Multirotor aircraft enjoy many intrinsic advantages, but as machines that fight gravity with brute force, energy efficiency is not considered among them. In the interest of stretching range, several air-ground hybrid designs have been explored. Flying cars, basically, to run on the ground when it isn’t strictly necessary to be airborne. But they all share the same challenge: components that make a car work well on the ground are range-sapping dead weight while in the air. [Youming Qin et al.] explored cutting that dead weight as much as possible and came up with Hybrid Aerial-Ground Locomotion with a Single Passive Wheel.
As the paper’s title made clear, they went full minimalist with this design. Gone are the driveshaft, brakes, steering, even other wheels. All that remained is a single unpowered wheel bolted to the bottom of their dual-rotor flying machine. Minimizing the impact on flight characteristics is great, but how would that work on the ground? As a tradeoff, these rotors have to keep spinning even while in “ground mode”. They are responsible for keeping the machine upright, and they also have to handle tasks like steering. These and other control algorithm problems had to be sorted out before evaluating whether such a compromised ground vehicle is worth the trouble.
Happily, the result is a resounding “yes”. Even though the rotors have to continue running to do different jobs while on the ground, that was still far less effort than hovering in the air. Power consumption measurements indicate savings of up to 77%, and there are a lot of potential venues for tuning still awaiting future exploration. Among them is to better understand interaction with ground effect, which is something we’ve seen enable novel designs. This isn’t exactly the flying car we were promised, but its development will still be interesting to watch among all the other neat ideas under development to keep multirotors in the air longer.
[IROS 2020 Presentation video (duration 10:49) requires no-cost registration, available until at least Nov. 25th 2020. Forty-two second summary embedded below]
Continue reading “One Wheel Is All We Need To Roll Into Better Multirotor Efficiency”
Since Back To The Future II first screened back in 1989, people have been waiting for hoverboards to become reality. Instead, we got a dangerous two-wheeled contraption going by the same name. Wanting something a little cooler, [Bartek Plonek] decided to convert his to a one-wheel design. (Video, embedded below.)
The hack starts by machining the hub motors of the hoverboard. They’re bolted together, and used as the hub of a single larger wheel. Care is necessary to avoid cracking the motor housing during this process, as [Bartek] found during his first attempt. The wheel is then fitted to the centre of a steel frame, upon which two halves of a skateboard are attached to act as a footplate. The original hoverboard controller is still used; we’d love to know if firmware modification was required to work with the new motor configuration.
It’s a classic garage hack that results in a viable personal electric vehicle. Plus, cornering is far easier, with the DIY onewheel capable of carving back and forth quite well. We’ve seen others aim to commute using similar builds.
Continue reading “Homebuilt Onewheel Uses Hoverboard Parts”
[Nick Thatcher] is a serial builder of self-balancing rides. His various Segway clones and unicycles have until now suffered from one significant problem, that of portability when not being ridden. Taking one on a train was a significant undertaking, hardly convenient in a personal transport machine.
His latest design, the Plan-B, is an electric unicycle designed to address this problem to create a truly portable piece of commuter transport. It has been designed to be as compact as possible with the ability to fold to fit in a confined space, and the weight has been reduced to a minimum.
Power comes from a 24V 350W geared motor kept on a leash through a Dimension Engineering motor controller by an Arduino with a gyro to maintain the unit’s stability The battery is an ULTRAMAX LiFePO4 , and the single wheel is an inexpensive plastic wheelbarrow part with chain drive from the motor.
The result is both rideable and portable, though with a 10mph top speed not the fastest of personal transport. He’s posted a video which you can see below the break, showing him taking it on a train journey and traversing the British urban landscape.
Continue reading “[Nick Thatcher]’s Plan-B Is A Commuter Electric Unicycle”
[XenonJohn] wrote in to let us know about updates and a recent test drive of an Electric Self-Balancing One-wheeled Motorcycle, fresh from the beach where he says it proved to be great fun to ride. The design and build have been updated since we last saw it as a semifinalist entry in the 2014 Hackaday Prize. The original, he says, “looked cool but was slow, cumbersome and really dangerous to ride.”
Since then it has been completely redesigned and now has a super fat kite-surfer wheel, a front crash skid with damper, and a variable geometry which allows it to steer properly despite just having one wheel. It does this by allowing the rider to shift their position relative to the wheel, instead of the seat always being rigidly locked directly above the axle.
That steering is a pretty clever upgrade, but we do wonder if the new crash skid will have an atlatl effect and really launch the rider in a crash. Our gut feeling aside, it is designed not to plant itself in the pavement, but to slide along (without ejecting the rider) until the vehicle loses all momentum.
There is something about self-balancing unicycles that attracts experimenters, each of whom takes a different approach. We see everything from this device constructed mainly from a Razor Scooter to this more polished-looking unit based on an earlier Segway clone design. [XenonJohn] reminds us that “there is still much to learn in this area and you can genuinely innovate even as a hobbyist. Also, you can only do so much on a computer, you then have to actually build something and see how well it works. [This recent test] shows what you can do if you just keep on experimenting.” Video of the test drive is below.
Continue reading “Self-Balancing One-Wheel Motorcycle Tears Up The Beach”
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.
Continue reading “Electric Motorcycle Rocks One Wheel”