Anti-Swing Control For Two-Dimensional Overhead Crane System

Overhead crane is a kind of commonly used large-scale handling machinery,which is widely used in docks,warehouses and other places.However,because the overhead crane system is a typical underactuated,strong coupling and nonlinear system,the system has complex internal dynamic characteristics,which brings great challenges to the automatic control of the system.At present,many scholars at home and abroad have made unremitting efforts to promote the theoretical development and practical application in the field of overhead crane automatic control.This paper focuses on the design of automatic anti-swing controller for twodimensional overhead crane system.Based on Lyapunov stability theory and La Salle invariant set principle,anti-swing control with finite rail length constraint,proportional-differential sliding mode control,proportional-differential-integral sliding mode control,proportionaldifferential sliding mode control based on disturbance observer and proportional-differentialintegral sliding mode control based on disturbance observer have been proposed.The research content of this paper includes the following three aspects:(1)Aiming at the anti-swing control problem of two-dimensional overhead crane system with finite rail length constraint,firstly,an anti-swing controller has been designed by using the boundedness of hyperbolic tangent function.Then the range of controller parameters have been given by Lyapunov stability theory.Finally,a simulation experiment has been designed to verify the effectiveness of the anti-swing controller proposed in this paper.The simulation results have showed that under the action of the anti-swing controller proposed in this paper,the twodimensional overhead crane system can achieve the control goal when the control force was small in the starting stage and the whole movement of the trolley did not exceed the maximum length of the rail.(2)Aiming at the problem of anti-swing control of two-dimensional overhead crane system with uncertain disturbance at the trolley end,firstly,based on the sliding mode control theory,a proportional-differential sliding mode controller and a proportional-differential-integral sliding mode controller have been designed respectively,and the value range of the corresponding controller parameters have been given.Then the reachability of the sliding mode surface and the stability of the system with the two controllers have been proved by constructing the Lyapunov function.Finally,the comparative simulation experiment and the confirmatory experiment on the self-made overhead crane experimental platform have been designed.The results have showed that the two kinds of sliding mode controllers designed in this paper both can make the overhead crane system achieve the given control goal.(3)In order to solve the problem that the switching amplitude of the sliding mode controller was too large in the sliding phase,firstly,a disturbance observer without acceleration term has been designed by introducing auxiliary variables,and the range of observer parameters which can make the observation error of the disturbance observer exponentially converge to a certain range have been given by Lyapunov stability theory.Then,based on the proposed disturbance observer,a proportional-differential sliding mode controller based on disturbance observer and a proportional-differential-integral sliding mode controller based on disturbance observer have been designed.Simulation experiments have been designed to verify the improvement of the switching amplitude of the observer-based controller in the sliding phase.The simulation results have showed that both the proportional-differential sliding mode controller based on disturbance observer and the proportional-differential-integral sliding mode controller based on disturbance observer can reduce the switching amplitude of sliding mode controller by more than half.