Input shaping techniques for anti-sway control of a 3-D gantry crane system

This paper presents investigations into the development of feedforward control schemes for anti-swaying control of a gantry crane system. A nonlinear 3-D gantry crane system is considered and the dynamic model of the system is derived using the Euler-Lagrange formulation. An unshaped bang-bang force input is used to determine the characteristic parameters of the system for design and evaluation of the input shaping control techniques. The positive zero-sway-derivative-derivative (ZSDD) and new modified specified negative amplitude zero-sway-derivative-derivative (SNA-ZSDD) input shapers are then designed based on the properties of the system for anti-sway control. Simulation results of the response of the gantry crane system to the shaped inputs are presented in time and frequency domains. Performances of the shapers are examined in terms of swing angle reduction and time response specifications. Finally, a comparative assessment of the proposed control techniques is presented and discussed.