Certainly! Here’s a rewritten version of the content:
A group of students from Purdue University has recently set a new Guinness World Record with their custom-built robot, which managed to solve a Rubik’s Cube in just 0.103 seconds, significantly faster than the previous record-holder. This remarkable achievement was not only about increasing the robot’s speed; the team implemented a mix of advanced technologies, including high-speed, low-resolution camera systems, a specially designed cube for durability, and an innovative solving method favored by human speedcubers.
The competitive landscape for Rubik’s Cube-solving robots began in 2014 when a robot named Cubestormer 3, constructed from Lego Mindstorms and a Samsung Galaxy S4, completed the puzzle in 3.253 seconds, surpassing everyone at that time. For context, the current human record is held by Xuanyi Geng, who solved the cube in 3.05 seconds. Over the past decade, engineers have progressively reduced the solving time to just milliseconds.
Last May, Mitsubishi Electric in Japan set a record with a robot that solved a cube in 0.305 seconds. This record lasted for nearly a year until the Purdue team—which included Junpei Ota, Aden Hurd, Matthew Patrohay, and Alex Berta—smashed it with their robot, affectionately named Purdubik’s Cube. Achieving a time below half a second required a shift from Lego components to optimized parts like industrial motors. Ultimately, the team identified various innovative methods to trim off crucial milliseconds down to the astonishing 0.103 seconds.
“Each robot that has previously held the world record focused on a different innovation,” Patrohay explained to The Verge. For instance, when MIT graduate students broke the record in 2018, they utilized top-tier industrial hardware that exceeded that of their predecessors. Mitsubishi’s design embraced motors particularly tailored to the cube’s rotation instead of merely opting for faster moving parts.
An integral improvement the Purdue students made was enhancing their robot’s ability to visualize the scrambled cube quickly. Unlike human competitors who can inspect the cube before starting the timer, the robotic record includes the time taken for the robot to ascertain the positions of all the bubbles. The students employed high-speed machine vision cameras from Flir, configured to capture three sides of the cube with 720×540 pixel resolution during brief exposures lasting as little as 10 microseconds.
Although the Purdubik’s Cube seems instantaneous, there’s a processing delay inherent in converting sensor data into a digital image. To expedite the process, the team designed a custom image detection system that skips standard image processing, focusing solely on a small cropped portion each camera captures—territory just 128×124 pixels—to minimize data transfer.
Sensor data is relayed directly to a high-speed color detection system that utilizes RGB measurements taken from even smaller areas on each face to discern colors more swiftly than other methods, including those powered by AI.
“It may be a tad less reliable,” Patrohay acknowledged, “but if it achieves even 90 percent accuracy, that’s sufficient, provided the speed is maintained.”
Despite the heavy investment in custom hardware, the Purdue team opted to utilize existing software to optimize their cube-solving strategies. They employed Elias Frantar’s Rob-Twophase algorithm, which takes into account robotic advantages, such as the ability to rotate two sides simultaneously.
Additionally, the team leveraged a technique known as corner cutting, allowing them to begin turning one cube side before completely finishing another perpendicular turn. This overlapping can result in substantial time savings, which is critical when aiming for a world record.
One challenge posed by corner cutting is that if forces are applied excessively, a Rubik’s Cube could be damaged or destroyed. Therefore, the students meticulously honed the timing of their robot’s movements and motor acceleration while also modifying the cube for optimum durability.
According to regulations from Guinness World Records and the World Cube Association, competitors are permitted to modify their cubes, as long as they maintain the standard configuration of nine colored squares on each face, ensuring consistent texture throughout. Materials beyond plastic can be used as long as the fundamental mechanics remain intact.
To enhance durability, the Purdue team upgraded their cube’s internal structure with a custom 3D-printed design using robust SLS nylon plastic. Moreover, while the WCA allows lubricants to facilitate smoother rotations, in this case, it assists in managing the cube’s responses to rapid movements.
“The cube we use for the record is incredibly tightly tensioned—almost humorously so,” Patrohay noted. “It’s challenging to turn manually, requiring significant wrist movement.” The lubricant smooths the cube’s transitions during high-speed solving, while the added tension curtails overturns and heightens control, essential for executing time-saving techniques like corner cutting.
The Purdubik’s Cube operates with six servo motors linked to metal shafts that connect to the cube’s center squares. After testing various configurations, the team concluded that a trapezoidal motion profile—where the servos could accelerate up to 12,000,000
