Research On Reverse Engineering Technology Based On Line Structured Light Vision Measurement

Data acquisition is the first and key step in Reverse Engineering. The accuracy and quality of CAD model reconstruction is determined by part digitization accuracy, and the measuring efficiency also has a direct impact on the speed of the reverse process. In recent years, along with the rapid development of photoelectric technology, microelectronics technology and computer technology, the application of laser and optics in measurement field has a major breakthrough, opening a time of modern non-contact measurement.Firstly, a system for line structured light 3D vision measurement is proposed and constructured.Then the 3D surface measurement technology based on line structured light vision sensor is researched in this thesis. Finally research on hybrid modeling method based on line structured light 3D vision measuring system and three coordinate measuring machine. Specific research works as follows:(1)A system for line structured light 3D vision measurement is desighed and constructured with advantages of simple structure, low cost, high feasibility.(2) Research on a camera calibration method based on 2D checkerboard and free-position, considering of the camera radial and tangential distortion coefficient, solving all camera parameters using a nonlinear optimization method. Research on a calibration method based on cross-ratio invariance theorem and 2D checkerboard to calibrate vision sensor structure parameters with good precision, which can acquire lots of calibration feature points in light plane. An integrated calibration method for line structured light vision measurement system is proposed, which only acquires all calibration images at one time, carries out camera and light plane equation calibration at one time. This method can reduce the content of calibration experiment, improving the calibration efficienct for measurement system.(3)The existing light stripe center extraction method is summarized. Based on the proposed line structured light vision measurement system, the whole process of line structured light 3D vision measurement is described in detail. Finally, the feasibility and simplicity of the line structured light 3D vision measurement system for non-contact measurement is verified with a measurement example.(4)Research on hybrid modeling method based on integrated measurement system of line structured light vision sensor and three coordinate measuring machine. Then, the flexibility of dada acquisition in the multi-sensor integrated measurement system is illustrated with a example.Hybrid modeling method based on integrated measurement instruments can improve the efficiency of CAD reconstruction for these products with curved surface and regular features.