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.

Continue reading “Compliant Quadruped Legs Using Servos” →

Robotic Eels Take Care Of Undersea Pipelines

March 15, 2020 by Al Williams 11 Comments

We can’t tell if the Eelume actually exists, or if it’s just a good CG and a design concept, but when we saw the video below, we wanted to start working on our version of it immediately. What’s an Eelume? A robotic eel that lives permanently under the ocean.

If you have to take care of something underwater — like a pipeline — this could be much more cost-effective than sending divers to the ocean floor. We liked the natural motion and we really liked the way the unit could switch batteries and tool heads.

We do have some questions, though. How do you get rid of one battery and pick up another? There would have to be some battery capacity that doesn’t exchange, but that’s not very efficient since the new battery would have to recharge the internal battery. Perhaps you can add batteries at either end. Some of the still pictures don’t clearly show how the batteries fit in, although they do show the flexible joints, sensors, cameras, and thrusters, which are all modular.

According to the web site, tools can go on either end and there’s a robot arm. The device can apparently shape itself like a U to bring both ends to bear on the same area. Generally, we like robots that mimic nature, but this is one of the best examples of that being practical we’ve seen.

There’s a video on the site of what appears to be real hardware tethered in a swimming pool, though we couldn’t tell how much of the device was subject to remote control and how much would be autonomous. Communicating underwater is finicky and usually requires either an antenna on the surface or a very low frequency (and, thus, not much bandwidth). While completely duplicating this would probably be a feat, it might inspire some hacker-friendly eels.

A lot of underwater vehicles seem to emulate biologic life. Shape-wise we had to remember [Alex Williams’] award-winning underwater glider, even though it doesn’t undulate.

Rover Runs Slow And Steady On Solar Power

March 15, 2020 by Danie Conradie 11 Comments

The solar panel technology we have available today doesn’t really lend itself to practical everyday transport. But when speed isn’t a concern, it can make for some very interesting autonomous rovers. One example of this is [Daniel Riley] aka [rctestflight]’s solar powered rover, which he built to live autonomously at his flight testing field, crawling around whenever it has gathered enough juice from the sun.

[Daniel] has thing for autonomous craft of all types, with quite a few aircraft and boats to his name. This rover is built around a welded steel frame, with each wheel driven by a brushless geared motors via a chain. While it’s technically a skid steer, the electronic speed controls are from a quadcopter and can’t reverse, so it doesn’t turn quite on the spot.

With the rigid steel frame, any small bump in the ground would cause one wheel to lose traction. To fix this, the frame was cut in two and a pivot added in the center, allowing all four wheels to always remain on the ground. Another problem is that the wheels would sometimes dig themselves into the soft wet ground, so this, [Daniel] attached a 3D printed “hump” to each drive wheel, which helps them to climb out of any soft spots. For the next version of this rover, [Daniel] plans to use cheap DC geared motors from a Barbie jeep. They’re a bit too fast though, so he’ll be adding 3D printed cycloidal reduction gearboxes. We’re definitely looking forward to seeing here this project goes from here.

There have been a number of projects to test solar powered robots for agricultural use. We really like the idea, with its potential for long duration missions. Imagine something like this roaming the Black Rock playa in the US, the Makgadikgadi Pan in Botswana, or even the Sahara Desert, while gathering environmental data and making awesome time-lapse videos.

Civilian RC Car Uses Lego NXT And Ada

March 14, 2020 by Al Williams 4 Comments

Back in the last century, the US Department of Defense declared that Ada was going to be used everywhere and for everything. Books were published, schools build curriculum. Working programmers, however, filled out waivers to continue working in their languages of choice. As a result, only a little bit of safety-critical software really used Ada. However, we’ve noticed a bit of a resurgence lately. Case in point: an RC car using Ada for the brains. You can watch it tool around in the video below.

This isn’t the first time we’ve heard about Ada in the past few months. Partially, this could be because of the availability of the GNU compiler, although that’s been around since 1995, so maybe there’s another explanation. Ada’s strong typing does tend to plug holes that hackers exploit, so while we would hate to say it is hack proof, it certainly is hack resistant compared to many popular languages.

Continue reading “Civilian RC Car Uses Lego NXT And Ada” →

Dexter Robot Arm Embraces New Manufacturing With First Micro-Factory

March 9, 2020 by Mike Szczys 32 Comments

Haddington Dynamics, the company behind the Dexter robot arm that won the 2018 Hackaday Prize, has opened its first microfactory to build robot arms for Australia and Southeast Asia.

You may remember that the combination of Dexter’s makeup and capabilities are what let it stand out among robotics projects. The fully-articulated robot arm can be motion trained; it records how you move the arm and can play back with high precision rather than needing to be taught with code. The high-precision is thanks to a clever encoder makeup that leverages the power of FPGAs to amplify the granularity of its optical encodes. And it embraces advanced manufacturing to combine 3D printed and glue-up parts with mass produced gears, belts, bearings, and motors.

It’s a versatile robot arm, for a fraction of the cost of what came before it, with immense potential for customization. And did I mention that it’s open source? Continue reading “Dexter Robot Arm Embraces New Manufacturing With First Micro-Factory” →

See The Damage 250-Pound Combat Robots Get

March 9, 2020 by Donald Papp 14 Comments

Combat robots have been a thing for a while, but we don’t normally get a close look at the end results of the sort of damage they can both take and deal out. [Raymond Ma] spent time helping out with season four of BattleBots and wrote about the experience, as well as showed several pictures of the kind of damage 250-pound robots can inflict upon each other. We’ve embedded a few of them here, but we encourage you to read [Raymond]’s writeup and see the rest for yourself.

The filming for a season of BattleBots is done in a relatively short amount of time, which means the pacing and repair work tends to be more fast and furious than slow and thoughtful. [Raymond] says that it isn’t uncommon for bots, near the end of filming, to be held together with last-minute welds, wrong-sized parts, and sets of firmly-crossed fingers. This isn’t because the bots themselves are poorly designed or made; it’s because they can get absolutely wrecked by the forces at play.

Continue reading “See The Damage 250-Pound Combat Robots Get” →

Robot Fights Fire With IR

March 8, 2020 by Kristina Panos 7 Comments

Fighting fire with robots may take jobs away from humans, but it can also save lives. [Mell Bell Electronics] has built a (supervised) kid-friendly version of a firefighting robot that extinguishes flames by chasing them down and blowing them out.

This hyper-vigilant robot is always on the lookout for fire, and doesn’t waste movement on anything else. As soon as it detects the presence of a flame, it centers itself on the source and speeds over to snuff it out with a fan made from a propeller and a DC motor.

Here comes the science: fire emits infrared light, and hobbyist flame sensors use IR to, well, detect fire. This fire bot has three of these flame sensors across the front that output digital data to what has got to be the world’s smallest Arduino – the ATmega32U4-based PICO board that [Mell Bell] just so happens to sell. Cover your mouth and nose and crawl along the floor toward the break to see how responsive this thing is.

Firefighters aren’t the only brave humans involved in the process of keeping the forests standing, or who feel the rising pressure of automation. Hackaday’s own [Tom Nardi] wrote a piece on a dying breed called fire lookouts that will no doubt ignite your interest.

Continue reading “Robot Fights Fire With IR” →