Research On Data Measuring And Point Cloud Pre-Processing

Reverse Engineering plays an important role in manufacturing for shortening development cycle of new product, reducting cost, prompting independent ability of product development. Data acquisition and point cloud pre-processing are two key links of RE. They are discussed in detail based on 3D digital laser measurement system in this paper, and perform an important function on product modeling and subsequent machining.Based on the research of 3D Laser measuring principle and lots of experiments, data acquisition is studied from the aspects of integrity, accuracy and efficiency of data measuring. According to the characteristic of measuring equipment and complexity of object contour, the measuring plan under different conditions was brought forward and the correctness of measuring planning was verified by experiments; In order to gain accurate point cloud, influence of LSH800 parameter setting and surface characteristic (such as surface color, inclination, surface curvature, roughness, luster, etc.) of prototype workpiece on measuring were analyzed, the rule of impact of different surface character on measuring data is obtained. Experiment results show that in order to get perfect point cloud, the reasonable measuring plan should be established, the appropriate measuring parameter should be choosed and necessary surface preparation should be done.Data pre-processing methods of multi-view registration, feature extraction and data blocking is studied. Scanned data from different view is transformed by superposition of three datum points, ICP algorithm was achieved; for the characteristic of linear scanning data, feature extraction method based on linear scanning data is given; on the basic of extracted characteristic line, the method of data blocking is formed.Point cloud pre-processing module was developed with OOD technique, VC++6.0 and OpenGL. The integration of pre-processing function and algorithm was realized. The operating and testing results indicate that the system could accomplish data pre-processing function, and the effect is satisfactory.