An electric unicycle (‘EUC,’ sometimes pronounced 'yuke') is a self-balancing personal transporter with a single wheel. The rider controls speed by leaning forwards or backwards, and steers by leaning and twisting the unit side to side with their feet. The self-balancing mechanism uses gyroscopes and accelerometers.
Most commercial units are self-balancing in the direction of travel only (single axis) with lateral stability being provided by the rider; more complex fully self-balancing dual-axis devices also need to self-balance from side to side. The control mechanisms of both use control moment gyroscopes, reaction wheels and/or auxiliary pendulums and can be considered to be inverted pendulum.
- See also Monowheel
A hand-power monowheel was patented in 1869 by Richard C. Hemming with a pedal-power unit patented in 1885. Various motorized monowheels were developed and demonstrated during the 1930s without commercial success and Charles F Taylor was granted a patent for a "vehicle having a single supporting and driving wheel" in 1964 after some 25 years of experimentation.
In 2003, Bombardier announced a conceptual design for such a device used as a sport vehicle, the Embrio. In September 2004 Trevor Blackwell demonstrated a functional self-balancing unicycle, using the control-mechanism similar to that used by the Segway PT and published the designs as the Eunicycle. In 2008 RYNO Motors demonstrated their prototype unit. In January 2009 Focus Designs demonstrates electric unicycle to Segway inventor. In March 2010 Shane Chen of Inventist filed a patent application for a seatless electric unicycle (associated with the "Solowheel" product launched in February 2011). In Oct 2010 Focus Designs published a video of an electric unicycle with hub motor and a seat. Late in 2015, the Ford Motor Company patented a "self-propelled unicycle engagable with vehicle", intended for last-mile commuters.
By the turn of the decade, several Chinese manufacturers dominate the market and continue to release EUC models with higher top speeds (above 65 km/h or 40 mph), longer range batteries, and new features like suspension.
- A self-balancing unicycle was described in 1969 in The Man From R.O.B.O.T., a short story by science fiction author Harry Harrison.
- Ballbot, a mobile robot designed to balance on a single spherical wheel
- Honda U3-X, which looks like a self-balancing unicycle, but balances on a powered Omni wheel
- Inertia wheel pendulum
- Onewheel, a sort of electric skateboard
- RIOT wheel, a ridable single-axis self-balancing unicycle with an unusually low centre of gravity, with its rider in front of, rather than on top of its single wheel
- Uno, a sort of dicycle
- Improvement in velocipede, 1869
- US Patent 325,548
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- Research papers (in reverse date order)
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- Ben S. Cazzolato, David Keith Caldecott, Andrew John Edwards, Matthew Anthony Haynes, Miroslav Jerbic, Andrew Christopher Kadis and Rhys James J. Madigan Micycle - A Self-Balancing Unicycle, University of Adelaide, 2010
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- A. Schoonwinkel, Design and test of a computer stabilized unicycle Ph.D. dissertation, Stanford University, California, 1987
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- Flexible two-wheeled self-balancing mobile robot, 9th IFAC Symposium on Robot Control (2009)