五、防抱死制动系统

The ABS works by measuring how fast the wheels are turning during braking and comparing their speeds.If any wheel is rotating much slower than the others（on the verge of locking up and skidding），the system reduces hydraulic pressure to that wheel’s brake caliper.When that wheel’s speed matches the other wheels，the system applies normal hydraulic pressure.This can take place several times per second at each wheel.You feel the ABS working as rapid pulsations in the brake pedal.

Each wheel has a wheel speed sensor assembly.As the wheel rotates，the sensor sends electrical pulses to the ABS control unit.The pulse frequency varies with the wheel speed.

【译文】

防抱死制动系统通过在制动过程中测量车轮的转速并与其速度相比较来发挥作用。如果任何一个车轮比其他车轮旋转得慢（处于锁定和打滑的边缘），该系统即给那个车轮制动器卡钳降低液压。当此车轮速度与其他车轮相一致时，该系统施以正常液压。对于每一个车轮，每秒钟可以测量几次。您会在制动踏板上感到ABS发挥作用时的快速脉动。

每一个车轮均有车轮速度感受装置。车轮旋转时，感受器将电脉冲传递给防抱死制动系统控制装置。此脉冲频率随着车轮速度的变化而变化。