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Recognition stages:
1 Recording of fingerprint by capacitive
sensor
2 Generation of a grey step image
3 Processing of sensor data in control
unit (image processing)
4 Characteristic feature filtering
The fingerprint contains information in
the form of ridges, branches, whorls and
loops.
The front narrow side of the START button
forms a stop to prevent excessive deviation in
longitudinal direction.
Due to the combination with the START
button, there is a possibility of non-
recognition if excessive force (> 12 N) is
exerted with wet hands. For this reason, in
the case of a second attempt following non-
recognition, the system switches to a trigger
mode which constantly reads in images and
does not evaluate an image until adequate
quality has been achieved.
There are very few people who are not
suitable for matching to the system because
the fingerprint sensor is not able to recognise
any usable images.
Possible examples include very dry and
chafed hands or skin disease.
Such people cannot make use of the driver
identification system.
Fingerprint recognition
The fingerprint recognition function
compares a print to the fingerprints stored in
the driver identification control unit.
The system is based on the fact that every
person has a different fingerprint with
particular characteristic features (minutiae)
regardless of whether the prints are from the
same finger.
For comparison of two fingerprints, at least
80 % of the area being compared must
coincide.
To ensure accurate results, the shape of the
START button was designed such that the
user's finger is always applied in virtually the
same position.
Control Units
SSP287_103
SSP287_104
SSP287_105
