Research On Three-dimensional Topography Reconstruction Technology Of The Inner Wall Of The Tube Parts Based On Linear Structured Light

Tube parts have been widely applied in automotive,aerospace and other fields.For instance,Aero-engine Drum Tube,Crystallization Device,Torque Converter and other parts were often required assembly with other parts to achieve its function,so the size of the components must be strictly controlled and tested during the processing.However,how to obtain the machining dimensions is very difficult in a limited space,it has been a research focus how to effectively obtain the inner wall processing size at present.Aiming at the involved problems of in the three-dimensional reconstruction of the inner wall of the tube,the theoretical research and experimental verification was carried out.The main content of this article is as follows:1.Camera model was analyzed,and the two-dimensional planar target was designed,The internal and external camera parameters was obtained by Zhang algorithm,which the factors of the calibration error were analyzed.2.According to sensor calibration,a calibration method based on planar target fullfield error control was proposed.This method makes full use of the coordinates of the target corner point and the center coordinates of the laser stripe,which can greatly reduce the randomness of the solution of the feature points,achieve high-precision calibration of the light plane,and analyze the error factors of the calibration results.3.Rotary axis calibration model was established,A calibration method based on coordinate transformation was proposed based on the calibration method of the existing rotary axis.The study adopts a full-rotation calibration method,it can effectively improve the calibration accuracy,thus the three-dimensional reconstruction accuracy of the tube wall was further improved.4.The processing algorithm of the system image was introduced in this paper.In order to realize the extraction of laser stripe center under complex background,a method based on area constraint factor-probability statistics was proposed.The method can effectively identify the laser stripe area and extract the laser stripe center coordinates,when the interference region exists.5.Using the system for workpiece measurement experiments,the inner wall of the tube part was visualized in three dimensions,the dimensional parameters of the inner wall were obtained and the accuracy was evaluated.In this paper,aiming at the measurement of various parameters of the inner wall of tube parts,a method for 3D reconstruction of the inner wall of the tube based on the line structured light was proposed.The method effectively completes the reconstruction of the inner wall three-dimensional topography and obtains the various dimensions of the inner wall,and the evaluation of various parameters.The experimental results show that the system can effectively measure the parameters of the inner wall of parts.