Preliminary R&D

Reflectance Sensors:

The Reflectance Sensors have a single infrared LED and a small phototransistor on the red board. It keeps track of the distance the AEV travels using the reflective tape on the wheel. In this lab, sensors help us control and monitor the distance that AEV traveled, they are important and necessary part in AEV.

Data Analysis Tool:

Code used:

/reverse
reverse(4);
// Accelerating motors
celerate(4,0,30,2);
//Run motors at constant speed 30
motorSpeed(4,30);
goFor(1);
  //Decelerate motors to 15
celerate(4,30,15,2);
  //REVERSE
reverse(4);
  //Accelerate motors to 25
celerate(4,15,25,2);
  // Run motors at constant speed 25
motorSpeed(4,25);
goFor(2);//Decelerate motors to 5
celerate(4,25,5,5);
  //brake
brake(4);
Graphs:
 
 In this graph, the AEV goes 0.1 meters while it accelerates. Once it was at a constant rate it wen to 0.23 meters. This then had the AEV go 0.6 meters at a constant speed. After the motor uses the most amount of power, the AEV goes 0.2 meters before the motors turn off. It then glides about 0.2 meters until the AEV stops by itself.
In this graph, the motors are accelerating for about 3 seconds. After, the AEV goes at a constant speed for about a second. Then, it slows down the motors for 2 seconds. After this, it uses about 8.6 watts to stop the AEV and reverse it. At 8 seconds the motors turn off and lets the AEV slow down by itself due to friction.

 

Concept Screening and Scoring:

For the concept screening and scoring matrices, five different prototypes were scored. With these scores, two prototypes were chosen to move onto the advanced research and design. For the concept scoring matrix (pictured below), many success criterias were chosen and given a weight to it. The lower the number was for each category, the worse it was. When the total score was calculated, if it was over 3, it was considered to move on. If the number was under 3, it was not considered at all. For the concept screening matrix (pictured above), these success criteria were then given +’s and -‘s. Depending on how many +’s, 0’s, and -‘s there were for each would determine if the design was moved on in the process.