Hey there folks, my name is Michael. I'm an electrical engineering student at Clemson University and I'm going to tell you how a wheel speed sensor works. Now, normally there will be a gear on the wheel's axle and some sort of sensor that can detect when one of the gears teeth comes close to the sensor. In this video, I'm showing you an inductant sensor, but hall effect sensors are also frequently used. So one of the tooths from this gear comes close to the sensor, it causes a change in voltage. If you graph these changes as a function of time, you'll get some of these similar to the square wave shown here. By using some pretty sophisticated computers, we can count the number of rising edges on this graph in a given period of time. Using that information in this equation right here, we can figure out exactly how fast our wheel is turning in radians per second, which is an angular velocity. If we also know the radius of our wheel, we can turn that number into something like miles per hour, which is a linear velocity. And that, folks, is how a wheel speed sensor works.