Lab 2 – External Sensors & System Analysis 1

Summary

Lab 02 consisted of two parts: Lab 02a and Lab 02b. The purpose of Lab 02a was to introduce the team to the external reflectance sensors, troubleshooting techniques and Arduino functions associated with the sensors attached to the AEV. Prior to Lab 02, a basic AEV was constructed with the two external sensors, called reflectance sensors, attached facing the side of the wheel covered in reflective tape. This setup was required so that the sensors could take readings as the wheels were rotating along the inside track. The next step was to test the reflectance sensors to make sure they were working so that they could be used to track and control the AEV’s position. First, the Arduino software was opened and a function named reflectanceSensorTest() was called under the 01_myCode tab. Second, the Arduino controller was connected to the computer using a USB cable and the code was uploaded. Third, the serial monitor was opened and set to 115200 baud and the start button was pressed on the Arduino board after 4 seconds. Finally, the wheel was rotated forward and backward and the serial monitor displayed increasing or decreasing marks based on the direction of rotation. Once the reflectance sensors had been tested and configured, a simple program was written to test the AEV on the inside track. The AEV did not run the first time, as the power percentage set for the propeller motors was not good enough for the AEV’s mass. After Adjusting the power in the Arduino code, however, the AEV moved swiftly to the gate as desired, despite it going out of control. The program code can be found in the appendices.

The purpose of Lab 02b was to familiarize the team with propulsion system efficiency and wind tunnel testing equipment in order to relate the AEV to real life objects. During lab 02b, wind tunnel testing techniques and equipment were employed to determine which propeller configuration out of puller 3030 or puller 2510 was more efficient and at what power settings the propeller performed the best. It was important to determine which power settings resulted in the highest efficiency because unlike other parts of the AEV, the electric motors that were provided are the only ones that may be used. During lab 02b, two wind tunnels were set up, one in each of the two configurations, and the potential was set to 7.4 volts, which is similar to what the fully charged lithium ion battery to be used in the AEV will provide. Data from the wind tunnels was collected and recorded and sent to the teams.

Takeaways

Lab 02 left the team with a basic understanding of the programming commands that will be used when designing the AEV control program. Additionally, the team learned how the reflectance sensors work and how to use wind tunnels to test the propellers.

Schedule

The lab will be completed on Tuesday, February 6th from 11:10AM – 12:30PM. Following the lab, the team will meet on Thursday, February 8th from 6:00PM-8:30PM to begin the progress report and complete as much of it as possible. If the progress report is not completed on Thursday, the team will meet again on Sunday, February 11th at 5:30PM and will work until it has been completed.

Meeting Notes

Date: 1 February 2017

Time: 6:00 P.M. (Remote – Skype)

Members Present: Gonzalo Diago, Trevor McDowell, Ryan Born, Khalid Musa

Topics Discussed: Progress Report re-do, and Lab 03 Progress Report

Objective:

Today, the group met in order to discuss the Progress Report re-do, as well as the Lab 03 Progress Report.

To Do:

  • Finalize AEV Designs (Drawings) (TM, KM, RB, GD)
  • Progress Report Re-do (TM, KM, RB, GD)
  • Lab 03 Progress Report

Timeline/Schedule

– The group will meet early next week, as of right now, Monday, to further discuss their plans for the upcoming Lab and AEV.

Decisions Made

  • The group will meet on Monday to continue working on the items discussed above.
  • The Group has also divided parts for the Lab 03 Progress Report.

Reflection

Last week went smoothly for the most part. Although many of the group members had midterms, were sleep deprived, and sick, the group was still able to accomplish all of their goals, and plan ahead. Some of the roadblocks that the group had to face this past week included conflict of schedules, unforeseen circumstances such as illness, and time constraints due to the combination of two labs into Lab 02.