Dynamics and control of multiple cranes with a connected payload

Cranes are used throughout the world to move large, heavy objects. When objects reach a size that cannot be moved by a single crane, multiple cranes are employed in a cooperative manner. For example, aerospace manufacturing companies will use multiple cranes to move plane fuselages or wings. For both single and multi-crane lifts, payload oscillation is a limiting factor for speed of operation, safety, and positioning accuracy. This paper will introduce a planar multi-crane model and identify key influences on natural frequency and payload oscillation. In addition, an input-shaping control algorithm to limit oscillation of the connected payload in multi-crane lifts is proposed. The key contributions are experimentally verified using a multi-crane system.