Self balancing unicycle built from old scooter

[Glenn] had an old electric scooter/motorcycle in his garage that had long ago given up the ghost. Without a working battery and motor controller this scooter wasn’t beyond repair, but [Glenn] thought he could use it to build something much, much cooler. What he came up with is a self-balancing unicycle that borrows inspiration from a Segway and other self-balancing robots.

After cutting the drive chain off his scooter, [Glenn] began work on installing a new motor controller and battery. To make this unicycle balance itself, he would need a few gyroscopes and accelerometers provided via an Arduino and Sparkfun IMU shield.

After tuning his PID loop, [Glenn] hopped on his new ride and took it for a spin with the help of a pair of ski poles. It’s much easier to ride than a traditional unicycle and [Glenn] says he’s getting better at riding it.

Self balancer does it differently than we’re used to seeing

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”

Self-balancing unicycle only for those with good balance

The only problem with this self-balancing unicycle is it’s inability to balance itself. You see, it automatically balances along the axis that is parallel to the line of travel. But since there’s only one wheel the rider is responsible for balancing perpendicular to travel. This is really not too much different from a bicycle; balancing while in motion is pretty simple. Only when you slow down or stop are you in trouble.

[Stephen Boyer] built the vehicle and uses it for most of his travel around the MIT campus. It carries a pair of 12V batteries that pack enough punch to travel five miles between charges. A 5DOF board senses motion and orientation, with an ATmega328 microcontroller calculating the corrections necessary to keep the rider upright.

The demo video after the break never really gives you good look at the thing, but it’s enough to prove that it does indeed work very well. We’re also glad to see that [Stephen] is using a kill-switch while riding.

If you’re aching for more electric unicycle video check out this other project too. Continue reading “Self-balancing unicycle only for those with good balance”

Self-balancing unicycle 2.0

Focus Designs has a new version of their self-balancing unicycle for sale. This improves upon their original design in several ways. The battery pack has moved to LiFePO4, which is becoming more common in electric transportation. There’s also regenerative braking and fall protection which kills the motor when you fall off.

We’ve embedded their marketing video after the break. Our favorite part is the shot seen above: a guy on the unicycle cruising along next to a woman who is running. There’s nothing like sitting on your bum while some else exercises.

At any rate, from what we see in the video they’ve turned out a solid product.

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Electric motorcycle rocks one wheel

We had to call it an electric motorcycle in the title because electric unicycle just sounds lame. But the video after the break shows you that this prototype is anything but lame. It takes minimalism to the extreme when you’re talking about powered transportation. The self-balancer is reminiscent of a Segway but the rider sits astride one wheel rather than the standing form-factor that [the Woz] loves so much for gaming. Looks like Ryno Motors is trying to gather capital to put these into production. We’re not going to hold our breath until we see them in the wild, but we’d be surprised if they don’t pop up on the big screen at some point in the near future.

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Commercial self-balancing unicycle

Focus Design sent us a video of their self balancing unicycle (looks like they’re taking on Focus Features too). The electric machine moves at 8MPH and lasts 1.5hrs on a single charge. It only weighs 24.6lbs. They say that new riders only need about 2hrs. practice. They’re building ten units to start for $1500 each.

Electric unicycles are nothing new to our community. We’ve long been fans of [Trevor Blackwell]’s electric unicycle. [Trevor] spent several months learning how to ride a regular unicycle before he could properly debug the electric version. There are several other designs out there: The Einrand-Fahrzeug has a wide wheel to make balancing easier. The eniCycle includes a steering mechanism. The Uniquecycle has a brushless motor in hub for a compact design. We did a roundup back in July that covers these plus many other motorized unicycle concepts.

Motorized unicycles

The Segway may be a technological wonder, but motorized balancing transportation has been around for a while. We’ve gathered up some of our favorite motorized unicycles for your knee scraping enjoyment.

The design above makes us immediately think of the very recent wonder by [Ben Gulak] that earned him the cover of Popular Science. Strangely enough, when reading about [Ben] we didn’t see any mention of Noah. Designed by [Andre Franca] of Brazil, it won 2nd place in the Plascar Automotive Design Contest in 2007. The designs are extremely similar.

Continue reading “Motorized unicycles”