Situation:
In addition to the tasks completed for Performance Test 1, the team created a code that picked up the caboose, held it for 5 secs, then reversed for a couple seconds. The code used is found here. The team only tested one design, the balsa wood design. This is because after testing and retesting the design, the team realized that weight is an important factor in the energy consumption and power usage of the AEV. The team decided to modify the design of the balsa wood model. They used a drill to decrease to weight in the nose of the AEV and drilled multiple tiny holes into the base and certain sections of the wings. This lessened the amount of material and decreased the weight significantly.
Results and Analysis:
By decreasing the weight of the balsa wood AEV, the team used much less energy in the Second Performance Test as compared to the First Performance Test. The weight of the AEV bodies without anything in them show how the team’s AEV model is the superior lightweight design. The standard AEV kit was 73 g while the ABS model of the space shuttle that was 3D printed was 141 g; Nearly twice as much as the standard kit. The balsa wood design is significantly less than both, with a weight of 40 g. Because of this, the AEV will be not only most power efficient, but most cost efficient with the resources used.
Regarding the Performance Test, the team completed all the tasks correctly, thus receiving a perfect score. The Power vs Time and Power vs Distance graphs are shown in Figures 1 and 2 below. The Power in both graphs is consistently around 10 Watts. In Figure 1, the vertical lines show each time where the power is cut and then turned back on. When the lines was horizontal, the power is shown to be consistent. In Figure 2, the horizontal lines also show the power is consistent and the vertical lines indicate where the vehicle stops or starts.
Figure 1: Power vs Time Graph
Figure 2: Power vs Distance Graph
For the Final Performance Test, however, there is much room for improvement. The team needs to modify the code so there is a smoother pick up of the caboose. The code completed the job, but the AEV came in with too much speed and bounced off the caboose. In future weeks, this problem will be analyzed and solved.
Takeaways:
The most important takeaway from the Second Performance Test was the effect of weight on power. As the weight decreases the motors need less power to move the AEV saving on battery and energy. As the team moves forward, more tests and graphs will be taken of Power vs Distance and Power vs Time, to improve the efficiency for the Final Performance Test. It will be compared against the graphs of the reference and the ABS designs to outline how much more efficient the balsa wood is.