Below are some graphs that display data of three separate runs: a test run to determine the optimal speed, performance test 2, and the best run of the final performance test.
Performance Test 2
The Shell was tested and proved to be just as energy efficient as the AEV without a shell. The graphs below show the energy usage for the AEV with no magnet or shell attached, and the AEV with the shell and magnet attached.
The figure above shows the power usage over time for the standard AEV design without a shell. The vehicle was set to drive at 40% power forward for 5 seconds and then a 40% reverse for half of a second.
This is the power usage over time graph for the first 8 seconds of PT2. The power usage is about the same as that used by the AEV without the shell. *PT2 stands for Performance Test 2.
Although the tests go on for different amounts of time, the power usage per time is the same. The battery is inputting the same amount of power between 0 and 4 seconds for both tests. The average wattage for both during that time period is about 13 watts. Note that on the tests with the shell on the right, the magnet adds a decent amount of weight that was not accounted for in the trial on the shown on the left.
Final Performance Test
The final performance test included stopping at the gate, picking up the payload, and bringing it back to the starting dock with another stop along the way. Our AEV proved to be successful at all tasks but stopped just short of the starting dock due to a calculation error.
Power vs. Distance of the final performance test. The sudden drops in power represent cuts in motor power from the AEV either stopping or coasting.
Power vs. Time of the final performance test. Notice the smaller spikes in power in the last three portions. These are the fail-safes activating to ensure the AEV reaches its destination (see Arduino Codes for more information about fail-safes).
For the final performance test, the final AEV design was used. The run was completed in 59 seconds using a total of 344.966 joules at 40% power traveling towards the payload, and 45% traveling back with the payload. Compared to performance test 2, the vehicle performance was similar. It still used an average of 12-13 watts per second omitting the fail-safes and the high power spikes, so it was very consistent throughout on the power usage. Overall, like in performance test 2, the AEV shell did not inhibit or improve performance necessarily; its main purpose was to protect the arduino.