Author: Brian McEvoy

266 Articles

The Little Cat That Could

October 10, 2018 by 10 Comments

Most humans take a year to learn their first steps, and they are notoriously clumsy. [Hartvik Line] taught a robotic cat to walk [YouTube link] in less time, but this cat had a couple advantages over a pre-toddler. The first advantage was that it had four legs, while the second came from a machine learning technique called genetic algorithms that surpassed human fine-tuning in two hours. That’s a pretty good benchmark.

The robot itself is an impressive piece inspired by robots at EPFL, a research institute in Switzerland. All that Swiss engineering is not easy for one person to program, much less a student, but that is exactly what happened. “Nixie,” as she is called, is a part of a master thesis for [Hartvik] at the University of Stavanger in Norway. Machine learning efficiency outstripped human meddling very quickly, and it can even relearn to walk if the chassis is damaged.

We have been watching genetic algorithm programming for more than half of a decade, and Skynet hasn’t popped forth, however we have a robot kitty taking its first steps.

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Help For High-Frequency Hobbyists

October 5, 2018 by 21 Comments

Dead-bug circuit building is not a pretty affair, but hey, function over form. We usually make them because we don’t have a copper circuit board available or the duty of making one at home is not worth the efforts and chemical stains.

[Robert Melville and Alaina G. Levine] bring to light a compromise for high-frequency prototypes which uses the typical FR4 blank circuit board, but no etching chemicals. The problem with high-frequency radio is that building a circuit on a breadboard will not work because there is too much added inductance and capacitance from the wiring that will wreak havoc on the whole circuit. The solution is not new, build your radio module on a circuit board by constructing “lands” over a conductive ground plane, where components can be isolated on the same unetched board.

All right, sometimes dead-bug circuits capture an aesthetic all their own, especially when they look like this and they do allow for a darned small package for one-off designs.

Walk It Off, Healing Robots

September 29, 2018 by 4 Comments

For many of us, our first robots, or technical projects, were flimsy ordeals built with cardboard, duct tape, and high hopes. Most of us grow past that scene, and we learn to work supplies which require more than a pair of kitchen scissors. Researchers at Carnegie Mellon University and Iowa State University have made a material which goes beyond durable, it can heal itself when wounded. To a small robot, a standard hole puncher is a dire assailant, but the little guy in the video after the break keeps hopping around despite a couple of new piercings.

The researcher’s goal is to integrate this substance into bio-inspired robots which may come to harm in the field. Fish-like robots could keep swimming after a brush with a bit of coral or a curious predator. Robot snakes could keep slithering after a fall or a gravel road.

Of course, robotic simulacrums are not the only ones who can benefit from healing circuitry. Satellites are prey to punctures from errant space debris.

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A Nibble And A Half Of Wooden Bits

September 25, 2018 by 8 Comments

If you are familiar with binary, what would you need to teach someone who only knows decimal? If you do not know how to count in binary, let us know if the video below the break helps you understand how the base-2 number system works. If learning or counting binary is not what you are interested in, maybe you can appreciate the mechanics involved with making a counter that cycles through all the ones and zeros (links to the video shown below). The mechanism is simple enough. A lever at the corner of each “1” panel is attached off-center, so it hangs when it is upside-down, then falls to the side when it is upright, so it can swivel the adjacent panel.

Perhaps this is a desktop bauble to show off your adeptness at carpentry, or skills with a laser cutter, or 3D printer. No matter what it is made out of, it will not help you get any work done unless you are a teacher who wants to demonstrate the discrete nature of binary. If wood and bits are up your alley, we have a gorgeous binary driftwood clock to feast your eyes on. Meanwhile if analog methods of working digital numbers suit you, we have binary math performed with paper models.

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Greasing Robot Hands: Variable Friction Makes Robo-Mitts More Like Our Own

September 23, 2018 by 7 Comments

Unless you are in the fields of robotics or prosthetics, you likely take for granted the fine motor skills our hands have. Picking up and using a pen is no small feat for a robot which doesn’t have a dedicated pen-grabbing apparatus. Holding a mobile phone with the same gripper is equally daunting, not to mention moving that phone around once it has been grasped. Part of the wonder of our hands is the shape and texture which allows pens and phones to slide around at one moment, and hold fast the next moment. Yale’s Grab Lab has built a gripper which starts to solve that problem by changing the friction of the manipulators.

A spring-loaded set of slats with a low-friction surface allow a held object to move freely, but when more pressure is exerted by the robot, the slats retract and a high-friction surface contacts the object. This is similar to our fingers with their round surfaces. When we brush our hands over something lightly, they graze the surface but when we hold tight, our soft flesh meets the surface of the object and we can hold tightly. The Grab Lab is doing a great job demonstrating the solution and taking steps to more capable robots. All hail Skynet.

We have no shortage of gripper designs to choose from, including pneumatic silicone and one that conforms to an object’s surface, similar to our hands.

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Submarine To Plane: Can You Hear Me Now? The Hydrophone Radar Connection

September 23, 2018 by 34 Comments

How does a submarine talk to an airplane? It sounds like a bad joke but it’s actually a difficult engineering challenge.

Traditionally the submarine must surface or get shallow enough to deploy a communication buoy. That communication buoy uses the same type of radio technology as planes. But submarines often rely on acoustic transmissions via hydrophones which is fancy-talk for putting speakers and microphones in the water as transmitters and receivers. This is because water is no friend to radio signals, especially high frequencies. MIT is developing a system which bridges this watery gap and it relies on acoustic transmissions pointed at the water’s surface (PDF warning) and an airplane with high-precision radar which detects the oscillations of the water.

The complexity of the described setup is mind-boggling. Right now the proof of concept is over short distances and was tested in a water tank and a swimming pool but not in open water. The first thing that comes to mind is the interference caused by waves and by aerosols from wind/wave interactions. Those challenges are already in the minds of the research team. The system has been tested to work with waves of 8 cm (16 cm measured peak to trough) caused by swimmers in the pool. That may not sound like much, but it’s about 100,000 times the surface variations being measured by the millimeter wave radar in order to detect the hydrophone transmissions. Add to that the effects of Doppler shift from the movement of the plane and the sub and you have a signal processing challenge just waiting to be solved.

This setup is very interesting when pitched as a tool for researching aquatic life. The video below envisions that transmitters on the backs of sea turtles could send communications to aircraft overhead. We love seeing these kinds of forward-thinking ocean research projects, like our 2017 Hackaday prize winner which is an open source underwater glider. Oceanic studies over long distances have been very difficult but we’re beginning to see a lot of projects chipping away at that inaccessibility.

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I Hear You Offer WiFi

September 22, 2018 by 13 Comments

We are swimming in radio transmissions from all around, and if you live above the ground floor, they are coming at you from below as well. Humans do not have a sensory organ for recognizing radio signals, but we have lots of hardware which can make sense of it. The chances are good that you are looking at one such device right now. [Frank Swain] has leaped from merely accepting the omnipresent signals from WiFi routers and portable devices to listening in on them. The audio signals are mere soundwaves, so he is not listening to every tweet and email password, merely a representation of the data’s presence. There is a sample below the break, and it sounds like a Geiger counter playing PIN•BOT.

We experience only the most minuscule sliver of information coming at us at any given moment. Machines to hack that gap are not had to find on these pages so [Frank] is in good company. Magnetosensory is a popular choice for people with a poor sense of direction. Echolocation is perfect for fans of Daredevil. Delivering new sensations could be easier than ever with high-resolution tactile displays. Detect some rather intimate data with ‘SHE BON.’

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