Study On 3D Spatial Measurement Method Based On Structured Light

Three dimensional vision measurement technology is widely used in the field of industrial measurement because of its characteristics of non-contact,high speed and flexibility.Among them,the active vision measurement technology based on structured light has attracted more and more attention in recent years because of its strong anti-interference ability and high precision.Three dimensional measurement method based on the structure light is studied in this paper.The structure is projected on the measured beam spatial contour surface,to obtain images of structured light stripe by high-speed camera,the camera platform and the structure light measurement system calibration of camera and structured light image processing,realize the conversion of 2D image points and optical structure three-dimensional space points,so as to calculate the carrying point cloud data measured 3D contour information,based on point cloud data filtering,streamline and plane and surface fitting processing,can be used to measure spatial contour information.The acquisition and processing of point cloud data is the core of 3D measurement based on structured light.According to this characteristic,this paper mainly studies the following aspects:(1)Study on the working principle of structure light measurement system based on the design and measurement of the corresponding experimental system,realize the three-dimensional spatial contour from point to line,from line to surface scanning,a structured light image pixel coordinates and the geometric relationship between the world coordinate contour points to be measured,so as to obtain the imaging model of measurement system.(2)Design a calibration method of 3D vision measurement system for fast,only the target moved two times in the camera view range,the initial level can be calculated,the focal length of the camera calibration and image principal point,rotation matrix and translation vector and the structure light angle and optical center coordinate system parameters.The model parameters of the calibrated system imaging,combined with the rotation angle of the camera head and head of the optical structure,based on space analytic geometry,calculated the 3D spatial contour surface.(3)In view of the point cloud data acquisition system,combined with the characteristics of the point cloud data obtained through experimental measurement,point cloud filtering method,sparse filter and mean filter combining,the point cloud data filtering,then simplify the point cloud data using uniform grid method,to reduce the amount of data,and get the 3D contour finally,the measured space fitting plane and surface of point cloud data.(4)The parameters of the measurement system are obtained by the calibration and calculation of the actual measurement data,and the error is inevitable in the measurement process.In order to improve the measurement accuracy of the system,design the system error compensation experiment,through the analysis of single point measurement data,measurement system gets correction values of the parameters,the parameters of the system calibration is modified,in order to achieve error compensation of measurement data.The feasibility and reliability of the three dimensional measurement method are verified by the experiment of the small cabin model.