Gw. Dejong et Gcm. Meijer, AN EFFICIENT RETRIEVING ALGORITHM FOR ACCURATE CAPACITIVE POSITION SENSORS, Sensors and actuators. A, Physical, 58(1), 1997, pp. 75-84
In capacitive position sensors many problems of mechanical origin can
be solved by using well-designed multi-capacitance sensing elements. T
his paper discusses a new and efficient algorithm to retrieve the meas
urand from data measured using multi-capacitance capacitive elements.
An overview is presented of the entire capacitive position-sensor syst
em and shows that the design aspects of the various system parts and t
he retrieving algorithm are closely related to each other. After formu
lating four basic requirements, the complete set of retrieving algorit
hms satisfying these four basic requirements is derived in a mathemati
cal way. From this complete set, an optimum algorithm is selected, wit
h respect to the smallest non-linearity possible, by applying the tech
nique of fine tuning. Numerical simulations and experiments show that
this algorithm is very effective in obtaining a high accuracy and a lo
w cross-sensitivity.