Slashdot Mirror


Robot Solves Rubik's Cube In Less Than a Second (livescience.com)

An anonymous reader quotes a report from LiveScience: In just over half of a second (0.637 seconds), the Sub1 Reloaded robot made each side of the Rubik's Cube show a single color. This breaks the previous record of 0.887 seconds achieved by an earlier version of the same machine using a different processor. German technology company Infineon staged the record attempt at the Electronica trade fair in Munich this week, as a way to highlight its self-driving-car technology. The company provided one of the Sub1 Reloaded robot's microchips. Infineon said more than 43 quintillion combinations of the Rubik's Cube's colored squares are possible. That same number of cubes would cover Earth in 275 layers, resulting in an approximately 65.6-foot-high (20 meters) layer of Rubik's Cubes, the company added. The record-breaking attempt began with the press of a button. Sensor cameras on the machine had their shutters removed, and the computer was then able to detect how the cube was scrambled. The computing chip, or the "brain" of the machine as Infineon called it, then determined the fastest solution. Commands to execute the solution were sent to six motor-controlled arms. "It takes tremendous computing power to solve such a highly complex puzzle with a machine," Infineon said in a statement. "In the case of 'Sub1 Reloaded,' the power for motor control was supplied by a microcontroller from Infineon's AURIX family, similar to the one used in driver assistance systems."

6 of 54 comments (clear)

  1. Human did it in 4.74 seconds 5 days ago by JoeyRox · · Score: 4, Informative

    Although that doesn't include the time he was allowed to examine it before starting. Here's the video:

    https://www.youtube.com/watch?v=tLksISrKtO8

    1. Re:Human did it in 4.74 seconds 5 days ago by Anonymous Coward · · Score: 4, Informative

      I don't see why a computer couldn't use a similar algorithm...

      Because the people that programmed this thing have never read any of the books written on solving a rubik's cube. There is *ONE* solution; one sequence of moves that when repeated will eventually solve the puzzle. There's no need to think out a solution. Simply pick up the cube and start repeating the pattern until all the sides match. (btw, that's how real people do it.)

      No such solution exists. The best you can do by repeating the same pattern is to cycle through 1,260 states, multiplied by the length of the permutation sequence: https://people.kth.se/~boij/ka...

      There does exist at least one sequence of moves that is guaranteed to solve the cube, eventually (it forms a Hamiltonian circuit.) It's 43 quintillion moves long, and you can download a (200MB) specification describing how to construct the sequence here: http://bruce.cubing.net/ham333... Iterating a sequence that long is well beyond the capabilities of both human and robot, sadly.

      Modern solvers use variations of the Kociemba algorithm, which can find near-optimal solutions very quickly: http://kociemba.org/cube.htm CPU power is important because more time spent searching can yield shorter move sequences - the slowest part of the solve (computer vision, solution search, twisting the cube) is the physical part. However, every millisecond spent searching for shorter sequences might be better spent actually executing a suboptimal solution.

  2. Re:Huh? by ShanghaiBill · · Score: 4, Interesting

    How is solving a rubik's cube ANYTHING like self driving?

    It isn't. Solving Rubiks Cube is trivial. Anybody can learn to do it, and many people can solve a randomized cube in under a minute.

    A computer can find the solution in a few microseconds. The hard part isn't finding the solution in software, but building a mechanical contraption to rapidly twist the cube without breaking it. This is an achievement in mechanical engineering, not software. TFA completely skipped over the substance to focus on the trivial.

  3. Re:What does it mean to 'solve a rubiks cube'? by ShanghaiBill · · Score: 5, Informative

    Solves -which- permutation of a Rubik's cube in less than a second? Every single one? How can they prove that before the end of the universe?

    It has been proven that 20 moves suffice to solve Rubik's Cube from any starting position.

    If you restrict each move to a quarter turn, then 26 moves suffice.

    The proof only took 35 years of CPU time.

  4. Newsflash: Machines faster than humans! by XxtraLarGe · · Score: 4, Funny

    That's why we make them. My chainsaw makes much faster work of a tree than I could chewing it with my teeth. I don't even want to think how long that would take.

    --
    Taking guns away from the 99% gives the 1% 100% of the power.
  5. Re:43 quintillion? by Plus1Entropy · · Score: 4, Interesting

    Apparently it still works out to be that large, according to this:

    There are 8! (40,320) ways to arrange the corner cubes. Seven can be oriented independently, and the orientation of the eighth depends on the preceding seven, giving 3^7 (2,187) possibilities. There are 12! / 2 (239,500,800) ways to arrange the edges, restricted from 12! because edges must be in an even permutation exactly when the corners are. [...] Eleven edges can be flipped independently, with the flip of the twelfth depending on the preceding ones, giving 2^11 (2,048) possibilities.

    8! × 37 × (12! / 2) × 2^11 = 43,252,003,274,489,856,000

    Including all permutations is about 12 times that, around 519 quintillion.

    --
    Only crack the nuts that crack. You don't put the ones that don't crack in the sack.