The parking assistance system provides the driver with information
whilst reversing relating to distance when approaching obstacles
which are behind the vehicle, which could be outside the driver's
field of view.The information that there is an obstacle
and its distance is transmitted to the driver by means of acoustic
signals whose frequency varies according to the distance of the
vehicle from the obstacle.An electronic control unit activates and
controls the operation of the four sensors located in the rear bumper,
processing the signals received and activating the acoustic signal
inside the luggage compartment on the left hand side.The system is activated when reverse gear
is engaged: under these conditions the control unit energizes the
transducers and sends them a request signal, receiving response
signals.The ultrasound technology sensors act as
intelligent transmitters/receivers through a triangulation technique:
this allows improved detection in critical situations or in the
presence of small obstacles. The impulses emitted are reflected
by any obstacles; the transducer therefore receives an echo which
is converted into a digital signal and sent to the electronic control
unit.The distance of the obstacle is signalled
by sounds with intermittent impulses: the frequency of this signal
increases gradually as the bumper approaches an obstacle: when the
distance calculated is less than about 30 cm, the sound becomes
high pitched and constant; the acoustic signal, on the other hand, ceases
when the distance of the obstacle increases.
For more details and information on the
operation of the system,
Characteristic of working principle 5580H parking obstacle detection
deviceThe control unit has an autodiagnostic function:
when it is switched on the control unit carries out an initial test
on the sensors.which are then continuously diagnosed during the
operation of the system.A fault with only one sensor inhibits the
operation of the entire system: in this case, the system excludes
itself: the failure status is signalled sending a suitable high
frequency acoustic warning.
The system is activated with reverse gear
engaged; the signal that the reversing light
See E2022 REVERSING LIGHTS
has
come on supplies the parking sensors control unit directly.