The first performance test required the team to create and run two AEV designs on the main test track and evaluate which one reaches and triggers the gate using the least amount of power. The AEVs were required to start at the beginning of the track, stop at the gate, then proceed through the gate. The team started by creating the two designs shown below which would be compared.
Cross-Base Design
Tee-Base Design
After the designs were created, a program was written for each design that would complete the requirements of the test. The codes are very similar to maintain a fair comparison between the designs but slight modifications to the stopping distances were required because the weight of the designs was different. After the codes were perfected, data was collected to compare the designs.
Code for Tee-Base AEV Design.
| Code | Comments |
|---|---|
| reverse(4); | //reverse both motors |
| rotateServo(30); | //rotate servo 30 degrees in positive direction |
| celerate(4, 0, 33, 2); | //accelerate both motors from 0% to 33% power over 2 seconds |
| motorSpeed(4, 33); | //continue both motors at 33% power |
| goToAbsolutePosition(241); | //continue previous settings until the AEV reaches 241 marks |
| brake(4); | //brake both motors |
| goToAbsolutePosition(317); | //coast until the AEV reaches 317 marks from starting point |
| rotateServo(-30); | //brake AEV by rotating servo 30 degrees in a negative direction |
| goFor(9); | //wait for 9 seconds |
| rotateServo(30); | //release servo by rotating 30 degrees in positive direction |
| celerate(4, 0, 30, 2); | //accelerate both motors from 0% to 30% power over 2 seconds |
| motorSpeed(4, 30); | //continue both motors at 30% power |
| goFor(3); | //continue current settings for 3 seconds |
| brake(4); | //brake both motors |
Code for Cross-Base AEV Design.
| Code | Comments |
|---|---|
| reverse(4); | //reverse both motors |
| rotateServo(30); | //rotate servo 30 degrees in positive direction |
| celerate(4, 0, 33, 2); | //accelerate both motors from 0% to 33% power over 2 seconds |
| motorSpeed(4, 33); | //continue both motors at 33% power |
| goToAbsolutePosition(243); | //continue previous settings until the AEV reaches 241 marks |
| brake(4); | //brake both motors |
| goToAbsolutePosition(318); | //coast until the AEV reaches 317 marks from starting point |
| rotateServo(-30); | //brake AEV by rotating servo 30 degrees in a negative direction |
| goFor(9); | //wait for 9 seconds |
| rotateServo(30); | //release servo by rotating 30 degrees in positive direction |
| celerate(4, 0, 30, 2); | //accelerate both motors from 0% to 30% power over 2 seconds |
| motorSpeed(4, 30); | //continue both motors at 30% power |
| goFor(3); | //continue current settings for 3 seconds |
| brake(4); | //brake both motors |
All code commands are explained in the Arduino Code Glossary.
The data collected shows the input power of the AEV over the distance traveled. Based on the data collected, the Tee-Base AEV design used less power in total to complete the test and the design costs $6,260 less to manufacture than the Cross-Base design. For these reasons, the Tee-Base design was chosen as the final design for our AEV.