MiniPupper

Robot Dogs Hack Chat

Join us on Wednesday, September 29 at noon Pacific for the Robot Dogs Hack Chat with Afreez Gan!

Thanks to the efforts of a couple of large companies, many devoted hobbyists, and some dystopian science fiction, robot dogs have firmly entered the zeitgeist of our “living in the future” world. The quadrupedal platform, with its agility and low center of gravity, is perfect for navigating in the real world, where the terrain is rarely even and unexpected obstacles are to be expected.

The robot dog has been successful enough that there are commercially available — if prohibitively priced — dogs on the market, doing everything from inspecting factory processes and off-shore oil platforms to dancing for their dinner. All the publicity around robot dogs has fueled a crush of DIY and open-source versions, so that hobbyists can take advantage of what the platform has to offer. And as a result, the design of these dogs has converged somewhat, with elements that provide a common design language for these electromechanical pets.

Afreez Gan has been exploring the robot dog space for a while now, and his MiniPupper is generating some interest. He’ll stop by the Hack Chat to talk about MiniPupper specifically and the quadruped platform in general. We’ll talk about what it takes to build your own robot dog, what you can do with one once you’ve built it, and how these bots can play a part in STEM education. Along the way, we’ll touch on ROS, lidar, machine vision with OpenCV, and pretty much anything involved in the care and feeding of your newest electronic pal.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, September 29 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

3D Printed Research Robotics Platform Runs Remotely

The Open Dynamic Robot Initiative Group is a collaboration between five robotics-oriented research groups, based in three countries, with the aim to build an Open Source robotics platform based around the torque-control method. Leveraging 3D printing, a few custom PCBs, and off-the-shelf parts, there is a low-barrier to entry and much lower cost compared to similar robots.

The eagle-eyed will note that this is only a development platform, and all of the higher level control is off-machine, hosted by a separate PC. What’s interesting here, is just how low-level the robot actually is. The motion hardware is purely a few BLDC motors driven by field-orientated control (FOC) driver units, a wireless controller and some batteries. The FOC method enables very efficient motor commutation, giving excellent efficiency and maximum torque.  A delve into the maths of how this method operates will be an eye opener for the uninitiated. Optical encoders attached to the motors give positional feedback for the control loop.

It is this control loop that’s kinda weird, in that operates over Wi-Fi! Normally one would do all the position, torque and speed sensing locally within the leg unit, with local control loops, as well as running all the limb kinematics and motion planning. This would need some considerable local processing grunt, which can make development more difficult.

This project side-steps this, by first leveraging the ESPNOW protocol, initially aimed at the ESP8266 and friends. By patching Ubuntu Linux, and enabling preemptive multitasking for real-time scheduling, as well as carefully selecting Wi-Fi drivers, it was possible to get raw packets out to robot in about 1 ms, enabling control loop bandwidths of around 1 Khz. And, that, was fast enough to run at least sixteen motors in parallel.

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3D Printer As Robot: The Functograph

A 3D printer is really a specialized form of robot. Sure, it isn’t exactly Data from Star Trek, but it isn’t too far from many industrial robots. Researchers from Meiji University made the same observation and decided to create a 3D printer that could swap a hot end for other types of robotic manipulators. They call their creation the Functgraph. (Video, embedded below.)

Some of the tasks the Functgraph can do including joining printed parts into an assembly, breaking support material, and more. The surprise twist is that — unlike traditional tool change schemes — the printer prints its own end effectors together with the print job and picks them up off the build plate.

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Stepping Down Voltage With Reliability

The availability of inexpensive electronics modules has opened up a world of opportunity for more complex projects to be completed quickly. Rather than designing everything from scratch, ready-made motor modules, regulators, computer vision modules, and control modules all ready to be put to work after arriving at one’s doorstep. Sometimes, though, these inexpensive electronics aren’t all they’re cracked up to be, so [Jan] decided to produce them from scratch instead.

[Jan] is the creator of several robots, and frequently makes use of 3.3V and 5V step down modules, but was not happy with the consistency offered by the prefab modules. The solution to this was to build them from scratch in a way that makes producing a large amount nearly as easy as ordering them. The boards are based around the SY8105 chip, and are built in two batches for the robotics shop based on the two most commonly needed output voltages. With their design they get exactly what they need every time, without worrying about reliability from a random board shop overseas.

The robotics shop is called RoboticsBrno and they have made the schematics available for anyone that wants to build their own. That being said, the design does not make considerations for low noise since it isn’t required for their use case, but if you’d prefer something simple and reliable this will get the job done. It’s also important to understand the limitations of the parts in a build that are built by a third party, although power supplies are a pretty common area to make improvements on.

2020: As The Hardware World Turns

By pretty much any metric you care to use, 2020 has been an unforgettable year. Usually that would be a positive thing, but this time around it’s a bit more complicated. The global pandemic, unprecedented in modern times, impacted the way we work, learn, and gather. Some will look back on their time in lockdown as productive, if a bit lonely. Other’s have had their entire way of life uprooted, with no indication as to when or if things will ever return to normal. Whatever “normal” is at this point.

But even in the face of such adversity, there have been bright spots for our community. With traditional gatherings out of the question, many long-running tech conferences moved over to a virtual format that allowed a larger and more diverse array of presenters and attendees than would have been possible in the past. We also saw hackers and makers all over the planet devote their skills and tools to the production of personal protective equipment (PPE). In a turn of events few could have predicted, the 2020 COVID-19 pandemic helped demonstrate the validity of hyperlocal manufacturing in a way that’s never happened before.

For better or for worse, most of us will associate 2020 with COVID-19 for the rest of our lives. Really, how could we not? But over these last twelve months we’ve borne witness to plenty of stories that are just as deserving of a spot in our collective memories. As we approach the twilight hours of this most ponderous year, let’s take a look back at some of the most interesting themes that touched our little corner of the tech world this year.

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Legged Robots Put On Wheels And Skate Away

We don’t know how much time passed between the invention of the wheel and someone putting wheels on their feet, but we expect that was a great moment of discovery: combining the ability to roll off at speed and our leg’s ability to quickly adapt to changing terrain. Now that we have a wide assortment of recreational wheeled footwear, what’s next? How about teaching robots to skate, too? An IEEE Spectrum interview with [Marko Bjelonic] of ETH Zürich describes progress by one of many research teams working on the problem.

For many of us, the first robot we saw rolling on powered wheels at the end of actively articulated legs was when footage of the Boston Dynamics ‘Handle’ project surfaced a few years ago. Rolling up and down a wide variety of terrain and performing an occasional jump, its athleticism caused quite a stir in robotics circles. But when Handle was introduced as a commercial product, its job was… stacking boxes in a warehouse? That was disappointing. Warehouse floors are quite flat, leaving Handle’s agility under-utilized.

Boston Dynamic has typically been pretty tight-lipped on details of their robotics development, so we may never know the full story behind Handle. But what they have definitely accomplished is getting a lot more people thinking about the control problems involved. Even for humans, we face a nontrivial learning curve paved with bruised and occasionally broken body parts, and that’s even before we start applying power to the wheels. So there are plenty of problems to solve, generating a steady stream of research papers describing how robots might master this mode of locomotion.

Adding to the excitement is the fact this is becoming an area where reality is catching up to fiction, as wheeled-legged robots have been imagined in forms like Tachikoma of Ghost in the Shell. While those fictional robots have inspired projects ranging from LEGO creations to 28-servo beasts, their wheel and leg motions have not been autonomously coordinated as they are in this generation of research robots.

As control algorithms mature in robot research labs around the world, we’re confident we’ll see wheeled-legged robots finding applications in other fields. This concept is far too cool to be left stacking boxes in a warehouse.

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Hackaday Links: November 29, 2020

While concerns over COVID-19 probably kept many a guest room empty this Thanksgiving, things were a little different aboard the International Space Station. The four-seat SpaceX Crew Dragon is able to carry one more occupant to the orbiting outpost than the Russian Soyuz, which has lead to a somewhat awkward sleeping arrangement: there are currently seven people aboard a Station that only has six crew cabins. To remedy the situation, Commander Michael Hopkins has decided to sleep inside the Crew Dragon itself, technically giving himself the most spacious personal accommodations on the Station. This might seem a little hokey, but it’s actually not without precedent; when the Shuttle used to dock with the ISS, the Commander would customarily sleep in the cockpit so they would be ready to handle any potential emergency.

Speaking of off-world visitation, the Hayabusa2 spacecraft is nearly home after six years in space. It won’t be staying long though, the deep-space probe is only in the neighborhood to drop off a sample of material collected from the asteroid Ryugu. If all goes according to plan, the small capsule carrying the samples will renter the atmosphere and land in the South Australian desert on December 6th, while Hayabusa2 heads back into the black for an extended mission that would have it chasing down new asteroids into the 2030s.

Moving on to a story that almost certainly didn’t come from space, a crew from the Utah Division of Wildlife Resources recently discovered a strange metal monolith hidden in the desert. While authorities were careful not to disclose the exact coordinates of the object, it didn’t take Internet sleuths long to determine its location, in part thanks to radar data that allowed them to plot the flight path of a government helicopters. Up close inspections that popped up on social media revealed that the object seemed to be hollow, was held together with rivets, and was likely made of aluminum. It’s almost certainly a guerrilla art piece, though there are also theories that it could have been a movie or TV prop (several productions are known to have filmed nearby) or even some kind of military IR/radar target. We may never know for sure though, as the object disappeared soon after.

Even if you’re not a fan of Apple, it’s hard not to be interested in the company’s new M1 chip. Hackers have been clamoring for more ARM laptops and desktops for years, and with such a major player getting in the game, it’s only a matter of time before we start seeing less luxurious brands taking the idea seriously. After the recent discovery that the ARM version of Ubuntu can run on the new M1 Macs with a simple virtualization layer, it looks like we won’t have to wait too long before folks start chipping away at the Walled Garden.

In the market for a three phase servo controller? A reader who’s working on a robotics project worth as much as a nice house recently wrote in to tell us about an imported driver that goes for just $35. Technically it’s designed for driving stepper motors, but it can also (somewhat inefficiently) run servos. Our informant tells us that you’d pay at least $2,000 for a similar servo driver from Allen-Bradley, so the price difference certainly seems to make up for the hit in performance.

Finally, some bittersweet news as we’ve recently learned that Universal Radio is closing. After nearly 40 years, proprietors Fred and Barbara Osterman have decided it’s time to start winding things down. The physical store in Worthington, Ohio will be shuttered on Monday, but the online site will remain up for awhile longer to sell off the remaining stock. The Ostermans have generously supported many radio clubs and organizations over the years, and they’ll certainly be missed. Still, it’s a well-deserved retirement and the community wishes them the best.