Study On Optical Calibration Method For Large Space And High Precision Measuring Camera

In recent years, aerospace industry is under fast development. Manufacture of related large size equipments, has brought large space and high precision measurement a bright future. Large space and high precision measurement and traditional vision measurement is of great difference. It can measure larger space, that is to say, the vision field is large and the scene depth is large, and the precision requirement is high. With the rapid development of electronic devices, the ability, such as resolution of camera's hardware can now fully meet the need of measurement, but the calibration of camera's parameters has become the key technical problem that limit its application. In this paper, pure optical method is applied to simulate the imaging process of camera. Through building the relationship between 3D spaces imaging beam and image points, build the corresponding relationship between image plane and space angle vector. It reflects and shows the reverse process of camera imaging correctly. It breaks through the limit of concrete space, and realizes precise calibration of large space and high precision measuring camera. Furthermore, the image result of calibration control points is processed.The main research content of this thesis is as follows:1. The calibration method is studied. The former camera calibration method is studied and its disadvantages are listed. Propose a new type of camera calibration method which will be applied in large space and high precision measurement. Its principle of calibration and the concrete implementation plan is analyzed, its research environment is introduced and its calibration platform.2. To implement the precise calibration of large space and high precision measuring camera, the construction of platform is very important, especially the pose adjusting of each tache and composing components. Adjustments are done on beam expanding collimation laser, laser light source, camera to be calibrated, and 6D turn table.3. Research calibration control points are done. Performance of infrared LED light source is analyzed. According to the situation of this system, choose infrared LED light source as calibration control points. Designed experiments separately. Based on data, the experiments analyzed the effects on accuracy of spot center extraction from spot size, distance, field angle and brightness of spot center.4. Research on calibration control point center extraction accuracy is done. Performance of several common center extraction algorithms are compared and analyzed. And by using experiment data, the effects on center extraction accuracy of calibration control points by distance, noise, and total energy of image spot are analyzed. Conclude the applicable conditions of these methods and how to improve the algorithm accuracy.