Lab 1- Programming Basics
This lab allowed us to get used to the Arduino board and how to upload the codes from the computer to the board. The team practiced simple coding such as getting the motor to accelerate, run for a number of seconds, brakes and reverse. This lab went smoothly as the instructions were pretty straightforward and simple.
Lab 2- External Sensors
In this lab, the team had to first test if the reflectance sensors were working. Much of the lab time was spent on building the AEV. The team bumped into some problem when installing the reflectance sensors mainly due to instructional errors as well as the wire being plugged in the wrong way. It took a while to troubleshoot and solve this problem. There was no time to run the program however, the codes for this lab has already been written and it would just be a simple upload and run in the upcoming lab.
AEV Analysis for aR&D
Motor Configuration – aR&D week One [Distance vs Power graphed]
In this lab, the codes and weight (except for run 2) of the AEV were kept constant. Since the code allows the AEV to use the same amount of power over the same amount of time for each run, efficiency was based on how far the AEV moved.
- Run one (shown in blue) utilized two motors placed side by side. This is the least efficient as using 106.561J, it traveled about 6.67m.
- Run two (shown in purple) utilized motors aligned about 3 inches above the AEV base, attached to a vertically oriented AEV base. This model came in third in efficiency as it used 105.875J to travel about 7m
- Run three (shown in yellow) utilized two motors placed on the top ends of the plane. This model came in second in efficiency as it used 104.333J to travel about 8.5m
- Run four(shown in red) utilized motors placed on the bottom ends of the plane. This is by far the most efficient model as it used 104.831J in about 9.33m
This is reinforced by an experiment done by NASA in 1985 where the the distance between the motors causes a difference in air disturbance and drag.
“A semispan wing/body model with a powered propeller has been tested to provide data on the total power plant installation drag penalty of advanced propfan-powered aircraft…Test results indicated that the total powerplant installation drag penalty can be as high as 77 drag counts (0.0077). However, the penalty was reduced to 18 drag counts by the addition of a wing leading edge extension, between the nacelle and body, in combination with a fillet and strake at the wing-nacelle intersections.”
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880004710.pdf
Key Takeaways
The team is trying to model this AEV based on efficiency as we see this as a long term project. While the initial cost of the AEV may be slightly higher, but the team believes that over time, it will pay off in terms of financially and environmentally. In the future, if time isn’t a constrain, the team might want to further test and find the optimal distance between the two motors.
The team will also be adjusting codes and deciding the most efficient codes to use when the test on the non-straight track begins. This brings in a totally new challenge as all the tests have been conducted on the straight line track. The team will have to take into account the acceleration and deceleration when on the slopes.
Current Design
