BMW I01 Product Information page 54

I01￿High-voltage￿Components
3.￿Electric￿Motor
In￿order￿to￿generate￿the￿drive￿torque￿using￿the￿electrical￿machine,￿the￿phase￿voltages￿(size,￿frequency
and￿phase)￿have￿to￿be￿generated￿at￿the￿coils￿of￿the￿electrical￿machine.￿This￿task￿is￿not￿completed￿by
the￿EDME￿itself,￿but￿by￿the￿electrical￿machine￿electronics￿EME.￿Via￿bus￿signals￿on￿the￿PT-CAN2￿the
EDME￿sends￿the￿requested￿drive￿torque￿to￿the￿EME.￿The￿EME￿control￿unit￿then￿calculates￿the￿phase
voltages￿and￿the￿power￿electronics￿of￿the￿EME,￿which￿is￿located￿in￿its￿own￿housing,￿generates￿the
phase￿voltages.
Shift-by-Wire￿function
Another￿important￿function￿of￿the￿drive￿control￿is￿the￿shift-by-wire￿function,￿which￿evaluates￿the
electronic￿gear￿selector￿switch￿and￿other￿signals,￿in￿order￿to￿simulate￿the￿drive￿positions￿of￿a
conventional￿automatic￿transmission￿(P ,￿R,￿N,￿D).
The￿change￿between￿the￿drive￿positions￿is￿achieved￿in￿the￿I01￿the￿same￿way￿as￿in￿conventional
vehicles￿with￿automatic￿transmission￿and￿electronic￿gear￿selector￿switch.￿Some￿important
preconditions￿and￿functions￿are￿listed￿below:
• Interlock:￿Change￿from￿P￿to￿another￿drive￿position￿only￿when￿driving￿readiness￿is￿switched￿on
• Shift￿lever￿interlock:￿Change￿from￿P￿or￿N￿to￿D￿or￿R￿only￿when￿brake￿pedal￿is￿operated￿at￿the
same￿time
• Change￿from￿P￿or￿R￿to￿N￿or￿D￿only￿when￿selector￿lever￿is￿operated￿at￿the￿same￿time
• Automatic￿engaging￿of￿P:￿P￿is￿automatically￿engaged￿from￿the￿other￿drive￿positions￿(at￿vehicle
standstill)￿if￿neither￿the￿brake￿pedal￿or￿accelerator￿pedal￿are￿operated,￿the￿driver's￿door￿is
open￿and￿the￿driver's￿seat￿belt￿is￿not￿inserted￿in￿the￿seat￿belt￿buckle.￿P￿is￿also￿automatically
engaged￿if￿the￿driving￿readiness￿is￿switched￿off
• Car￿wash￿function:￿When￿the￿driving￿readiness￿is￿switched￿on￿engage￿drive￿position￿N,￿switch
off￿driving￿readiness.￿N￿remains￿engaged.
As￿the￿transmission￿of￿the￿I01￿only￿has￿a￿fixed￿ratio,￿there￿are￿no￿gears￿and￿thus￿also￿no￿adaptive￿EGS,
no￿Sport￿program￿and￿also￿no￿manual￿program.￿The￿transmission￿also￿has￿no￿clutch￿to￿interrupt￿or
establish￿the￿power￿transmission.￿There￿is￿also￿no￿reverse￿gear￿in￿the￿transmission￿of￿the￿I01.￿The
following￿table￿shows￿how￿the￿drive￿control￿in￿the￿EDME￿realizes￿the￿individual￿drive￿positions:
Drive￿position
Drive￿D
Reverse￿R
Neutral￿N
Parking￿P
48
Activation￿of￿the￿electrical￿machine
Direction￿of￿rotation￿forwards,￿engine￿or
alternator￿depending￿on￿accelerator￿pedal
operation
Direction￿of￿rotation￿reverse,￿engine￿or
alternator￿depending￿on￿accelerator￿pedal
operation
Direction￿of￿rotation￿is￿specified￿by
movement￿direction￿of￿vehicle,￿torque￿is
adjusted￿to￿0 Nm
Standstill,￿torque￿at￿0 Nm
Actuator￿for￿parking
lock
Disengaged
Disengaged
Disengaged
Engaged