Situation:
The goals of the Performance Test 1 were as followed: The AEV would travel to from the starting point to a gate, which will trigger a sensor. After the first sensor is triggered, the AEV waits seven seconds before the gate opens again. The code used can be found here. The team strived to test two different concept designs, one of balsa wood and one of ABS, however, the ABS wasn’t printed on time so the reference vehicle was used instead. After testing, the performance of the two were noted and compared. The images outlining these designs are shown below in Figures 1, 2, and 3. The purpose of this Performance Test was to begin thinking about the overall goals of the project and complete the first piece of the code for the overall run. This was done to keep the team on track.
Figure 1: Reference AEV
Figure 2: Balsa Wood AEV
Figure 3: Unassembled ABS AEV
Results and Analysis:
The team ran the two concepts and the runs had some notable differences. To begin, the balsa wood design added weight to the vehicle so it was necessary to add more power when the AEV would go up the small incline. The group was expecting this change, they just didn’t know how much more energy would have to be consumed. In addition, the wooden AEV was wider and bulkier than the reference AEV, making it more stable and balanced. The outer shell helped the wires from being exposed which made a difference since in the past the wires have gotten in the way of the propellers in reference AEV. In the end, both AEV’s completed the tasks.
Looking at Figures 4 and 5 below, the performance of the balsa wood design can be analyzed through the Power vs Time and Power vs Distance graphs. In Figure 4, the power is at about 10 W for the first 3.75 meters but as soon as the servo kicks on, the power dramatically decreases, shown by a vertical line since the distance isn’t increasing. At about 3.9 m, the power kicks on to a little under 10 W and is consistent until it’s instructed to stop again. Looking at Figure 5, the Power vs Time can be analyzed. The power is consistent at about 10 W for the first 5.25 s and it decreases to 0 W at about 9 s which takes place when the AEV is waiting at the gate. It waits for 7 s then the motors kick on again at 9.5 W of power until about 12 s when the servo brakes the vehicle, causing the power to go to 0 W again.
Figure 4: Power vs Distance Graph of Performance Test 1
Figure 5: Power vs Time Graph of Performance Test 1
Takeaways:
The team is going to make the balsa wood AEV lighter by hollowing parts to get the power consumption down, making it more efficient. In addition, it is useful to have a reference AEV to test against and compare the outcomes. Hopefully next week, the team will have the opportunity to test the ABS design against the balsa wood AEV.