Yamaha YP250A 1999, Дополнительное руководство по обслуживанию

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ANTI-LOCK BRAKE SYSTEM (ABS)
CHAS
Vehicle speed
Wheel speed
Pressurizing
Decompressing
Brake force
NOTE:
WHEEL SLIP AND THE HYDRAULIC CON-
TROL
The ABS computer calculates each wheel speed
according to the rotation signal receiving from the
front and rear wheel sensors. In addition, the com-
puter calculates the vehicle travel speed and rate
of speed reduction with wheels based on the
wheel speed values.
Differences between the travel speed and wheel
speed of wheels calculated as above are equal to
the wheel slip. When the wheel tends to lock, the
wheel suddenly reduces its speed. When the slip
of wheel and speed reduction rate of wheel ex-
ceeds the preset value, the ABS computer judges
that the wheel is in the tendency to lock. If the slip
is large and the wheel tends to lock (A point in the
figure), the ABS computer decompresses the
brake fluid of caliper and increases the pressure
when the locking tendency disappears (B point in
the figure).
If slip is large and the wheel tends to lock (A point
in the figure), the ABS computer executes the
pressure reduction and increases the pressure
when the locking tendency disappears (B point in
the figure).
ABS OPERATION AND THE VEHICLE CON-
TROL
When the ABS is activated, it means that the
wheel has a tendency to lock and the vehicle con-
trol is close to its limit. To recognize this vehicle
condition, the brake lever is designed to generate
the reaction force.
Reaction force to the brake lever while the ABS
works is normal.