Research On Key Techniques Of NC Laser Three-dimensional Measurement

Modern numerical system and non-contact measurement technology is profoundly studied in the thesis. A three-dimensional measurement software platform is developed by employing the numerical system's improving speed, accuracy and open architecture. Fast and accurate post data processing are implemented based on the platform, which can be applied in advanced manufacture, electronic packaging, product inspection and so on. The machinery, hardware and software architecture of the numerical controlled three-dimensional measuring system are introduced in the thesis, then several key techniques of the system are studied.Influence of laser beam's offset from coordinate axis to measurement accuracy of the point light source scanner is analyzed. Principle of calibrating the offset angle is introduced and a simulation program is developed to check the calibration progress. Simulation results and calibration error are studied. For the line-structured laser scanner, the laser plane's orientation error is analyzed in the thesis. A practical method for aligning the line-structure laser scanner is presented. A simulation procedure is made to help users to adjust the laser plane's direction in an interactive way. An automatic method of geometrical feature extracting from three-dimensional scattered datacloud is presented. The algorithm is applied in a diesel engine's datacloud post processing and a dental cast's datacloud post processing. Boundary models in lines are reconstructed for the two objects.Based on the above achievements, a software module that is capable of rendering, slicing and sorting and two-dimensional feature extraction is developed for three-dimensional laser scanned datacloud processing.