BRAKE CONTROL SYSTEM


  1. CONSTRUCTION


    1. Active type speed sensors, which can detect the rotational direction of the wheel, have been provided. This type of sensor contains a sensor IC, which consists of 2 Magnetic Resistance Elements (MREs).

    2. The magnet type rotor, which consists of N and S poles that are arranged in a circle, is integrated with the hub bearing inner race.

      Figure 1. Front Axle

      A019QGIC01
      *1 Front Speed Sensor *2 Sensor Rotor

      Figure 2. Rear Axle

      A019QX9C01
      *1 Rear Speed Sensor *2 Sensor Rotor

  2. OPERATION


    1. The active type speed sensor uses a sensor IC to detect magnetic field changes caused when the sensor rotor rotates, and the sensor outputs the detected information to the skid control ECU as digital pulses.

      A019QORE02

    2. To detect the rotation direction, the output waves are used to determine the relationship of the pulses that are generated by the 2 Magnetic Resistance Elements (MREs).

    3. Upon receiving this signal, the sensor IC outputs a forward or backward wave.

      A019R5PE02
      *1 Forward
      *2 MRE A: Hi
      *3 MRE B: Lo
      A019QOYE02
      *1 Backward
      *2 MRE A: Hi
      *3 MRE B: Hi

    4. The frequency of the output pulses is used to detect the vehicle speed. Because the active type sensor outputs digital pulses, it can detect vehicle speeds even when the vehicle is nearly stationary.

      A019R2KE02
      *1 Vehicle Speed
      *2 Sensor Output