Xj. Li et al., THE APPLICATION OF THE CAPACITORS PHYSICS TO OPTIMIZE CAPACITIVE ANGULAR-POSITION SENSORS, IEEE transactions on instrumentation and measurement, 46(1), 1997, pp. 8-14
The distributions of the potential and charge density in a capacitive
angular-position sensor with three electrode disks in an axis-symmetri
cal configuration have been found by creating a suitable physical mode
l and solving Laplace's equation, The influences of geometrical parame
ters on the nonlinearity, which originates from the electric-field-ben
ding effect, are discussed in detail for a capacitive angular-position
sensor, The approximately analytical results are verified by a numeri
cal analysis and are found to be very useful to predict the influences
of geometrical nonidealities, The calculations are experimentally ver
ified by using a novel, absolute angular-position sensor with a nonlin
earity of less than +/- 17'' and +/- 50'' over measurement ranges of 1
5 degrees and 90 degrees, respectively.