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Unicycle with gimballed gyroscopes

Another attempt to gyroscopically stabilise a unicycle
  [vote for,

From a small bicycle, discard the front wheel, replace the handlebars with a fixed handle to hold onto and then move the seat back so the centre of mass is under the remaining (rear) wheel. Keep the one wheel, the seat, the pedals, and enough of the frame to connect them together.

Mount two spinning gyroscopes on gimbals, with a normally vertical spin axis.

One gyroscope (A) has gimbals that normally prevent tilting left or right relative to the vehicle, but allow tilting backwards and forward. This is used to prevent the the vehicle leaning left or right - if there's torque trying to push it over, instead you get precession tilting the gyro forwards or backwards.

The other gyroscope (B) has gimbals that normally prevent tilting forward or back relative to the vehicle, but allow tilting left and right. This is used to prevent the the vehicle leaning forward or back - if there's torque trying to push it over, instead you get precession tilting the gyro left or right.

Also if the active stabilisation system needs to make the vehicle lean left or right, it can apply torque between the gyro (A) and the vehicle, as if to tilt one forward and one back. But due to precession, (A) tilts left or right, making the vehicle lean left or right, and (B) prevents the vehicle from leaning forward or back, instead (B) tilts left or right.

Similarly, the active stabilisation system can make the vehicle lean forward or back when it needs to by applying torque to (B)

If you've been leaning left too much, the (A) gyroscope may be off level, so the active stabilisation system makes you lean right for a bit until they go back to level. Similarly, it can correct for too much leaning right, forwards, or backwards.

Batteries power the gyroscopes and the active stabilisation system, so if they are charged you can turn it on and wait for it to be stable before you get on. A generator powered from the pedals or wheel recharges the batteries. When the batteries have plenty of charge you can also power the drive wheel, otherwise you have to pedal to move.

I'm not sure about turning. There could be handlebar control that turns the wheel against another gyroscope, but if you keep making left turns and there was any friction on the ground resisting turning, eventually the gyroscope precession would build up and the active stabilisation couldn't do much about it except try to get you to turn right instead. Otherwise when you lean the vehicle left or right, the curve of the wheel makes you turn, but it might not be the right amount. Or you could drag your foot on one side to turn.

If you want to be able to lean left and right, e.g. for a turn, you can unlock the normally locked gimbal on gyroscope (A), so that the bike can tilt left and right without tilting the gyro. Similarly you can unlock (B) to lean forward or back for acceleration and braking.

Note you can also shift your weight relative to the vehicle, so you can lean back while braking without the vehicle also needing to lean back.

After you dismount you can leave the gyro stabilisers on while you transport it upright on its wheel, then turn it off once you've finished. It folds down smaller when not in use.

caspian, Oct 25 2018

Unicycle segway Unicycle_20segway
Similar but has less detail about the mechanism and may power the wheel for forward/back balance [caspian, Oct 25 2018]

Ahem....the Honda U3 2009 https://www.youtube...watch?v=RDSqjvBIpWg
[not_morrison_rm, Oct 25 2018]

Gyrostabilized Unicycle Gyrostabilized_20Unicycle
One without gimbals [caspian, Oct 25 2018]

Control moment gyroscope https://en.wikipedi...ol_moment_gyroscope
The name for using a gyroscope to stabilize a vehicle by applying a torque perpendicular to its rotation [notexactly, Nov 07 2018]


       Looking at the U3X ... it's like a Segway but for left and right as well. Nice and portable, but it would be nice to have a pedalling option so you can keep using it if the battery gets low.   

       I like the fold-out seat, that would go well with the gyro-unicycle. Fold the left and right seat halves up out of the circle, then fold *down* from the same circle the two gyroscopes on the left and right.
caspian, Oct 25 2018


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