Preface

Hello, Nyanyan (reading is prima facie "Nya Nyan") is. From this time on, I will explain the robot that solves the Soltvvo: 2x2x2 Rubik's cube that I made. The structure of the article

Overview
Algorithm
Software
Hardware will do. I will write it as simply as possible, but I plan to write the content in quite detail, so you can pick up and eat what you care about. As soon as the article is completed, we plan to post a collection of videos related to this article on YouTube. In this video collection, I will hide the details and give a rough outline. We will introduce a video at the beginning of each article, so please have a look if you like.

Expected reader

Those who are interested in algorithms (full search)
Those who are interested in making robots
Those who are interested in Rubik's Cube

Video collection related to this article

The playlist is here.

The trigger for the project

Um, aren't you free? I wanted to make something, and for the time being, I wrote a program that solves 2x2x2 in the shortest amount of time, and it was unexpectedly fun, so I wondered if I could actually make a robot that solves 2x2x2 using this procedure.

Prerequisite knowledge

In the algorithm section, I try to write it in a simple way (after all, the person who writes the article is a light blue person at AtCoder), so I do not assume any prerequisite knowledge. For software, Python and C ++ (Arduino) are used. I think that these minimum knowledge is necessary. In the hardware section, technical terms may appear in some places, but I think that you can understand them by google. Therefore, no prerequisite knowledge is required. In addition, basic knowledge about Rubik's Cube is required throughout the article, so I will introduce it here.

Basic knowledge about Rubik's cube

How the Rubik's Cube works

The Rubik's Cube is often referred to as a "color-aligning puzzle", but it is actually a ** puzzle that aligns the location and orientation of parts **. First, let's put a disassembled photo of a normal 3x3x3. 分解.png There are two types of moving parts for the Rubik's Cube, edges and corners, each with a different shape (for example, the edge parts have two stickers and the corner parts have three stickers), so the edge parts are in the corners. It does not come to position or vice versa. In the case of a 2x2x2 cube, the structure is similar to 3x3x3, but the edge parts are buried inside and only the corner parts are visible.

Rotation symbol

The rotation symbol is used as a symbol to indicate the rotation of the Rubik's cube. This is when you hold the cube in a certain reference orientation

Turn the top side: U (Up)
Turn the bottom surface: D (Down)
Turn the front side: F (Front)
Turn the back side: B (Back)
Turn the right side: R (Right)
Turn the left side: L (Left) For each letter (assumed to be X), "X" is 90 degrees clockwise when facing the front, "X'" is 90 degrees counterclockwise, and "X2" is 180 degrees. Rotate. For reference, page of a company called tribox is posted.

Actually, the types of rotation symbols (rotating surfaces) used in the 2x2x2 cube are only U, F, and R. please consider. Turning R and turning L are equivalent (ignoring the change in cube orientation). Therefore, you can create all the messed up states (scrambles) just by turning 3 of the 6 faces.

Finally

Well, I think it will be a long collection of articles, but I hope you enjoy reading it!

Let's make a robot that solves the Rubik's Cube! 1 Overview