Performance Test 1
Figure.1 : Prototype 1
Figure.2: Prototype 2
Situation
There are two goals for performance test 1, the first one is to finalize the prototype design and the second is to complete the performance test 1. In performance test 1, the prototype should stop in front of the gate and trigger the photoelectric door. Then the Prototype should wait for 7 seconds until the other gate open and go through the gate. The key for success is the code which can be seen in the Appendix A : Audrino Code. When implementing the performance test 1, data about the prototype condition should be collected as well. By comparing the data such as energy usage, speed and stability, the final design for the prototype will be determined. The first candidate is Prototype 1 which is smaller and lighter but its mass center is closer to the back of the centerline so when hanging on the horizontal track it will backward lean. The second candidate is Prototype 2which is a little heavier but its mass center is exactly on the centerline. As a result, Prototype 2 wins in the competition, the reasons and analysis will be followed in the Results and Analysis part. So the next steps such performance tests and code polishing can proceed on the Prototype 2.
Figure.3 : Power vs Time 
Figure.4 :Power vs Distance
Figure.5 : Track used in the lab
Figure.6: Energy Consumed by two prototypes
Results and Analysis
After several tests for the two tests, graphs of Power vs. Time and graphs of Power vs. Distance are drawn. Choose Figure.1 : Performance Test 1 Power vs. Time and Figure.2 : Performance Test 1 Power vs. Distance from Appendix B : Performance Test 1 as an example. From the Figure.1 : Performance Test 1 Power vs. Time the start power of the Prototype1 is higher than the Prototype2 because of the backward leaning will waste much energy. From t=0 to t=6.5, it is the process for the two Prototypes going through the horizontal track and climbing up to the inclined track. Due to the inclination of the track the Prototype1 can set on the track without leaning. In this process, the two prototypes move the same distance within the same time. The two prototypes seem to have no difference but when looking at the and Figure.2 : Performance Test 1 Power vs. Distance some difference will be shown. After climbing up the inclined track, the two prototypes will stop for seven seconds and then keep moving on the horizontal track. Take this process moving on the horizontal track as process 2. During process 2, the two prototypes moves the same distance about 3.4 meters from Figure 4. But Prototype 1 uses 13 seconds more than Prototype 2 from Figure 3. Considering the total time consumed is about 25-37 seconds. 13 seconds difference is a significant difference between two designs.
The main reason is when Prototype 1 moving on the horizontal track, it will be a little backward leaning, which will cause some vibration when moving on the track and some loss of the power it gains. Assuming the angle it backward leaning is ѳ, the power the propellers give to it is P, after backward leaning, the power along the track will become Pcosѳ<P. Because P=FV, F is the force needed to move the prototype will not change, the power Prototype gets after backward leaning is smaller than the power before backward leaning. So the velocity after backward leaning is smaller. It illustrates the reasons why Prototype 1 need more time than Prototype 2 in the process 2.
Backwards
There are some potential problems exists in the experiments. Firstly, every time the distance for the two prototypes has no consistence. Because using the inertia to get the gate is greatly affected by the power efficiency which is related to the uncontrolled factor like temperature of the motors. So in the future, ‘reverse’ code should be used to stop the prototype. Second problem is that the prototype does not have enough power to drag the other vehicle, which is required in performance test 2. Till now, no effective solution is proposed to tackle the problem.