[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.
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.
Continue reading “Robotic Open Source Puppy Needs A Home”
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”
When the Skynet baseball bot swarms attack, we’ll be throwing [Carl Bugeja] some dirty looks for getting them started. He’s been working on 4B, a little quadruped robot that can transform itself into a sphere almost perfectly.
Before [Carl] was distracted by the wonders of PCB actuators more than a year ago, he started working on this little guy. He finally found some time to get it moving on its own, and the preliminary results look promising to say the least. Inside the 6 cm sphere is a total of 12 servos, 3 for each leg. All of the mechanical parts were 3D printed in nylon on an SLS machine, and the custom PCB has a BLE microcontroller module, an IMU and IR proximity sensors onboard. Everything is open source with all the files available on the Hackaday.io project page.
The microcontroller runs a full inverse kinematic model, so only the desired tip and base coordinate for each leg is input and the servo angles are automatically calculated. Ultimately [Carl] aims to have the robot both walking and rolling controllably. So far he’s achieved some degree of success in both, but it still needs some work (see the videos below. We’re eager to see what the future holds for this delightfully creepy bot.
Walking robots are always an interesting challenge. For more of our future overlords, check out this adorable little cat and this truly terrifying strandbeest.
The more we read about [Josh Pieper]’s quadruped, the mjbots quad A0, the more blown away we are by his year of progress on the design. Each part of the robot deserves its own article: from the heavily modified brushless motors (with custom planetary gears) to the custom motor driver designed just for this project.
[Josh], realized early on that the off-the-shelf components like an ODrive just weren’t going to cut it for his application. So he designed his own board, took it through four revisions, and even did thermal and cycle testing on it. He ended up with the compact moteus board. It can pump out 400 Watts of peak power while its 3Mbit control protocol leaves plenty of bandwidth for real time dynamic control.
The motors and gearboxes are also impressive. It took thorough experimenting and taking inspiration from other projects before he arrived at a 8108 quad copter motor modified and upgraded so heavily its own mother wouldn’t recognize it. This is all packed into a leg unit with three degrees of freedom that puts even the fanciest servo based quadruped to shame.
Finally it’s all packed into a neat four-legged robot frame with batteries and a Pi. You can get a video summary of the robot here or after the break, and we recommend reading his blog for some more images and details.
Continue reading “Amazing Open Source Quadruped Capable Of Dynamic Motion”
There’s an old saying about standing on the shoulders of giants, but how about doing so with an open source leg? Well, your robots might do so at least, thanks to OpenLeg, a new open source project for building robot legs. Created by [Joey Byrnes], this started out as a senior project for a course at the University of Illinois. The idea is to create a robot leg that others can use to build four-legged robots that can amble around the neighborhood, much like those built by Boston Dynamics. Continue reading “OpenLeg – The Open Source Robot Leg”
The sound a set of machined robot legs tapping on concrete make is remarkable. If for nothing more, the video after the break is worth watching just for this. It’s what caught my attention when I first wandered by the Mech Warfare area at Maker Faire, as one of the competitors had their bot out wandering around as a demo during the setup day.
Installing target plate
Making sure the ammo is set to go
This is truly a hacker’s robotics competition. There are constraints, but there’s also a lot of room for freedom. Meet a dozen or so requirements and you be as creative as you want with the rest. My favorite part is that this is not a destructive event like many the battle-based robot TV shows that tend to turn my stomach. Instead, these robots each carry an electric AirSoft gun and seek to hit any of four target panels on their competitor’s robot. Continue reading “Mech Warfare: Like Driving A Building-Sized Robot Through A Busy City”