SINGLE WHEEL (Ball) Robots
One wheeled robots are extremely difficult to keep balanced due to the single point of contact with the ground.
Multi-wheel statically-stable mobile robots tall enough to interact meaningfully with people must have low centers of gravity, wide bases of support, and low accelerations to avoid tipping over. These conditions resent a number of performance limitations.
Accordingly, we are developing an inverse of this type of mobile robot that is the height, width, and weight of a person, having a high center of gravity, that balances dynamically on a single spherical wheel. Unlike balancing 2-wheel platforms which must turn before driving in some direction, the single-wheel robot can move directly in any direction. We present the overall design, actuator mechanism based on an inverse mouse-ball drive, control system, and initial results including dynamic balancing, station keeping, and point-to-point motion.
A signiﬁcant, but frequently overlooked problem is that statically-stable one wheeled mobile robots can easily become dynamically unstable.
-If the center of gravity is too high,
-or the robot accelerates/decelerates too rapidly,
-or is on a sloping surface,
-the machine can tip over.
A robot must be tall enough to be able to interact with people and the human environment at a reasonable height. On the other hand, it must be skinny enough to easily make its way around without bumping into things or getting into peoples’ way.
See All Types Of Robots - By Locomotion