* All Information Found In Preliminary R&D
Define
The residential area chosen to be the focus of Smart Columbus is Linden. The town of Linden is cut off from many services such as employment, health care and grocery stores due to I-71. In addition, public transportation in the area is lacking, leaving residents stranded. In order to provide the people of Linden equal opportunities, a new type of transportation needs to be produced. To accomplish this, an electric, autonomous AEV will be created to transport people from not only Linden but Easton and Polaris too. By implementing this AEV we hope to make Columbus a smarter city.
Represent
There are many criteria associated with this project, especially the route that must be taken.
Figure 1 AEV Course Map (MCR, p4)
Above is the route that the AEV must traverse.
AEV Course Route
Above is the same route, but with the necessary actions of the AEV shown. It will move forward and stop at a gate while waiting for it to open. Then the AEV will move through the gate to the other end of the track where it will pick up a hitch. When the AEV attaches to the hitch it will have to successfully take it back through the gate to the starting position.
Plan
Iteration 1: Prototypes
Design #1
Weight: 44.1058 grams
Total Cost: $142,777
Bill: Arduino: $100000, Motors: $19800, Count Sensor and Connector: $8000, Propellers: $900, Arm: $395, Body: $1214, Wheels : $7500, Battery Clamp Narrow: $307, Angle Brackets : $103, Screw Driver and Wrench: $4000, Motor Clamps: $501, #55 Slotted Strip: $57
Erica used the angled design to make the vehicle very aerodynamic. It is very compact and not allow much air resistance to occur. However, this design would not be very aerodynamic when traveling in reverse and the pointed front doesn’t allow for placement of the magnet. This design would be successful in completing the scenario because it would be very quick, minimizing the cost of the time factor of the budget.
Design #2
Weight: 65.8908 grams
Total Cost: $144,048
Bill: Arduino: $100000, Motors: $19800, Count Sensor and Connector: $8000, Propellers: $900, Body: $2530, Arm: $350, Wheels: $7500, Battery Clamp Narrow: $307, Angle Brackets: $103, Screw Driver and Wrench: $4000, Motor Clamps: $501, #55 A Slotted Strip: $57
Keith made his design in a way that would make the vehicle very durable and front heavy. However, this design is very bulky, not very aerodynamic, and would not have the ideal mass which would slow it down. This design would be successful in this scenario because it will be very trustworthy and will travel faster when moving forward.
Design #3
Weight: 44.2818 grams
Total Cost: $132,115
Bill: Arduino: $100000, Motors: $9900, Count Sensor and Connector: $8000, Propeller: $450, 2” x 6” Rectangle Body: $1620, L Shape Arm: $338, Wheels: $7500, Battery Clamp Narrow: $307, Angle Brackets $103, Motor Clamp: $250, Screw Driver and Wrench: $4000, #55 A Slotted Strip: $57
Kevin designed his vehicle to reduce the mass making it more lightweight and easier to move. He also made it a very simple design. However, this design would not be very reliable or powerful since it only uses one fan. This idea would be successful in completing the scenario because it will minimize human error when constructing the vehicle.
Design #4
Weight: 59.3698 grams
Total Cost: $143,578
Bill: Arduino: $100000, Motors: $19800, Count Sensor and Connectors: $8000, Propellers: $900, Body: $2350, Arm: $350, Wheels: $7500, Battery Clamp Narrow: $307, Extra 3D Printed Part: $60, Angle Brackets: $103, Screw Driver and Wrench: $4000, Motor Clamps: $501, #55 A Slotted Strip: $57
Mikaela made her design to be very narrow and aesthetically pleasing. This would make the vehicle very aerodynamic from the front. However, this design is bulky, and would not be very aerodynamic when traveling in reverse which would slow it down. This plan would be successful because it would allow the vehicle to travel with maximum velocity when moving forward.
Design #5 (Team Design)
Weight: 40.4878 grams
Total Cost: $132,795
Bill: Arduino: $100000, Motor: $9900, Count Sensor and Connectors: $8000, Body: $2530, L-Shaped Arm: $338, Wheels: $7500, Batter Clamp Narrow: $307, 3D Printed Parts: $60, Angle Brackets: $103, Screw Driver and Wrench: $4000, # 55 A Slotted Strip: $57
In our team design, we knew that we had to design the vehicle to be lightweight and we had to make the base in a way that would be aerodynamic from both the front and the back. While testing the sample vehicle, we noticed that the propellers weren’t ideal as they took a while to accelerate and decelerate the vehicle and required too much power. After some brainstorming, we decided that we could make the base as a diamond or oval so that it would have the same aerodynamic property while traveling forward as it does traveling in reverse. Instead of using the air created from the propellers to move the vehicle, we decided that we would connect a motor directly to the wheels by using a gear system or by using a cone-shaped piece that would connect the smaller motor to the larger wheel directly. We could create either the system or piece in SolidWorks and 3-D print it. With this design, when the motor turns, the vehicle’s back wheel will automatically turn, minimizing the time it would take the vehicle to reach top speed and to come to a stop.
Development Decision
Keith’s design was very powerful, but it was too massive and it was not very durable. Kevin’s design was very aerodynamic, and it had a decent size, but it was only powered by one motor, so we concluded that it would not be powerful enough to pull its weight. Erica’s design was both powerful and aerodynamic in the front, but it was very back heavy and it would not be very aerodynamic while traveling in reverse. Mikaela’s design was both durable and aerodynamic, but it was decided that it was too large to carry its own mass. We decided that with improvements, both Kevin’s and Erica’s design had the potential to be developed and were worth implementing moving forward. The main priority for the team is to focus on using parts of Kevin and Erica’s designs, to better the team design.
Concept Screening and Scoring
Focus Areas
Division O has a few priorities for AEV design and performance. The biggest priority we have is efficiency as well as cost. Now efficiency is something that is composed of mass and performance. So for our design, we need to stress a lightweight design that has sufficient power. The consumer is going to want an efficient and affordable mode of transportation. This brings us to our next priority, which is the cost. Division O supports affordable manufacturing and materials in order to make our final design competitive. Our original design and testing had the cost under control, but the efficiency of the AEV was lacking. The original design was too heavy and underpowered, and therefore we have now focused our interests on making the AEV lighter and more powerful in order to change our strategy after our initial data collection.
Implement
Taking the focus areas and applying them to our AEV, the team came up with the concept for a direct gear drive system. The idea is that the gears would directly spin the wheels and only require the usage of one motor. By using one motor the team hoped to improve the amount of energy consumed when compared to the sample AEV. The team tested the AEV against the sample and recorded the data. The test results can be seen by looking under the Advanced R&D page. The results show significant evidence that the gear drive system performed marginally better than the sample in terms of energy.
Throughout the design process of the AEV, multiple performance tests were used to gauge the team’s progress. The team performed three tests using the gear drive AEV in order to successfully carry passengers from Linden to the commercial districts. Code used for all the performance test can be found under the Arduino Code Index.
Performance Test 1
The initial performance test required the team to code the AEV in order to have it travel from a starting point, move to a stop sign at the gate, pause for it to open and travel through.
At the start of testing the team’s AEV struggled to make consistent runs each time. The AEV didn’t use reflectance sensors and so all distances it traveled were based solely on time. Because of this, the AEV would sometimes hit the gate or not travel far enough. The team was able to successfully pass the performance test but decided to start considering how to implement sensors to improve consistency.
Performance Test 2
For the second test, the goal was for the AEV to travel through the gate, go to the other end of the track, attach to a load, and move back towards the gate.
The team went into the test with the hope of success, but unfortunately, the AEV was unable to complete the trial. The AEV struggled to consistently make distances and thus the team decided to add reflectance sensors to the AEV.
Final Performance Test
For the final test, the AEV needed to travel through the gate, pick up the load, and travel back through the gate and stop in the loading zone on the other side.
Using the new reflectance sensors, the team designed a new code for the AEV using if-statements. The new code was able to check the AEV’s current position and move forward if needed. The final test was unsuccessful though, due to an issue with the AEV’s gears being loosened over all the runs. Because of this, the final cost of the AEV was $1,238,337.64.
Evaluate
Performance Test 1:
This test showed the team that the direct drive was a more efficient design, but due to the gear covering the wheel, the reflectance sensors were not implemented. This proved to be a major issue because the team had to work with trial and error to determine the ideal run time. This was a problem because the ideal run time varied with battery power. As the power supplied decreased over time, it required more time to reach the same spot.
Performance Test 2:
This test showed the team that with implemented reflectance sensors, the vehicle became a lot more accurate. It was able to be coded to arrive at a much more precise location. The team also noticed that the rubber bands that were used for traction were causing an issue because they were causing the vehicle to be unstable on the track.
Performance Test 3:
This test showed the team that the vehicle was a lot more stable without the rubber bands. The team noticed that the vehicle was becoming very inaccurate again. They initially thought that this was caused by the battery power, but changing to a completely charged battery did not change much. The team realized that the motor rod that was attached inside of the gear had stripped the housing to the point that the rod was slipping inside.
Future Directions:
If the team decides to continue to pursue this iteration of the AEV, they need to change out the worn down gears. In addition, the team needs to explore the distance inaccuracies as discovered in aR&D3. By adjusting and fixing these two issues with the AEV, the design provided by the AEV is sure to get better test results and an overall lower final cost.