When the project began, the group assembled the AEV similar to the base AEV provided within the course resources pages. The AEV is displayed below.
Original AEV Prototype
During the reflectance sensor testing lab, the team decided to change the main AEV design to accommodate for the battery on top, rather than below. The code for the reflectance sensor test is available here. The reason for this design change was to ensure that the battery is secured safely so that it cannot fall while the AEV is travelling. The design described is pictured below.
AEV Prototype with Gray Propellers
The group then conducted the Propeller Configuration lab, which lead the team to the discovery that the black propellers were the most effective at moving the AEV, which is clear when examining the graphs presented in the Propeller Configuration lab. The conclusions based on this lab allowed the team to improve the working AEV design by using only the black propellers, which were objectively the most efficient. The AEV model with the black propellers is pictured below.
AEV Prototype with Black Propellers
As the group moved forward toward the performance tests, they needed to choose two designs to move forward with and test against one another. Because of time restrictions, as well as acceptance of new information from other groups, the team decided to go with a simplistic AEV design. The first design was similar to the concept sketch 3 from the creative design preliminary lab. It had a flat base, with 45-degree wings. The difference was the lack of a shell casing, which was present in all of the concept designs presented. The second design the team carried forward was a slight variation of the first design. Instead of 45-degree wings, the AEV had flat wings. This very small difference in the design was used because the team wanted to focus on perfecting the code, rather than the design. Another team presented their findings that said that designing the AEV to be more aerodynamic had a significantly small effect on its overall efficiency, and thus the group adopted this idea.
The first performance test determined which of the two AEV designs was carried forward. Both of the designs were able to pass the performance test, but the data collected during the performance test signified that one design was better than the other. During the test, the flat-winged AEV traveled at a lower average velocity and required less time to stop, all while maintaining roughly the same power usage. Thus, the flat-winged AEV was carried forward, rather than the 45-degree-winged AEV. Below is a drawing of the flat-winged AEV.
Flat-Winged AEV resulting from Performance Test 1 Results
The last alteration of the design was the removal of the brackets. There were four brackets securing the wings to the body. These wings were secured with the motor clamp, reducing stability and cost, yet keeping the performance relatively constant. If the brackets were not removed, the AEV would be over-budget. Below is a picture of the final design.
Final AEV Design with removed brackets