The Cubli: Modeling and Nonlinear Attitude Control Utilizing Quaternions

Описание: This video presents the nonlinear attitude control of the Cubli, a cube with three reaction wheels mounted on orthogonal faces that becomes a reaction-wheel based 3D inverted pendulum when positioned in one of its vertices.

The proposed approach utilizes quaternions instead of Euler angles as feedback control states. A nice advantage of quaternions, besides the usual arguments to avoid singularities and trigonometric functions, is that it allows working out quite complex dynamic equations completely by hand utilizing vector notation.

The derived nonlinear control law is based on Feedback Linearization technique, thus being time-invariant and equivalent to a linear one dynamically linearized at the given reference. Moreover, it is characterized by only three straightforward tuning parameters.

Paper: https://ieeexplore.ieee.org/document/...
PhD Thesis: https://www.teses.usp.br/teses/dispon...
Source code: https://github.com/fbobrow/cubli-firm...

0:00 - Intro
0:04 - Context
0:22 - Technical specifications
0:52 - 2D stabilization control
1:05 - 3D stabilization control
1:14 - 3D trajectory control
1:26 - 3D linear/non-linear comparison
1:35 - 3D disturbance rejection
1:54 - End