacitance errors of the spherical capacitive sensor are deduced and validated through a simulation using Ansoft Maxwell. The results show that the measurement accuracy of the spherical capacitive sensor is significantly affected by the shape of plates and ball, the axial offset, and the inclined angle of the plate. In contrast, the effect of the radial offset of the plate is quite small.
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MDPI and ACS Style
Wang, W.; Qiu, W.; Yang, H.; Lu, K.; Chen, Z.; Ju, B. Error Analysis of a Spherical Capacitive Sensor for the Micro-Clearance Detection in Spherical Joints. Micromachines 2020, 11, 837. https://doi.org/10.3390/mi11090837
AMA Style
Wang W, Qiu W, Yang H, Lu K, Chen Z, Ju B. Error Analysis of a Spherical Capacitive Sensor for the Micro-Clearance Detection in Spherical Joints. Micromachines. 2020; 11(9):837. https://doi.org/10.3390/mi11090837
Chicago/Turabian StyleWang, Wen, Wenjun Qiu, He Yang, Keqing Lu, Zhanfeng Chen, and Bingfeng Ju. 2020. "Error Analysis of a Spherical Capacitive Sensor for the Micro-Clearance Detection in Spherical Joints" Micromachines 11, no. 9: 837. https://doi.org/10.3390/mi11090837
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