Study On The Deformation Measurement Method Of Concrete Structure Model Based On Digital Photogrammetry

With the rapid development of construction industry in our country,the structure as an important component of the large engineering,its shape changes and has important effect on the engineering quality,thus attracting widespread attention.The deformation measurement on the surface of the structure is as important as the deformation measurement of the building.Digital photogrammetry,as an optical deformation measurement method,has the advantages of non-contact,high measurement accuracy,low environmental requirement and strong practicability.In this paper,digital photogrammetry is applied to the deformation measurement of the structure model,and the feasibility of the three-dimensional deformation measurement in the structure model is studied.In this paper,base on the principle of digital photogrammetry,were studied by using single camera on structure model of in-plane deformation measurement method and using two cameras on the structure model of three-dimensional deformation measurement method.In the deformation calculation of the structure model,the points of the interest boundary are processed by the reliability confidence guidance technology,and the multi-thread confidence guiding technology is introduced to improve the computational efficiency.At the same time,the gradient value of each pixel of the image,the value of heissen matrix and the initial value of each seed point are preprocessed to improve the computational efficiency of the program.The effect of interpolation function and subregion size on displacement measurement precision is studied by means of precise control of the displacement of texture image and the influence of texture quality and measurement environment.Through the translational experiment of the structure model,the influence of measuring distance and measuring Angle on the accuracy of displacement measurement is studied.According to the experimental results,the measurement accuracy of the Biquintic Bsplines interpolation function is significantly higher than that of the Cubic spline interpolation function,and the increase of interpolation function can obviously improve the measurement accuracy.Area size in 11 x 11 ~ 31 x 31(pix),measuring distance between in 70 ~ 110 cm,photogrammetry angle at 0 ~ 5° within can achieve better accuracy of measurement.In this paper,the reliability of the 3-D deformation measurement method proposed in this paper is verified by simulating the experiment of rigid body translation and the field unidirectional force displacement.The experimental results show that the relative error of the displacement is within 6% and the relative error of the displacement is within 25%.The results show that the relative error of 80% is less than 10% when the displacement is greater than 1mm.