  In this communication, we present a high resolution tactile plate that can
localize one or two contact fingers. The localization principle is based on
Lamb wave absorption. Fingers' contact will generate absorption signals while
Lamb waves are propagating in a thin finite copper plate. These signals can be
related to the contact positions and can be calibrated before the use of
tactile plate. Fingers' contact positions are calculated by finding the closest
calibration signal to the measured signal. Positions are carried out in less
than 10 ms with a spatial resolution of 2 mm for one finger localization.
Multi-points localization by this technology is developed and a two-point case
is initialized and tested. Several optimization methods are also presented in
this paper, as the double validation check which could improve the accuracy of
single-point localization from 94.63% to 99.5%.
