by David Miller, Clemson Automotive Engineering Graduate Student
The following video demonstrates how a wheel speed sensor works:
The variable reluctance sensor is a current-carrying coil. It measures the change in inductance as the magnetic field changes due to the variations in the tooth ring.
The tooth ring is steel and has evenly spaced teeth which, when rotated, generate the signal used to calculate wheel speed. The center bracket was custom machined for this project out of aluminum by Gary Mathis of CU-ICAR
The basics of the wheel speed sensor:
A vehicle's computer will only receive the wheel speed sensor signal as a pulse stream. The computer can then use this information to calculate the wheel speed and use it for any applicable system. To show how a computer might calculate wheel speed from the input signal, the wheel speed in RPM is calculated as follows:
