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Lego Robot Solves Rubik's Cube Puzzle In 3.253 Seconds

Posted by Soulskill on from the we-build-toys-to-play-with-our-toys dept.

SternisheFan sends this news from CTV: "The Cubestormer 3 took 18 months to build but only needed 3.253 seconds to solve [a Rubik's cube], breaking the existing record. Unveiled at the Big Bang Fair in Birmingham, U.K., the Cubestormer 3 is constructed from the modular children's building-block toy but uses a Samsung Galaxy S4 smartphone with a special ARM chip addition as its brain. It analyzes the muddled-up Rubik's Cube and powers each of the robot's four 'hands,' which spin the cube until all sides are in order. Created by ARM engineer David Gilday and Securi-Plex security systems engineer Mike Dobson, Cubestormer 3's new record shaves just over two seconds off the existing record, set by Cubestormer 2, which the pair also built."

1 of 60 comments (clear)

  1. They can probably compute a just-over-20-move solu by ToastyKen · · Score: 5, Informative

    As The boojum said, you can theoretically solve a cube in any configuration in 20 moves, but it might take a long time to find that optimal solution. Computers can quickly find a just-over-20-move not-quite-optimal solution, though.

    Human-friendly algorithms generally take over 50 moves, with the absolute best solves still taking more than 40.

    I stepped through this video frame by frame. They rotate the cube 5 times to inspect each face first (I guess they only have one camera), paused about 0.2 seconds (presumably to calculate a solution) and then they made 21 moves plus 4 rotations to solve it. (The rotations were necessary because it only has 4 arms and can't spin the top and bottom layers.)

    So yeah, looks like they computed a nearly-optimal solution, and I imagine they can probably get a just-over-20-move solution every time.