One of the challenges with humanoid robots, besides keeping them upright, is finding compact combinations of actuators and joint mechanisms that allow for good range of smooth motion while still having good strength. To achieve that researchers from the IRIM Lab at Korea University of Technology and Education developed the LIMS2-AMBIDEX robotic humanoid upper body that uses a combination of brushless motors, pulleys and some very interesting joint mechanisms. (Video, embedded below.)
From shoulder to fingers, each arm has seven degrees of freedom which allows the robot to achieve some spectacularly smooth and realistic upper body motion. Except for the wrist rotation actuator, all the actuators are housed in the shoulders, and motion is transferred to the required joint through an array of cables and pulleys. This keeps the arm light and its inertia low, allowing the arms to move rapidly without breaking anything or toppling the entire robot.
The wrist and elbow mechanisms are especially interesting. The wrist emulates rolling contact between two spheres with only revolute joints. It also allows a drive shaft to pass down the centre of the mechanism and transfer rotating motion from one end to the other. The elbow is a rolling double jointed affair that allows true 180 degrees of rotation.
Cue up the [Christopher Walken] memes, it’s time for moped turn signals with more cowbell. Because moped turn signals with less cowbell are clearly the inferior among moped turn signals.
It seems that [Joel Creates] suffers from the same rhythm recognition disorder that we do. The slightest similarity between a rhythmic sound such as turn signals, and any song in our seemingly infinite intracranial playlist cues up that song for the rest of the day. [Joel] heard “(Don’t Fear) The Reaper” in his turn signals, and that naturally led to a need for More Cowbell. So with a car door lock actuator, a relay, an improvised clapper, and a lot of hot glue and cable ties, the front of his scooter is now adorned with a cowbell that’s synchronized to the turn signals. The video below shows that it’s of somewhat limited appeal in traffic, but at least [Joel’s dad] was tickled pink by it.
Kudos to [Joel] for marching to the beat of his own [Gene Frenkle] on this one. It may be a little weird, but not as weird as an Internet of Cowbells.
The 2019 Hackaday Prize, which was announced last week, is very much on everyone’s mind, so much so that we’ve already gotten a great response with a lot of really promising early entries. As much as we love that, the Prize isn’t the only show in town, and we’d be remiss to not call attention to our other ongoing contest: The Flexible PCB Contest.
The idea of the Flexible PCB Contest is simple: design something that needs a flexible PCB. That’s it. Whether it’s a wearable, a sensor, or a mechanism that needs to transmit power and control between two or more moving elements, if a flexible PCB solves a problem, we want to know about it.
We’ve teamed up with Digi-Key for this contest, and 60 winners will receive free fabrication of three copies of their flexible PCB design, manufactured through the expertise of OSH Park. And here’s the beauty part: all you need is an idea! No prototype is necessary. Just come up with an idea and let us know about it. Maybe you have a full schematic, or just a simple Fritzing project. Heck, even a block diagram will do. Whatever your idea is for a flexible PCB project, we want to see it.
To get the creative juices going, here’s a look at a few of the current entries
A lot of projects require linear motion, but not all of them require high-accuracy linear slides and expensive ball screws. When just a little shove for a door or the ability to pop something up out of an enclosure is all you need, finding just the right actuator can be a chore.
Unless someone has done the work for you, of course. That’s what [Ali] from PotentPrintables did with these 3D-printed linear actuators. It’s a simple rack-and-pinion design that’s suitable for light loads and comes in two sizes, supporting both the 9-g micro servos and the larger, more powerful version. Each design has a pinion that has to be glued to a servo horn, and a selection of rack lengths to suit your needs. The printed parts are nothing fancy, but seem to have material in the right places to bear the loads these actuators will encounter. [Ali] has included parts lists and build instructions in with the STL files, as well as sample Arduino code to get you started. The video below shows the actuators in action.
We’re heartened to learn that [Ali] was at least partly inspired to undertake this design by a previous Hackaday post. And we’re glad he decided to share his version; it might save us a few steps on our next build.
Despite what we may have seen in the new Winnie the Pooh movie, our cherished plush toys don’t usually come to life. But if that’s the goal, we have ways of making it happen. Like these “robotic skins” from Yale University.
Each module is a collection of sensors and actuators mounted on a flexible substrate, which is then installed onto a flexible object serving as structure. In a simple implementation, the mechanical bits are sewn onto a piece of fabric and tied with zippers onto a piece of foam. The demonstration video (embedded below the break) runs through several more variations of the theme. From making a foam tube (“pool noodle”) crawl like a snake to making a horse toy’s legs move.
There’s a serious motivation behind these entertaining prototypes. NASA is always looking to reduce weight that must be launched into space, and this was born from the idea of modular robotics. Instead of actuators and sensors embedded in a single robot performing a specific function, these robotic skins can be moved around to different robot bodies to perform a variety of tasks. Such flexibility can open up more capabilities while occupying less weight on the rocket.
This idea is still early in development and the current level prototypes look like something most of us can replicate and improve upon for use in our projects. We’ve even got a controller for those pneumatics. With some more development, it may yet place among the ranks of esoteric actuators.
While “The Clapper” probably first conjures images of low-budget commercials, it was still a useful way to remotely switch lights and other things around the house. But if the lights you want to switch weren’t plugged into the wall, like a ceiling fan, for example, The Clapper was not going to help you. To add some functionality to this infamous device, [Robin] built one from scratch that has all the extra features built in that you could ever want.
First, the new Clapper attaches to the light switch directly, favoring mechanical action of the switch itself rather than an electromechanical relay which requires wiring. With this setup, it would be easy to install even if you rent an apartment and can’t do things like rewire outlets and it has the advantage of being able to switch any device, even if it doesn’t plug into the wall. There’s also a built-in microphone to listen for claps, but since it’s open-source you could program it to actuate the switch when it hears any sound. It also includes the ability to be wired in to a home automation system as well.
If the reason you’ve stayed out of the home automation game is that you live in a rental and can’t make the necessary modifications to your home, [Robin]’s Clapper might be just the thing you need to finally automate your living space. All the files are available on the project site, including the 3D printing plans and the project code. Once you get started in home automation, though, there’s a lot more you can do with it.
Popcorn! Light and fluffy, it is a fantastically flexible snack. We can have them plain, create a savory snack with some salt and butter, or cover with caramel if you have a sweet tooth. Now Cornell University showed us one more way to enjoy popcorn: use their popping action as the mechanical force in a robot actuator.
It may be unorthodox at first glance, but it makes a lot of sense. We pop corn by heating its water until it turns into steam triggering a rapid expansion of volume. It is not terribly different from our engines burning an air-fuel mixture to create a rapid expansion of volume. Or using heat energy to boil water and trigger its expansion to steam. So a kernel of popcorn can be used as a small, simple, self-contained engine for turning heat energy into mechanical power.
Obviously it would be a single-use mechanism, but that’s perfectly palatable for the right niche. Single-use is a lot easier to swallow when popcorn is so cheap, and also biodegradable resulting in minimal residue. The research paper demonstrated three recipes to harness popping corn’s mechanical energy, but that is hardly an exhaustive list. There’s an open invitation to brainstorm other creations to add to the menu.