Dynamic Analysis and Structure Parameter Research on a Hydraulic Anti-Swaying System for Container Cranes

An anti-swaying or swaying-reduction effect for a container crane is key for improving the rapidity and safety of container handling operations. By analyzing the structure of a container crane hydraulic anti-swaying system, a dynamic system model was developed in the time domain, and the changing law of the load swaying angle was studied. In order to study the attenuation effect of the load swaying angle and the different working states of the anti-swaying system, the frequency domain equation of the load swaying angle was developed in the frequency domain. A time domain study on the dynamic model shows that the structure parameter is the key parameter that affects the load anti-swaying effect, and a larger structure parameter produces a better anti-swaying effect. A study regarding the load swaying angle in the frequency domain shows that the container crane hydraulic anti-swaying system works in a critical-damping state when the structure parameter load ratio is equal to twice the system frequency, and in this case, the hydraulic anti-swaying system has good load swaying-reduction effect and a small dependence on changes in the hoisting rope length. The longitudinal and transverse installation distances of the anti-swaying fixed pulleys jointly affect the structure parameter. In engineering applications, the longitudinal and transverse distances can be selected according to size near that of a standard container. To obtain a good swaying-reduction effect, data such as the hoisting load mass, the hoisting rope length, and the hoisting load swaying speed can be obtained in real-time and used to calculate the required pressure adjustments for the relief valve of the hydraulic anti-swaying system.