Faster than a second: robots continue to improve Rubik's cube assembly time

The first attempt to assemble the Rubik's cube intuitively, without using already developed and well-described methods, stumbles upon a powerless defeat. After reviewing the relevant instructions, the task is solved, although repeating the algorithms takes a minute. But what is the minimum time needed to bring each of the faces of a randomly mixed cube to the same color? People reached five seconds. And cars have recently become faster than a second. We are talking about the already described robot Jay Flatland and even faster new contender for the world record Sub1.

So, the task is to get a randomly mixed 3 × 3 × 3 cube, familiarize yourself with its configuration and rotation, bring each of the faces to the same color. You do not need to do this blindly or in the dark, movements are in no way limited. All you need is speed. Acceptable dice models, mixing order and other details are regulated by the organization that records the result. One thing remains unchanged: the maximum optimal number of moves can never be more than 20. This is the so-called number of God .

Now the record among people belongs to the American teenager Lucas Etter. He set it in the fall of 2015, solving the puzzle in 4.9 seconds. The record is registered by the World Cube Association, an organization that regulates Rubik's Cube competitions. Result isgradual improvement over the past decades . For example, in 1982, the record was 19 seconds.

The current best result among people.

Achieving such results requires training and full automatism of movements. Why solve the problem with machines and not with clumsy fingers? Like humans, robots smoothly improve results, albeit much faster. For example, in 2011, CubeStormer 2 was able to cope in a little over 5 seconds . In 2014, CubeStormer 3 brought each facet of the cube to one color in 3.253 seconds . For some time, the Guinness Book of Records recorded a 2.39 second robotic result. But a few days ago he was replaced by a time of 0.900 seconds.

The record holder was the robot of two software developers Jay Flatland and Paul Rose from the city of Olate in Kansas. In January, the authors posteda YouTube video with a device that was able to solve the puzzle in 1.1 seconds. A robot is a collection of relatively publicly available electronic components and software. This is the implementation of the Kotsemba two-phase algorithm , 4 webcams and 6 stepper motors.

After removing the barriers, four USB cameras record the cube configuration. Data comes to a regular personal computer running the Linux family of operating systems. The application program calculates the state of the cube, receives a solution from the implementation of the Kotsemba algorithm, and controls the motion process. Rose rewrote the Java sample in C ++ and made the program faster. Stepper motors rely on a frame created using a 3D printer. DRV8255 engine drivers are controlled by an Arduino chip. At their ends are small printed legs, through which contact is made with the puzzle. The cube itself is slightly modified: in the central segment of each of the faces 4 tiny holes are drilled, where these legs enter at the ends of the engine axes. It can be argued that the design of the puzzle has been changed. But the result is recorded by the Guinness Book of Records according to its own criteria, which include WCA requirements. Previous record-breaking robots also used slightly modified cubes that did not breaksubsection 3h defining permissible modifications.

On February 5, the Flatland and Rose robot assembled a TNoodle mix cube in 0.900 seconds and 18 moves in the presence of Guinness Book of World Records. Changes in the decision algorithms are noticeable - in earlier demonstrations, the result was around 1.1 seconds. According to Flatland, he managed to achieve a result of a little more than 0.8 and even 0.7 seconds, but of the three attempts pending by the judge, 0.9 was the best.

Accelerated record shows the speed of movement. The original video at normal speed is up to the kat.

However, this record may soon be broken. In a way, he is already beaten: the creator of Sub1, Albert Beer, claims that he was the first in the world to enter in a second. On January 23, 2016 in Munich in the Cubikon store, a result of 0.887 seconds was demonstrated. This time turned out on the third attempt. The first gave 1,043 seconds, the second ended with an incorrect decision due to glare on the cube. A typical time is in the region of 0.9-1.0 seconds. The record result was not officially recorded.

Little is known about the design. As you can see, the 57A high-speed ZhanChi WCA cube is held by a steel structure, not a plastic one from a 3D printer. Beer specifically learned to cook for his project. As motor controllers, Toshiba TB6560 boards are used.

The new challenger for the record is Sub1.

Flatland praised Beer 's work. The author of the current record liked the design of the structure, neat cable management and lighting. Flatland even said that Sub1 could be better than its model, and with the help of such a robot, results can be achieved in the region of half a second.

0.887 seconds of resolution at normal speed and five times slower.

The new Sub1 record still needs to be registered. Competition cannot be described as a battle. The current record holders have already played enough with their project and would like to change it to something else, for example, creating videos for YouTube. Flatland even friendlyly offered Beer his advice and help.