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ANTI-LOCK BRAKE SYSTEM (ABS)
CHAS
A
B
Brake force
Side force
Slip ratio(%)
Friction force between the
tire and road surface
Friction force between the
tire and road surface
Less slippery
road surface
Controlling zone
Slippery road surface
Slip ratio(%)
Slip ratio
When the brake is applied, slipping occurs be-
tween tires and road surface, then the difference
is made between the wheel speed and chassis
speed. This is called a slip.
Slip ratio is the value to show the rate of slipping
and defined by the following formula.
Slip ratio =
Chassis speed – Wheel speed
Chassis speed
100 (%)
0%:
There is no slip between wheels and road
surface providing the complete rotation
of wheels.
100%: The wheel speed is “0”, i.e. the state of
wheel locking.
BRAKE FORCE AND THE VEHICLE STABILITY
When the brake pressure is increased, it brakes
the wheel and the slip occurs between the tire and
road surface to generate the brake force. The limit
of this brake force is determined by the friction
force between the tire and road surface and has a
close relation with the state of slipping. Slipping
state is shown by the slip ratio.
Therefore, the side force has also a close relation
with the slipping state . Figure A shows the rela-
tion of them. If the vehicle is braked while keeping
the proper slip ratio, it is possible to gain the maxi-
mum brake force without losing the much side
force.
The ABS has a function which allows these tire
characteristics to bring their ability into full play on
the slippery or less-slippery road. (Figure B )
Содержание YP250A 1999
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Страница 48: ...40 ANTI LOCK BRAKE SYSTEM ABS CHAS ABS CONNECTOR LOCATION CHART ...
Страница 76: ...68 ANTI LOCK BRAKE SYSTEM ABS CHAS 6 Install Wheel sensor lead 1 ...