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 sensors located in the rear bumper,
processing the signals received and activating the acoustic signal
inside the instrument panel. 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 sensors use ultrasound technology and
act as intelligent transmitters/receivers with triangulation technique:
this allows improved detection in critical situations or where small
obstacles are present. The impulses emitted are reflected by any
obstacles; the transducers 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 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 and sends a fault message, the failure status is signalled
to the instrument panel lighting up the dedicated warning light
and sending a suitable acoustic warning.
The signal that the reversing light has
been switched on
See E2022 REVERSING LIGHTS
is
managed by the Body Computer which forwards this information to
the parking sensor control unit via the CAN network.
Rear obstacles are not signalled if there
is a trailer
See E2050 TRAILER WIRING
.
The system is supplied via a circuit protected
by a specific fuse in the underfacia control unit.