Reflectance Sensor

The situation provided for the team in the Reflectance Sensors lab taught the team the importance of running the reflectance sensor test as well as the procedure in which to do so. The lab provided the team with a set of lines that needed to be coded that would allow the team to test to see if the reflectance sensors have been set up correctly. Also, not only did the lab provide the team with the code but it gave the team a set of ideas to troubleshoot if the code or reflectance sensors do not work at any point in time.

The Reflectance Sensor Test is absolutely vital to make sure that the craft is fully functioning before use. The reflectance sensor measures exactly how many times the wheels have made a cycle with a conversion of  0.4875 inch to one mark. The code to use the sensor test is found here:

// accelerate all motors to 25% over 3 seconds
// set all motors to speed of 25%
// run motors for 2 second
// set motor speed of all motors to 20%
// run all motors for 2 seconds
// reverse all motors
// set motor speed to 25% (in reverse)
// run all motors in reverse at 25% for 2 seconds
// brake all motors.

The reflectance sensors had a specific way to attach them to the craft before running any tests. The proper orientation of the reflectance sensors is shown below:

(The reflectance sensors are the red chips just below the wheel nuts)

Notice that each sensor is facing inwards towards the wheel, and the way that wires are connected to each sensor. This orientation is key, and if there is any deviation from this exact configuration the sensors will not function.

Team D realized that without the reflectance sensors properly in place, the team could have run a test and the AEV would have not understood about how far it should go. This could possibly result in the craft running off of the track, even falling off or injuring someone in the process. Given that safety is one of the most integral aspects to the team’s designs, the group will make sure that this extends to this test and that it will be done before each and every test.