Below is a picture of the reflectance sensors attached to an unfinished AEV design:
The function of the reflectance sensors is to measure distance/location by using a single infrared LED and a small phototransistor. The sensor works using reflective tape on one of the AEV’s wheels that the AEV uses to move along the track. The AEV uses two of these sensors so that it can tell when the wheel changes direction. The sensors record each time a non reflective surface passes over the sensor, and calls it a mark. For each wheel rotation, the AEV records 8 marks, 4 for each sensor. To convert marks to inches, the conversion .4875 marks to inches is used. For this project, being able to record distance traveled/location is crucial for completing the MCR. Without recording the distance traveled or the location of the AEV, moving the AEV to a predetermined location would be very difficult.
(All of the information above is adapted from “The Ohio State University Advance Energy Vehicle Design Project Reflectance Sensor User Manual”)