Resonance-Based Tossing Control for Bulk Materials Transportation of an Overhead Crane

Transportation of bulk materials using an overhead crane system possesses a special property, that is, the transferred materials can be dropped/discharged while in the air. In order to exploit such a unique feature, this article introduces a new concept, named tossing control methodology, to enhance transportation productivity. A specific type of tossing controller is proposed, which relies on the phenomenon of linear resonance to induce oscillation in periodically increasing amplitude. A novel resonance-based tossing controller-comprising an optimal linearization law and a resonance evoking component-is formulated. It will be shown that, under similar requirements of bulk materials transportation, conditions, and actuator constraints, the resonance-based tossing control can reduce the transferring time up to 26.5% compared with the well-known minimum-time vibration controller-the fastest member of the vibration control group. The results show that, although it is not always able to obtain a faster transportation using the resonance tossing controller, evidence for breaking the time limitation of the minimum-time vibration control is provided. Both simulation and experimental results are presented to verify the effectiveness of the proposed resonance tossing control method, and possible future developments are discussed.