Research On Anti-swing Control System Of Overhead-Crane Based On Hierarchical Sliding Mode Control

As modern transportation machinery, crane is widely used in modern factories, construction sites, modern warehouse, container yard and other various fields of national product because of the advantages that it is convenient and efficient, time-saving and labor-saving and of small working area. Crane is connected with a load by a flexible rope in the course of work, as the change in the operating status of the hoist; the load will swing back and forth due to the acceleration and deceleration of trolley carts, which will seriously affect the productivity. The load swing brings security risks to the aerial workers. So the research on anti-sway control is of great significance.In this paper, several aspects of the crane anti-sway control system were designed and also designed the controller.Firstly, the operating principle, the nature of work of the bridge crane and the principle of Lagrangian dynamics modeling were analyzed in this paper. Lagrangian dynamics modeling is very suitable for the application in the under-actuated nonlinear systems just as the bridge crane, so the bridge crane was three-dimensional Lagrangian dynamics modeled, and the rules of the bridge crane linearized model was put forward here in the view of the regular pattern of actual operation, then the obtained model was simulated, which aims to provide theoretical support for the crane in actual operation so as to instruct the operation of the crane anti-swing.Secondly, based on the model of the bridge crane after linearized, the traditional control method PID was applied to design the controller. According to the simulation result, the PID is of fairly good control effect on the linearized model, but it needs a longer settling time, besides, it is sensitive to the parameters changing of the crane load system and the swing angle is larger, the ability to reject the disturbance is weak and also in the course of practical work, it is difficult to accurately model because of the existence of nonlinear and the change of the wind, so the PID control is sort of limitations.Finally, aiming at the limitation of the traditional PID control, considering the bridge crane system of nonlinear, time-varying, uncertainty, and strong coupling, the test comes up with combining sliding mode variable structure control method which is simple and good robustness, not sensitive parameters changing, the advantages of easy to implement, this paper puts forward the hierarchical sliding mode control is applied to the underactive crane system, by adopting the idea of layered on displacement and angular to design the sliding mode surface, respectively, and then general sliding mode surface design to the whole system, finally complete the synovial controller design. Use equivalence of narrowing of crane load system simulation with Matlab software for simulation, the simulation results verified the effectiveness of control method.Finally, the research content of this paper was summarized, and the future research direction was prospected.