Quadruped Robot Thinks It’s A Puppy

October 18, 2013 by 12 Comments

puppybotBack at New York MakerFaire 2012, we noticed an amazing little steampunk quadruped robot walking around in the crowd outdoors. The robot was amazingly well executed, and had a unique ability to draw children over with it’s puppy like animations. It turns out this is [Drew’s] Little Walking Robot (AKA Puppy Bot).

Puppy Bot has actually been around for quite a while. He was born from the spare parts [Drew] had left over after competing in Robot Wars and Battlebots. The robots in these competitions were often controlled by Radio Control plane or car transmitters. Most of these systems are sold as packs for an RC car or plane. In addition to the transmitter and receiver, the pack usually included a battery and 3 or 4 servos. Standard RC servos were much too weak for use in battle robots, so they remained in his parts box.

On what [Drew] calls a slow weekend, he started putting the servos together, and ended up with a basic robot that could crawl around the room. After that the robot took on a life of its own. [Drew] improved the battery system, and added a microcontroller to automate the various gaits and animations. He brought the robot along with him to one of his battlebot competitions, and it took home the “Coolest Robot” award – even though it wasn’t actually competing!

Continue reading “Quadruped Robot Thinks It’s A Puppy” →

Quadruped Walks Of Four Legs, Rolls On Four Treads

May 4, 2013 by 40 Comments

tracked-quadruped-robot

This robot doesn’t know if it’s a walker or a tank. It’s the brain-child of [Marc Hamende] who works as a mechanical engineer by day and mad roboticist at night. The best place to find full details is by digging into the long thread he’s been posting to for about six weeks. It will give you a pretty good snapshot of his approach, starting with SolidWorks renderings of the project, and adding in assembled components as he brings the project together.

The mechanism for each foot is fascinating. He milled the white pieces which stack together to encapsulate the motor that runs the treads. These assemblies pivot to bring the metal rod serving as a walking foot in contact with the ground. But they also make it possible to adjust the treads to deal with rough terrain. A Propeller chip drives the device, with an Xbee module to communicate with the controller.

Don’t miss the video after the break. You’ll hear some skidding as it makes turns, but [Marc] plans to add code to adjust motor speed in order to compensate for the inside/outside differential issues. He’s also posted an image album over at Flickr.

Continue reading “Quadruped Walks Of Four Legs, Rolls On Four Treads” →

An Arduino Based Quadruped Robot

May 27, 2012 by 6 Comments

Arduino-Based-Four-Legged-Robot

Sure, we see hexapods all the time at [HAD], but moving around with four legs can be more tricky kinematics-wise. This Instructable shows you how to make one out of balsa wood.

Although one might not think of balsa to make their robot out of [vexedpheonix] explains that this was chosen because it’s extremely light and easy to work with. Since he was trying to keep costs down, the cheapest servos available were used. These weren’t all that powerful, so the lighter the body the better! According to the included bill of materials, he was able to keep the entire robot build under $100.

According to the article, the hardest part was making four copies of the same leg. We might suggest using a CNC router, but building one would obviously add a huge layer of complication to the project!

Thanks for the tip on this one [SteveT]! Be sure to check out the video of this little robot waving one of it’s legs or trying to walk after the break! Continue reading “An Arduino Based Quadruped Robot” →

Quadruped Military Vehicles From Back In The Day

May 28, 2011 by 14 Comments

walking_truck

While Boston Dynamics’ Big Dog is pretty impressive, check out this video of the US Army’s first attempt at a quadruped vehicle. Created in the early 1960s with the help of GE, this Army experiment was the first successful attempt of replicating a four-legged animal with a mechanical machine.

This “Walking Truck” was driven by a single operator who moved each of the vehicle’s legs using force-feedback hydraulic levers. Choreographing the machine’s movement was quite complicated, and during testing the Army found that the operator needed a mental break after only 15 minutes of use. As you can see in the video, the vehicle flexes some serious muscle. It kicks a Jeep out of its way with little effort, but it is still able to gently step on a light bulb without breaking it, due to the level of tactile feedback received by the operator.

If it weren’t for government budget cuts, we could be living out [George Lucas’] dream of AT-AT based combat right this minute!

[via Gizmodo]

DIY Robotic Actuator Built For Walking Robots

June 30, 2023 by 2 Comments

[Aaed Musa] has built a variety of robots over the years, but found off-the-shelf servos to be underwhelming for his work. Thus, he set out to build a better actuator to support his goals of building a high-performance walking bot in future.

[Aaed] decided to try and build a quasi-direct drive actuator, similar to those used in MIT’s agile mini Cheetah robot. It consists of a powerful brushless DC motor driving a 9:1 planetary gear reduction built with 3D printed parts, which provides high torque output. It’s designed to be run with an ODrive S1 motor controller with encoder feedback for precise control.

The actuator weighs in at a total of 935 grams. It’s not cheap, with the bill of materials totaling just under $250. For your money, though, you get a responsive robotic actuator with a hefty holding torque of over 16 Nm, which [Aaed] demonstrates by having the actuator shake around some dumbells on a long lever arm.

Walking robots have exploded in popularity ever since Spot hit the scene. We’ve seen everything from complex builds to super-simple single-servo designs.

Continue reading “DIY Robotic Actuator Built For Walking Robots” →

Robodog Goes Free Thanks To Unofficial SDK

June 24, 2023 by 7 Comments

What’s better than a pretty nice legged robot? One with an alternate SDK version that opens up expensive features, of course. The author didn’t like that the original SDK only came as pre-compiled binaries restricted to the most expensive models, so rolled up their sleeves and started writing a new one.

The manufacturer’s SDK limits access to programmatic functions, but that needn’t stop you.

There are a number of commercially-available robotic quadrupeds that can trace their heritage back to the MIT Mini Cheetah design, and one of them is the Unitree Go1 series which sports a distinctive X-shaped sensor cluster on its “face”. The basic models are affordable (as far as robots go, anyway) but Unitree claims only the high-priced EDU model can be controlled via the SDK. Happily, the Free Dog SDK provides a way to do exactly that.

The SDK is a work in progress, but fully usable and allows the user to send various high level and low level commands to the Go1 robots. High level examples include things like telling the robot to perform pushups, turn 90 degrees, or walk. Low level commands are things like specifying exact positions or torque levels for individual limbs. With the new SDK, doing those things programmatically is only a Python script away.

Know any other robots that might be based on the same system? This SDK might work on them, too.

Robotic Fox Is Part Dog, Part Cat — Just Like The Real Thing

June 8, 2023 by 8 Comments

Foxes are cat software running on dog hardware, or so they say. And [Will Cogley] seems to have taken that to heart with this 3D-printed robotic fox, which borrows heavily from projects like Boston Dynamics Spot robodog. True, the analogy breaks down a bit when you include MIT’s Cheetah on the inspiration list, but you get the point.

Very much a work in progress — [Will]’s RoboFox lacks both a head and a tail, which he aims to add at some point — there are some interesting design elements on display here. Whereas commercial quadruped robots tend to use expensive harmonic drives for the legs, [Will] chose simpler, cheaper hobby servos for his fox’s running gear. Each leg has three of them — one each for the upper and lower leg, and another that moves the whole leg in and out relative to the body. The dual-servo design for the leg is particularly interesting — one servo drives the upper leg directly, while the other servo drives the lower leg through a gear drive and a captive bearing arrangement connected to a parallelogram linkage. The result is a quite compact assembly that still has twelve degrees of freedom, and isn’t anywhere near as “floppy” as you might expect from something driven by hobby servos.

The video below shows off the design details as well as some of the fox’s construction, including some weirdly anatomically correct poses while it’s on its back. The fox is still getting its legs — you can see a few times when the servos get the jitters, and the umbilical is clearly a hindrance for such a lightweight robot. But [Will] has made a great start here, and we’re keen to see RoboFox progress. Although we’re not sure about giving the future head animatronic eyes.

Continue reading “Robotic Fox Is Part Dog, Part Cat — Just Like The Real Thing” →