Reflectance Sensors
The AEV has a wheel attached to it that allows it to move along a rail. The wheel has reflective tape attached to it which allows the reflectance sensors to record 8 Marks per 1 revolution of the wheel, which is how many times light reflects off the tape and is recorded by the sensors. Marks can be converted into inches (1 Mark = 0.4785 inches) which can then be used to find the distance the AEV has traveled. The reflectance sensors can also be useful by allowing the user to tell the AEV to go to a certain position or to go a certain distance by inputting the amount of marks that distance is.