Active Way of Clearing of Fluctuations of Freight after a Stop of the Bridge Crane

Abstract

Necessary condition of increase of productivity of cranes of bridge type is reduction of residual pendular fluctuations of freight on a flexible rope suspension after its moving to а target final position. For clearing of residual fluctuations of freight it is offered to use the hydraulic drive. Improvement of a design is executed by means of two hydraulic cylinders located perpendicularly in the horizontal plane. The problem of clearing of residual fluctuations of freight on a flexible rope suspension in one of the vertical planes of three-dimensional space after a full stop of the bridge was formulated (or as version of the main cargo cart) the bridge crane. Spatial fluctuations of freight at small corners of deviations of a cargo rope from a gravitational vertical can be presented as superposition of fluctuations in two mutually perpendicular vertical planes. Therefore the developed active way of clearing can be applied also to spatial residual fluctuations of small amplitude. The active way of clearing of residual fluctuations of freight consists in synthesis by means of imitating model of the bridge crane with proportional-integral-differential the regulator of function of acceleration of movement of a point of a suspension along a horizontal axis. On the movement of a point of a suspension, i.e. hydraulic cylinder rod with the specified weight, restrictions in the form of characteristics of a hydraulic actuator are imposed: the maximum acceleration developed by a rod, the maximum gathered speed, and the maximum course of a rod. The hydraulic cylinder is influenced by the axial force of resistance. According to the offered scheme of communications, with use of blocks of a package of mathematical modeling of the mechanical SimMechanics Second Generation MATLAB systems, the model of mechanical system of the bridge crane with proportional-integral-differential regulation, allowing to study various modes of clearing of residual fluctuations of freight at a design stage of the bridge crane was developed. The developed way allows to provide reduction of time of residual pendular fluctuations of freight. As a result crane productivity increases.