Study Of Bridge Crack Dynamic Change Based On Digital Image Detection Technology

Bridge is one of the important facilities of transportation.It plays a more and moreimportant role in increasingly heavy transportation task.Based on its role of a link, thetransportation department will conduct regular detection and maintenance to the bridges inservice. As its pervasiveness and serious harm, bridge crack becames the focus of the bridgesafety detection.The visual observation and single photo of bridge cracks can only reflect thestatic condition of the damage, cannot reflect its dynamic variation. To obtain the tendency ofbridge crack’s dynamic variation and then make predictions for bridge safety condition ismuch more realistic.Through the analysis of the present situation on bridge crack detection technology athome and abroad, the paper spreads the study on detection of dynamic changes according tothe characteristics of the bridge crack. The full text is based on digital image processingtechnology, conducted study on dynamic change of bridge crack with the aid of imageacquisition and transmission equipment.Through the change of crack width and growth trendof cusp in load case to reflect the bridge safety condition. The paper mainly includes fouraspects as following:1Through the discussion of camera, lens, lighting system, transmission mode,buildhardware platform of the bridge crack acquisition system in optimal way under the laboratoryenvironments.Realize the acquisition of bridge crack image with multithreaded collectionprocedures.2Traditional image processing algorithms were applied to crack images, and its detectioneffects were compared. The most suitable algorithm for the acquisition of image edgeaccording to the characteristics of bridge cracks were selected,and it proves a very goodeffect on recognition. A new way to deal with crack image which makes the algorithm’s effectbetter were put forward.3Digital image processing methods has been used to extra three kinds of crack featureinformation including length,width,area. A more optimal algorithm were put forward and thenemphatically discussed.Different types of crack calculation error under the same algorithmwere analyzed. The variation curve of crack width and area of cusp were depicted. 4Adopted VS2008as development platform, using c++language to write the softwarefor detection of crack dynamic changes. Crack image were loaded in to procedure and thenrecognized, the feature informations of crack were extracted.Through the construct of hardware platform to achieve acquisition and transmission ofthe crack image, apply digital image processing technology to crack, and the detection ondynamic changes of crack has been realised. The paper lay the foundations for the dynamicmonitoring of bridge crack.