Research on modeling and time-delay control of rotary tower cranes

A rotary tower crane is a flexible system containing three rigid modes and the motions of the rigid structures induce the spatial pendulum-like motion of payloads. The motions of transferring and slewing affect the amplitude of the sway, while motion of raising or lowering changes the frequency and damping of the flexible mode. To eliminate the sway, we present a control scheme, which control one flexible mode, while another is cancelled by a mechanical structure. And an optimal time delay controller is designed to depress the residual vibration, which minimizes the maximum value of the residual energy. The simulation results verify the validity of the control scheme.