Point cloud is a kind of digital media to represent the three dimensional model of an object, which has become a common data structure used in engineering application with the advantages of convenient acquisition, simplicity of data structure, strong expression ability, and rich detail description. This thesis focuses on the key technologies of point cloud based surface inspection and target localization. The application fields include automatic surface inspection of complex workpiece and optical deep space navigation. The main contributions are addressed as follows. (1) A 6 degree of freedom robot based scanning system is built for workpiece surface inspection. The measurement principle, measurement model, and calibration method of the scanning system are also analyzed. Firstly, the structure of the scanning system is introduced. Secondly, the measurement principle of the structured light scanner is described, and the scanner parameters which are required to be calibrated are pointed out. Thirdly, the measurement model of the scanning system is built, and the system parameters which are required to be calibrated are also pointed out. Fourthly, the calibration method for the scanning system is proposed and implemented. (2) A model-based scanning path planning method is proposed for workpiece surface inspection. Firstly, the scanning constraints used in path planning are analyzed. Secondly, the data structure of a triangular mesh model is introduced. And a mesh refinement algorithm and a neighborhood searching algorithm are proposed based on the data structure. Thirdly, a region growth based viewpoint generation method and a model framework based viewpoint generation method are proposed, respectively. Comparison experiments are presented between the two methods. Fourthly, a greed genetic algorithm based shortest scanning path generation method is proposed to generate practical scanning path of the robot end. Lastly, the path planning method is tested to verify its effectiveness through simulated and practical experiments. An airplane wing surface is taken as an example for the practical experiments based on the automatic scanning system. The surface inspection results of the airplane wing are presented. (3) A point cloud based contour feature library building method is proposed for irregular objects. Firstly, a viewpoint sampling method is proposed to obtain the pose and position of viewpoints. Secondly, a point cloud based contour generation and extrac...
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