Research On Partial Feedback Linearization Control Of Overhead Crane Systems

In recent years,overhead cranes,as a cargo transportation tool,are widely utilized in many industrial sites such as workshops,warehouses,and shipyards.Moreover,as a typical nonlinear underactuated system,overhear cranes possess fewer control inputs than degrees of freedom,which initiates challenges in control design.Therefore,controlling overhead cranes is of both practical and theoretical importance due to their underactuated characteristics.As a consequence,control of overhead cranes has attracted much attention of many researchers from the control community and has become a hot research topic in the control community.The basic tasks of overhead crane systems include driving a cargo from the initial point to the desired point,suppressing and eliminating the cargo swing during the transportation process.With the rapid developments of communication,computer and control techniques,extensive research has been done on overhead cranes and some of existing methods have been used to control the practical overhead crane systems.However,there exist some problems and drawbacks for the existing methods.To this end,some insightful studies are carried out for the anti-swing and positioning control of overhead cranes in this dissertation.The main work of this dissertation is summarized as follows:1.Anti-swing and positioning control of two-dimensional(2-D)overhead crane systems.To improve the anti-swing control performance of the closed-loop system,an enhanced damping control method is proposed in this thesis.First,a damping signal is introduced on the basis of a swing-related energy function.Subsequently,a Lyapunov function is constructed and a corresponding nonlinear anti-swing control method is proposed straightforwardly.The equilibrium point of the overall closed-loop system is proven to be asymptotically stable by Lyapunov techniques and La Salle's invariance principle.Finally,some experimental results are provided to demonstrate the feasibility and effectiveness of the proposed method.In addition,to illustrate the superior control performance of the proposed method,a comparison study between the designed control method and the existing control methods is provided as well.2.Segmented analysis based controller design for overhead cranes.To achieve both precise trolley positioning and sufficient payload swing elimination,a new Lyapunov function is introduced in a segmented manner and a nonlinear control law is proposed in this thesis.The stability of the closed-loop system is proven through rigorous theoretical analysis.At last,the control performance of the proposed approach is verified by simulation and experimental tests.3.Trajectory tracking control of 3-D overhead crane systems.To increase the flexibility of overhead crane systems,an improved anti-swing tracking controller is developed in this thesis,which can be applied to both trajectory tracking control and regulation control.The crane system is transformed into an interconnected form consisting of two subsystems,based on which a novel trajectory tracking control law is designed.Both subsystems and the interconnected system are proven to be input-to-state-stable(ISS)by rigorous theoretical analysis,and the equilibrium point of the resulting closed-loop system is proven to be asymptotically stable.Finally,the trajectory tracking control and regulation control performance of the presented method is examined via extensive experimental tests.4.Regulation control of 3-D overhead crane systems.To increase the transportation efficiency and ensure the safety of the crane system,based on the energy shaping methodology,a regulation controller with superior control performance is devised in this thesis.First,an appropriate energy function is constructed by solving partial differential equations,and then a regulation controller is obtained straightforwardly.Subsequently,the stability analysis of the closed-loop system is provided using Lyapunov method and La Salle's invariance principle.Finally,detailed simulation and experimental results are given to illustrate the practical control performance of the presented control strategy.