Continental Automotive GmbH MARSKEYLESS 用户手册
DAIMLER MARS EIS ECU
– Homologation of LF-Driver Part
Author:
Dept.:
Sebastian Henke
E-B-D2-HW
Doc. name:
Process
Process
Hardware Description
DAI_MARS_EIS_Homologation.docx
Doc.
version
1.1
Page:
3/31
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Hella
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2 LF- Performance in Typical Application
In the MARS EIS ECU the Hella LF Driver Part is connected with Hella LF Antennas.
A UID
– also manufactured from Hella – is to be found inside or outside the vehicle, whether a special
occasion happens.
Here are some examples:
Here are some examples:
-
Passive Entry / Exit
A Person with the UID nears to the locked vehicle.
If he grabs the door handle capacitive unlock sensor is activated and the complete Keyless Entry
Protocol is started. The side LF antenna is transmitting LF data and a carrier signal, which can be
recognized and judged by quantity (RSSI-measurement) by the UID.
The measured field strength is sent to the ECU and is judged.
If the magnetic field strength is high enough (a certain border is reached). The doors will unlock.
The additional LF communication guaranties the functionality, that only the valid key OUTSIDE the
vehicle authenticates the system to unlock the car passively.
If the magnetic field strength is not high enough (e.g. the UID is too far away from the vehicle, the
border is not reached), the UID shuts down again and waits for the next LF Data. The vehicle is still
locked.
A Person with the UID is leaving the vehicle. If he touches the capacitive lock sensor at the door
handle, the complete Keyless Exit Protocol is started:
The side LF antenna is transmitting LF data and a carrier signal, which can be recognized and judged
by quantity (RSSI-measurement) by the UID.
The measured field strength is sent to the ECU and is judged.
If the magnetic field strength is high enough (a certain border is reached). The doors will lock.
The additional LF communication guaranties the functionality, that only the valid key OUTSIDE the
vehicle authenticates the system lock the car passively. If the UID is left
inside the car, the car won’t
lock.
If the magnetic field strength is not high enough (e.g. the UID is too far away from the vehicle, the
border is not reached), the UID shuts down again and waits for the next LF Data. The vehicle is still
open.
If the magnetic field strength is not high enough (e.g. the UID is too far away from the vehicle, the
border is not reached), the UID shuts down again and waits for the next LF Data. The vehicle is still
open.
-
Passive Start
A Person with the UID inside of the vehicle is pressing the Start-Stop-Switch. The Start-Stop-Switch
activates the complete Keyless Start protocol:
The interior antenna is transmitting the LF Data and a carrier signal, which can be recognized and
judged by quantity (RSSI-measurement) by the UID.
The other two interior antennas IN1 and IN2 transmit two additional carrier signals sequential.
If the magnetic field strength of one of these transmits is high enough (a certain border is reached) then
the UID authenticates the system to start the vehicle.
If the magnetic field strength of all antenna transmits are too low (the field strength border is not
reached, maybe the UID is laying outside or is held 10cm outside the vehicle) the car won’t start.