How Do Self Balancing Dual Wheels, Segways and Uni-Wheels Work ?
One of the most amazing abilities of many personal electronic vehicles like Segways, dual wheels and uni-wheels is their ability to self balance. But just how do they achieve this?
Well in order to stay upright these rideables use a type of gyroscope. Typically a gyroscope is a rotor held on a spinning axis inside a gimbal connected to a gyroscopic frame. The orientation of this rotor when spinning on its axis will remain unaffected by tilting or rotation of the frame or mounting. Unfortunately this is fairly delicate and involves several moving parts, this is far from ideal for use in a rideable so a modern electrical alternative is used, but the principal remains the same. These are commonly known as a solid state gyroscope, vibrating structure gyroscope or MEMS gyroscope.
This is usually a combination of accelerometers, gyroscopic sensors and magnetometers, which when combined can precisely detect the angle of a device and its pitch or yaw. These are very low power and light weight components but highly reliable and is rather low cost as the gyro is electronic rather than mechanical.
This movement is passed on to a mini computer on board the ridaeble that works as the brain of the vehicle, this will control the two electric motors to apply tiny adjustments to the drive on the wheels to compensate for movement and keep it in balance.
So when the vehicle tilts forwards both motors can be driven forward to bring the center of balance back under the vehicle and prevent it from tipping over. If turning from side to side then one motor can operate at a different speed and even in a different direction from the second motor to pivot the device on the spot.
Because some devices have two wheels and two motors powering them then they can each make minor adjustments to compensate for balance and this is why dual wheel rideables like the Segway and Galactic wheels are easier to ride learn how to ride than the Uni-wheel.