Study On The Method Of Adjustment And Calibration For Multiple Vision Sensor In Billet Weight

In the method of the continuous casting billet vision weight based on linear structured light, the coincidence degree and the calibration result of two structured light planes for measuring the cross-section area of the continuous casting billet affect the weight accuracy. At present, the coincidence degree of the two structured light planes is mainly adjusted by human, which has defects of low efficiency and low accuracy. In addition, two structured light sensors are used to measure the cross-section area of continuous casting billet, which requires a suitable calibration method to calibrate two structured light planes at the same time. Therefore, it is the important research content of this thesis to study the reasonable method to achieve the adjustment and calibration of two structured light planes.The main research work in this thesis includes the establishment of the adjustment mathematical model of the multiple vision sensor and the adjustment system, the image processing for adjustment system, the calibration of structured light planes, the development and design of the adjustment software. In the mathematical model aspect,the method of using the box shaped dot target to adjust two linear structured planes has been proposed on the basis of the theory of vision measurement and the theory of spatial coordinate transformation. The adjustment mathematical model has been established and verified by experiments; In the system construction aspect, the adjustment system has been established according to the weight principle and the adjustment mathematical model. In the image processing aspect, based on linear structured light imaging characteristics in the system, the ideal image has been obtained by image preprocessing. Then, the sub-pixel center coordinate of the light stripe has been obtained with the improved gray gravity method and the center of target dot has been obtained with the centroid method. In the calibration of structured light planes aspect, the movable type double-sided symmetrical target was used to complete the calibrating experiment based on the Invariance of Cross Ratio and the precision has been analyzed. Finally, in order to realize the visualization adjustment, the system of the continuous casting billet weight multiple visual sensor adjustment has been developed and designed using MATLAB.The method proposed in this thesis for the adjustment and calibration of two structured light planes has solved the problems of the adjustment and calibration of the two structured light planes in the continuous casting billet vision weight based on linear structured light, which makes the continuous casting billet cutting system to better play its advantages.