In Performance Test 2, the team created two codes to determine the energy consumption. For the coding 1(Code Tab ), the team have included the back thrust part to ensure the AEV stop instantly. It is because in the previous coding, the team used the brake command to stop the AEV, but the team found out that the AEV coasting before its stop. In order to pass through the first gate, the Arduino code must include a back thrust to prevent the AEV from coasting. The only issue for the coding 1 is the team has a trouble to code for stopping the AEV at the exact position. The team need to figure it out before the upcoming by asking help from the GTA or TA to figure out this problem. For the coding 2(Code Tab), the team decided to change the coding by using the “motorSpeed” command at certain amount of time and used brake command to make the AEV glide. It is because the team want to reduce the usage of the energy used. The “motorSpeed” command will make the AEV have a speed for a few seconds and then it will glide The team concluded that the coding 2 have a slight higher energy efficiency than the coding 1. However, the team decided to use coding 1 because the coding 2 have a bigger issue on its consistency of run as it tend to stop before the gate and it takes much more time to complete one full cycle.
In Performance Test 3, the team tested the AEV on the track based on the two code from Performance Test 2 and analyzie the energy consumption by using the MATLAB analysis tools. Figure 4 below shows the supplied power to AEV using the coding part 1(Code Tab). The calculation was done by using AEV analysis tool in the matlab. In figure below, the supplied power against time graph is classified into four phases. The phases were based on the arduino command.
Based on the figure above, there are two significant changes of power which is at the beginning of third phase and also the fourth phase. The supplied power is at its highest in phase third and fourth because the AEV require more power to move backward. As shown in the phase 1 above, the speed is set at 30% power. After the AEV reached the first gate, the power is decreasing. This is because the team used the brake command to cut the power supply. In phase 2, the power does not show any significant changes. At this point, the AEV is moving at same speed to the position before reaching the cargo area. In phase 3, the power shows a drastic increase due to the load that the AEV is carried over to the first gate. The AEV is still moving after the command for a few seconds and stop right before the gate. However, in the phase 4, the AEV did not stop at the drop-off. This clearly shows in the table above that there is a constant power supplied over certain amount of time. Thus, the team concluded that energy which is 609.56 joules, the code have some error at the end of fourth phase that makes the team unable to determine the energy efficiency. It is because the team have some trouble to determine the exact mark for fourth phases in the arduino.
For the coding part 2, the team did not have enough time to complete the full cycle based on the MCR. The team did only managed to code and record the AEV performance analysis from the start point to the cargo area. The team decided to change the coding from using the “gotoAbsolutePosition” command to using brake command. It is because the AEV still have inconsistent run to reached the first gate as sometimes the AEV might stop too soon or too late. The team concluded the coding part 2 have higher energy efficiency than the coding part 1 because the coding part 2 did not use a constant power energy consumption to reach the first gate, instead the AEV was glide to the first gate. Eventually, the team finally decided to combine the coding part 1 and coding part 2 by removing the “absolute position” command, replace it by using a “motorspeed” command at certain time,adding the brake command and the back thrust part. It is to ensure the AEV have a consistent run in order to complete the MCR.