Predictive control of crane system with algorithm for sway reduction
Abstract
Transport in the modern globalized world is one of the important factors that significantly affects the functioning and development of industry. The introduction of shipping containers in transport reduced the waiting time of ships in the port, and the modernization of port terminals paved the way for automation and the application of industrial computers in loading and unloading cargo. Crane systems are very flexible, due to the poorly damped poles introduced by the cargo. The flexibility of the cargo introduces the sensitivity of the system to external influences such as wind. The consequence of poorly damped poles is oscillation, which occurs during cargo transfer. Cargo oscillation negatively affects the speed of cargo transfer and safety in the vicinity of the crane. This paper presents a predictive controller, which ensures rapid transfer of cargo to the target location while preventing cargo oscillation. An appropriate mathematical model of the crane is proposed, which takes into account the dynamics of changes in the height of the cargo. A cargo with a fixed and variable center of mass is considered. A cargo with a variable center of mass introduces additional oscillations in the crane system, which can lead to instability of the control system. The proposed predictive controller was tested and compared with a classical crane control system through simulation and experimental tests on a laboratory model.
