Development Of Large Steel Structure Deformation Detection System Based On Structured Light

In recent years,with the sustained and rapid development of the national economy,various large-scale engineering steel frame buildings are emerging.These steel frame buildings will be deformed due to the influence of various external factors during construction or operation.Once they exceed the design allowable value,they may bring structural damage,fracture,swing Resonance shaking and other problems that affect personal safety and waste material and financial resources,and even cause huge disasters such as dam break,bridge subgrade collapse,landslide,building collapse and so on.At present,domestic and foreign scholars usually use total station,level,three-dimensional laser scanning and other technical means to detect the deformation of steel structures in different engineering stages.Although these methods are relatively mature,they can not meet the requirements of the times due to many factors,such as heavy workload,low work efficiency,high safety risk,high labor cost,poor measurement accuracy and low degree of automation.Therefore,this paper develops a large steel structure deformation detection system based on structured light,which has the advantages of high precision,low cost and simple operation.The main research work and achievements of this paper are as follows:(1)Design of large-scale steel structure deformation detection system.The position measurement benchmark based on structural light is established,the position reference point transmission method and the ectopic deformation detection method in the field of large-scale steel structure engineering are studied,the system principle prototype is designed,and the static simulation and thermal deformation simulation of the designed prototype structure are carried out.(2)Research on system image processing algorithm.Based on the in-depth analysis of the traditional gray center of gravity algorithm,by dividing the gray value in the spot image into regions,the qualified spot pixels are extracted,and a more widely applicable spot center position extraction algorithm adaptive regional gray center of gravity method is deduced.The algorithm comprehensively uses to extract all the qualified light According to the gray information of spot pixels,the gray center is extracted row by row and column by mathematical analysis,and then the center position of spot is extracted.(3)Research on error compensation of detection system.Firstly,the source of system error is analyzed,such as the system error caused by ambient stray light,temperature and humidity,image processing and the system itself.Secondly,experiments are used to verify that the errors caused by stray light interference,temperature change and system calibration are real.Finally,the distribution characteristics of system error are estimated by experimental method,and the error compensation method is formulated,The system error is reduced by about 0.2mm.(4)Experimental research on detection system.The experimental results show that the deformation detection system of large steel structure proposed in this paper is feasible in principle;Secondly,taking the construction site of a jacking frame structure as an example,the field test of the principle prototype of the system is carried out.The test results show that the maximum displacement of the measured point in the vertical and horizontal directions changes within 1mm in 72 consecutive hours,which proves that the large-scale steel structure detection system developed in this paper can have certain applicability in engineering.