Research On The Control Strategy Of Cargo Swing Of Bridge Crane Based On Input Shapin

Bridge cranes are widely used lifting equipment in heavy industries due to their stable structure,flexible mobility,and minimal floor space requirements.However,during the transportation of cargo,the constant acceleration and deceleration of the trolley can cause the suspended cargo to swing.Failure to control this swinging can result in reduced transportation efficiency and even pose safety hazards.Therefore,controlling cargo swing in bridge cranes has become one of the technical problems of current research.This thesis focuses on the swinging problem of cargo during the operation of bridge cranes.Through dynamic model analysis of the swinging motion,a swinging control strategy based on input shaping is proposed,and the designed control strategy is simulated and verified using MATLAB/Simulink simulation software.The main research contents are as follows:(1)Based on the Lagrange dynamics equation,this thesis establishes a mathematical model of single-pendulum and double-pendulum bridge cranes.The impact of changes in wire rope length and the length of rope between cargo and hook on the stability of the crane system,as well as the frequency,period,and swinging angle of the cargo are analyzed.In addition,three common input shaping controllers are introduced,and input shaping strategies are designed for the control objectives of bridge crane cargo swinging control.The effectiveness of the input shaping control strategy in controlling the swinging of cargo for single-pendulum and doublependulum bridge cranes is verified through the use of MATLAB/Simulink simulation software.(2)For the single-swing bridge crane swing problem,a PD combined with input shaping control strategy is designed.Additionally,an adaptive control method is introduced to the traditional PD control strategy to improve the robustness and stability of the control system,and to achieve better swinging control effect.Compared with using PD feedback control alone or no control,adding input shaping to the PD feedback control strategy can significantly reduce the swinging angle of the effective cargo,the maximum reduction of swing angle reaches 37.8%.After adding the adaptive element,the bridge crane system’s ability to adapt to changes in rope length is further enhanced,and the maximum reduction range of the swinging angle reaches60.9%.Moreover,when input shaping is added to the control strategy,the swinging angle of the cargo reaches a stable state faster.(3)For the double-swing bridge crane swing problem,based on the swing control strategy of the single-pendulum bridge crane,two input shaping strategies,cascade input shaping and PD combined with input shaping,are designed for the double-pendulum bridge crane.Traditional input shaping controllers are only applicable to single-mode second-order oscillation systems and cannot meet the requirements of multi-mode oscillation of the bridge crane.The cascade method can suppress the swing of the hook and load of the double-pendulum bridge crane,but it is easily affected by external disturbances.Therefore,PD feedback controller is added to improve the stability and robustness of the control system.Simulation results show that the PD combined with input shaping strategy has certain robustness and stability,and can effectively suppress the swing of the load when the length of the wire rope and the rope length between the hook and the cargo change.(4)Based on the study of swing control of cargo,the control force acting on the bridge crane was analyzed.When the bridge crane is running in empty travel,the PD combined with input shaping control can significantly reduce the overshoot of the displacement curve of the trolley mechanism and has a faster adjustment time.Compared to PD feedback control system,the PD combined with input shaping control consumes less control energy at the same proportional gain.Under PD feedback control,the larger the proportional gain,the greater the overshoot and control force produced.However,The PD combined with input shaping control strategy is able to reduce overshoot and control force,thus allowing larger proportional gains compared to PD feedback control and thereby improving the transportation efficiency and positioning accuracy of the bridge crane.When the bridge crane is transporting cargo,the control force acting on the bridge crane gradually increases with the increase of cargo mass.After adding input shaping on the basis of PD feedback control,the control force acting on the bridge crane is significantly reduced,and the reduction is relatively large.This indicates that input shaping has a good effect on reducing the control force of the bridge crane.