Lab 07 (Preliminary Design Review (PDR))

Results and Discussion

Based on first prototype of the AEV, the team decided to prioritize stability, power efficiency, energy efficiency and coding consistency. The first prototype of AEV (design E) was not stable when moving in a straight line and in turn. The design was more focussed on the speed and the deployment of the wings on the AEV to make it more stable like an aeroplane. Then, the team tried to make a few adjustments to make the AEV looks more stable and steady when it moves on the track. Unfortunately, the addition of the wings didn’t affect the performance of AEV and it still shaking upon turning. Another major problem is the coding consistency. The first prototype uses two motors which is believe as the main reason of the fast consumption of battery thus producing inconsistency when testing several times on the track. The team get inspired to proceed with this design at first time because the team believed that with the deployment of the wings like Akmal’s and Affiq’s design will help the AEV to complete the MCR with low
consumption of energy and consistency in every trial. Next, the team used the reversed function in the Arduino code to reverse the rotation of the motor and slow down the fast-moving AEV in between of first and second sensor at the middle gate. However, the team realized that by using two motors, the AEV will move at the high speed and it will cause the AEV difficult to stop at the right time. Therefore, more calculation that involve with the position and time are required to stop the AEV at the gate. The first prototype also used large amount of energy especially when it comes to stop the AEV at the gate. This is because the spike from the reverse function that used to stop the high-speed AEV exactly at the perfect point so that it will complete the MCR. So, the team has discussed and decided to change the way to tackle the main problem which is the inconsistency and high energy used for the AEV. The team decided to make the AEV moves at a lower speed which only uses one motor and it would improve the team to achieve coding consistency.

For the second prototype of the AEV, the team decided to focus on the power efficiency, coding consistency, and stability. The team come up with a new idea which is very different compare to the first prototype. In the new design, the team only used one motor with Pusher EP-3030 configuration instead of using two motors at first prototype. After many trial on the track, the team made a hypothesis that the number of motors is directly proportional with the amount of energy used in the AEV. So, the team try to make an AEV model with only used one motor with the approximately same coding with the first prototype. The values that are differ from the first prototype are time and distance travelled of the AEV because the second prototype is more lighter and the inertia of the model is lower compared to the first model. Even though the new design doesn’t have wings on the side of the AEV, the second prototype was observed to be more balance in a straight line, turning at the corner, and doesn’t shake a lot when it wants to stop at the gate. The second prototype was inspired by the Haiqal’s design which used only one motor to move the AEV on the track. There are many issues at first to proceed with this idea because the team has no reference that proved one motor AEV will minimize more energy compared to the AEV that uses two motors. Although the second prototype takes 10 seconds longer than first prototype, the second prototype has saved about 20 watts of total power compared to the first prototype.

  Table 5 : Concept Screening Matrices

Table 6: Concept Scoring Matrix

  

Table 7: Phase Breakdown for Design E

 

Figure 8: Propulsion Efficiency against Advance RAtio Graph for EP-3030