Robot sets Guinness World Record by placing 100,000 dominoes in 24 hours

A new robot known as Dominator (Domino Robot, Dominator) has set a Guinness World Record by placing 100,000 dominoes in just over 24 hours. Dominator was created by YouTuber and former NASA engineer Mark Rober. The robot was the result of hard and lengthy work. Rober was assisted in building the unusual bot by two first-year students from Stanford University and a software engineer.

The Project in Brief

The team programmed more than 14,000 lines of code and equipped the robot with components such as omnidirectional wheels and 3D-printed funnels to create a "friendly robot that is very good at only one thing: laying a ton of dominoes really fast".

Unlike professional domino artist Lily Hevesh, Dominator used its ability to place 300 tiles at once to work about 10 times faster than a human. The robot needed about two hours to lay more than 9,000 dominoes.

Although Dominator is the face of the project, much of its efficiency comes from a separate sorting mechanism consisting of a Kuka robotic arm and nearly 5 km of Hot Wheels tracks. A series of conveyor belts sorts the dominoes by color before the arm places them in the appropriate chute. When Dominator arrives at the refill station, the bottom platform slides away, instantly loading all the dominoes it needs into its 3D-printed funnels to place 300 at once. This way, downtime is minimized.

The project's final achievement: a team of seven experienced domino builders would need about a week to create a mural resembling Super Mario Bros., while Dominator needed just over a day.

Origin Story

The whole project began in May 2019. After one of his talks, Mark Rober was asked what he had always wanted to do but could not. He replied that he had a vision of a robot that would set up tons of dominoes in a gym overnight, but he had tried to build several prototypes without success.

Then Alex Baucom, passionate about robotics, engineering and science, emailed Rober saying he could help with such a project. Two Stanford University students also became interested in working on the project, and that is how the team began.

After the first brainstorming session, the researchers faced several clear problems: the scale of the undertaking and localization. Initially, Mark wanted to place at least 100,000 dominoes. In early prototypes, the robot carried all the dominoes and placed them one at a time. By calculation, 100,000 dominoes weigh about 850 kg, and placing them one by one could take 3.5 days without breaks. In addition, the robot had to place the dominoes close enough for them to knock each other over, but not so close that it toppled the ones already placed.

Therefore, the robot needed to know its position very precisely. Another serious problem was ensuring accurate driving. After lengthy testing and several prototypes, all the parts of the robot were in place. The only remaining step was to begin scaling up the tests and finding out what could break.

The final version of the robot was able to localize itself better while moving across the warehouse thanks to sensors that significantly improved angular tracking over long distances. Engineers added "safety" features, such as automatically cutting off the motors to prevent the bot from driving into the dominoes if communication was lost.

After resolving all the reliability issues, the robot performed its task excellently and placed more than 100,000 dominoes in just 24 hours of operation.

What Dominator Is Made Of

Dominator's hardware consists of many parts. The main body is built from a frame with a steel base plate on which the drive system is mounted. At the front of the bot is a large tray used to hold 300 dominoes in a grid. The 3D-printed funnels are used to make it easier for the dominoes to fit into the grid.

At the rear of the robot is a small counterweight that keeps the rear wheel gripping the ground enough to avoid slipping. The device itself moves on three omnidirectional wheels. Special control of these wheels allows the robot to move freely in any direction, which is crucial for precisely aligning the dominoes before the next section is placed.

Ultra-precise and fairly powerful ClearPath motors connect to the wheels via a 1:4 belt drive, allowing the wheels to provide enough torque to move a robot that weighs 90 kg. All the motors are powered by a pair of lithium-polymer batteries.

As for electronics, the robot's main brain runs on a Raspberry Pi 4, which handles all high-level communication, heavy computation and decision-making. It is connected via a USB hub to both downward-facing cameras, internal Marvelmind GPS sensors and a ClearCore motor controller.

All of the above concerns the robot's main hardware components. The software for Dominator was developed from scratch and distributed across three different computers. One of the key components the robot required was a method for generating the trajectory it had to follow. Engineers also developed a custom robot control system.