This paper discusses the effects of mechanical errors of the cylindrical capcitive sensor (CCS) for active magnetic bearing (AMB) spindles, including the roundness error of a rotor and the mounting error of a sensor. The CCS has earned much interest as an AMB sensor due to its advantages of high resolution and spatial-averaging effect. An analytical model of the CCS is given and its spatial-averaging effect is shown quantitatively. The analytical model of the measuring process with the variation of sensor geometry shows that the CCS is more robust to roundness errors than the generally used probe sensor. This is verified through simulations and experiments on measuring orbits of rotors with harmonic roundness errors. In addition, the effects of mounting errors of the sensor are modeled and investigated. [S0022-0434(00)02601-0]

Issue Section:
Technical Papers
Keywords:
Cylindrical Capacitive Sensor, Error Analysis, Active Magnetic Bearing, capacitive sensors, error analysis, rotors
Topics:
Errors, Rotors, Sensors, Carbon capture and storage
1.
Chapman
,
P. D.
,
1985
, “
A Capacitive based Ultraprecision Spindle Error Analyser
,”
J. Prec. Eng.
,
7
, No.
3
, July, pp.
129
–
137
.
2.
Salazar
,
A. O.
,
Dunford
,
W.
,
Stephan
,
R.
, and
Watanabe
,
E.
,
1990
, “
A Magnetic Bearing System Using Capacitive Sensors for Position Measurement
,”
IEEE Trans. Magn.
,
26
, No.
5
, pp.
2541
–
2543
.
3.
Chang I. B., 1994, “A Study on the Performance Improvement of a Magnetic Bearing System Using Built-in Capacitive Type Transducers,” Ph.D. thesis, Seoul National University, Korea.
4.
Chung, S. C., 1996, “A Study on the Dynamic Characteristics and Control Performance Improvements of an Active Magnetic Bearing System for the High Speed Spindle,” Ph.D. thesis, Seoul National University, Korea.
5.
Mitsui, K., 1982, “Development of a New Measuring Method for Spindle Rotation Accuracy by Three-Points Method,” Proceedings of the 23rd International MTDR, pp. 115–121.
6.
Gao
,
W.
,
Kiyono
,
S.
, and
Sugawara
,
T.
,
1997
, “
Roundness Measurement by New Error Separation Method
,”
J. Prec. Eng.
,
21
, pp.
123
–
132
.
7.
Jay
,
F. Tu
,
Bernd
,
Bossmanns
, and
Spring
,
C. C. Hung
,
1997
, “
Modeling and Error Analysis for Assessing Spindle Radial Error Motions
,”
J. Prec. Eng.
,
21
, pp.
90
–
101
.
8.
Hammond
, Jr.,
J. L.
, and
Glidewell
,
S. R.
,
1983
, “
Design of Algorithms to Extract Data from Capacitance Sensors to Measure Fastener Hole Profiles
,”
IEEE Trans Instrum. Meas.
,
32
, pp.
343
–
349
.
9.
Ahn, H. J., Lee, S. H., and Han, D. C., 1999, “Precision AMB Spindles with Cylindrical Capacitive Sensors,” Proceedings of 10th World Congress on TMM(IFToMM), 5, pp. 2043–2048, Oulu, Finland, June 20–24.
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