An Anti-Swing Closed-Loop Control Strategy for Overhead Cranes

Xianghua Ma,Hanqiu Bao

doi:10.3390/app8091463

Abstract

The payload swing of an overhead crane needs to be controlled properly to improve efficiency and avoid accidents. However, the swing angle is usually very difficult to control to zero degrees or for it to even remain within an acceptable range because the overhead crane is a complex nonlinear underactuated system, especially when the actual working environment is accompanied by strong disturbances and great uncertainty. To resolve this, a real-time anti-swing closed-loop control strategy is proposed that considers external disturbances. The swing angle is measured in time and it functions with the load displacement as feedback inputs of the closed-loop system. The nonlinear model of the crane is simplified by a linear system with virtual disturbances, which are estimated by the equivalent input disturbance (EID) method. Both simulation and experimental results for a 2-D overhead crane system are investigated to illustrate the validity of the proposed method.

Highlights

Overhead cranes play an important role as one of the tools of heavy cargo transportation in seaports, steel plants, and other workplaces [1]
As a typical underactuated system, an overhead crane is affected by various external disturbances so that the load is frequently swinging in the process of transportation, which seriously affects the positioning accuracy of the load and brings many unsafe possibilities while at the same time of reducing the efficiency of the system [2,3]
Most of the above methods are based on some harsh assumptions, for example, the disturbances such as wind resistance and stochastic collision frequently occur. These initial payload swing angle should be zero, the accurate real-time angle of the payload swing can be above methods are weak in disturbance suppression and poor for real because they known a priori, or velocity sensor measurements can be taken without noise.applications

Summary

Introduction

Overhead cranes play an important role as one of the tools of heavy cargo transportation in seaports, steel plants, and other workplaces [1]. Most of the above methods are based on some harsh assumptions, for example, the disturbances such as wind resistance and stochastic collision frequently occur These initial payload swing angle should be zero, the accurate real-time angle of the payload swing can be above methods are weak in disturbance suppression and poor for real because they known a priori, or velocity sensor measurements can be taken without noise.applications. UnacceptableA range in actual working some external disturbances such as wind resistance and stochastic collision frequently occur These above angle measurement values of the payload swing is the most effective way to tackle the anti-swing are weak in disturbance suppression and poor for real applications because they belong problem.methods. Closed-loop control strategy isusually proposed this paper This their control system has two Further, overhead cranes are linearlyin modeled, which ignores nonlinear characteristics andfeedback quantities ofcannot trolley movinga crane’s displacement and swing angle, which are bothclosed-loop measured in real time.

Mathematical Model

Result simulation

Result

The experimental experimental used tothree

Conclusion