Bridge inspection platform

Bridge Inspection Platform:

A Lightweight Bridge Inspection System Using Dual-Cable Suspension Mechanism

雙索懸吊式輕量橋樑檢測系統

Bridge Inspection Platform:

A Lightweight Bridge Inspection System Using Dual-Cable Suspension Mechanism

雙索懸吊式輕量橋樑檢測系統

Related references

1. Yi Chu Chen, Chi EnYang and Shih Chung Kang, “A Lightweight Bridge Inspection System Using A Dual-Cable Suspension Mechanism,” Australasian Conference on Innovative Technologies in Construction From Building Information Modeling to Beyond, Wuhan, China, December 6-7, 2012.

2. Y. C. Chen, S. C. Kang and C. E. Yang, "A Lightweight Imaged Based Bridge Inspection System Using Fishing Pole, Fishing Line and Fisheye Camera," Proceedings of 28th International Symposium on Automation and Robotics in Construction (ISARC), Seoul, Korea, June 29-July 2, 2011.

Related Awards

1. 2012(第十六屆)營建工程與管理學術研討會暨營建業聯合徵才博覽會, A Prototype of Lightweight Bridge Inspection System, 最佳論文獎-首獎, 2012.

2. 曾冠霖、楊基恩、陳奕竹, 參加「財團法人中技社100年度科技獎學金」評選, 獲得「科技創 意組團體組獎學金」, 2011.

Bridge Inspection Platform 雙索懸吊式輕量橋樑檢測系統 現行橋梁檢測主要以「視覺檢測」為主，然而當橋梁檢測員進行目視檢測時，檢測員所處的工作環境較為危險，為了增 加檢測員之安全，已有許多橋梁檢測研究發展橋梁檢測車及檢測用機器手臂，但是此種大型設備需要的工作範圍較大， 因此只適用於較大型的橋梁。基於上述原因，本研究發展出一種新型的橋梁檢測系統，本系統具有幾種特性：易攜帶、 簡易、便宜、適用於為數眾多的小型橋梁。本橋梁檢測系統主要包含「雙索懸吊式輕量橋樑檢測機構」以及「橋梁檢測 策略」，而檢測機構又細分為：控制端、雙索懸吊機構、檢測平臺，其中檢測平臺配備數位相機，橋梁檢測員可藉由操 作雙索懸吊機構，將檢測平臺降至橋面板下方以取得檢測影像。相較於大型檢測設備或機器手臂，雙索懸吊機構具有自 重輕以及高承重之特性，因此本研究所發展之檢測機構自重及硬體成本皆可大幅減低。除了橋梁檢測機構之外，本研究 所提出之橋梁檢測策略具有幾種特性：完整、有效率、靈活。檢測策略又細分為「垂直檢測策略」與「水平檢測策略」 ，而水平檢測策略包含適用於一般橋梁結構的「序列式檢測法」以及複雜結構的「多視角檢測法」。本研究完成了橋梁 檢測系統的原型，並以臺北市附近的兩座混凝土橋進行現地實驗，實驗結果發現本檢測系統不會影響車流，而每分鐘檢 測橋梁長度可達八公尺，檢測所得影像的解析度可達公分等級，可清楚辨識出一般橋梁缺陷，例如：裂縫、混凝土剝落 。本研究所提出的檢測系統及檢測概念預期可增加檢測檢測之效率。

System Architecture:

(a) System Overview

The system can be divided into three major parts: the controller, the dual-cable suspension and the inspection platform. The dual-cable mechanism includes a primary cable and a secondary cable. The primary cable is close to the inspector, and connects to the front end of the inspection platform, where the digital camera is mounted.

(b) Controller

(c) Inspection Platform

A Lightweight Bridge Inspection System Using Dual-Cable Suspension Mechanism

Visual inspection is currently the major approach to evaluate the structural condition of a bridge. Since visual inspection requires engineers locating themselves in risky environments, many researchers developed inspection vehicles and robot arms to increase the safety and reachability of inspections. However, such heavy equipment is highly restricted in working space and may only suit for large bridges. Therefore, this research aims at developing an innovative bridge inspection system that is portable, simple, affordable, and can be easily applied on smaller yet large number bridges. We developed a systematic approach, which includes a lightweight inspection system using dual-cable suspension mechanism, and inspection strategies to conduct inspections. The inspection system composes of three parts: the controller, the dual-cable suspension, and the inspection platform. By using the dual-cable suspension mechanism, the bridge inspector can manipulate the controller to stretch the inspection platform beneath the bridge and capture images with digital vision devices. Unlike robot arms or heavy vehicles, the cable-based system can sustain much more weight than its own weight. This means the total weight is greatly reduced and the cost can be lowered than existing methods. On the other hand, the inspection strategies developed in this research can provide complete, efficient and flexible inspection procedure. Vertical and horizontal inspection strategies were developed to manipulate the inspection system, including sequential inspection for normal structures, and multi-view inspection for special structures. We made a prototype of the inspection system and conducted field experiments to test the feasibility of the proposed method.

Inspection Strategy:

To accurately control the dual-cable suspension mechanism, math models were developed. They can be categorized into vertical and horizontal strategies. Vertical strategy is a mathematical model was developed for obtaining theoretical values of camera elevation and pitch angle when desired inspection range is given. Horizontal inspection strategy includes two strategies: sequential inspection for normal structure and multi-view inspection for complicated structure.

(a) Vertical Strategy

(b) Horizontal Strategy

Zebra Field Experiments:

We have conducted ďŹ eld experiments on two dierent bridges, in order to verify the feasibility of the proposed system.

(a) inspector measuring the width of the bridge (c) inspection in progress (b) deployment situation (d) overview of inspection process

Inspection Result: (a) inspection image of bridge deck bottom. The structure and the pipeline are both very clear, and no defect was found. (b) inspection image of the cap beam-column connection. The column has one steel bar exposed in the air and there is a small damage on the cap beam surface. (c) original size of (b). The high resolution image provides clear details of the inspection area.

Shih-Chung Jessy Kang sckang@ntu.edu.tw sckang.caece.net