An image of Kitten Mittens and its 3lb counterpart

Why Make A Combat Robot That Walks?

October 1, 2021 by Jim Heaney 13 Comments

If you watch it on TV or see clips on YouTube, you’ll notice that most combat robots have wheels, which would make sense. They are simple, work well, and if designed right they can take a bit of a beating. So why did [Luke] design his 12-pound bot with no wheels, or any locomotion system for that matter? You can find out more about this peculiar bot in his build report with more than 130 images.

[Luke’s] bot, called Kitten Mittens, is a gyro walker combat robot. This means that instead of traditional tank treads or wheels to move about, [Luke] navigates by angling his bot’s weapon and using the angular momentum to lift up one side of the bot to “walk” forward. Watch the video after the break to see it in action. While this does leave Kitten Mittens much slower and less agile than competitors, it gives one massive leg up; weight. Kitten Mittens fights in the 12-pound combat robotics weight class, but most leagues have weight bonuses for bots that have no wheels or use otherwise nontraditional locomotion. Where [Luke] competes, the Norwalk Havoc Robot League, this means that his bot can be up to 6 pounds heavier than the other competitors!

A 3D-printed prototype of Kitten Mittens' weapon — A printed prototype of the weapon, showing off the integrated hub motor.

So how did [Luke] take advantage of that extra 6 pounds? The biggest thing was the weapon. It is made of 3/4-inch S7 tool steel and has a custom hub motor integrated into the center, bringing its rotating weight to 5.5 pounds. In addition to thickness, the added weight allowance permitted a larger spinning diameter so that Kitten Mittens could hit opponents before they hit him.

[Luke] is not new to the world of combat robotics, and knew it would take more than just a big weapon to win. Part of the extra weight budget was also used to beef up his armor and internal structure of the bot, so that hits from opponents would just bounce him around the cage harmlessly. This even included custom bent titanium guards surrounding the weapon, to help in self-righting.

When it first debuted in February of 2021, Kitten Mittens was a smashing success! It went 4-0 in the 12lb weight class at NHRL, winning the $1,000 prize and earning its spots in the annual finals, where [Luke] will compete against other finalists from the rest of the season for a chance to win the $12,000 first-place prize.

Bots that walk, shuffle, or crawl are becoming more of a trend lately in all weight classes. Even Overhaul, a 250-pound bot, has been given a new set of feet to shuffle around on. You can read more about this interesting concept here.

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Project HERMITS Robots Mimic Crabs With Mechanical Shells

September 27, 2021 by Lewin Day 1 Comment

Hermit crabs are famous for being small critters that, from time to time throughout their lives, abandon one shell carried on their back to pick up a new one. Project HERMITS by [Ken Nakagaki] is inspired by this very concept, and involves table-top robots that dock with a variety of modules with different mechanical mechanisms.

As shown in the project video, the small robots augment themselves by interfacing with attachments referred to as “mechanical shells.” They variously allow the robot to move differently or interact in a new way with the world.

One shell allows the robot to activate a small fan, while another lets it rotate arrows in various directions. others let robots work together to actuate a bigger mechanical assembly like a gripper or a haptic feedback joystick.

A particularly cute example is the “lift shell” which allows one little robot give another one a boost in height. Another series of shells allows the robots to play the role of various characters in a performance of Alice in Wonderland.

The technology is all built around Sony’s tiny two-wheeled toio robots, but adds a vertical actuator to the platform that lets the robots actively dock with a variety of shell designs. It’s an involved hack, but key to the whole enterprise. The individual bots are all controlled by Raspberry Pis communicating over Bluetooth.

We always love to see cute robots working together. Video after the break.

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3D Printed Research Robotics Platform Runs Remotely

September 27, 2021 by Dave Rowntree 8 Comments

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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A tiny solar-powered robot that even works indoors

Tiny BEAM Robot Smiles Big At The Sun

September 25, 2021 by Kristina Panos 14 Comments

What have you been working on during the Great Chip Shortage? [NanoRobotGeek] has been living up to their handle and building BEAM robots that are smaller than any we’ve seen before. What are BEAM robots, you say? Technically it stands for Biology Electronics Aesthetics and Mechanics, but basically the idea is to mimic the movement of bugs, usually with found components, and often with solar power. Here’s a bunch of tutorials to get you started.

The underbelly of what might be the world's smallest BEAM robot. — This was before the large, flat storage capacitor came and covered everything up.

This here is an example of a photovore or photopopper — it moves toward light using simple logic by charging up a capacitor and employing a voltage monitor to decide when there’s enough to run two tiny vibration motors that make up its legs and feet.

[NanoRobotGeek] started in a great place when they found these 25% efficient monocrystalline solar panels. They will even make the bot move indoors! If you want to build one of these, you can’t beat [NanoRobotGeek]’s guide. Be sure to watch it toddle around in the demo video after the break.

We love to see people work at all different scales. Last time we checked in with [NanoRobotGeek], they had built this solar-powered ball-flinging delight.

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Self Balancing Robot Needs A Little Work

September 20, 2021 by Al Williams 6 Comments

A self-balancing robot isn’t a new idea, but we liked the aesthetics of [Maker ATOM’s] build. The use of a breadboard and a printed bracket looks good, as you can see in the video, below.

Like most first-time projects, though, there were some lessons learned. The power supply needs a little work and the range of balance compliance didn’t meet expectations. But those problems are soluble and, as usual, you often learn more from working through issues like these.

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Line Following Robot Uses PID For Speed

September 18, 2021 by Al Williams 19 Comments

While a line-following robot may not be the newest project idea in the book, this one from [Edison Science] is a clean build using modern components and gets a good speed thanks to PID control feedback instead of the more traditional bang-bang control you see in low-end robots.

Of course, PIDs need tuning and that seems to be the weak link — you’ll have to experiment with the settings. The sensors also require calibration, but we bet both of those issues could be fixed pretty easily.

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GLaDOS Voice Assistant Passive-Aggressively Automates Home

September 13, 2021 by Ryan Flowers 7 Comments

With modern voice assistants we can tell a computer to play our favorite music, check the weather, or turn on a light. Like many of us, [nerdaxic] gave in to the convenience and perceived simplicity of various home automation products made by Google and Amazon. Also like many of us, he found it a bit difficult to accept the privacy implications that surround such cloud connected devices. But after selling his Home and Echo, [nerdaxic] missed the ability to control his smart home by voice command. Instead of giving in and buying back into the closed ecosystems he’d left behind, [nerdaxic] decided to open his home to a murderous, passive aggressive, sarcastic, slightly insane AI: GLaDOS, which you can see in action after the break.

Using open source designs from fellow YouTube creator [Mr. Volt], [nerdaxic] 3d printed as much of the GLaDOS animatronic model as he was able to, and implemented much of the same hardware to make it work. [nerdaxic] put more Open Source Software to use and has created a functional but somewhat limited home AI that can manage his home automation, give the weather, and tell jokes among other things. GLaDOS doesn’t fail to deliver some great one liners inspired by the original Portal games while heeding [nerdaxic]’s commands, either.

A ReSpeaker from Seeed Studio cleans up the audio sent to a Raspberry Pi 4, and allows for future expansion that will allow GLaDOS to look in the direction of the person speaking to it. With its IR capable camera, another enhancement will allow GlaDOS to stare at people as they walk around. That’s not creepy at all, right? [nerdaxic] also plans to bring speech-to-text processing in-house instead of the Google Cloud Speech-To-Text API used in its current iteration, and he’s made everything available on GitHub so that you too can have a villainous AI hanging on your every word.

Of course if having GLaDOS looming isn’t enough, you could always build a functional life size Portal turret or listen to the radio on your very own Portal Radio.

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