Sensatech have
developed a capacitive sensor specifically for use on commercial or
public service vehicles as a collision warning device.
A version of the unit is intended as a
reversing sensor. This is activated when the driver engages reverse
gear. The sensor alerts the driver to many of the possible dangers,
which may be invisible behind their vehicle, by sounding an audible
alarm.
Capacitive sensors have advantages over the more frequently used ultrasonic devices for this application.
A
fundamental difference is that a capacitive sensor is a field sensing
device rather than a beam sensing device and as such is free from blind
spots which can occur between beam lobes. For instance, our sensors are
able to look through materials so a sensor could be placed internally
behind the bumper of a vehicle without the need for external holes
which ultrasonic devices require.
Capacitive sensors also exhibit low
sensitivity to target material type and orientation. A wire fence for
example would be detected as reliably as a brick wall by a capacitive
device whereas a beam device may have difficulty detecting it at all.
The Clarks International "Foot Gauge" is a
non-contact sensing system, developed by Clarks International and
Sensatech, which measures human feet. This allows for correct shoe
fitting and matching suitable footwear to retail customers.
The sensor arrays map each foot and software produces a measurement of each foot. These arrays each comprise of more
than 2000 individual electrodes. Signal processing takes into account
that only the sole of the foot is in contact with the mat and the
widest and longest parts of each foot are not in direct contact with
the sensor array.
Specialist software was created to do the reverse transform on the capacitive data to recreate the shape of the target object.
By including sensor within the carpet or
within display stands, a system can record the movements of people
throughout the retail environment. This would provide analysis of the
movement and the amount of people from when they enter the shop to when they leave.
Also, capacitive systems can be used as an
anti-theft mechanism. Any object will alter the electric field of the
sensor. When that object is moved the sensor will respond.
