Mhw. Bonse et al., FINITE-ELEMENT MODELING AS A TOOL FOR DESIGNING CAPACITIVE POSITION SENSORS, Sensors and actuators. A, Physical, 46(1-3), 1995, pp. 266-269
In this paper a short overview is given of the methods that are availa
ble for modelling the capacitance response of capacitive sensors. This
includes the influence of alignment errors and electrode errors (geom
etrical errors and defects) as well as parasitic capacitances. Three m
ethods are presented: direct calculation of the capacitance by solving
the electric-field equations; approximation of the capacitance by sim
plifying the electric-field distribution; and modelling using the fini
te-element method. The suitability of each of these methods for differ
ent purposes is discussed. Conclusions are that in most cases approxim
ations based on simplification of the electric field can be used to ge
t an impression of the capacitance response, while for more complicate
d cases and for higher accuracy the more time-consuming finite-element
method can or even must be used.