Backward Looking Summary
Situation
During the Advanced Research and Development, Team C tested propeller configurations and different base materials. The first propeller configurations tested was with two propellers attached to the front of the AEV base, pulling the vehicle down the track which can be seen in Figure 3. The other design was with two propellers on the rear of the AEV base, pushing the vehicle down the track which can be seen in Figure 6. The two designs were run with the same code to isolate the data to strictly testing propeller configuration efficiency. The procedure for the propeller configuration called for four different configurations but to due time constraints and only having two propellers, only two configurations were tested.
The next topic discussed among teammates was the materials used to construct the AEV. The materials available were 1/8″ acrylic, 1/4″ acrylic, 1/4″ MDF (wood), 3/32″ ABS, and the provided 1/8″ polypropylene seen in Figure 7. The weights of the varied materials were compared to determine which material would allow the vehicle to move faster. The durability was also tested by holding moving the materials around and seeing how easily they bend when a force is applied. Durability was tested because a more durable material would result in a safer AEV. Both these research topics have helped the team to figure out the objects that can make the AEV vehicle more energy efficient and aerodynamic to have consistency of runs on the monorail track.
Results and Analysis
The results were filed into graphs of Power (Watts) vs. Time (seconds) and Power (Watts) vs. Distance (Meters) which are included in the Appendix as Figures 1 and 2. The graphs claimed that the pull design used less wattage during the route. The peak of the push Power vs. Time graph surpassed 11.67 Watts from Figure 2, while the peak of the pull Power vs. Time graph slightly passed 10.89 Watts from Figure 5. Also, on the Power vs. Distance graphs, the pull method made it a further distance in the same amount of time, since the same code was used. Therefore, the pull method uses less wattage and will make the AEV more efficient. The black 30×20 propellers were significantly faster and this was determined from observation. the original propellers resulted in a very small amount of movement. These propellers were changed and a significant increase in velocity was observed with the black 30 x 20 propellers. Black 30×20 propellers make the AEV more marketable because it will be able to travel further in less amountof time. The AEV has also been improved by changing to using two pull propellers, and this also contributes to the AEV running faster and more efficiently because the same code was run using both push and pull propellers and the AEV traveled significantly faster with pull propellers.
After some discussion and comparing each of the materials’ relative weight the team decided to use the 1/8″ acrylic to construct the AEV. It was found that, despite the added sturdiness that the 1/4″ wood and 1/4″ acrylic pieces provided, they ultimately added too much weight. It was also found that the 3/32″ ABS would not provide a stable base for the number of elements attached to the AEV’s base, even though it was by far the lightest option. The team looked further into the 1/8″ acrylic and decided it was much lighter than the provided 1/8″ polypropylene. Materials for the AEV were also changed to increase durability and safety whilst also maintaining an efficient vehicle. The 1/8″ acrylic should provide the most ideal combination of safety and efficiency.
Takeaways
AEV – Propellers-black 30×20 pull propellers will be used
AEV-Material – ⅛” acrylic will be used
General project learnings – The team works well when the work in lab is divided into two parts:
one for constructing the AEV and the other for designing the code.
Forward looking Summary
The upcoming week is not a full time working week because of spring break. The team has two work sessions on Monday and Wednesday to get prepared for performance tests. The first performance test is the main goal of Team C. The team will be testing varied materials and the best design is selected. To accomplish the goal of adequately passing the performance test, the team will work on constructing a code that will accelerate direct AEV and then stop the AEV at the desired location (at the gate). Secondary to this goal, is making the AEV as energy efficient as possible. Team C would be using the information discovered in the Advanced R&D labs to meet these goals. The base of the vehicle is changed to ⅛ acrylic to increase stability which will decrease the cost of maintenance. Apart from that the team has also decided to mount the 30×20 propellers in a ‘pull’ configuration on the front of the AEV to ensure low power is consumed for the most distance. To make the AEV stop at a specific position, Team C will measure the track and convert inches to marks and test to see at which point the motors should be reversed so the AEV is brought to a halt. This may take several attempts depending on vehicular maintenance as well as track variance.
Forward Looking Goals
The main goal of Team C is to construct an energy efficient AEV that will stop at the designated marks on the track. Another goal is to implement what was discovered in the Advanced R&D into the AEV. During the next experiment, the first goal is to change the base of the AEV to ⅛ acrylic. Then, Team C will position the propellers on the front of the AEV. T0 make sure the AEV stops where desired, the team will convert inches to marks and implement the findings into the code. If these procedures are accomplished, the goals will be achieved.
Forward Looking Schedule
Table 1: Week 12 schedule
| Task Start | Members Present | Date | Due Date | Time Needed |
| Lab 9a (getting prepared for performance test) | All | 3/8/18 | 3/8/18 | 2hrs |
| Lab 9b (executing performance test) | All | 3/19/18 | 3/19/18 | 1hr |
| Lab 9c (final performance test) | All | 3/21/18 | 3/21/18 | 1hr |
| Lab 10a (distributing tasks for CDR among the team) | All | 3/20/18 | 3/22/18 | |
| Lab 10b (getting prepared for performance test 2) | All | 3/26/18 | 3/26/18 | 1hr |
| Lab 10c (performance test 2) | All | 3/28/18 | 3/28/18 | 2hrs |
Appendix
Meeting 4:
Date: 2/25/2018
Time: 11 am
Members present: Marley Mclaughlin, Nathan Teeters, Sanila Reza, Shreya Byreddy
Location: Hitchcock hall
Topics discussed:
The performance of the team to discuss all the findings and the process for finishing the website update 3
Objective:
The main objective of today’s meeting is to split work among team members to successfully finish the website update 3. Moreover the team has come up with topics that each team member has to cover in the oral presentation.
To do/action items:
Complete website update 3 and get prepared for the oral presentation including the powerpoint slides.
Decisions:
Marley is assigned the task of discussing the finding from the tests performed for the propeller configuration, including the analysis of the power graphs.Nathan would be working on developing the proof for selecting a material that best fits for the AEV design. Shreya Byreddy is responsible for adding figures, tables and the code used in the lab walong with comment statements. Shanila has taken the responsibility of concluding all the findings from the advanced research process.
Reflections:
All the team members have cooperated and finished all the work assigned to them. The team was also helpful by adding in their time also to finish the task much quicker. Team has also explained their limitations beforehand, this eventually helped the team to figure out other alternatives
Meeting 5
Date: 3/7/2018
Time: 3:00 pm
Members present: Marley Mclaughlin, Nathan Teeters, Sanila Reza, Shreya Byreddy
Location: Hitchcock hall
Topics discussed:
Steps that need to be followed to complete progress report 2 which includes the division of work equally among team members so that the tasks are not stressed on one person.
Objective:
Completing progress report 2 according to the instructions decided by the team. Apart from that the team also came up the topics that need further analysis and which are to be researched.
To do/action items:
The main actions that the team has decided to finish is the progress report within span of two days.
Decisions:
Marley has to perform the job of working on tables and figures and the takeaways for both the advanced research topics selected by the team. Nathan would be working on explaining the limitations and errors experienced while performing the tests. Shreya Byreddy has to be looking over the appendix for both the research processes and include all the figures and tables related to the experiment. Shanila would be taking of the entire backward looking summary, including situation, results and analysis and takeaways from the labs.
Reflections:
The team has finished all the work with the available time and got through all the troubles with the support of all the team members.
Code used for testing the propellers:
celerate(4,0,40,3);//accelerates all motors from 0 to 40 for 3 seconds
motorSpeed(4,40);//runs all motors at a speed of 40 for 3 seconds
goFor(3);
brake(4);//breaks all motors
Limitations, Delimitations, and Errors
There were several obstacles that obstruct the progress of the team. Initially in the preliminary Research & Development, the team struggled to compile and accurately gather data. Throughout the initial testing a variety of troubleshooting techniques were applied, but to no avail. After testing where the error was located, it was discovered that the Arduino itself was malfunctioning. Due to this faulty equipment the time allowed for advanced Research & Development was dramatically limited compared to the initial allotted time. In order to make up for this lost time, the team had to condense the two desired labs into one. The propeller configuration lab was shortened from testing 4 configurations to testing 2 configurations. The team tested a ‘Pull’ and ‘Push configuration, with the propellers staying in the same relative position. For the next R&D topic, the team was fortunate enough to have chosen a test that didn’t need actual data recorded to come to a conclusion. The materials used for the AEV base was that test. The team researched the density and relative weight of bases made from wood, acrylic, polypropylene, and ABS (the team chose the acrylic base).
Another error that occured while testing the AEV was the improper attachment of the reflectance sensors on several tests. This caused any from of distance collection to be incorrect and sometimes not even be recorded. Initially, it was believed the Arduino malfunction was to blame for this lack of data. However upon further inspection of the AEV setup revealed the sensors’ plugs were plugged in to the Arduino backwards. Upon fixing this mistake, the subsequent tests were carried out and data was successfully collected. These errors also greatly reduced the amount of time available for the advanced R&D, but Team C successfully accomplished their goals nonetheless.