Week 3
Situation
In Lab 02: External Sensors & System Analysis, the team became familiar with the use of the sensors and tested the different propeller designs in the wind tunnel. During the lab, most of the team worked on calibrating the sensors and writing the code so that the AEV could test run on the track, and one of the members went to test the propellers and collect data at the wind tunnel. The team was able to calibrate the sensors by using the special function call, and once that was complete the AEV could run along the rail using the code written for the lab. At the wind tunnel one of the members took data such as current, thrust scale reading, and RPM while testing different power levels. The sensors are key to the proper motion of the AEV, so it is optimal to gain familiarity with their basic functions now. Also, the wind tunnel testing provided the team with a basis to choose which propeller to use on the AEV.
Results and Analysis
The team was not able to prepare the AEV with enough time to run it on the overhead rail. By the end of the lab, the sensors were calibrated and ready along with the code, but there was not enough time to make a proper run.
In this lab the team learned how to use the “goToRelativePosition” and “goToAbsolutePosition” functions as well as the calibration function, “reflectanceSensorTest().” These functions will be essential in allowing the team to properly transport the R2-D2 unit since the commands allow for the AEV to move to precise locations of the track. With all the functions that learned so far, the team has the capability to write a code to move the AEV across the track at various speeds and to any distance desired.
From looking at the wind tunnel results, the team felt that the 3030 propellor configuration would work the best. This decision was reached since the 3030 provided a significantly larger amount of thrust when given the same power as the 2510. As seen in figures one and two, the 3030 reaches up to over 300 grams of thrust while the 2510 maxes out at a little under 225.
Figure 1: Thrust v. Power for the 2510 Propeller Configuration
Figure 2: Thrust v. Percent Power for the 3030 Propeller Configuration
Figure 3: Propulsion Efficiency vs.Advanced Ratio for the 3030 Propellor Configuration
Figure 4: Propulsion Efficiency vs. Advanced Ratio for the 2510 Propellor Configuration
Takeaways
- AEV – The team thought that the 3030 propellor configuration would be the best choice.
- AEV – The “goToRelativePosition” and “goToAbsolutePosition” functions will be very useful in moving the AEV specific distances acorss the track
- General – The team still needs to focus on using proper time management to get the most work done during labs as possible.