Modeling and simulation analysis of capacitive position sensor based on FEM to identify metal objects

Ao  Feng

doi:10.6180/jase.202501_28(1).0012

Modeling and simulation analysis of capacitive position sensor based on FEM to identify metal objects

Aerospace Engineering

Ao FengThis email address is being protected from spambots. You need JavaScript enabled to view it.

School of Automation, Shenyang Aerospace University, Shenyang, China, 110000

Received: April 16, 2023
Accepted: February 4, 2024
Publication Date: March 27, 2024

Copyright The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited.

Download Citation: ||https://doi.org/10.6180/jase.202501_28(1).0012

The long development of the economy requires modern industries to gradually achieve more advanced production capacity for example position measurement of metallic objects. In this paper, a five-terminal capacitive position sensor is proposed and a simulation modeling analysis based on Finite Element Method (FEM) is performed to identify metal objects by the capacitive position sensor. A simplified simulation model of the five-terminal capacitive position sensor is constructed by Comsol software to investigate the sensing principle of metal object proximity and the sensing capability of the sensor, and the direct solver and iterative solver have analyzed the effect of direct and iterative solvers on the accuracy and time efficiency of the simulation result. The direct solver is selected and the full coupling method is used to deal with the problem of a nonlinear system of equations. The simulation results show that the dynamic detection range of the five-terminal capacitive position sensor for metal objects is 10 cm − 20 cm, and the sensitivity of the sensor is highest when the metal object is 14 − 18 cm away from the sensor. The sensor model built in this paper can sense the position of metal objects in space, which shows that the model is superior to the design of position sensors at the simulation level, enriches the sensor types and develops the metal object position measurement technology.

Keywords: Capacitive sensor; Location detection; Metal object detection; Finite element method

[1] S. Yamazaki, H. Nakane, and A. Tanaka, (2002) “Basic analysis of a metal detector" IEEE Transactions on Instrumentation and Measurement 51(4): 810–814. DOI: 10.1109/TIM.2002.803397.
[2] Z. Liu and Y. Lai, (2005) “Research development of position sensor technique" Journal of Transducer Technology 24(10): 5–7. DOI: 10.13873/j.1000-97872005.10.002.
[3] Y. Wen, S. Yin, Z. Wang, and et al, (2022) “Optimal design and sensitivity analysis of array capacitance sensor" Journal of Electronic Measurement and Instrumentation 36(2): 229–234. DOI: 10.13382/j.jemi.B2104302.
[4] Y. Zheng. “Design of parallel-plate capacitor based microdisplacement detecting system". (mathesis). China: Dalian University of Technology, 2010.
[5] Y. Bai, Z. Zhou, and e. a. H. Tu, (2009) “Capacitive position measurement for high-precision space inertial sensor" Frontiers of Physics in China 4(2): 205–208. DOI: 10.1007/s11467-009-0019-5.
[6] S. Bera, J. Ray, and S. Chattopadhyay, (2006) “A lowcost noncontact capacitance-type level transducer for a conducting liquid" IEEE Transactions on Instrumentation and Measurement 55(3): 778–786. DOI: 10.1109/TIM.2006.873785.
[7] S. C. Bera and H. Mandal, (2012) “A flow measurement technique using a noncontact capacitance-type orifice transducer for a conducting liquid" IEEE Transactions on Instrumentation and Measurement 61(9): 2553–2559. DOI: 10.1109/TIM.2012.2192345.
[8] P. Zhang. “Research on the mechanism of disturbance of radio energy transmission system by metallic obstacle". (mathesis). China: Tiangong University, 2016.
[9] C. Chen, X. Huang, W. Sun, and et al, (2014) “Impact of metal obstacles on wireless power transmission system based coupled resonance" Transactions China Electrotechnical Society 29(9): 22–26. DOI: 10.19595/j.cnki.1000-6753.tces.2014.09.005.
[10] W. Shi, F. Grazian, J. Dong, and et al. “Detection of metallic foreign objects and electric vehicles using auxiliary coil sets for dynamic inductive power transfer systems”. In: Delft, Netherlands: IEEE, 2020, 1599–1604. DOI: 10.1109/ISIE45063.2020.9152424.
[11] H. Zhang. “Research on metal object detection and position guiding of wireless power transfer system in electrical vehicle". (mathesis). China: Shanghai Jiao Tong University, 2019.
[12] K. Du, G. Zhu, J. Lu, and et al, (2022) “Metal object detection method in wireless electric vehicle charging system" Journal of Zhejiang University (Engineering Science) 56(1): 56–62+74. DOI: 10.3785/j.issn.1008- 973X.2022.01.006.
[13] V. X. Thai, G. C. Jang, S. Y. Jeong, and et al, (2019) “Symmetric sensing coil design for the blind-zone free metal object detection of a stationary wireless electric vehicles charger" IEEE Transactions on Power Electronics 35(4): 3466–3477. DOI: 10.1109/TPEL.2019.2936249.
[14] Anon, (2011) “Gefran’s new 0NP1-A magnetostrictive linear position transducer has ONDA noncontracting design flexibility" Assembly Automation 31(1): 93–95. DOI: 10.1108/aa.2011.03331aad.001.
[15] G. Donoso and L. L. Celso, (2016) “Measuring nonlinear oscillations using a very accurate and low-cost linear optical position transducer" European journal of physics 37(6): 1–2. DOI: 10.1088/0143-0807/37/5/055301.
[16] T. Kelemenov, M. Dovica, E. Jakubkovic, and et al, (2017) “Condition evaluation of optical position sensor" Journal of Automation and Control 5(2): 37–40. DOI: 10.12691/automation-5-2-1.
[17] Y. Z. Bai, Z. B. Zhou, H. Tu, and et al, (2009) “Capacitive position measurement for high-precision space inertial sensor" Frontiers in Physics 4(2): 205–208. DOI: 10.1007/s11467-009-0019-5.
[18] Y. Zhang, A. S. Sezen, and R. Rajamani, (2021) “A low-profile supercapacitor-based normal and shear force sensor" IEEE Sensors Journal 21(1): 239–249. DOI: 10.1109/JSEN.2020.3014174.
[19] L. Areekath, B. George, and F. Reverter, (2021) “An auto-balancing capacitance-to-pulse-width converter for capacitive sensors" IEEE Sensors Journal 21(1): 765– 775. DOI: 10.1109/JSEN.2020.3014206.
[20] K. Xiang, W. Wang, and Z. Chen, (2022) “Analysis of main error sources for the error motion measurement of a precision shafting using a t-type capacitive sensor" Micromachines 13(2): 221–222. DOI: 10.3390/MI13020221.
[21] R. Dai, N. Jin, Q. Hao, and et al, (2022) “Measurement of water holdup in vertical upward oil-water two-phase flow pipes using a helical capacitance sensor" Sensors 22(2): 690–693. DOI: 10.3390/S22020690.
[22] F. Mo, Y. Huang, Q. Li, Z. Wang, R. Jiang, W. Gai, and C. Zhi, (2021) “A Highly Stable and Durable Capacitive Strain Sensor Based on Dynamically Super-Tough Hydro/Organo-Gels" Advanced Functional Materials 31(28): 2010830. DOI: https: //doi.org/10.1002/adfm.202010830.