The inverted pendulum is a pretty classic dynamics problem and reaction wheels are cool. That’s why we like [Mike Rouleau]’s self-balancing stick.
The video, viewable after the break, was fairly sparse on details, but he furnished some in the comments. The little black box on the top is a GY-521 Gyroscope module. It sends its data to an Arduino attached to the black cord which trails off the screen. The Arduino does its mathemagic and then uses a motor controller to drive the reaction wheels at the correct speeds.
Continue reading “Stick Balances Itself With Reaction Wheels”
Looking at this legged robot gives us the same feeling we had the first time we saw a two-wheeled balancer. At first glance it just shouldn’t work, but after a little thought it makes a lot of sense. The six-legged bot called OutRunner uses two sets of three legs to propel itself. The footfalls are staggered to mimic how a biped runs, but mechanically it’s just spinning wheels to which the legs attach. If you have a smart enough algorithm it will not only remain upright but be steerable too.
This is a Kickstarter offering to let you can get your hands on an unassembled kit for $200. That version comes with a universal camera mount but no camera. This may not sound like a problem, but look closer and you may notice what we have: The thing is remote-controlled and can run up to 20 MPH, but there’s not footage of it running slowly. We’d wager the need to keep itself balanced equates to the need to run rather than walk. Since it’s going to get away from you very quickly you probably need a camera and a wearable display (or a chase car like in the video) to make the most out of the OutRunner. But hey, who’s complaining about that? Sounds like a ton of fun to us!
Why is it that this thing looks delightful but all of the Boston Dynamics running bots scare the crap out of us?
Continue reading “Robot Runs on 6 Legs But Never More Than 2 at a Time”
From the looks of the latest update [James] has made quite a bit of progress on his bipedal robot. He added to the top of the post just a few days ago, but didn’t include the video link which you’ll find embedded after the break. There’s about ten minutes of explanation before he gets down to demonstrating the static and dynamic balance which can be chosen using the buttons on a TV remote.
We looked in on the project about one year ago. The most notable change is the control electronics anchored in the torso of the robot. At first it makes us a bit nervous that he hasn’t built a protective cage around the components. But after seeing the latest stability demonstration we guess it’s because this thing is fantastic at staying upright. The torso is connected at the hips in such a way that no matter where each leg is it will always remain upright. All together the thing stands twenty-six inches tall, but that will grow when he gets around to building a head for it.
Continue reading “Update on [James’] bipedal robot”
This robot is able walk the tightrope (translated). Well, it’s more of a shuffle than a walk, but still a lot better than we could do.
In the video after the break you can see the bot starting on the platform to the right. As it steps out onto the wire (which rides in a groove on the bottom of its foot) the robot spreads its arms to help maintain balance. When the other foot leaves the platform that is the last stride we will see until it reaches the other side. The rest of the act consists of sliding the feet a little bit at a time until it gets all the way across.
[Dr. Guero] has been working on at least one other balancer as well. Also embedded after the break is a robot riding a bicycle. It actually puts a foot down when stopped, and gives a stuttering push-off to get going again. This guy would be right at home riding past you in the hallways of the Death Star.
Continue reading “Robot performing a tightrope act”
This self balancing robot still uses just two wheels, but it’s balancing very differently than we’re used to seeing. Where most of the projects use a form factor that’s similar to a Segway, this works just like a bicycle. But it doesn’t need to keep the front and rear wheels spinning to stay upright. In fact, the video after the break shows it balancing perfectly while at a complete standstill. [Aoki2001’s] creation isn’t stuck in one place. He included distance sensors on the front and back which are used to move the bike as if by repulsion.
The large wheel where the rider would be is what makes sure the vehicle doesn’t topple over. It acts as an inverted pendulum, pushing against the large wheel’s inertia by rotating the motor to which it is attached. The same concept was seen back in march on a full-sized bike. But why use two wheels when you only need one? His unicycle version can also be seen embedded after the break.
It’s worth looking at [Aoki’s] other YouTube offerings too. He’s got a small robot which balances on top of a ball. It’s the desk-sized version of this hack.
Continue reading “Self balancer does it differently than we’re used to seeing”
[Nick Thatcher] has built several iterations of a homebrew Segway, and the latest version is very impressive. When developing the project he figured there was just no way the thing would ever work, which led to its name, the No-way.
After the break you can catch a video of [Nick’s] test-ride. Looks like the two-wheeler is ready for daily use. You can just make out a red kill-switch on the right side of the polycarbonate body. This lets you disconnect the power if things get out of hand, or just when you’re done riding it. But there is also a dead-man’s switch which we believe uses two sensors where your feet go on the enclosure’s top surface. The handle has some indicator lights built into it, as well as buttons under each thumb which are used for steering. Control circuitry includes an Arduino UNO which reads a gyroscope/accelerometer sensor board from SparkFun. Two 7.2 Ah batteries provide 24V for the pair of electric scooter motors that turn the wheel-barrow wheels.
We love looking at these Segway clone project. So if you’re working on one of your own don’t forget to document your progress!
Continue reading “Self-balancing transport is Arduino-controlled”
[Lauszus] really put together an impressive self balancing robot platform. It is virtually motionless when balancing in place, and that stability is never lost even when motoring across the room.
Part of the success behind this build is the use of quality components. He’s got a really nice set of motors with built-in encoders which give feedback to the balancing system. They work in conjunction with a gyroscopic sensor and PID code to keep the two-wheeled platform upright. An mbed board running 96 MHz provides plenty of computing power for the balancing system. But an Arduino can also be found on board. This was included to facilitate Bluetooth connectivity with the remote control as [Lauszus] didn’t want to port the code he had already written.
The fourteen minute video after the break shares the details behind how the PID controller is tuned and how [Lauszus] implements target angle and a few other factors. Of course he talks about the hardware choices, and demonstrates functionality by driving the bot around using a wireless PS3 controller.
The construction method which uses masonite strips and threaded rod does a good job of protecting the hardware mounted on it. We’re always a bit worried about these bots falling over and some of the projects we see offer little or no protection. Once thing that helps protect against a spill is a piezo buzzer which sounds when the battery is getting low.
Continue reading “Short and squat balancing bot is extremely stable”