Robotic Ball Bouncer Uses Machine Vision To Stay On Target

March 5, 2020 by Dan Maloney 20 Comments

When we first caught a glimpse of this ball juggling platform, we were instantly hooked by its appearance. With its machined metal linkages and clear polycarbonate platform, its got an irresistibly industrial look. But as fetching as it may appear, it’s even cooler in action.

You may recognize the name [T-Kuhn] as well as sense the roots of the “Octo-Bouncer” from his previous juggling robot. That earlier version was especially impressive because it used microphones to listen to the pings and pongs of the ball bouncing off the platform and determine its location. This version went the optical feedback route, using a camera mounted under the platform to track the ball using OpenCV on a Windows machine. The platform linkages are made from 150 pieces of CNC’d aluminum, with each arm powered by a NEMA 17 stepper with a planetary gearbox. Motion control is via a Teensy, chosen for its blazing-fast clock speed which makes for smoother acceleration and deceleration profiles. Watch it in action from multiple angles in the video below.

Hats off to [T-Kuhn] for an excellent build and a mesmerizing device to watch. Both his jugglers do an excellent job of keeping the ball under control; his robotic ball-flinger is designed to throw the ball to the same spot every time.

Continue reading “Robotic Ball Bouncer Uses Machine Vision To Stay On Target” →

Ping Pong Ball-Juggling Robot

January 22, 2017 by Bryan Cockfield 6 Comments

There aren’t too many sports named for the sound that is produced during the game. Even though it’s properly referred to as “table tennis” by serious practitioners, ping pong is probably the most obvious. To that end, [Nekojiru] built a ping pong ball juggling robot that used those very acoustics to pinpoint the location of the ball in relation to the robot. Not satisfied with his efforts there, he moved onto a visual solution and built a new juggling rig that uses computer vision instead of sound to keep a ping pong ball aloft.

The main controller is a Raspberry Pi 2 with a Pi camera module attached. After some mishaps with the planned IR vision system, [Nekojiru] decided to use green light to illuminate the ball. He notes that OpenCV probably wouldn’t have worked for him because it’s not fast enough for the 90 fps that’s required to bounce the ping pong ball. After looking at the incoming data from this system, an algorithm extracts 3D information about the ball and directs the paddle to strike the ball in a particular way.

If you’ve ever wanted to get into real-time object tracking, this is a great project to look over. The control system is well polished and the robot itself looks almost professionally made. Maybe it’s possible to build something similar to test [Nekojiru]’s hypothesis that OpenCV isn’t fast enough for this. If you want to get started in that realm of object tracking, there are some great projects that make use of that piece of software as well.

Hackaday Prize Entry: Programming Juggling Props

June 7, 2016 by Brian Benchoff 6 Comments

It takes balls to learn how to juggle, but once you do you’re quickly moving on to rings, chainsaws, and those very strange juggling clubs. For their Hackaday Prize entry, [Laurent B] and [michael.creusy] are bringing the Internet of Things to juggling clubs. Their Rastello Club is a glowing, LED illuminated juggling prop with a 9-DOF IMU that makes juggling look even cooler than it already is.

Because there is a market for everything, glowing, programmable juggling clubs already exist. These clubs have a few limitations, though. They don’t have nine-axis orientation sensors, there is no communication to a computer or between individual clubs, and of course they’re not Open Source. The Rastello Club fixes these problems, makes programmable juggling clubs easy to use, and adds a bunch of visualizations.

Inside these juggling clubs are a bunch of LEDs, of course, along with a rather powerful STM32F4 ARM processor, the 9-axis IMU, and the circuitry to charge a battery. The radio connection between individual clubs and a computer will be handled with an RFM75 transceiver. No, it’s not WiFi, Bluetooth, or ZigBee; this radio module is faster than Bluetooth, cheaper than Zigbee, and lower power than an ESP8266.

The HackadayPrize2016 is Sponsored by:

Juggling Robot Deftly Handles Balls

October 5, 2015 by Brian Benchoff 22 Comments

A well-designed robot can do any action a human can do. Whether this is an acrobatic performance, or just writing with a pen, there’s a robot out there for any single action a human can perform. This includes juggling, but never before has the human action of juggling been replicated at this scale. [Nathan] built a robot that can juggle seven balls simultaneously. That’s more balls in the air than any other juggling robot.

While the original plan was to build a low-cost version that could juggle balls by throwing them up in the air, this proved to be very difficult. Instead of giving up, [Nathan] simplified the problem by rolling the balls up a ramp. The entire build is documented in an imgur gallery, and there’s some interesting tech going on here. The 3D printed arms are controlled by beefy stepper motors running at 60V. To stop the balls from bouncing around in the arms, [Nathan] included and electromagnet to hold the balls in place for a fraction of a second during each cycle.

Juggling seven balls is amazing, but how about eight? This is the question every builder of a juggling robot will get, and it’s not quite as simple as adding another ball. The motion of juggling an even number of balls is completely different from juggling an odd number. That being said, [Nathan]’s robot does have four balls under its belt. It should probably get that looked at.

This isn’t [Nathan]’s first amazing 3D printed robot, and it probably won’t be the last, either: he recently built a Skittles sorting machine for the next time Van Halen comes to town. There’s an amazing amount of skill in all his projects, and he’s certainly an asset to the entire hackaday.io community.

Continue reading “Juggling Robot Deftly Handles Balls” →

ShakeIt – An Interactive Light Game

June 3, 2015 by Anool Mahidharia 7 Comments

Learning becomes interesting when you make it fun, interactive and entertaining. [Arkadi] built ShakeIt – an interactive game for the Mini MakerFaire in Jerusalem to demonstrate to kids and grownups how light colors are mixed. It is a follow up to his earlier project – Smart juggling balls which we featured earlier.

The juggling balls consist of a 6 dof sensor (MPU 6050), a micro controller, transmitter (NRF24L01+), some addressable RGB LED’s and a LiPo battery. An external magnet activates a reed switch inside the balls and triggers them in to action. The ShakeIt light fixture consists of an Arduino Nano clone, NRF24L01+ with SMA Antenna, buck converter, 74 addressable RGB LED’s, and a bluetooth module. The bluetooth module connects to a smartphone app.

[Arkadi] starts out by handing three juggling balls, each with a predefined color (Red, Green, Blue). When the ball is shaken, the light inside the ball becomes stronger. The ShakeIt light fixture is used as a mixer. It communicates with the balls and receives the value of how strong the light inside each of the smart balls is, mixing them up, and generating the mixed color.

The fun starts when the interactive game mode is enabled. Instead of just mixing the light, the Light fixture generates patterns based on how strong the balls are shaken. At first the light fixture shows all three colors filling up the central ball. The three contenders then fight out to get their color to fill up the sphere completely until only one color remains and the winner is declared.

The kids might be learning some color theory here, but it seems the adults are having a “ball” playing the crazy game. If you’d like to build your own shoulder dislocating ShakeIt game, head over to [Arkadi]’s github repository for the ShakeIt and the Juggling Balls. Check the video below to see the adults having fun.

Continue reading “ShakeIt – An Interactive Light Game” →

Smart Juggling Balls

April 28, 2015 by James Hobson 20 Comments

For the 2015 Hack a Day Prize, [Arkadi] is working on an educational platform using the Arduino for Smart Juggling Balls.

His goal for this is to create an open-source platform which, beyond juggling, can be used to teach physics in both an interactive and fun way. The juggling balls feature a RGB LED, an Arduino pro mini, and some MPU’s. They can be programmed to change color based on acceleration, gravity, centripetal force, rotation, or even controlled remotely. As the project develops further, he also plans on creating lecture content to go alongside the project, which would make it an excellent and interactive project for a high school (or even college) tech or physics class.

It’s not completely done yet but he’s already posted all the source code and instructions for making your own set over on GitHub. Stick around after the break to see the prototype balls in action and don’t forget to get cracking on your own Hackaday Prize entry!

Continue reading “Smart Juggling Balls” →

Seven story robot juggles three VW Beetles

Step Right Up Or Cower In Fear; The 7-Story Car-Juggling Robot Is Here

July 1, 2014 by Kristina Panos 73 Comments

Sometimes we see a project that’s just as frightening as it is awesome. The Bug Juggler is a prime example of this phenomenon. A seven-story diesel-powered humanoid robot is one thing, but this one will pick up two VW Beetles, put one in its pocket, pick up a third, and juggle them. Yes, juggle them.

The Bug Juggler will be driven by a brave soul sitting in the head-cage and controlling him through haptic feedback connected to high-speed servo valves. A diesel engine will generate hydraulic pressure, and the mobility required for juggling the cars will come from hydraulic accumulators.

The project is in the capable hands of team members who have built special effects, a diesel/hydraulic vehicle for hauling huge sections of pipe, and mechanisms for Space Shuttle experiments. In order to attract investors for the full-scale version, they are building an 8-foot tall proof-of-concept arm assembly capable of tossing and catching a 250lb. mass.

If you prefer to see Beetles crushed, check out Stompy, the 18-foot rideable hexapod. Make the jump to see an animation of the full-scale Bug Juggler in action. Don’t know about you, but we wouldn’t stand quite so close to it without a helmet and some really good health insurance.

Continue reading “Step Right Up Or Cower In Fear; The 7-Story Car-Juggling Robot Is Here” →