Critical Design Review

To Do:

 

Executive Summary(refer to lab manual)

 

  • ( background / results / recommendations )
  • Specifically:
    • Provide the research focus on the need for an Advance Energy Vehicle. Address the overall goals and objectives.
    • Briefly discuss the research methods used to obtain results.
    • Discuss major results and findings from the Performance Tests 1-3 to help obtain the final design vehicle.

 

Introduction ( purpose / background ) amirah (if you dont mind)

Experimental Methodology ( procedure / Equipment – thorough description with pictures or diagram of setup ) amirah (if you dont mind)

 

Address the overall goals and objectives, and discuss the research methods briefly. Discuss major results from the performance tests 1-3.

 

Result & Discussion

  • Objectivity / Observations / Data Placement
  • Data Analysis
  • Tables and Figures

( system efficiency vs. advance ratio // plot vs. time or vs. distance // table that has a breakdown of supplied energy for each line of the code of the AEV’s operation)

  • Analysis (identified & relate to purpose) / Potential Error
  • Comparison to theory / Defense of Final AEV model (with data and theory)
  • Discuss efficiency / cost etc…
  • Screen and Scoring (with data and theory)
  • Observation from final run (with data and theory)
  • Specifically:
    • Provide a brief description of the group’s two prototype AEV concepts used in Performance Test 1 (include a figure of each concept in the report). Describe the evolution of the concepts in Lab 4 (Creative Design Thinking) to the two prototypes in Performance Test 1 to the final product. Amirah
    • Provide a screening and scoring tables (Lab 5: Concept Scoring and Screening to help defend the final design to all concepts and prototypes.(Amirah)
    • Discuss the cost of the system. What was done to reduce the cost of the overall system?
    • How did this Performance Test affect the team’s design process? Discuss the results from the design cycle and the energy optimization during the performance tests.
    • Incorporate the following figures into the discussion (from both AEV prototype concepts):
      • System Efficiency vs. Advance Ratio from wind tunnel testing similar to the one constructed in System Analysis 1 to help aid in the team’s decision in the propeller used
      • Figure of supplied power vs time/distance (team can pick either to plot vs. time or vs. distance).
      • Table that has a breakdown of Supplied Energy for each line of code of the AEV’s operation (each phase of the vehicle’s motion that consumes energy)

** Make sure you include a brief discuss of the figures and tables. Verify that the figures and tables are labeled correctly with appropriate units, title, and x- and y-axis labels **

    • What observations did the team make during final testing? How did the AEV behave? How efficient was the vehicle? This is where you discuss the scores on the final test score sheet (include the team’s scoresheet in the Appendix). Sugene

 

Conclusion and Recommendations (Sugene)

  • Summary (experiment, results and discussion)
  • Conclusion (supported by data and relevant to purpose)

(defend the final design and discuss why the team’s AEV is the best design compared to the rest of the class // advantages of team’s AEV)

  • Resolving error and recommendations (address error / reasoned)

 

Appendix

  • Schedule (completed/start/end dates, group members, percentage completed, roles, tasks, and estimated hours)
  • Solidworks models ( with bill of materials, overall dimensions, weight, cost and 3 views)

 

 Critical Design Review

__________________________

 

Submitted to:

Inst. Dr. Kadri Parris

GTA Sheena Marston

 

Created by:

Team F

Amirah Azlan

Stephen Balko

Sugene Park

Shane Ruiz

 

     Engineering 1182

The Ohio State University

Columbus, OH

21 April 2017

 

Executive Summary

 

The focus of this project has been to create an energy efficient vehicle that abides by the constraints presented in the Mission Concept Review (MCR). The Mission Concept Review calls for an this vehicle to be an Advanced Energy Vehicle (AEV). In the Mission Concept Review, the scenario laid out calls for the vehicle to transport R2D2 units on a distant planet where power is a finite resource. Since power is a finite resource on this planet, the Advanced Energy Vehicle needs to be as energy efficient as possible. The lab team’s AEV focus’ on how much energy is consumed during trips to obtain R2D2, as well as other factors in design that will make the Advanced Energy Vehicle be more efficient in order to achieve the goal laid out in the Mission Concept Review. The tests undertaken during the allotted lab times utilize multiple techniques in order to determine, which facets of the Advanced Energy Vehicle are optimal. Some of the techniques utilized are screening, scoring and collecting power consumption data. With some of these  various factors taken into account, the team was able to test the Advanced Energy Vehicle in order to make the runs more efficient or to correct any imperfections within the code. The team later found that the code was acting inconsistently due to the diminishing power provided by the battery and other factors, so the team had to alter the code for when the battery was low on power and when it was at full power. Additionally, problems with the arduino short circuiting, along with balance problems made the process shaky.  When taking the ideas presented in this assignment to the real world, there are some direct applications because if a design is more efficient than another design in the real world, it will cost less money and consume less resources.  

 

When constructing the Advanced Energy Vehicle, the team really honed in on aerodynamics and balance as the priorities for focus. With this being said, the design that the team came up with has a cone shaped front(streamline front) in order to make it aerodynamic. The new design that was in the works a couple weeks ago was finally completed, and it met those important criteria when testing it. After using the baseline code from the weeks prior to having the design allowed a smooth transition from the use of the code from the  makeshift design to our actual design. The code worked relatively well when it was applied to the new design, however battery inconsistencies caused some problems. Additionally, the battery placement caused some balance problems, which impacted the amount of energy used along with the code.

 

Some errors that the team ran into during the testing process involved the code, however that wasn’t the source of all of the errors observed. When testing the code of the Advanced Energy Vehicle there were some inconsistencies with the performance of the code, and after multiple tests the team concluded that the diminishing power caused the  Advanced Energy Vehicle to operate at non-optimal conditions. After observing this,  a new battery had to be obtained in order to make the  Advanced Energy Vehicle to operate properly, although when using a fully charged battery, the Advanced Energy Vehicle yet again didn’t work as expected. What the team got out of this is that the battery caused significant variation in the code, so it was necessary to have multiple codes in place as the battery dies down. Additionally, when the first Advanced Energy Vehicle picked up R2D2, the magnet was connecting to the back of the Advanced Energy Vehicle in such a way that it caused the back wheel of the Advanced Energy Vehicle to be pulled off of the track. In turn, the reflectance sensors weren’t reading the distance traveled on the track, and it never stopped. As  result, the group decided to put a couple spacers in between the 90-angle bracket and the screw in order to raise the positioning of the connection and that ended up working out. Another problem that we encountered involved the arduino short circuiting when coming in contact with metal parts on the AEV. When the Arduino came in contact with any metal parts, the code just didn’t function properly, and we realized that the arduino was short circuiting. On top of that, some of the team’s runs were very inconsistent at times, which was questionable, and the team realized that the lack of balance on the AEV caused that. The AEV was balanced aside from where the battery was placed. The battery placement had a pretty profound impact on the amount of energy used as well as how functional the code was.

 

All in all, the group has made serious progress throughout the performance testing, as they went from not having the design one week, to having the design with a completed code the next. I think the team’s design at the end of the day was the optimal design due to its shape, along with the attention to coding. As previously stated, the group focused on aerodynamics and balance, which will clearly make the  Advanced Energy Vehicle utilize less energy. Based on the team’s final test, the team’s design has had optimal functionality, as well as having an energy efficient code. With all this being said, our AEV ran well enough to pass the final run, which was a major goal.

 

Table of Contents

 

Executive Summary………………………………………………………………………

 

Table of Contents………………………………………………………………………….

Introduction…………………………………………………………………………………………………

Experimental Methodology……………………………………………………………………………

Results……………………………………………………………………………………

Discussion……………………………………………………………………………………………………

Conclusion & Recommendations…………………………………………………………

Appendix……………………………………………………………………………………………………….

 

Introduction

 

The Advanced Energy Vehicle design project is a team-based project that requires teamwork, time management and creativity. Each team is expected to build their own design considering the cost, weight, durability, stability and energy efficient. The team’s AEV design must complete the  Mission Concept Review for this project. The MCR has the background from the Star Wars universe, where the rebel alliance needs to be prepared for the war by transporting the R2D2 from the construction location to the base for use. More specifically the AEV would travel across a monorail stop at a gate for seven seconds pick up the R2D2 return to the gate and stop for another 7 seconds and then continue on to the starting position with the R2D2 in tow.

 

The group created a design for the AEV that would optimize efficiency through balance, aerodynamics, and stability. The design may have been a little bit heavier than other designs, however this did not greatly impact the final results and efficiency of the design as a whole. The code used was based around the position of the AEV so that the movements could be more precise even with changes in the power supplied to the engines.

 

Experimental Methodology

 

The purpose of the first lab was to familiarize the team members with the software, coding of the AEV, how to upload the code to the arduino and understand the purpose of each command. The code was developed by using basic functions calls: brake(), celerate(), motorSpeed(), goFor() and reverse(). The second lab was used to familiarize the students with how to use the external sensors as well as how to use the sensor function calls; goToRelativePosition() and goToAbsolutePosition(). At the same time, the students worked on the propulsion efficiency of the AEV by performing wind tunnel testing using the tool in Figure 1 to determine how efficient the propulsion system is and which propeller configuration is the most energy efficient for the AEV design. From this lab, the team concluded that using the EP-3030 propellers would allow for the power to be equally supplied whether using pusher or puller method, so that the first and second times around the track could be more easily determined.

 

Figure 1: Wind Tunnel Equipment

 

The third lab required creativity of the team members in designing the AEV by using two methods; brainstorming and keeping project portfolio. The purpose of the project portfolio is to keep and update the progress of the project for future reference. For the first 15 minutes of the lab, each of team members were required to produce an individual design. The designs by team members are shown in Figures 3, 4, 5, and 6 below. The next 15 minutes required the students to discuss as a team which criteria were most important in designing the most energy efficient AEV while taking account of the design constraints.

 

Figure 2:Sketch 1

 

Figure 3: Sketch 2

 

Figure 4: Sketch 3

 

Figure 5: Sketch 4

 

The actual testing of the AEV on the track started in lab 4 where the purpose of the lab was to familiarize the students with the analysis tool. During the first part of the lab, the team began by doing a trial run for the AEV on the track. After the trial run, the team downloaded the data from the Arduino to the computer and convert the data into physical parameters. The team then analyzed the performance of the AEV by using MATLAB. In the second part of the lab, the team used the Design Analysis Tool to analyze the data downloaded from the Arduino. The same procedure was done where the team complete a trial run on the track, download the EEPROM data and analyze the data using AEV Analysis Tool. The AEV Analysis Tool shown in Figure 2 has been used throughout this project to determine the performance of the AEV.

 

Figure 6: AEV Analysis Software

 

Design decision making was done in Lab 5 where the team used the screening and scoring methods to narrow down the choices of AEV design. Only one design was constructed and tested on straight track. From the run, the team develop the success criteria the needs to be included in scoring and screening sheet. Using scoring and screening method, the team compared the sample AEV design with the team members design from Lab 3 with success criteria such as stability, maintenance, durability, cost and environmental.

 

Labs 6 and 7 were used as points to determine the teams progress through the project. During these labs there was no testing nor data collection being done, and instead the focus was on looking back at the previous labs to determine how to best complete the rest of the project in the remaining time.

 

During Performance Test 1 (Lab 08 A/B/C), the team developed two designs using the results from the scoring and screening methods. The purpose of the Performance Test 1 was to compare the two designs and choose one design from the two designs as the team’s final design. To compare, the team built the AEVs and tested both of the AEVs on the track and compared the data obtained. Design B was chosen as the team’s final design and additional parts were submitted to be 3D printed.

 

In Performance Test 2, the team was supposed to construct two codes and compare which one is more consistent and energy efficient. With the chosen AEV design, the team should test the two separate codes considering the consistency, flexibility to a different track and energy efficiency. The team then should observe the performance of the AEV on the track, compare the performance data and decided which code was the best. The team could not complete the task for this lab as the Arduino was not working and thus the comparison could not be made.  As a result, the team used the code that was made in Performance Test 1 and made slight alterations to include time, before determining that position was better and used this in the final code. Performance Test 2 focused on testing smaller variations on the chosen code with the chosen AEV design. The purpose was to optimize the energy used by the AEV and to ensure its consistency in completing the MCR. The team made some small variations in the code, tested the AEV using the modified code and analyzed the data obtain whether the small changes should be kept or not.

 

Finally, final testing was done in Performance Test 3 and the it was evaluated by the UTA. The team was given two runs to do the final testing on the AEV and the better run of the two runs was score awarded. The team tested their AEV on the last day of the Performance Test 3 and the score sheet is included in Appendix D.

 

Results & Discussion

 

Figure 7 and 8 below show the results of lab 02 in which the power generated by different propellers and their configurations were tested. In the graphs it can be seen that Propeller EP-3030 was relatively consistent in it’s  efficiency whereas EP-2510 was rather poor at the lower percents and had a bigger difference between methods. Also as can be seen in Figure 9 the propulsion efficiency is greatly decreased in EP-3030 when using higher power values, however this is because the propeller barely increases in thrust at higher power values which allowed the group to use lower power values to get the same amount of advance ratio. Due to these variables the group decided to use propeller EP-3030 in order to stay consistent in power efficiency.

 

     Figure 7: Propeller EP-3030 Power Efficiency       Figure 8: Propeller EP- 2510 Power Efficiency

 

Figure 9: EP-3030 Advance Ratio

 

During Lab 4 figures 3-6 were created by each team member. using these designs the main feature that every design had was a hood to improve aerodynamics, along with this the group decided to keep the longer but more stable body of the designs in order to create the first design shown in figure 10 below. In figure 11 the hood part was scrapped in order to focus on a wider design in hopes that balance would be easier, however the design did not take into account the excess of weight that is put on the back of the AEV. Due to this design 1 was determined to become the main source of inspiration for the absolute final design which essential moved the propellers and flipper the design so that the hood was in the back of the AEV.

 

Figure 10: Orthographic view of Design 1

Figure 11: Orthographic view of Design 2

 

As can be seen below the screening and scoring methods were used in order to best choose the designs that would be used as inspiration for the final designs. In these we used the team’s designs in figures 3-6 as well as other crafted and hypothesized designs in order to determine which features were best to carry on and which could be eliminated. Design A used a method of making the design very thin but long which was ultimately scrapped. Design B was very similar to figure 3 where the front had a conical shape and was the main source of inspiration later for Design 1 in figure 10 and ultimately the final design used in the project. This design was heavily used because of how well it did in the screening and scoring methods.

 

Figure 12: Screening Method

 

Figure 13: Scoring Method

 

The entire system ended up costing $66.50 before including the cost of the arduino and battery as these can be easily varied depending on the requirements of the task. Using the arduino that was used by our group the cost would be $166.50, however the cost of the battery was not given. The cost was not highly prioritized by the group because the costs of the parts was seen to be so similar with the main difference being whether or not the servo was used which the group did not use.

 

During the performance test there were a few major occurrences that influenced the team. First was the problem that where the design would have had the arduino resting on metal so it would occasionally short circuit. This was fixed by installing a screw underneath the arduino to hold it above the metal strips. Other than that the team had some major setbacks when trying to incorporate time into the code, because of these which mainly were inconsistencies between runs that were not even slightly predictable the team decided to proceed using only position to determine when the AEV should change the act that it is in the process of. The last major thing that the group was able to discover was that when the AEV drifted to the gate less power was needed to slow it down and the period of it being off allowed for less energy to be consumed overall.

 

In the final code there were 4 phases that repeated and phase 1 was increased in power in order to become phase 5 as shown in figure 12 below. The team determined that this was the best strategy because it allowed for the track to be tested by using the section before R2D2 to get positions that worked well and then just having to adjust the power in order to complete the task.

Figure 14: Power vs. Time Final Test

 

Table 1: Code Phase Breakdown

 

Phase Code Time (Seconds) Total Energy (Joules)
1 motorSpeed(4,27.5);

goToAbsolutePosition(-200);

 4.8 32.0(2x)
2 motorSpeed(4,0);

goToAbsolutePosition(-385);

 3.6 0
3 reverse(4);

motorSpeed(4,30);

goFor(1);

 1.0 8.0(3x)
4 brake(4);

goFor(8);

 8.0 0
5 motorSpeed(4,42.5);

goToAbsolutePosition(-600);

 6.7 82.0(2x)

 

Total Energy: 263.5

 

For the final run the team was able to complete all of the track with only a slight hiccup being that it stopped a few marks short of the gate the second time. Otherwise, all of the objectives the AEV had to meet were met. It stopped in between the sensors at the first gate, picked up R2D2 in the proper manner, and it stopped at the end of the run in between the proper markings. Additionally, the AEV seemed to be pretty balanced through the run, which certainly helped out the overall functionality of the AEV’s run. All in all, the AEV performed as it had been expected, meeting nearly all of the criteria. The AEV performed better than a truck which would be around 6 times less efficient than our vehicle at a little over 5000 J/kg, whereas our vehicle was only 900J/kg. From this comparison we can say our vehicle was fairly efficient however it is not better than the best freight trains which come in around 450 J/kg or about twice as efficient as our vehicle.

 

Conclusion & Recommendation

 

Several things were learned throughout designing and testing the AEV. First the group learned that a design focused on balance and aerodynamics lead to the most efficient energy consumption. Also using position as a measurement was found to be more accurate and more efficient than using time. Lastly using a slightly higher power for a shorter time was more efficient than using a lower power for a longer time.

 

When testing time proved to be a very inconsistent variable whereas position seemed to be fairly reliable. During the trials when time was introduced the AEV would change by up to a third of the distance it traveled between runs while position would only change small amounts unless something else was causing a bigger issue. Because of this and the ability to turn off the AEV at a specific point the team decided to use position as the main way to reference what the aEV would do at any given moment.

 

Another large error that occurred in trials was not properly balancing the AEV. Whenever this occurred the AEV would alter the run by up to half of the distance traveled. This was easily fixed by adjusting battery placement, however this had to be checked in between each run.

 

The final design was chosen based upon it allowing for the arduino to be centered and ease of access to the battery, which were the main components of balance in our design. Alongside this the aerodynamic hood at the back allowed for the AEV to be able to travel more efficiently when the R2D2 was picked up.

 

The main recommendations that the group would make for future testing would be to ensure that the device is fully balanced as well as making sure that the reflective tape is far above the minimum reflectance for the sensors to pick up, as this seemed to be part of the reason why some of the runs would change distances. Alongside this the track could be made to the same size between rooms so that the code will be able to perform in a very similar way independent of the location it is used at.

 

In the end the group was able to complete the entire code but not with 100% consistency. This was due to several variables including battery discharge, balance changing during the run, and reflectance sensors not working the exact same 100% of the time. The run can be seen as a success considering that the AEV performed all of the tasks and was only off by a small margin which can be accounted for by errors that were hard to track.

 

Appendix A:

 

Table 2: Team Meeting Schedule

 

No. Task Start End Due Shane Sugene Amirah Stephen % Complete
1 Project Portfolio 1/25 4/20 4/21 x x x x 100%
2 Finish AEV Design 1/25 4/7 4/8 x x x x 100%
3 Complete Code 1/25 4/14 4/14 x x 100%
4 PDR Report 2/25 3/1 3/3 x x x x 100%
5 CDR Draft 4/8 4/13 4/14 x x 100%
6 CDR Report 4/12 4/20 4/21 x x x x 100%
7 Final Presentation 4/12 4/19 4/19 x x x x 100%

 

Appendix B:

 

Figure 15: Final Design Orthographic

 

Figure 16: Final Design Bill of Materials

 

Item No. Part Identification Quantity Cost

($)

 Total Cost

($)
1 Large Rectangle 1 $9.00 $9.00
2 Tiny Rectangle 2 packaged with 1 packaged with 1
3 Flat Bracket 4 $1.26 $5.04
4 Screw 21 $2.88 $2.88
5 Support Arm 1 $2.00 $2.00
6 90-deg bracket 3 $0.84 $2.52
7 Nut 23 Packaged with 4 Packaged with 4
8 Motor Mount Clip Aluminum 2 $0.59 $1.18
9 Propeller Assembly 2 $10.44 $20.88
10 Wheel with Reflective Tape 1 $7.50 $7.50
11 Wheel 1 $7.50 $7.50
12 Washer 6 Packaged with 4 Packaged with 4
13 Battery 1 varies on choice of battery varies on choice of battery
14 Battery Pack Clamp Plate 1 $1.00 $1.00
15 Hex Nut 2 Packaged with 4 Packaged with 4
16 Magnet Cube 1 unknown unknown
17 Reflective Sensor 2 $2.00 $4.00
Overall Cost $66.50
Total Weight 270 grams

 

Table 3: Final Design Cost and Weight

 

Appendix C:

 

Final Code-

 

motorSpeed(4,27.5); \\set all motors to 27.5% power

goToAbsolutePosition(-200); \\goto 200 marks from the start

motorSpeed(4,0); \\turn all motors off

goToAbsolutePosition(-385); \\goto 385 marks from the start

reverse(4); \\reverse all motors

motorSpeed(4,30); \\set all motors to 30% power

goFor(1); \\continue for 1 second

brake(4); \\brake all motors

goFor(8); \\idle for 8 seconds

reverse(4); \\reverse all motors

motorSpeed(4,27.5); \\set all motors to 27.5% power

goToAbsolutePosition(-620); \\goto 620 marks from the start

motorSpeed(4,0); \\turn all motors off

goToAbsolutePosition(-805); \\goto 805 marks from the start

reverse(4); \\reverse all motors

motorSpeed(4,30); \\set all motors to 30% power

goFor(1); \\continue for 1 second

brake(4); \\brake all motors

goFor(5); \\idle for 5 seconds

motorSpeed(4,42.5); \\set all motors to 42.5% power

goToAbsolutePosition(-600); \\goto 600 marks from the start

motorSpeed(4,0); \\shut all motors off

reverse(4); \\reverse all motors

goToAbsolutePosition(-450); \\goto 450 marks from the start

goFor(1); \\continue for 1 second

brake(4); \\brake all motors

goFor(8); \\idle for 8 seconds

reverse(4); \\reverse all motors

motorSpeed(4,42.5); \\set all motors to 42.5% power

goToAbsolutePosition(-180); \\goto 180 marks from the start

motorSpeed(4,0); \\turn all motors off

goToAbsolutePosition(-30); \\goto 30 marks from the start

reverse(4); \\reverse all motors

motorSpeed(4,42.5); \\set all motors to 42.5 %

goFor(1); \\continue at speed 42.5 for 1 second

brake(4); \\brake all motors

goFor(7); \\idle for 7 seconds

 

Appendix D:

 

Figure 15: Final Scoresheet