Control strategy for robotic yo-yo

In the paper we address a problem of controlling an oscillating motion with a robot. As the object we have selected a yo-yo. Yo-yo is a toy made of two discs connected with a short thin axle, which can be moved up and down by moving a string tied to the axle. Although it is very easy to play with yo-yo for a human, designing a control system for a robot is quite a challenge. We present a simplified model of a yo-yo, which is intended for control analysis and design. Our model has one degree-of-freedom and the behaviour at the end of the string is modelled as an impact. Next we discuss the control strategy and present a control method, which allows playing the yo-yo at a selected top height.