A Study on the Effects of Unmodelled Rotational Load Swing Dynamics on the Anti-Swing Control of an Overhead Crane

In this paper, the effects of the mass moment of inertia of the load on the anti-swing control of an overhead crane are studied with realistic computer simulations. First, the dynamic equations of motion are derived for a 2-dimensional overhead crane, based on Lagrange’s equations, in which the rotational load swing dynamics is included. Then, based on a coupled sliding surface [4], an anti-swing control scheme is designed without considering the rotational swing dynamics. In this case, the rotational load swing dynamics can be considered as unmodelled dynamics. The conventional anti-swing control scheme with an anti-swing trajectory generator will be simulated on the control of the overhead crane having the unmodelled dynamics. In this simulation, a delay of one-sampling period will be included in the feedback loop as in practical control applications in industry. For high simulation accuracy, the dynamic model of the crane including the rotational load swing dynamics will be solved by using the fourth-order Runge-Kutta formula with an adaptive step size.