Ball in double hoop: demonstration model for numerical optimal control
Provides an educational demonstration model for numerical optimal control and hybrid systems, but the contribution is incremental for control theory researchers.
The paper extends the classic ball-and-hoop system by adding an inner hoop and free-fall mode, creating a hybrid dynamics model. They demonstrate trajectory generation and stabilization for two challenging tasks, with experimental validation.
Ball and hoop system is a well-known model for the education of linear control systems. In this paper, we have a look at this system from another perspective and show that it is also suitable for demonstration of more advanced control techniques. In contrast to the standard use, we describe the dynamics of the system at full length; in addition to the mode where the ball rolls on the (outer) hoop we also consider the mode where the ball drops out of the hoop and enters a free-fall mode. Furthermore, we add another (inner) hoop in the center upon which the ball can land from the free-fall mode. This constitutes another mode of the hybrid description of the system. We present two challenging tasks for this model and show how they can be solved by trajectory generation and stabilization. We also describe how such a model can be built and experimentally verify the validity of our approach solving the proposed tasks.