Pouring and Sloshing Suppression Control of Cylindrical Ladle in Self-Transfer-Type Automatic Pouring Robot with Complex Motion of Pouring and Transfer

Abstract

This paper is concerned with development of self-transfer-type automatic pouring robot using a cylindrical ladle. Especially, the paper focuses on the pouring control of the cylindrical ladle and sloshing suppression during ladle transfer and tilting. In order to realize fast pouring, the robot's pouring system was constructed by a feed-forward controller with a system inverse to the pouring process. In order to suppress the sloshing of the liquid in the ladle, the natural frequency of the sloshing caused by the transferring and pouring motion was identified by short-term Fourier transform. The feedback controllers in the control system were then designed by the Hybrid Shape Approach using notch filters corresponding to the identified natural frequency of sloshing. The proposed pouring and sloshing suppression controls were applied to an automatic pouring robot that had both automatic detection of the mold's status filled or unfilled with liquid and tracking control to the mold. The effectiveness of the developed control system was shown through experiments.