Pneumatic Rotary Vane Joints Lend A Gentle Helping Hand

May 3, 2017 by Steven Dufresne 20 Comments

Festo has released a video showing the workings of their BionicCobot, a pneumatic robot arm developed for lending a helping hand to humans at a workstation. Since it works intimately with humans, it has to be safe, producing no harmful movements, and reacting when encountering an obstacle such as an arm containing delicate human bone. This it does using pneumatics and rotary vanes.

The arm has seven degrees of freedom, three in the shoulder, one in the elbow, another in the lower arm, and two in the wrist. But you won’t find any electric motor or gears. Instead each contains a rotary vane. Compressed air pushes on both sides of the vane. If the air pressure is the same on both sides of the vane then it doesn’t rotate. But with more pressure on one side than the other, the vane rotates. This is much like in a human arm, where two muscles work together to bend the arm, one muscle contracts while the other relaxes. Together they’re referred to as an antagonistic pair. In addition, each joint has a circuit board with two pressure sensors for monitoring the joint.

Using pneumatics, if an obstacle is encountered, the pressure can be released, making it instantly safe. And air being compressible, the joint can behave like a spring, further adding to the safeness. By controlling the pressure, the spring can be made more or less tense.

You can see it in action in the video below the break, along with more details such as how they use ROS, the popular, open system Robot Operating System which we’ve seen here a lot before, along with their Festo valve bank, one of which our own [James Hobson] used for his slick elysium exoskeleton. The video also covers how they handled running the hoses, the kinematics and the UI software.

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Robotic Glockenspiel And Hacked HDD’s Make Music

May 2, 2017 by Jack Laidlaw 12 Comments

[bd594] likes to make strange objects. This time it’s a robotic glockenspiel and hacked HDD‘s. [bd594] is no stranger to Hackaday either, as we have featured many of his past projects before including the useless candle or recreating the song Funky town from Old Junk.

His latest project is quite exciting. He has incorporated his robotic glockenspiel with a hacked hard drive rhythm section to play audio controlled via a PIC 16F84A microcontroller. The song choice is Axel-F. If you had a cell phone around the early 2000’s you were almost guaranteed to have used this song as a ringtone at some point or another. This is where music is headed these days anyway; the sooner we can replace the likes of Justin Bieber with a robot the better. Or maybe we already have?

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Hackaday Prize: An Autonomous Beach Art Robot

April 29, 2017 by Dan Maloney 28 Comments

Some people find it hard to look at a huge, flat expanse of floor or ground and not see a canvas. From the outfield grass of a baseball park to some poor farmer’s wheat field, trampling, trimming or painting patterns can present an irresistible temptation. But the larger the canvas the more challenging the composition will be, which is where this autonomous beach-combing art robot comes into play.

Very much still a work in progress, [pablo.odysseus]’ beach bot was built to take advantage of the kilometers-wide beaches left by the receding tides near his home. That immense canvas is begging to be groomed, and this bot is built for the task. The running gear itself is simple – an extruded aluminum chassis powered by wheelchair drives with added optical encoders and dragging a retractable rake – but the bot is bristling with electronics dedicated to navigation. A pair of Arduinos run the dual odometers, compass, and a GNSS receiver, as well as providing a smartphone interface for on-the-fly changes. The art is composed as a DXF file converted to latitude and longitude points and exported to Google Earth as a KML. That means the bot can just be brought to the beach and allowed to draw autonomously. An early test run is seen below the break; better “brushes” are in the works.

Watching the art unfold on a beach would be relaxing, like watching a zen garden being created. We’re looking forward to [pablo]’s progress on this one. Of course, art bots aren’t the only autonomous machines that big, wide beaches attract.

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Look At Me With Your Special Animatronic Eyes

April 25, 2017 by Adam Fabio 25 Comments

Animatronics for movies is often about making something that works and is reliable in the short term. It doesn’t have to be pretty, it doesn’t have to last forever. [Corporate Sellout] shows us the minimalist approach to building animatronics with this pair of special eyes. These eyes move in both the pan and tilt. Usually, that means a gimbal style mount. Not in this case. The mechanical assembly consists of with popsicle sticks, ping-pong balls, film canisters and dental floss.

The frame for the eyes is made of simple popsicle sticks hot glued together. The eyes themselves are simple ping-pong balls. Arduino powered servos control the movement. The servos are connected to dental floss in a cable arrangement known as a pull-pull system. As each servo moves, one side of the arm pulls on a cable, while the other provides enough slack for the ping-pong ball to move.

Mounting the ping-pong balls is the genius part of this build. They simply sit in the open end of a couple of film canisters. the tension from the dental floss holds everything together. We’re sure it was a finicky setup to build, but once working, it’s reliable. Only a glue joint failure or stretch in the dental floss could cause issues.

There are plenty of approaches to Animatronic eyes. Check out the eyes in this Stargate Horus helmet, which just won our Sci-Fi contest. More recently we saw Gawkerbot, which uses a CD-ROM drive to provide motion for a creepy robot’s eyes.

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Papa Loves Mamba: Slithering Robot Is Reconfigurable

April 25, 2017 by Al Williams 6 Comments

It makes sense considering evolution, but nature comes up with lots of different ways to do things. Consider moving. Land animals walk on four feet or two, some jump, and some use peristalsis or otherwise slither. Oddly, though, mother nature never developed the wheel (although the mother-of-pearl moth’s caterpillar will form its entire body into a hoop and roll away from attackers). Human-developed robots which, on the other hand, most often use wheels. Even a tank track has wheels within. [Joesinstructables] latest robot still uses wheels, but it emulates the slithering motion of a snake, He calls it the Lake Erie Mamba.

The most interesting thing about the robot is that it can reconfigure and move in several different modalities. Like the caterpillar, it can even form a wheel like an ouroboros and roll. You can see that at the end of the video, below.

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Gawkerbot Is Watching You

April 23, 2017 by Adam Fabio 13 Comments

While sick with the flu a few months ago, [CroMagnon] had a vision. A face with eyes that would follow you – no matter where you walked in the room. He brought this vision to life in the form of Gawkerbot. This is no static piece of art. Gawkerbot’s eyes slowly follow you as you walk through its field of vision. Once the robot has fixed its gaze upon you, the eyes glow blue. It makes one wonder if this is an art piece, or if the rest of the robot is about to pop through the wall and attack.

Gawkerbot’s sensing system is rather simple. A PIR sensor detects motion in the room. If any motion is detected, two ultrasonic sensors which make up the robot’s pupils start taking data. Code running on an ATmega328 determines if a person is detected on the left or right, and moves the eyes appropriately.

[CroMagnon] used an old CD-ROM drive optics sled to move Gawkerbot’s eyes. While the motor is small, the worm drive has plenty of power to move the 3D-printed eyes and linkages. Gawkerbot’s main face is a 3D-printed version of a firefighter’s smoke helmet.

The ultrasonic sensors work, but it took quite a bit of software to tame the jitters noisy data stream. [CroMagnon] is thinking of using PIR sensors on Gawkerbot 2.0. Ultrasonic transducers aren’t just for sensing. Given enough power, you can solder with them. Ultrasonics even work for wireless communications.

Check out the video after the break to see Gawkerbot in action.

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[Hari] Prints An Awesome Spider Robot

April 22, 2017 by Elliot Williams 14 Comments

Although we have strong suspicions that the model’s designer failed entomology, this spider robot is very cool. [Hari Wiguna] made one, and is justifiably thrilled with the results. (Watch his summary on YouTube embedded below.)

Thanks to [Regis Hsu]’s nice design, all [Hari] had to do was order a hexapod’s dozen 9g servos for around $20, print out the parts, attach an Arduino clone, and he was done. We really like the cutouts in the printed parts that nicely fit the servo horns. [Hari] says the calibration procedure is a snap; you run a sketch that sets all the servos to a known position and then tighten the legs in place. Very slick.

The parts should print without support on basically any printer. [Hari]’s is kinda janky and exhibits all sorts of layer-to-layer irregularities (sorry, man!) but the robot works perfectly. Which is not to say that [Hari] doesn’t have assembly skills — check out the world’s smallest (?) RGB LED cube if you think this guy can’t solder. Of course, you can entirely sidestep the 3D-printed parts and just fix a bunch of servos together and call it a robot. It’s harder to make building a four-legger any easier than these two projects. What are you waiting for?

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