Research On The Application Of Image Processing Algorithms In Electrostatic Levitation Experiment Device

With the continuous development of science and technology, research in materials science are constantly depth. Analysis of the preparation and characterization of materials has been rapid development. Containerless processing has become an important experimental experimental technique for materials processing and thermophysical property studies for several resons.The first is that the contamination from a crucible can be avoided. The second is that it promotes deeper undercooling in molten materials since the source for heterogenous nucleation is precluded. The third is that it provies the opportunities to measure accurately such thermophysical properties as density, surface tension, viscosity, and specific heat in undercooled. Electrostatic levitation compared to other suspension technology has advantage of wide application range, ultra-high vacuum environment, individually heating and levitation controlled, and convenience undercooled research.Due to the advantages of a linear, high processing accuracy, breadth and flexibility digital image processing technology are widely used in aerospace, biomedical and communications engineering. The image processing technology play important role on the used in electrostatic levitation of materials research and analysis. The materials thermophysical property studies and the measurement of sample position are the important use of image processing technology in the electrostatic levitation. Therefore, this article analysis the key image algorithms used for materials thermophysical property research and the measurement of sample position.This article analyzed the status of the electrostatic levitation and the application of image processing technology in the electrostatic levitation. Analysis the basic principles of the electrostatic levitation and the process of electrostatic levitation. Introduce the composition of the electrostatic levitation experimental apparatus in the Center for Space Science and Applied Research, Chinese Academy of Sciences, while analyzing the position detection and control techniques and sample heating and temperature dection technology in the experimental device. Then introduce the basic concept of digital image processing and image preprocessing techniques such as image filtering and format conversion of image, at the same time introduce global threshold of image segmentation and adapitive threshold processing methods and related concepts of threshold processing. Introduction the concepts and princile of edge detection for the suspension samples and the differences between the classical edge detection operator and the study of interference filter algorithm, the algorthms about center of the suspension sample and density of materies. Finally, processing the suspension sample image use the image filtering algorithm, threshold segmentation algorithm and edge extraction algorithm. Analyzed and compared the results to select the median filtering algorithm, Otsu method and Canny endge detection algortthm as image filtering, threshold segmentation and edge detection algorithms. Using analog interference electrostatic levitation sample image to verify the applicability of the frame difference method and the results show that frame difference method can be better to remove the interference information on the image of the suspension.The article also calculate the sample center using the edge image, which obtained by the image processing techniques, laid the foundation for sample position control. At the same time, we using the formula calculation method and the integral method to get the relationship between volume and temperature by using the images of zirconium material, which heated to the temperature of between 1860.5℃~2124.9℃ by electrostatic levitation devices。Using the formula method to calculate the volume and get the relationship between density and temperature between 1860.5 ℃ ~2124.9 ℃ of zirconium materials is 3?/ g cm11.165 0.0026T?? ? ?,mean square deviation is 3.33%, the coefficient of cubical expansion is ? ?1?/ =1/ 4182 T?℃?.Using the integral method to calculate the volume and get the relationship between density and temperature between 1860.5 ℃ ~2124.9 ℃ of zirconium materials is3?/ g cm11.623 0.003T?? ? ?,mean square deviation is 2.83%, the coefficient of cubical expansion is ? ?1?/ =1/ 3874 T?℃?.