Load vibration reduction in rotary cranes using robust two-degree-of-freedom control approach

Huimin Ouyang,Xin Deng,Deming Wang,Guangming Zhang,Lei Mei

doi:10.1177/1687814016641819

Abstract

In the control of the rotary crane, it is important to consider the trade-off between the boom positioning characteristics and the sway of the load. However, it seems difficult to obtain good control performance in both of them using 1-degree-of-freedom control approach. Therefore, a robust 2-degree-of-freedom control approach is proposed in this article. First, a linear dynamic model of a rotary crane is derived using a disturbance observer. Next, a state feedback controller with integrator is designed based on the model, and controller gains are determined by using linear matrix inequality optimization for achieving robustness with respect to rope length variance. Then, a feedforward controller is designed by solving an optimal regulator problem based on the model of closed-loop system for improving the boom positioning characteristics of the crane. Finally, the experimental results confirm the effectiveness of the proposed method. Hence, the crane can be easily operated without sensor systems for measuring rope length, and consequently, the structure of the crane can be simplified and implementation cost can be reduced.

Highlights

Because crane systems use fewer actuators and have a simpler structure than industrial robots, they are widely used to transport heavy loads and hazardous material in industrial locations, such as shipyards, factories, nuclear installations, railway yards, and high-rise construction sites
The main purpose of this study is to propose a controller for moving the load from point to point as well as suppressing load vibration from the viewpoint of reducing the burden on human operators and increasing their safety
The reason of selecting this model for feedforward controller design is that it is at the center between the ones under condition l = 0:25 m and l = 0:75 m, and if the general results could be obtained for each rope length using this model, the whole design time including the time for modifying the original reference could be cut down

Summary

Introduction

Because crane systems use fewer actuators and have a simpler structure than industrial robots, they are widely used to transport heavy loads and hazardous material in industrial locations, such as shipyards, factories, nuclear installations, railway yards, and high-rise construction sites. From their structures, shapes, and purposes, cranes can be classified into two major types: overhead cranes and rotary cranes.[1]. Load vibration suppression control for rotary cranes is an essential issue. The main purpose of this study is to propose a controller for moving the load from point to point as well as suppressing load vibration from the viewpoint of reducing the burden on human operators and increasing their safety

Objectives

Results

Conclusion