| Modern industry develops rapidly.In the process of industrial production and operation,engineering machinery and equipment,as an essential material handling equipment,is also constantly innovating,surpassing breakthroughs and creating updated records,especially in the field of crane,the subsector of underdrive system.Many events show that our industry must unswervingly follow the path of independent research and development,understand the core technology of control system,so as to develop for a long time.Reform and opening up so far,our country "industry mode" has realized the leap-forward development,with the rapid growth of total industry,a large number of new technology and capital influx,has promoted the domestic improvement and development of various models of cranes.In this paper,the bridge crane is characterized by high underdrive degree,poor robustness,high control difficulty,and the existing simple control model,resulting in insufficient control accuracy,efficiency and pendulum effect.Considering the factors of rope length variation in the process of dropping,the analytical model of double-pendulum bridge crane beam is established,and the corresponding controller is designed according to the tracking control strategy.Thus,the control problem of crane system is deeply explored.The main research contents of this paper are as follows:(1)Firstly,the Lagrange equation method is used to establish a simple pendulum model,analyze and compare the single-stage system with different rope lengths,and discuss the influence of rope lengths on the system control effect.At the same time,the influence of different reference trajectories on load swing is explored,which provides reference for the selection of the reference trajectories of the subsequent bounded tracking controller.(2)Secondly,Lagrange equation method was used to establish a fixed rope length double pendulum model,and MATLAB Simulink software package was used for modeling and simulation of the mathematical model,and the feasibility of the model was analyzed.PD control strategy was selected to carry out PD control on the double pendulum model,and the effectiveness of PD control was verified by simulation.(3)Then,Lagrange equation method is used to establish a more accurate double-pendulum model with variable rope length,and some small quantities of high order are linearized in the accurate model.Based on this,the tracking control strategy is adopted to design the controller,which intends to adjust the horizontal movement of the trolley and the swing of the load in real time by changing the input signal of the driving motor,so that the track and the reference track in the actual running process can be kept in the preset range.The mathematical proof of the design process is given.(4)Finally,based on the double pendulum model with variable rope length and the corresponding controller,the system is simulated and analyzed by Simulink using the reference trajectory proposed above,and the control effect of the controller under different load conditions is discussed.Compared with other control methods,the double pendulum theory model with variable rope length proposed in this paper is closer to the working condition of the double bridge crane beam in engineering practice,and the designed controller has a good effect of eliminating the pendulum,and the control accuracy can be guaranteed to a certain extent.It is intended to provide some theoretical guidance for the accurate positioning,fast dropping and efficient anti-pendulum of this kind of system. |
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