Construction And Function - Honda Acura NSX 1991 Service Manual

TCS Control unit
Acceleration Control:
The TCS control unit gets signals from the wheel sensors about the rotational speed of each wheel. Traction control
is activated when the rotational speed of the driving wheels differs from the rotational speed of the driven wheels (i.e.,
vehicle speed).
Handling Control:
Based on signals about driving wheel and driven wheel rotational speeds, the control unit calculates the car's "yaw"
rate (i.e., the turn rate of the car's body). Based on signals from the steering angle sensor, the control unit also calculates
the yaw rate expected by the driver. If the difference between actual and expected yaw rates is substantial-that is,
if the direction of the car's body will exceed the driver's expected line -the control unit signals the throttle actuator,
which closes the throttle valve, thus reducing engine power and maintaining the expected line.
Rough Road Control:
Based on signals from the wheel sensors, the control unit detects a rough road based on frequency of wheel rotational
vibration. The control unit then signals the throttle actuator to relax engine power, thus improving acceleration efficiency.
Grip Control:
Based on signals about wheel speed and yaw rate, the control unit determines the efficiency of the grip of the tires on
the road and signals the throttle actuator to relax engine power if necessary, thus improving grip.
Acceleration
control .
Target slip
ratio
.
Speed difference in the
left and right wheels
right wheels
Actual
yew rate
Vehicle speed -
Advance acceleration
Tire grip control
- -
Rotational
v i b r a t i o n
Handling
actuator (step motor)
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control
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