Measuring Method Research Of Deformation Displacement About Structure Specimen In The Shaking Table Test Under Binocularcular Vision

Shaking table test is an important method to investigate the anti-seismic property of a structure specimen.In order to obtain the velocity and displacement of a specific test point on a structure specimen,different drive signals were imported into the Shaking table test.Through the analysis of the displacement of a specific test point,obtaining the deformation displacement of a specific test point on a structure specimen is of great significance.In this work,machine vision technology was applied to measure the deformation displacement of the specific test point on a structure specimen in the shaking table test.Two cameras were used to catch the structure specimen synchronously which moved together with the shaking table.Then through the processing and analysis of the images,the deformation displacement of the structure specimen was calculated based on the Binocular vision measurement principle and the measure method which was proposed in this paper.The aim of this work is to provide a new method which can offer more extensive data sources for the shaking table test.The main work of this paper is as follows:(1)In order to improve the measurement accuracy of the deformation displacement of the structure specimen,an artificial circular logo which was made by back light reflective materials was designed and it was pasted on the surface of the structure specimen.The specimen images which were pasted the artificial circular logo were analyzed using the knowledge about the image processing techniques.Comparing the processing speed and results of the several different methods,an appropriate method was chosen.After the process of the artificial logo and background adhesion which occurred during the processing process,the adhesion was eliminated.And using the improved least-squares ellipse fitting method fitted the position of the artificial logo.(2)On the matching problem of the artificial logo between the two cameras in the corresponding moment,the polar constraint criterion was used based on the symmetry test.For the tracking of the sequence image in the artificial logo point,the Kalman filtering algorithm was adopt.(3)The camera calibration principle was deeply investigated.The Zhang calibration method was used to calibrate the camera.During the calibration process,not only the distortion was considered,but also the precision was corrected deeply.And then the high precision of the camera calibration was achieved.In addition,according to the research object the measuring algorithm was proposed based on the binocular vision measurement principle.And the deformation displacement of the specimen under fixed displacement signal and the encouraged wave signal on the Shaking table was measured.It was proved to conform to the objective facts according the measured results.