Research On Anti-swing Tracking Control Of Overhead Crane

Overhead crane system is a kind of handling and lifting mechanical system that is widely used in complex environments such as workshops,ports,and construction sites.Traditional overhead cranes use manual operation as the main operation method.This method not only consumes manpower and material resources,but also has disadvantages such as low efficiency and safety problems.Compared with manual operation,the automated bridge crane system has the advantages of transportation efficiency,positioning accuracy and high safety factor,so it is important in the field of automatic control.This subject mainly studies the trolley trajectory tracking and load reduction during the operation of the overhead crane.Overhead crane is a typical under actuated system.In addition,overhead crane also has the characteristics of non-linearity and high coupling.The uncertainties caused by unmodeled dynamics such as friction and air resistance and external disturbances also bring certain difficulties to the system control design.The existing bridge crane control theory methods generally have limitations such as excessive reliance on the system model and poor robustness.Therefore,for the bridge crane system,a highly applicable and robust control that does not depend on the mechanism model is proposed.The method has important theoretical significance and practical value.In this project,a kind of backstepping control design algorithm based on online estimation is studied for the under actuated system of bridge cranes with unmodeled dynamics and uncertain disturbances.The system model is estimated by measuring the input and output states of the crane system online,and get rid of the dependence of the control design on the mechanism model is analyzed,and the Lyapunov function is used to ensure the control stability of the system.Its effectiveness is verified in the two-dimensional bridge crane system simulation and physical experiment.However,for the three-dimensional bridge crane,due to its higher coupling degree and stronger nonlinearity,the existing online estimation inversion algorithm fails to obtain the ideal control effect.To this end,this subject combines the input shaping algorithm with the online estimation backstepping control algorithm to deal with the problems of the increase in the dimensions of the three-dimensional crane and the decrease in control performance caused by the coupling of variables.The main contents of this subject are as follows:1.Design and build a bridge crane experimental platform,and perform dynamic analysis and modeling on this basis.The experimental platform design involves displacement module,winch module and communication module respectively.Perform actuator selection,connection mechanism design and embedded controller design for each module.Based on the crane platform,the vector mechanics analysis method is adopted,and the dynamic analysis and modeling of the Lagrange equation are used to obtain the dynamic model of the bridge crane.2.Study the control problem of overhead cranes including uncertain models.Among them,for the problem of crane model uncertainty,online observation method is used for online model estimation;for load swing angle under-driving problem,an inversion control strategy is used for stability control,and then an online observation inversion control strategy is formed.Compared with other methods,the method in this subject does not require a specific system dynamics model,and does not need to decouple the system.It only uses the real-time measurement data of the system,online model information and inversion algorithms to complete the estimation and control design.The validity of the algorithm is verified through system simulation and physical platform.3.On the basis of the study of two-dimensional bridge cranes,the dynamic modeling of three-dimensional cranes is studied,the algorithm of online estimation backstepping control is designed,and the system simulation verification is carried out.Through research,it is found that the algorithm in this subject has an unsatisfactory effect on the load swing angle of the threedimensional crane.This is the three-dimensional crane has more complex nonlinearity and stronger coupling than the two-dimensional bridge crane,so it is more difficult to ensure the stability of the swing angle.In addition,its complex nonlinear dynamic characteristics will increase the complexity of the designed controller,which will cause the system to be extremely sensitive to parameters.In order to solve these problems,this topic adopts a strategy that combines online estimation backstepping control and input shaping.Use input shaping for offline target path design,and online estimated inversion control for closed-loop control design to make the online estimated inversion control move along the planned path,so as to obtain a good swing angle suppression effect and ensure the real-time stability of the system.This subject adopts online estimation method for the difficult problem of bridge crane modeling.Aiming at the problem that the stability of the underdriving system is difficult to guarantee,the inversion control based on Lyapunov function is adopted.Aiming at the anti-swing problem of three-dimensional bridge cranes,a combined input shaping method is adopted.Through physical platform construction,modeling analysis,algorithm design,controller improvement,system simulation,physical platform experiment and other steps,the feasibility and effectiveness of the algorithm are finally verified.