BMW I01, Информация о продукте

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I01�High-voltage�Components
4.�Electrical�Machine�Electronics
68
Activation�of�the�parking�lock
The�electromechanical�parking�lock�of�the�I01�including�its�operating�principle�and�activation�is
described�in�detail�in�the�section�"Electric�motor".�Therefore,�only�the�key�aspects�of�the�activation�are
mentioned�here.�The�electrical�machine�electronics�contains�the�following�components�required�for
the�parking�lock:
• Output�stage�for�the�activation�of�the�electric�motor�in�the�parking�lock�module
• Current�sensor�for�the�monitoring�of�the�electric�motor
• Evaluation�electronics�for�sensor�signals.
The�output�stage�for�the�activation�of�the�electric�motor�only�comprises�one�bridge�circuit�of�power
transistors.�It�is�able�to�supply�the�electric�motor�with�the�necessary�current�of�about�3 A�to�4 A�during
the�operation,�as�well�as�supply�the�high�starting�current�for�the�electric�motor�of�up�to�10 A.�The
bridge�circuit�is�designed�so�that�it�will�not�suffer�damage�in�the�event�of�a�short�circuit�at�the�output
(current�limitation).�In�order�to�protect�the�electric�motor�and�the�line�against�overloading,�the�EME
control�unit�monitors�the�current�level�of�the�output�stage�and�also�restricts�it�if�required.�For�this
purpose,�the�output�stage�contains�a�current�sensor,�whose�signal�is�evaluated�by�the�EME�control
unit.
The�two�redundant�position�sensors�in�the�parking�lock�module�are�hall-effect�sensors.�The�EME
control�unit�provides�the�voltage�supply�for�the�sensors.�It�also�reads�in�the�signals�from�the�position
sensors,�validates�their�plausibility�and�evaluates�them.�Using�the�signals�of�the�position�sensors
the�EME�control�unit�determines�the�status�of�the�parking�lock�(engaged/disengaged)�and�makes
the�status�available�as�a�bus�signal.�This�is�read�in�for�example�by�the�EDME�control�unit�where�the
transmission�functions,�e.g.�engaging�the�drive�positions,�are�calculated.
The�familiar�graphic�from�the�chapter�"Electric�motor�>�Transmission >�Parking�lock"�shows�the
electrical�interface�between�the�parking�lock�module�and�the�electrical�machine�electronics.