Issue 51

K. Li et alii, Frattura ed Integrità Strutturale, 51 (2020) 386-397; DOI: 10.3221/IGF-ESIS.51.28 390 I MPLEMENTATION OF 3D LASER SCANNING SYSTEM Bracket he bracket is used to support and stabilize the transmission actuator, including the main body of the bracket, the base and the wheel. The overall composition is shown in Figure4. Figure 4 : Bracket composition. The main body of the bracket is made up welded I-shaped steel with a total length of 1200mm. The overall height of the bracket is 1300mm. In order to facilitate the installation and movement of the sliding group, a hole is placed on each side of the struts 50mm apart, for a total of 23 holes. The maximum effective detection height is 2000mm, and can be adjusted arbitrarily according to the on-site inspection environment. In order to ensure good stability and portability of the struts, the struts and the base are fixed by welding. The pulleys are installed on the four corners of the base. Sliding module The combination of sliding mode is as the basic support of the transmission system, including the strut, stepper motor, slider, screw, as shown in Figure 5. In order to ensure a perfect nested connection between the sliding group and the bracket body, M4 nut slots corresponding to the bracket body are disposed on both sides and the rear of the pillar. For the purpose of improving module accuracy, a 1200 rpm stepper motor and a grade C7 & G1610 ball screw are provided. The slider is a rectangular parallelepiped with a threaded hole in the center that can pass through the screw. Connection and fixation There is a nested connection between the bracket and the sliding group. There is a fixed connection between the stand and the scanner. These two types of connections directly affect the scanning accuracy of the entire drive system. In order to ensure accurate nesting connection between the bracket and the sliding group, the drilling of the nested connection is set, and the specific connection manner is shown in Figure. 6(a). For the purpose of calibrating the flatness of the back of the laser sensor, a connecting plate in which the laser sensor is fixedly connected to the slider is fabricated. The four connection holes in the middle of the connecting plate are subjected to countersinking treatment, and the specific connection form is shown in Figure. 6(b). T