ITERATIVE METHOD FOR CONTROLLING THE SWAY OF A PAYLOAD ON TOWER (SLEWING) CRANES USING A COMMAND PROFILE APPROACH

摘要

This work describes a nouel method able to reduce the sway of a suspendedload during the slewing motion of a tower (or jib) crane. The proposed method is based onan iterative calculation of the sway angle and of the corresponding applied velocity proas input to the crane motors. The"command smoothing method is used for reducingthe sway, that is an additional damping is introduced into the system in order to controlthe sway, obtaining the values of the coefficients k with the observer method. A detailmathematical model is developed, taking account of also the non-linear components ojthe forces, as centrifugal and Coriolis forces, on the system. Simulation results showthat the proposed anti-suay method is able to damp the oscillations of the suspended Loadduring the contemporary movement along the three perpendicular Cartesian aaes, that isthe tuo horizontal ares (said trolley and slewing axes)and the third vertical aais (saidalso hoisting axis). Furthermore, as a consequence of being an iterative method,possible to obtain a complete damping of the sway at the end of the movement, alsothe velocity set is changed many times by the human operator, during the control of thecrane movement: that is possible even if the previous damping of the oscillations uasaaain in progress and not completely finished.