Summary
There were several goals accomplished throughout labs 1-7 of this project. In lab 1, the team learned how to program the AEV using the Sketchbook program. The team refined these skills by writing different programming scenarios. The next lab tested the propeller efficiency utilizing wind tunnel testing. The results revealed that the puller configuration is more efficient than the pusher configuration. Using this data, the team chose to design an AEV that utilizes a puller configuration for the propellers. In lab 3, each team member designed an AEV prototype by drawing orthographic projections. The team used these drawings to compare and decided on a group design AEV combining the best features from each prototype. The team then employed screening and scoring matrices to compare each design with the reference design and examined their performances in accordance with certain criteria decided on by the team.
The team then used the data analysis tool on Matlab to gather information about the performance of the AEV. The tool provided information about the voltage, current, time, and marks from the sensors. This data was used to construct a graph of power vs time to analyze the performance of the AEV and the different phases involved. In lab 6 of the project, the team had the time to test different codes on track. Different codes were written to make the AEV stop at the desired location and time. The team wrote the code using knowledge of basic commands like brake, and the fact that it doesn’t stop the AEV right away. The reverse command was used to reduce the speed by reversing the polarity of the motors for a short period of time then the brake command was used to cut the power from the motors. The team also used goToAbsolutePosition to manipulate the AEV to stop at the desired location. Finally, lab 7 was used to test the friction force between the AEV and the track. It was also used to test the accuracy and performance of the AEV by running it on the straight track and measuring the distance travelled. The team then analyzed the data from these trials using the data analysis tool. The team learned from this data that improvements had to be made to reduce the mark errors and have better control over the AEV.
Results
The team will be testing two design concepts this week. The first one is different from the reference AEV. The first difference is that there is no wings on the side of the base of the AEV. The team decided to have two small plastic arms come down from the bottom of the AEV, and the motors attached to the side of the arms. This allowed for a more lightweight AEV in comparison to the reference AEV while also being more aerodynamic. This also helped the weight be distributed more evenly and allowed the AEV to have a better center of balance while traveling on the rail. Design concept one also has the arduino on the bottom of the AEV and the battery and battery holder on the top of the AEV. This was put in place with the idea that the AEV would have to transport something, creating more room on top of the base of the AEV. This design uses the same base and L-shape arm to hold the AEV on the rail as the Reference AEV.
Design concept two is similar to design concept one, but with a few modifications. First off, The AEV is constructed on a smaller base. This allows the AEV to have less drag and more lightweight than both design concept one and the reference AEV. Design concept two has the arduino on the top of the base; however, there is no battery holder. The battery will be attached to the L-shape arm that holds the AEV onto the rail. This will also reduce the weight of the AEV. This design has only one small plastic arm coming out the bottom of the base of the AEV towards the middle with the motor strapped to it. The other motor will be screwed into the bottom of the base of the AEV in the front. The team decided to do this in order to increase the force from the propellers, making the AEV more energy efficient.
Both of these design concepts incorporate changes to the reference AEV that will make the AEV more energy efficient. Whether it is cutting weight or making the AEV more aerodynamic, every change that was made has a specific reason behind it. Having the AEV complete the specific tasks while using the least amount of energy is the ultimate goal, and to do this many changes have to be made to the reference AEV. The changes that design concepts one and two incorporated will be tested and data will be extracted in order to see how the changes affected the AEV. The team will hopefully find pros and cons of each design and then use these results to design an energy efficient AEV.
Team Meeting Notes
Date: 3-8-2017
Time: 6:00-7:50 pm
Members Present: Evan Berry, Alex Savelieff, Ahmed Negnm
Topics Discussed: Distributing parts of the lab report.
Objective: Identify who is taking which parts as well as getting a template set for the lab.
To do/Action Items: Split up each section between each other. Plan for all the parts to be completed by Thursday night.
Decisions: Everyone will complete their part by Thursday night, any time, we will then meet Friday morning to wrap all the parts together and make the final copy, ready to turn in.
Date: 3-10-2017
Time: 8:30-9:30 pm
Members Present: Evan Berry, Alex Savelieff
Topics Discussed: Proofreading and finalizing the progress report
Objective: Ensure all parts are present and up to the team’s standards
To do/Action Items: Read through the entire document and ensure there are no major issues
Decisions: The progress report will be checked and turned in on time
The figure above depicts the concept screening scoresheet. This graph displays success criteria developed by the team which includes covering curves, blockage, center of gravity, durability, cost, environmental aspects, and efficiency. A score is given for each design and awarded a plus if the new design improves this area in comparison to the old design, a minus if it makes it worse, and a zero if it remains the same.
The figure above depicts the Concept Scoring Matrix, which describes the different success criteria using a weighted scale. Each criteria is rated on a scale of 1-5, and a weighted score is produced by multiplying the score by the weight. A total score was produced for each design. The reference design, Cameron’s design, and the group design were all rated using this method.
The figure above depicts the code that was tested.
The figure above displays the teams revised code.