5/4

Today, Robert and I addressed a few design features on the obstacle course. We tested the Boe-Bot several times on the obstacle course, which resulted in needing to rearrange some of the electrical tape. We also talked about the final presentation with Mrs. Vestal. Lastly, we discussed edits we need to make in our report. We're nearing the end of the semester and we're looking forward to presenting our project!

4/29

On Wednesday, we spent the entire day constructing the obstacle course out of foam core board, creating the electrical  tape path, and programming the Boe-Bot to follow the electrical tape. We found line following programming for 3 QTI sensors online. We couldn't follow the programming given to us in the line follower attachment instructions because it was for 4 QTI sensors. We had to modify some of the online programming, but it worked! We ended up staying an extra two hours. The physics professor was kind enough to let us use the corner of his classroom during his class.

I took the foam core boards home and started drawing details on them to make them look more like roads.

We came in early on Friday and finished coloring the obstacle course as well as connecting the boards with packing tape and trying to figure out how to program the Boe-Bot to complete a continuous 3-point turn. Until this point, we had to stop and program the Boe-Bot for each individual movement needed to complete a 3-point turn during its performance of the routine. We knew we had to include subroutines in our programming, but we didn't know how. After looking for online advice, we learned how to create subroutines and added two different subroutines: one for stopping at intersections and one for pivoting backwards (useful for the 3-point turn). The programming took 4 hours to complete, but now the Roadbed 3000 completes a continuous route!!

This weekend Robert and I are working on the report. We divided the responsibilities and we plan to finish the report by Monday so that we can practice the presentation on Monday during class. Robert is a great partner and I'm looking forward to our final presentation! It's going to be great!

4/27

Before class today I felt there was endless work to be done in order to finish our project, but Robert and I were able to accomplish so much during class (we stayed an extra hour) that I can see the light at the end of the tunnel! We started by continuing our efforts with installing the line follower from last week. We were having trouble with our far right sensor. It sensed black, even when we put it on a completely white paper. It was really frustrating! After switching out the sensor and the  corresponding wire, Robert and I decided to look for an option to use only 3 sensors for the line follower. We found a video of a line follower using only 3 sensors so we knew it was possible. Then we found a website that had the exact instructions and diagrams for what we wanted to do and it included the related programming. After reconstructing the whole line follower system and entering the programming, we tested each of the sensors and they worked! It was really exciting! We moved on to programming the Boe-Bot so that it would "follow" the line by moving along a black line on a white surface; however, when we tested the programming our Boe-Bot wouldn't move at all. We went back to the basics and tested the servos (wheels) and they didn't work. That was super frustrating, but we checked all of our connections and found out that our VIN, VDD switch was broken. The switch had chipped earlier in the project and now it wasn't functioning at all. Robert and I scrounged around the room for extra parts and we found an unused Boe-Bot so we switched the switches. We tested the line follower programming again and our Boe-Bot moved the distance of the electrical tape. It was so amazing to see our hard work....well working! We spent the last minutes of class planning out the obstacle course. Robert had brought in foam core and lego buildings to help us visualize the course. We searched online for the actual NC driving test route on Google Maps as remembered from experience and we started marking roads on the posterboard. We're nearing the end of the project and I'm really excited to present our final prototype! On Wednesday, Robert and I are going to construct and test the obstacle course and delegate report responsibilities.

4/22

Today, Robert and I installed the line follower mechanism on our Boe-Bot. We also programmed and tested the line follower as seen in Figure 1; we are still in the process of troubleshooting it. The line follower mechanism allows the Boe-Bot to distinguish between light and dark areas. This quality is perfect for an obstacle course because we can lay down black electrical tape on a white background and program the Boe-Bot to "follow" the black electrical tape lines.

Figure 1 Adding the line follower to the standard Boe-Bot.

Robert and I also discussed the required objectives our Boe-Bot will perform to match those of the North Carolina road test that teenagers complete in order to receive a state driver's license. Below, Figure 2 explains our list of objectives in order from start to finish. These objectives were researched online and recalled from personal experience taking the road test.

Figure 2 The list of tasks performed during a NC road test to be performed by the Boe-Bot.

The last thing we did during class was plan out the obstacle course for the road test. The obstacle course is based on the actual route used for the NC road test. Figure 3 is the rough sketch we will use to create the obstacle course for the Boe-Bot to navigate. We've decided to use foam board as the foundation for the obstacle course and electrical tape as the lines for the Boe-Bot to follow. The obstacle course will be explained in detail next week when we start to construct it.

Figure 3 The rough sketch of the obstacle course that the Boe-Bot will navigate based on the actual route taken by students during the NC road test.

4/20/15

Today, Robert and I met for the first time in 2 weeks. Robert explained to me the construction of the Boe-Bot (which he finished quite fast) and the basic programming tools. We downloaded the Parallax programming software and centered the servos (motors that turn the wheels). We proceeded to practice basic programming objectives out of the microcontroller handbook. Robert showed me the line follower and the obstacle course construction pieces he brought from home. They're perfect! For the rest of the week, we will continue to work on programming the Boe-Bot and designing the obstacle course!

4/15

I was not in class today, but Robert informed me he is going to take the Boe-Bot home and work on programming as well as finishing up constructing the device so that we can stay on schedule. Last week, I completed most of the paperwork so he could begin construction this week. During the planning phase, I informed Robert of my absences and we agreed this would be a good way to ensure everyone remained involved in the project even though we wouldn't be able to meet for two weeks.

4/13

I was absent on 4/13. However, Robert worked to stay on schedule by beginning to construct the Boe-Bot. On Monday, we hit our first obstacle. We didn't realize that the Boe-Bot had to be programmed before it was constructed and so Robert is working on integrating this new information into our WBS schedule. This new info may require additional work outside of the classroom.

4/1

In class Robert and I started working on our Work Breakdown Structure (WBS); it still needs some finishing touches. We looked at previous groups' final reports. After viewing the different options for the final report, we decided that we're going to try using MindView software to standardize our report documents and presentation. Over spring break, we decided to finish our initial WBS and Gantt Chart and then start building the week after. Robert and I can't believe how fast this project is moving. We're worried and excited, but mostly we just hope we can remember everything we need to work on! It's just a bit overwhelming, but we can do it if we give it our best effort. I'm really grateful Robert is my partner because we compliment each other really well in our work ethic and engineering strengths and weaknesses.

Boe-Bot Final Project 3/30

Today, we reviewed how to write an effective problem statement. Robert and I finalized our problem statement, presented it to the class, and integrated feedback into our statement to make it more clear and specific. In our problem statement, we stated that we would base our RoadBot prototype on the NC state driving test, but this might change if another state driving test is more practical regarding the limits of programming. We also listened to the other teams present their ideas and provide feedback to help guide their preparation.

We started brainstorming objectives for our WBS. Robert and I are looking forward to finishing up our WBS and Gantt Chart and beginning to construct our Boe-Bot this week during lab class.

3/25

Today was the first time we were able to view the parts of the Boe-Bot and look at the manuals. Last week, Robert and I developed an idea to use the Boe-Bot as a mail delivery device (featured on team consensus linked below). However, this idea was deemed unrealistic when we were made aware of the actual dimensions of the Boe-Bot (it is barely bigger than a sticky note). So, we went back to the drawing board.

Today, Robert and I worked on filling out our team contract and team consensus. We also worked on defining our problem statement and developing a realistic function for the Boe-Bot. We decided we'd like to create a Driver's Ed training device that Driver's Ed instructors use in the classroom to show the students the specific obstacles that will be tested on the state driving test. The Boe-bot will perform a set of programmed obstacles (ex: parallel parking and avoiding orange cones) in succession to simulate the state driving test. Although each state has a different driving test, the Boe-Bot can be customized for each state's test.

This week, we are also starting to work on our WBS (Work Breakdown Structure) for the Boe-Bot project. Robert and I know this will be a very detailed report of the procedures and steps necessary to complete this project and are a little intimidated because we don't want to leave a step out of the report or misjudge the respective time requirements for the objectives.

The Start of the Final Project

This week we begin working on our Engineering Final Project. We were split into teams and given the assignment of designing, developing, and testing a Boe-Bot to solve a realistic problem. This week we begin by researching the electronic capabilities of a Boe-Bot and completing a Team Contract to set the ground rules for the project. My partner is Robert. The next step is to begin brainstorming possible problem statements. I'm really looking forward to this project because I've never built a robot before and Robert says he's really great at putting things together. I think there's a lot for me to learn and I'm excited!

Transportation Success/ Failure

Professor Vestal assigned each student an example of a transportation success and a transportation failure. It is our task to research and summarize the various aspects of each structure and present our findings to the class. My assigned transportation success is the Forth Bridge in Scotland.

Transportation Success: Forth Bridge, Scotland

Location: The Forth Bridge stretches from South Queensferry to North Queensferry in Scotland. This area received a lot of ferry traffic and the increase in railway transportation in the late 1800s emphasized a need for a bridge at this location.

When: Construction of the Forth Bridge began in 1883 and it was opened for operation in 1890.

Type of bridge: Cantilever
The Forth Bridge consists of three cantilever structures situated on granite platforms. Cantilevers are supported on one side and carry a load on the other.

Significant attributes: The Forth Bridge is regarded as the first 100% steel bridge in Britain. Additionally, the Forth Bridge was an attempt to achieve a successful transportation system in the area after the collapse of the Tay Bridge in 1879.

Dimensions: Height: cantilevers are 100 m (110m above surface of water at high tide)
                     Weight: 53,000 tons
                     Length: 2.5 km (521 m cantilever spans)

Cost: About 3 million pounds

Awards: At the time of construction, the spans of the individual cantilevers (521 m) were the longest and second longest in the world and remained so for 28 years. The Forth Bridge is still the longest cantilever bridge in the world. The Forth Bridge is protected as a Category A site in Scotland with national importance and is currently a nominee for a UNESCO World Heritage Site.

Unique Features: This year is Forth Bridge's 125th anniversary. It underwent a major paint-job restoration from 2001-2011 and there are plans for a viewing platform and a thrill climb (gallery and videos at this site) to be opened in the next year or so. The Forth Bridge is also known for its red oxide paint, which was color matched during the bridge's restoration paint job (Figures 1-3 below).

Why was this bridge a success? The Forth Bridge is a success because it has fulfilled its purpose for 125 years and remained in good working condition. Additionally, it has become an internationally recognized bridge.

Figure 1: Full view of the Forth Bridge

Figure 2: Train crossing the Forth Bridge

Figure 3: The underside of the Forth Bridge (structural layout)

Transportation Success Presentation

Sources:

http://www.britannica.com/EBchecked/topic/214233/Forth-Bridge

http://forth-bridges.co.uk

http://www.railway-technology.com/projects/forth-rail-bridge-firth-scotland/

http://www.forthbridgeexperience.com

Transportation Failure: Arroyo Pasajero Twin Bridges

Location: The Arroyo Pasajero Twin Bridges were located near Coalinga, California over the Arroyo Pasajero Creek.

When: The twin bridges were built in 1967 and they collapsed twenty years ago today, March 10, 1995.

Type of bridge/Significant attributes: I could not find the type of bridge stated outright, but I do know that the twin bridges included wing walls, vertical abutments, and three piers made of six columns each. A web wall was later added to provide extra support to the groups of columns.

Dimensions: 122 ft long

Cost: I did not find the original cost of the bridge. However, the bridge that replaced the Arroyo Pasajero bridges after they collapsed cost $6 million. Additionally, travel time lost due to the collapse cost local residents $550,000.

Unique Features: The bridges operated as a 4-lane interstate (Interstate 5).

Why did the Arroyo Pasajero Twin Bridges fail?
Several factors contributed to the collapse of the Arroyo Pasajero bridges. The main factors include flooding, lack of planning for a web wall, increased drainage, limited space for flow, long-term degradation, scouring, and lack of adequate steel supports for columns.
At the time the bridge collapsed, California was experiencing the effects of El Nino, which included relentless storms that led to major flooding. Several years prior to the collapse in 1969, there was another flood that lowered the bed of the creek 6 ft. A web wall was constructed after this flood to provide extra support for the columns. After construction, the Arroyo Pasajero Creek was connected by a manmade channel to Chino Creek. This channel increased the amount of drainage in Arroyo Pasajero Creek by 33%. Additionally, the creek width upstream of the 122 ft bridge was 300-400 ft. The flow of water in this larger width was limited by the bridge, leading to a build-up of water during the 1995 flooding. Between the time of construction and the time of the collapse, the land level had been reduced 10 ft by degradation (wearing down of soil). During the flooding, scouring (erosion of soil around supports) exposed a depth of the columns that did not have steel supports. These factors combined to undermine the strength of the bridges and the bridges collapsed.

Bridge replacement modifications and redesign: The twin bridges were effectively replaced in 10 days. The newly redesigned bridge was built with a railroad flatcar superstructure, steel supports, a concrete column foundation, and a steel grate surface covered in trench plates and rubberized asphalt (Figures 1-3 below).

Why were the Arroyo Twin Bridges a failure? They failed in their purpose to provide safe and reliable transportation. Additionally, they were not properly maintained, which led to the death of seven people.

Figure 1: Caption located on digital image.

Figure 2: Replacement bridge after the twin bridges collapsed.

Figure 3: Underside of the new bridge.

Transportation Failure Presentation

Clarification: Today in class, I said the twin bridges were made up of two bridges, each carrying two lanes of one way traffic. However, this was an assumption based on the information I had read and collected.

Sources:
http://www.fhwa.dot.gov/publications/publicroads/98julaug/planning.cfm

http://www.nytimes.com/1995/03/12/us/heavy-rains-roll-their-destructive-way-down-california-coast.html

http://www.sfgate.com/news/article/I-5-Tragedy-Unites-Residents-Of-Rough-and-Tumble-3041270.php

http://www.fhwa.dot.gov/publications/publicroads/95fall/p95au2.cfm

http://isddc.dot.gov/OLPFiles/FHWA/010590.pdf

http://water.usgs.gov/edu/earthgwlandsubside.html

Egg Drop Math/Lessons Learned

The math behind the egg drop project:

Figure 1: Potential and kinetic energy equations for the egg drop.

Basically, the egg's potential energy and kinetic energy remains constant throughout the drop; however, the respective values of the potential and kinetic energy change. Before the egg is dropped, the egg has a certain amount of potential energy. After the egg is dropped and as the egg is falling, the original potential energy is converted into kinetic energy. Right before the egg makes contact with the egg catcher, the egg has reached its peak value of kinetic energy and has essentially no potential energy.

Note: The "m" in the parentheses in the last step of the math stands for "height in meters."

Lessons Learned

1. One person never has all the ideas and/or resources to complete the project

Megan and I depended on one another to brainstorm ideas we thought might work for the design of our contraption. Additionally, we searched the Internet for successful precedents for our project; however, we didn't find any products that matched our criteria. So Megan and I worked to design a product we thought would work. We both contributed to the design and worked to combine our ideas. JTEC (our egg catcher) was a combination of both our valuable efforts!

2. It's ok to go back to the drawing board

Megan and I revised our design several times in order to achieve a satisfactory final product. As we went on in the design process, new knowledge came to our attention, which encouraged us to rethink our original plans. Our product developed in quality due to these opportunities for revision.

3. Asking for help is not a weakness

Throughout the design process, Megan and I asked and received help from other teams. Cameron taught us how to drop the egg to increase our accuracy and precision (terms we learned about in a previous chapter). Team Canada helped us drop our last egg by holding the measuring tape 16 ft in the air while we set up our contraption. Engineers cannot survive alone. We are collaborative by nature.

Overall, I really enjoyed this project and I think I have a better understanding of the engineering design process and its importance! Doing the work takes time, but it's definitely necessary!

Egg Drop Final Test!

Last Wednesday, we finally tested our egg drop contraption, which Megan and I named the JTEC (Jamestown Egg Catcher) because Mrs. Vestal said it looks like a Jamestown fort!

First, we weighed three different eggs (Well, actually four because one rolled off the scale). We named our eggs EA, MA, and AM.

We dropped each egg in order of weight, greatest to least, while increasing our dropping heights.

Here is a video of our second drop (Jordyn took this video!)

We successfully dropped and caught our first two eggs, but on our third drop I hesitated and accidentally aimed outside of the catcher causing the egg to fall on Lia's phone, which was strategically placed on the ground near the egg catcher facing up so that we could film the egg falling. Sorry Lia! Because of our success during the first two drops, Megan and I agreed not to make changes to our contraption during the final tests.

These are the results:

The hardest part of the drop test was measuring the height accurately, which meant the person dropping the egg had to measure the height with a tape measure in one hand and hold the plum bob in the other. However, the other teams worked to help us with this task and that made it easier.

Finally, part of our lab project included finding the math behind the egg drop and solving for the final velocity of the egg just before it hits the catcher or the floor.

Mrs. Vestal helped us figure out the math and explained the reason behind it:

Basically, the egg's potential energy and kinetic energy remains constant throughout the drop; however, the respective values of the potential and kinetic energy change. Before the egg is dropped, the egg has a certain amount of potential energy. After the egg is dropped and as the egg is falling, the original potential energy is converted into kinetic energy. Right before the egg makes contact with the egg catcher, the egg has reached its peak value of kinetic energy and has essentially no potential energy.

Note: The "m" in the parentheses in the last step of the math stands for "height in meters."

So for our three drops:

Egg 1 (drop 2) velocity: 7.25 m/s        final kinetic energy: 1.6 J

Egg 2 (drop 1) velocity: 6.58 m/s        final kinetic energy: 1.41 J

Egg 3 (drop 3) velocity: 9.80 m/s        final kinetic energy: 2.72 J

Overall, this was a great learning experience and I really enjoyed working in teams. Megan is an awesome partner and I feel really excited that our catcher worked! We came in second place and I think we fulfilled our goal of creating an effective egg catcher. Go JTEC! If the first place team combined the top of their catcher (which looks like a wrestling ring) with the base of our catcher, we would create a world class egg catcher because our base is a bit more stable than theirs and their top has a larger catching area. I'm so glad engineers are collaborative because it leads to wonderful solutions!

Week 2 Great Egg Drop

This week, Megan and I revised our problem definition. We realized our original definition was actually our identification of the solution.

Problem Definition: Currently, Mrs. Vestal's chickens are laying eggs at various heights (less than or equal to 17 feet). Mrs. Vestal is having trouble collecting eggs because the eggs crack open when they hit the ground.

We also starting the building process for our chosen solution to the problem. Our original design looks like this:

As we put the parts together, we realized a couple of things. First, it made more sense to have a square foundation because the center basket would be more effectively attached and supported. Second, our design would be most effective if we used both a straw bottom and a tape drape for the basket. Third, we would use resources more efficiently by scrapping our plans for the top half of the structure.

Our structure's foundation is composed of straw triangles and the basket is made of straws cut in thirds as well as a tape drape interior with straw supports.

We are still working on the mathematics behind the structure and its performance.

Additionally, we tested our contraption with a real egg from 2 inches. It made it unharmed! We tried from a higher distance with the plumb bob guiding our aim, but I got nervous and completely missed the contraption! Oops.

We'll have to practice our aim this week so we'll be ready for next week's tests!


The final product looks like this:






















Megan and I are working really well together and are excited to represent Japan! We are able to listen and  build on each other's ideas. We are also very patient and optimistic in our endeavors. This project has been a great lesson on teamwork and taking things one step at a time.

The Great Egg Drop Week 1

For the next three weeks, our class has divided into teams representing various countries responsible for creating a contraption that can catch eggs from a height greater to or less than 17 feet.

The instructions for the project can be found here and the instructions for the report can be found here.

The first week is designated to complete the beginning of the design process:
Problem Definition
Defining Criteria
Idea Generation

Megan and I are a team representing Japan.

Figure 1: Problem definition, criteria, and the beginning calculations of the physics behind the Egg Drop (work in progress, will become more specific with further understanding)

Figure 2: Top view of our Egg Drop design. The second sketch shows scattered layers of tape hammocks.

Figure 3: The side or full view of our design with two different options for the basket located in the middle of the contraption responsible for catching the egg (the resting place).

 Throughout our design process, we tried to focus on minimizing our materials and maximizing our understanding of the physics and calculations behind the performance of the egg drop.

We used the following online picture as a basis for our egg drop design:

Inspiration for egg drop

We used the following links to help guide our mathematical understanding:

Acceleration

Kinetic and Potential Energy

Kinetic energy and potential energy equation

Megan and I work well as a team and are looking forward to the remaining weeks of preparing for the competition!