| As an important equipment for short-distance transportation of goods,bridge cranes are widely used in automatic terminals,digitization plants,warehousing and logistics and other fields.As a kind of typical underactuated system with nonlinear and strong coupling,the bridge crane is easy to be disturbed by external factors to produce load swing during operation,which will affect the positioning accuracy and work efficiency of the bridge crane.The anti swing and positioning strategy of crane,as the key technology to realize the accurate positioning and fast anti swing of bridge crane,has become a study hot-spot in the control field of bridge crane.In this paper,a three-dimensional dynamic model of bridge crane is established by using Lagrange dynamic equation,and the three-dimensional dynamic model is decoupled into a two-dimensional dynamic model.Taking the two-dimensional model as the research object,a segmented control method for anti swing positioning of bridge crane based on energy coupling is designed.Firstly,the energy storage function related to the speed and swing angle is constructed in the anti swing stage to realize the anti swing function of the bridge crane,and the energy storage function related to the target position is constructed in the positioning stage to realize the positioning function of the bridge crane.Then the weighted sum of the energy storage function is taken as the Lyapunov function of the system,and an anti swing positioning control strategy is proposed.Simulation results show that this method can achieve accurate positioning of the trolley.Compared with PID control,load generalized regulation control and enhanced coupling control,this method is superior to other control methods in restraining load swing.In order to verify the effectiveness of this method in practical application,the anti swing positioning control system of bridge crane is designed based on the actual platform of bridge crane.The system includes hardware circuit and software control algorithm.The hardware circuit is mainly composed of data acquisition sensor,PLC as the control core and output mechanism frequency converter.The software control algorithm first draws its program flow chart according to the anti swing positioning working principle of the bridge crane,then compiles the anti swing positioning control program and direction judgment program according to the program flow chart,and finally downloads the program to the control core PLC to execute the control algorithm and provide control output to complete the anti swing positioning control of the bridge crane.During the normal operation of the anti swing positioning control program of the bridge crane,the monitoring interface is designed to observe the operation effect of the anti swing positioning control algorithm implemented by the bridge crane.From the control results,the designed anti swing positioning control method can effectively eliminate the load swing,realize the accurate positioning function of the trolley,show a good actual control effect,and provide a reference for the practical application of the project. |
