Open-loop trajectory planning and nonlinear control for underactuated spherical wheel mobile robot (Ballbot)

This paper investigates three-dimensional dynamic model of underactuated spherical wheel mobile robot (Ballbot) in the presence of input coupling and friction. The way of how such a robot moves is considered and an approach is proposed for accurate trajectory generation for linear and circular paths. Due to the high reliability of the approach, no position feedback is used and it is simulated open-loop. A collocated partial feedback linearization is introduced for Ballbot that ensures body angles trajectory tracking. The open-loop trajectory generation with collocated partial feedback linearization is simulated which shows a very low position error.