In this research a method of open-loop control of an anti-sway system by varing slope of ropes, on which an object is hanged, is developed to reduce pendulus motion of the object.
For this, a dynamic model of the system is created and corresponding kinematic and dynamic system equations for analysis are derived. In the modeling, ropes are treated as one-way springs. Then an optimization problem is defined by selecting a quadratic function of horizontal displacement and velocity of the object as the cost function, driving velocity and control time of a screw unit that changes slopes of ropes as design variables, system equations as the state equations, and various operating conditions as design constraints.
An Adjoint Variable technique is utilized for the first order design sensitivity analysis of functions of the optimization problem which optimization is carried out of the Gradiant Projection algorithm.
A program based on the theory is developed and tested with an example of a container crane anti-sway system. Research result shows that modelling, analysis and control technique suggested are valid and the oscillation of the crane is well controlled within the required range.
