Spherical Quadruped Arduino Robot

May 21, 2020 by Orlando Hoilett 9 Comments

[Greg06] started learning electronics the same way most of us did: buy a few kits, read a few tutorials, and try your hardest to put a few things together. Sound familiar? After a while, you noticed your skills started increasing, and your comfort level with different projects improved as well. Eventually, you try your hand at making your own custom projects and publishing your own tutorials.

Few are lucky to have a first-project as elaborate as [Greg06’s] quadruped robot. We don’t know about you, but for some of us, we were satisfied with blinking two LEDs instead of just one.

[Greg06’s] robot has a quadruped based, housed within a 3D printed spherical body. The legs are retractable and are actuated by tiny servo motors inside the body. [Greg06] even included an ultrasonic distance sensor for the obstacle avoidance mechanism. Honestly, if it weren’t for the ultrasonic distance sensor protruding from the spherical body, you might think that the entire robot was just a little Wiffle ball. This reminds us of another design we’ve seen before.

If that weren’t enough, the spherical head can rotate, widening the range of the ultrasonic distance sensor and obstacle avoidance mechanism. This is accomplished by attaching another servo motor to the head.

Pretty neat design if you ask us. Definitely one of the coolest quadrupeds we’ve seen.

Robotic Open Source Puppy Needs A Home

May 12, 2020 by Richard Baguley 20 Comments

Personally, I am a fan of the real thing, but dogs aren’t an option for all. Plus, robotic dogs are easier to train and don’t pee on your couch. If you are looking to adopt a robotic companion, Stanford Pupper might be a good place to start. It’s a new open source project from the Stanford Robotics Student group, a group of robotic hackers from Stanford University. This simple robotic quadruped looks pretty simple to build, but also looks like a great into to four-legged robots.

This is the first version of the design, but it looks pretty complete, built around a carbon fiber and 3D printed frame. The carbon fiber parts have to be cut out on a router, but you can order them pre-cut here, and you might be able to adapt it to easier materials. The Pupper is driven by twelve servos powered from a 5200 mAh 2S LiPo battery and a custom PCB that distributes the power. That means it could run autonomously.

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Compliant Quadruped Legs Using Servos

March 22, 2020 by Danie Conradie 4 Comments

Walking robots that move smoothly are tricky to build and usually involve some sort of compliant leg mechanism — a robot limb that can rebound like natural physiology for much better movement than what a stiff machine can accomplish. In his everlasting quest to build a real working robot dog, [James Bruton] is working on an affordable and accessible Mini Robot Dog, starting with the compliant leg mechanism.

The 3D printed leg mechanism has two joints (hip and knee), with an RC servo to drive each. To make the joints compliant, both are spring-loaded to absorb external forces, and the deflection is sensed by a hall effect sensor with moving magnets on each side. Using the inputs from the hall effect sensor, the servo can follow the deflection and return to its original position smoothly after the force dissipates. This is a simple technique but it shows a lot of promise. See the video after the break.

A project can sometimes develop a life of its own, or in the case of [James]’s OpenDog, spawn experimentally evolving offspring. This is number four, and it’s designed to be a platform for learning how to make a quadruped walk properly, and to be simple and cheap enough for others to build. We’re looking forward to seeing how it turns out.

If you missed it, also check out this robot’s weird sibling, self-balancing Sonic.

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DARPA Challenge Autonomous Robot Teams To Navigate Unfinished Nuclear Power Plant

March 6, 2020 by Roger Cheng 4 Comments

Robots might be finding their footing above ground, but today’s autonomous robots have a difficult time operating underground. DARPA wanted to give the state of the art a push forward, so they are running a Subterranean (SubT) Challenge which just wrapped up its latest round. A great review of this Urban Circuit competition (and some of the teams participating in it) has been published by IEEE Spectrum. This is the second of three underground problem subdomains presented to the participants, six months apart, preparing them for the final event which will combine all three types.

If you missed the livestream or prefer edited highlight videos, they’re all part of DARPAtv’s Subterranean Challenge playlist. Today it starts with a compilation of Urban Circuit highlights and continues to other videos. Including team profiles, video walkthrough of competition courses, actual competition footage, edited recap videos, and the awards ceremony. Half of the playlist are video from the Tunnels Circuit six months ago, so we can compare to see how teams performed and what they’ve learned along the way. Many more lessons were learned in the just-completed Urban Circuit and teams will spend the next six months improving their robots. By then we’ll have the Caves Circuit competition with teams ready to learn new lessons about operating robots underground.

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DARPA Subterranean Challenge Urban Circuit Now Livestreaming

February 20, 2020 by Roger Cheng 1 Comment

Currently underway is the DARPA Subterranean Challenge (SubT) systems competition for urban circuits streamed live on YouTube now through Wednesday, February 26th.

The DARPA Grand Challenge of 2004 kicked research and development of autonomous vehicles into high gear. Many components on today’s self-driving vehicles can be traced back to systems developed for that competition. Hoping to spur further development, DARPA has since held several more challenges focused moving the state of the art in autonomous robotics ahead.

To succeed in this challenge, robots must handle terrain that would confuse today’s self-driving cars. Cluttered environments, uneven surfaces of different materials, even the occasional flooded section are fair game. These robots also lose access to some of the tools previously available, such as GPS. The “systems track” denotes teams building physical robot systems versus a separate “virtual track” for simulation robots. “Urban circuit” is the second of four phases in this competition, environments of this phase are focused on man-made underground structures. (Think subway station.) For more details on this competition as well as description of various phases, see our introductory post or the competition site.

Those who rather not watch robots tentatively exploring unknown territory (and occasionally failing) may choose to wait for summaries published after competition rounds are complete. The first phase (tunnel circuit) from August-October 2019 was summarized by IEEE Spectrum here. Or you can go straight to DARPA for details on the systems track and virtual track with overall results posted on the competition site.

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Unique Clock Finally Unites Hackers And Sequins

January 30, 2020 by Tom Nardi 24 Comments

We’ve all seen the two-color sequin fabrics you can “draw” on by dragging your finger over so the pieces flip to the other color. It’s fun stuff to play with, and very popular with the kids right now, but if you asked us if the material had any practical application we’d have said no. But that was before we saw this clever clock created by [Ekaggrat Singh Kalsi] that he calls Sequino.

Since a clock (at least one that only shows hours and minutes) doesn’t need to refresh very quickly, [Ekaggrat] thought that the sequin material could work as a display. Of course the tricky part is figuring out how to actually draw on it reliably. It can’t be done from the back, and since the sequins are plastic, you can’t use a magnet. The only way to do it is with a robotic “finger” and some very slick kinematics.

The most obvious feature of the Sequino is the belt drive that goes the length of its cylindrical shape. When the two motors connected to the belt are turning in the same direction, the pointer is moved left or right. But when the motors turn in opposite directions, the tension on the belt forces the pointer to extend and contact the sequins. It’s like an H-bot , but with the shortest ever Y axis. The front bar is moved up and down with rotating rings inside of the device. It will probably make a lot more sense once you watch the video of it in operation after the break.

[Ekaggrat] says this project was developed as part of his quest to build “doodle clocks” that draw out the time continuously. The advantage of using the sequin fabric is that it shouldn’t be damaged by repetitive use, an issue he’s tried to solve via photonic means in the past.

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Teardown: BilBot Bluetooth Robot

January 20, 2020 by Tom Nardi 16 Comments

Historically, the subject of our January teardown has been a piece of high-tech holiday lighting from the clearance rack; after all, they can usually be picked up for pocket change once the trucks full of Valentine’s Day merchandise start pulling up around the back of your local Big Box retailer. But this year, we’ve got something a little different.

Today we’re looking at the BilBot Bluetooth robot, which over the holidays was being sold at Five Below for (you guessed it) just $5 USD. These were clearly something the company hoped to sell a lot of, with stacks of the little two-wheeled bots in your choice of white and yellow livery right by the front door. With wireless control from your iOS or Android device, and intriguing features like voice command, I’d be willing to bet they managed to move quite a few of these at such a low price.

For folks like us, it can be hard to wrap our minds around a product like this. It must have a Bluetooth radio, some kind of motor controller, and of course the motors and gears themselves. Yet they can sell it for the price of a budget hamburger and still turn a profit. If you wanted to pick up barebones robotics platform, with just a couple gear motors and some wheels, it would cost more than that. The economies of scale are a hell of a thing.

Which made me wonder, could hackers take advantage of this ultra-cheap robot for our own purposes? It’s pretty much a given that the software for this robot will be terrible, and that whatever control electronics live inside it will be marginal at best. But what if we write those off and just look at the BilBot as a two-wheeled platform to carry our own electronics? It’s certainly worth $5 to find out.

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