First Performance Test
The first performance test required the AEV to travel from the starting point, to the gate, pause for 5 seconds to wait for the gate to open, and proceed through the gate. Developing code for the AEV designs proved difficult initially, as the team struggled to find the proper number of marks the AEV had to travel before braking at the gate. After multiple trials, the team was able to determine the correct number of marks so that the AEV was able to stop within the required range at the gate. After stopping at the gate, the AEV then passed through the gate after waiting for 5 seconds and the team collected data using the AEV Analysis tool. The team decided to utilize coasting into the gate and increasing initial motor speed before the power braking sequence because this method decreased the energy consumption by the AEV as well as the amount of time for the trial. Because of this, the AEV was able to cut approximately $45,000 from its original testing cost. By using the method outlined above, the team was able to complete the first performance with two different designs and found that AEV Design Two was superior due to its lower energy consumption and quicker time to complete the test. Below are the Power vs. Time graphs for each AEV design.
Power vs. Time for AEV Design 1
Design 1 completed the first performance test in approximately 22seconds with a total power consumption of 97 joules. The team found that although this design was able to complete the test, Design 2 was not only more power efficient, but also completed the test in less time, making it the superior option for further performance tests. The data collected from Design 2 is shown below.
Power vs. Time for AEV Design 2
The team found that Design 2 was both more power efficient and more time efficient than Design 1. With a total power consumption of 93 joules over only 13 seconds, the team found that this design was significantly more cost effective due to nearly halving the amount of time required to perform the test. This led to the team deciding that Design 2 will be used for the future performance tests.
Second Performance Test
The second performance test required the AEV to proceed through the gate and connect with the caboose in the loading zone. Once connected the AEV had to wait 5 seconds then exit the loading zone. The team developed two sets of working code that allowed the AEV to proceed through the gate quickly, but also coast into the loading zone so that the caboose and AEV could couple without recoil. This required many tests to determine the appropriate number of marks before starting the coasting and power braking sequences because the braking must be able to slow the AEV enough to prevent recoil without causing the AEV to stop before coupling with the caboose. The team then had to determine how long to have the motors braked, as the 5 second waiting period did not start until the AEV had come to rest, making the wait time higher than 5 seconds after braking the motors. The team set the brake to the original 5 seconds, and measured how much additional time was needed so that the 5 second complete stop was satisfied. The team found that significantly more power was necessary to transport both the AEV and the caboose because the caboose added additional weight to the system. After analyzing the power consumption and time required for each code, the team decided that code one was more power and time efficient, making it the superior option for use in the final performance test. After performance test two was completed, the team had developed half of the code required for the final performance test, provided key insight for developing the remaining code for the final performance test. Shown below is the Power vs. Time data for code 1 is shown below.
Performance Test 2: Power vs. Time for Code 1
The team found that code 1 for the second performance test was superior than code 2 due to its higher level of efficiency. Code 1 used 177 joules over 32 seconds to proceed from the gate, to the caboose, and back to the gate. Code two, however, required 213 joules over 41 seconds, making code 1 the superior option for the final performance test. By choosing between code 1 and 2, the team was able to determine the best design and code to use as a foundation for the AEV that completed the final performance test.
Final Performance Test
Once the first and second performance tests were completed, the team then had to complete the final performance test. This test consisted of attaching to the caboose, and proceeding back to initial AEV starting point. This test proved to be the most difficult for the team, as the additional weight of the caboose to the AEV increased inconsistencies when stopping at the gate and the loading zone. By utilizing knowledge of the first two performance tests, the team was able to determine the ideal number of marks and motor speed for stopping the AEV and caboose at the gate and the loading zone. Once this was determined, the team was able to collect data for the final performance test, and found that the AEV required 215 joules and 42 seconds to complete the test. Shown below is the Power vs. Time data for the final performance test.
Power vs. Time for Final Performance Test Run 2
As seen above, the AEV completed the final performance test in 42 seconds with a power consumption of 215 joules. The team found that this caused the AEV to be highly efficient when compared to other AEV’s in the class, as the team AEV completed the test in the fastest time of any AEV. Based on the power consumption, time required, and capital costs of the AEV, the team calculated the overall cost of the project using the table shown below.
Costs for AEV Final Performance Tests
Based on the team’s most efficient test, the total cost of the project was $605,848.68, which was determined to be on budget. Because of this, the team was able to design and develop an AEV that satisfied the goals outlined in the Mission. Code for the Final Performance Test can be found under the Final Design and Code tab, and codes for the first and second performance tests can be found under the Previous Codes Tab.