Optimal Control of the Crane System Using the Maximum Speed of the Trolley

Abstract

In the control of a crane system (for example, an ore unloader), the following requirements must, be satisfied.(1) The traversing time of the trolley must be reduced as much as possible.(2) The swing of the grab must be stopped at the end point.For these requirements, we divide the traversing interval into three parts, that is, the accelerating interval, the interval of constant speed and the decelerating interval.In the interval of constant speed, the trolley runs at the maximum speed under a condition that the grab has no swing, and in the other intervals, the traversing time is minimized by the minimum principle.Assuming that the rope length is constant, we show a table by which an optimal switching time can be achieved. The utility of the proposed scheme is demonstrated by using a model of the crane system.Alsop et al. proposed a similar control scheme, but the traversing time was not optimized.