Research On The Key Technology Of Visual Measurement Of Coded Marks On Flexible Structures

In the field of Aeronautics and Astronautics,how to measure the structural vibration of solar panels is a major problem.Nowadays,binocular stereo vision is widely used in vibration testing,because of its advantages such as non-contact and high precision,binocular stereo vision has replaced the traditional accelerometer and other contact sensors in some situation.Therefore,in order to apply binocular stereo vision to the flexible solar panel system,two problems,which are large field of view and accurate matching,are urgently needed to be solved.Because of the surface texture characteristics of flexible solar panels are not clear,they cannot be matched by solar panels itself,we need to set the mark point artificially.In order to satisfy the large field of view and multi angle measurement,the coding mark points is the best choice,it can be distinguished from each other,not only accurate identification,but also a large number of mark points.The main research work of this paper:(1)The binocular stereo vision vibration measurement system is set up,and the movement track of several non-coding mark points in vibration condition is reconstructed.The experimental results show that the circular mark is more suitable for the test.First of all,this paper introduced several typical non-coding mark detection methods,and then use high-speed industrial cameras,capture cards,flexible solar panels,coded mark points,computers and other structures built the binocular stereoscopic vision system,to make analysis to the three marks,point,and cross under the vibration test of sinusoidal signal.Based on the parameters of camera calibration,the three kinds of signs are obtained,and the motion in the Y direction is basically in accordance with the sine model.Therefore,several typical non-coding markers are tested on the shaking table,and compared the landmarks different of three-dimensional reconstruction under sinusoidal motion.At last,the RMSE value of three kinds of marking points relative to the initial signal is fitted by fitting the toolbox.(2)This paper designs a kind of coding mark with initial information.The experimental results show that the proposed method is stable and reliable.The threepoint mark encoding designed in this paper by the starting point,positioning points,and encoding,which can meet the affine invariance in the design,development in a number of very,is the number of times around the same encoding.This paper gives a detailed description of the encoding and decoding of the coding scheme,and the experimental images are used to verify the feasibility of the scheme.(3)By using of the mentioned coding mark points on the flexible solar panel,we measured the shape of the flexible solar panels.The results show that the shape of the flexible solar panel is not as good as that of the 3D scanner.In this paper,the method of binocular stereo vision is used to measure the flexible solar panel.After that,by using the coordinate information of the public signs in the adjacent regions,the results of the stepwise measurement are fused with the theory of the Brusa,and the whole threedimensional information of the flexible solar panel is obtained.Finally,the plane fitted with three-dimensional scatter flexible solar panel 3D scanner,and the results show that the results of flexible solar panels can meet the experimental requirements.