Study On Automation Calibration Technology And Accuracy Of 3D Laser Scanner System

3D vision measurement is a newborn and promising technology and it is widely used in Reverse Engineering, rapid inspection of product etc. Based on the theory of binocular stereo in computer vision, some key technologies of 3D vision measurement such as computer vision model, calibration technology, calibration process automation and measurement error factor are studied in this thesis. A 3D laser scanner system named HRE and its system software called REPRO2004 have been designed and developed as a commercial product.Calibration method is crucial for the results of 3D vision measurement system. Therefore, this thesis introduces an effective calibration method, which takes lens distortion into account, to meet the need of high-accuracy 3D measurement. The exterior and interior parameter of camera can be calibrated by two-stage calibration technology.Most applications of computer vision are limited by the complexity of calibration process and 3D vision measurement system is not an exception. Author introduces an original camera calibration process technology called calibration process automation technology which makes the process of camera calibration automatically done by the computer without any manual operation. The result shows that this calibration technology has many advantages such as high-robustness, easy-operation, non-noise-sensitivity and high-accuracy. Furthermore, this technology can be applied to other computer vision industrial fields as a common calibration automation technology.The issue of measurement error has been discussed deeply in the thesis. This thesis covers many factors which can make the measurement result uncertain and focuses on three key factors such as the offset of image center, lens distortion and the depth of field. The influence of these three factors has been analyzed theoretically, which offers a basis for achieving higher accuracy. Software is the soul of the 3D laser scanner system. The system software REPRO2004 characteristic of reliability and good automation is well-designed and developed successfully. During development, an enhanced waterfall development model was introduced according to the project and the development team. This model not only avoids the shortcomings of pure waterfall such as low-flexibility and potential venture coming from the insufficiency of demand analysis but also shortens the development time because the collateral development mechanism has been introduced.