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11-16 3) Basic ABS Control Operation of ABS control unit ▶ Applications of the ABS control unit The signals produced by the wheel sensors are evaluated in the electronic control unit. From the information received, the control unit must first compute the following variables: Wheel speed Reference speed Deceleration Slip - - - - Reference speed ▶ The reference speed is the mean, I.e. average speed of all wheel speeds determined by simple approximation. Simplified ABS control ▶ If, during braking, one wheel speed deviates from the reference speed, the ABS control unit attempts to correct that wheel speed by modulating the brake pressure until it again matches the reference speed. When all four wheels tend to lock, all four wheels speeds suddenly deviate from the previously determined reference speed. In that case, the control cycle is initiated again in order to again correct the wheel speed by modulating the brake pressure. |