Backward Looking Summary:
During the couple weeks of AR&D our group continued to explore different components of the AEV that will make the final design the best and most efficient it can be. The two main topics that were investigated were motor configuration and wind tunnel lab. Explanation of how these labs were preformed is present in the AR&D section. The motor configuration lab helped discover the most power and distance efficient orientation of the motors on the AEV to help with the config in the continued prototype designs. The wind tunnel lab was used to figure out the most efficient ratio between distance and the power the arduino is set at. Using this information the arduino code can be refined to make to best outcome occur.
AR&D
The motor configuration lab was about using the same code with different orientations of the motors and comparing the differing data. The four orientations that were used were both facing backwards, both facing forwards, and two orientations with one facing forward and the other facing backwards. The major result that was found was that the best ratio between power and distance is when both motors were facing backwards and pulling the AEV. The other discovery that came about from this lab is an elaboration of a former discover in a past lab that there is a big power spike when braking. This can be expanded upon to find that this power spike can be cut out if one motor is in the front and the other is in the back but the truster should always be the motor in reverse pulling the AEV. The wind tunnel lab helped find the best power to propeller efficiency when coding. It was found that the power output is more efficient the smaller the power is set to and therefore it is in the coder’s best interest to try and find the smallest power that is needed to complete the task at hand.
(Results and Analysis After Meeting Notes)
Takeaways:
As mentioned above, motor configuration lab showed that there is a noticeable difference in power demand and power output between forward thrust and reverse thrust. Reverse thrust provided the highest power output with a lower power demand. Moving forward, the team is putting our forward motor into reverse mode to maximize its propulsion capabilities and using the reverse motor for braking. This motor layout will eliminate the issue of a power spike caused from switching a motor direction from forward to reverse as it changes from propelling to braking. A double motor design In the wind tunnel lab, data showed that the energy efficiency is highest for when the motor power level is lowest. As expected, when the power levels rose the thrust also increased. Taking away from this, the lowest power level to propel the AEV needs to be determined as it will lead to the highest energy efficiency.
Forward Looking Summary:
As testing continues into the final steps of designing the AEV the experimenter want to focus their testing into a few different areas to maximize the efficiency of the AEV and code associated with such. One of the topics that will be investigated is the testing of the custom printed propeller. The group found in PR&D that the more blades on a propeller, the more thrust it will provide and therefore a new propeller with six blades was printed. This new propeller needs to be tested to see if it is even plausible to use in the final design or if it hinders the AEV overall. Another topic that will continue to be researched is to find the most balanced configuration of the AEV to make it more efficient and to complete one of our overall goals of the entire AEV project to keep the AEV as balanced as possible. The next topic that will be looked into is if it is feasible to use only one motor as the thrust of the entire AEV and one as the brake. This topic connects to the final topic of making the code as minimal as possible to make it as most efficient as possible to get the task done. If only one motor can be used as thrust then the power will have to be more but the objective is to find the least power that will still complete the task.
Goals:
The custom parts and AEV design will be tested to ensure they are performing as expected. This included running the AEV with the custom propellers to show the power output difference compared to the provided propellers. The offset will be assembled into our AEV design to determine if it is strong enough to support the motors. The goal of the component testing is to show that the AEV can complete the overall objective. Testing will be performed during performance test one to complete a code that will allow the AEV to complete the track. Code modifications include determining the lowest power setting possible for the lone AEV and the AEV with the caboose. Also, braking and timing will be tested to ensure the AEV is able to pass through the gate without collision. During testing, balance will be observed and component locations modified to even out the weight. Goals from the code modification and balancing will improve the overall energy efficiency and AEV performance. These goals are for the overall continuation of our final research and testing but the more pressing goal of the upcoming weeks will be to make sure the custom parts work and make sure the AEV will be able to carry the caboose’s added weight.
Plan:
Team Schedule
Currently, the team does not have a hard set schedule as we are unable to determine how long certain tasks will take, but meets once a week on Sunday evenings. Over the next few weeks, meetings will be assigned as necessary. Upcoming tasks include performance test 1, performance test 2, and CDR draft in which all members will participate. Meetings outside of class for the performance tests will include constructing the AEV design, coding for testing, and planning out lab time for efficient use. Meetings for the CDR draft will be planned according to later time demands.
R&D Specialists
The R&D Specialists will be focusing on executing the performance tests, especially that of determining the effectiveness of the offset piece and the 3D-printed propellers. They will write and modify the arduino codes as well as perform the tests, collecting the necessary data and analyzing it to effectively improve the performance quality of the the AEV. They will execute testing on whether to use a time based arduino code or a position based code to get consistent results.
PR Rep
The PR Representative is responsible for distributing the results of the tests from the R&D Specialists to the website in a professional manner. He will compile the results from the performance test, while assisting the R&D specialists in executing the tests, and record them to be uploaded to the website.
HR Rep
The HR Representative will continue to organize the team, making sure every member knows when and where team meetings will be held, as well as recording the key findings and moments from the meetings to analyze. He is responsible for ensuring that the team is on pace to meet their deadlines, and he will be assisting the R&D specialists as they test the AEV.
Meeting Notes:
Meeting 1
Location: Hitchcock Hall 224
Time: 9:35 am-10:55 am
Attended: Bryce, Tom, Duke, Cameron
Discussion: Designing the AEV project was discussed along with different ideas to brainstorm for the project requirements. Everyone brainstormed together talking about testing if one or two motors would be more efficient. The team then agreed on redesigning the propellers to increase the surface area and to redesign the base to a rectangular fashion to reduce weight. Next, the team discussed having a servo rotate 180 degrees to rotate the motor. Regarding testing, the team agreed to test the servo’s turn speed, motor strength, push vs pull strength of motors, and propellers.
Upcoming Tasks: Everyone get together to complete the assignments due by our next lab.
Meeting 2
Location: First Floor 18th Library
Time: 9:35 pm – 11:00 pm
Attended: Bryce, Tom, Duke, Cameron
Discussion: Team M got together to do the Team Meeting Minutes and complete Website Update.
Upcoming Tasks: Everyone work on brainstorming more ideas.
Meeting 3
Location: Basement of Hitchcock
Time: 5:00 pm – 7:00 pm
Attended: Bryce, Tom, Duke, Cameron
Discussion: All participated in getting together to create progress report 1 and performed website update 2. Also, lab 3 and 5 were finished with their questions answered.
Upcoming Tasks: Everyone works to improve our two designs that were selected from the decision matrix and perform tests.
Meeting 4
Location: Drackett Tower
Time: 5:30-6:30 pm
Attended: Bryce, Tom, Duke, Cameron
Discussion: Finalized the grant proposal and prepared for the committee meeting
Upcoming Tasks: Analyze motor configuration data and perform wind tunnel testing.
Meeting 5
Location: Hitchcock
Time: 5:00 – 6:30 pm
Attended: Bryce, Cameron, Duke
Discussion: The group analyzed the data from aR&D labs 1 and 2 placing the information onto the website to complete the website update. Also, the oral presentation was started and planned went into how we would carry it out in person.
Upcoming Tasks: Finish the slides for the oral presentation and practice the presentation for Monday.
Meeting 6
Location: Hitchcock
Time: 7:00-9:00 pm
Attended: Bryce, Cameron
Discussion: Finish the oral presentation slides and upload them by midnight. Also, determine how long the presentation will go for and split up the slides into multiple speaking parts.
Upcoming Tasks: Meet in the morning before lab to practice the parts and finalize the speaking parts.
Meeting 7
Location: Hitchcock
Time: 8:45 – 9:30 am
Attended: Bryce, Cameron, Tom
Discussion: Finalized the speaking parts and practiced the presentation to ensure time constraints were achieved and to improve the flow of the presentation.
Upcoming Tasks: Work on progress report 2 and prepare for day 1 of the performance testing.
Meeting 8
Location: Hitchcock
Time: 4:00 – 6:00 pm
Attended: Bryce, Cameron
Discussion: Finish progress report 2 from previous work done by Tom and Cameron.
Upcoming Tasks: Build the AEV for continued performance testing coming up and work on the CDR draft.
Results and Analysis
Motor Configuration Lab
Figure 1-Comparative Graph of Different Motor Configurations
In this lab multiple motor configuration were tested to find the most efficient distance achieved with a constant Arduino power input of 50% for two seconds.
Trends Found In the Graph
- The farthest distance by far was achieved when both motors were reversed.
- The shortest distance that was achieved was when one of the motors was going forward and one was reversed.
- The least efficient configuration was when both of the motors where in the forward configuration because the power to distance ratio was the worst.
- The two trails with the configuration of one motor going forward and the other going reverse seem to be directly scale-able.
Codes For the Four Configurations
2 Motors Forward:
- celerate(4,0,50,2);
- motorSpeed(4,50);
- goFor(2);
2 Motors Reverse:
- reverse(4);
- celerate(4,0,50,2);
- motorSpeed(4,50);
- goFor(2);
Front Motor Reversed, Back motor Forward:
- reverse(1)
- celerate(4,0,50,2);
- motorSpeed(4,50);
- goFor(2);
Front Motor Forward, Back Motor Reversed:
- reverse(2)
- celerate(4,0,50,2);
- motorSpeed(4,50);
- goFor(2);
Wind Tunnel Lab
Summary:
Testing was performed using a wind tunnel to determine the effects of different power settings on the efficiencies of a propellor output. This information is critical for determining a power setting that will ensure maximum output while efficiently using the power of the battery. If the battery’s power is inefficiently used throughout the AEV run, it could result in the battery being drained and a suboptimal performance.
Figure 2 – Wind Tunnel Settings
Figure 3 – Results for Variable Power Settings
Figure 4 – Power Settings Analysis
Results:
Testing shows that there is a direct correlation between a lower power setting for the Arduino and an increase in propulsion efficiency. A minimal propeller output will be required to propel the AEV to the caboose as efficiently as possible. If this is not done at maximum efficiency, then when the AEV needs to pull the caboose at a higher required thrust there could be reduced performance. Also, as the battery’s power is decreased it could cause inconsistent results leading to the AEV performing differently than anticipated. The motors will be tested to determine the lowest possible power setting to ensure that power efficiency is maximized, while also ensuring that the run’s time remains reasonable.