Planning - Week of 2/16/15

The Second Week

During my second week of my SRP, I researched further into the Miura fold and wrote up a “final product” proposal for my onsite advisor, Dr. Melde. Unfortunately, Dr. Melde was extremely busy with her grad students this week, so she will look at the proposal during my third week. Here is a quick diagram of my final product (the rover) I drew up in MS Paint:

 

If all goes well, this “rover” should be able to collapse onto the center square. Although the design is simple, I foresee a few problems in my idea:

1. The wires would probably interfere with how the rover folds because they cross the folding joints of the rover.
2. The thickness of the solar panels may interfere with how the rover folds. The thickness of the material being folded is one of the constraints of the Miura fold.
3. The rod that connects the wheels will be split into 3 pieces when the rover folds.
4. The motor will be positioned awkwardly both when the rover is compacted and decompressed.
5. What kind of foldable material will the solar panels be on?

In my proposal, I included a few possible responses to these problems:

1. Minimize the amount of wires needed and use the thinnest wires possible.
2. Use thin solar panels or embed the solar panels into the material that will be folded.
3. Have the wheels be controlled by two different motors
4. The rover will still function even if the motor is placed awkwardly, so it should not be a too big of an issue.
5. I will do some research and some tests to find the ideal foldable material for this project.

I also noticed that many of the examples of the Miura fold I found online (like the one I posted last week) were 5 by 7 in dimensions, which made me question whether my 3 by 3 rover would work. I researched into the topic, and it turns out that in Japan, copy paper is made such that when cut in half parallel to its shorter side, the two new pieces are proportional to the original copy paper. After doing some math, it can be shown such paper must have a length to width ratio of √2, which is about 1.4. It also turns out that 7/5 is 1.4. Essentially, the 5 by 7 dimensions of Miura fold is the result of the dimensions of copy paper in Japan, and these dimensions result in making the parallelograms of the Miura fold as close to being squares as possible. I am not too sure why this would be a requirement, but it would mean my 3x3 rover would work as long as the material is a square rather than a rectangle.

In other news, I finally have an access code to the room I am working in! Now I don’t have to knock every time I want to enter this room:

 

 

Until next time!

 -Parthib Samadder