BMW G12 - Lane & Traffic Jam Deactivation Criteria

G12�Driver�Assistance�Systems
22.�Lane�&�Traffic�Jam�Assistant
141
• Speed�must�be�below�210�km/h.
• Above�70�km/h:�both�lane�edges�must�be�detected.
• Below�70�km/h:�both�lane�edges�or�a�vehicle�driving�ahead�must�be�detected.
• The�lane�width�must�be�sufficient.
• The�vehicle�should�be�positioned�as�centrally�as�possible�in�the�lane.
• There�must�be�a�sufficient�curve�radius.
• At�least�one�hand�must�be�on�the�steering�wheel�rim.
• The�turn�indicator�must�not�be�activated.
• The�camera�calibration�process�must�be�completed�immediately�after�vehicle�delivery.
The�active�lateral�control�function�with�data�evaluation�of�the�KAFAS�stereo�camera�is�implemented
with�the�assistance�of�the�lane�markings�identified�on�the�left�and�right.
In�order�for�the�system�to�be�activated,�two�lane�boundary�lines�must�be�detected.�Below�a�speed�of
approximately�70km/h�a�vehicle�driving�ahead�in�the�same�lane�is�sufficient�to�activate�the�system.
The�system�is�put�in�Standby�mode�if�the�marginal�conditions�are�not�satisfied�(e.g.�hands�not�on
steering�wheel,�lane�too�narrow�or�dazzling�of�KAFAS�stereo�camera).�Once�all�marginal�conditions
have�been�met,�the�system�is�re-enabled�automatically.
To�activate�the�system,�the�speed�of�the�vehicle�is�another�input�quantity�that�is�evaluated.�The�system
uses�these�values�to�decide�which�function�is�enabled.�As�mentioned�above,�the�threshold�values�are
set�as�follows:
• The�traffic�jam�assistant�can�be�enabled�within�a�speed�range�of�0�to�70km/h.
• The�lane�control�assistant�can�be�enabled�within�a�speed�range�of�70to�210km/h.
22.1.3.�Lane�change
For�a�lane�change�to�be�as�comfortable�as�possible,�the�steering�and�lane�control�assistant�including
traffic�jam�assistant�is�put�silently�into�Standby�mode�when�the�turn�indicator�is�activated�and
reactivates�itself�automatically�once�the�turn�indicator�is�back�in�its�initial�position�and�a�lane�change
has�occurred.
22.1.4.�Function�logic
The�main�function�logic�of�the�lateral�guidance�is�implemented�in�the�optional�equipment�system�(SAS)
control�unit.
The�majority�of�the�data�for�the�function�is�provided�by�the�KAFAS�stereo�camera,�where�algorithms�for
the�lane�and�object�detection�run.
Vehicle�dynamics�data,�such�as�the�driving�speed,�wheel�speeds,�yaw�rate,�steering�angle,�lateral
acceleration,�longitudinal�acceleration,�etc.,�is�provided�by�the�rest�of�the�vehicle�network�via�a�FlexRay
or�CAN�connection.
A�target�trajectory�(also�known�as�a�path�curve)�is�calculated�in�the�optional�equipment�system�(SAS)
control�unit.�This�is�used�to�determine�whether�a�steering�correction�is�required.