Design Of Single-line Structured Light Three-dimensional Measuring System For Metal Structural Parts Measurement

With the continuous development of computer and optics,there are more and more measurement methods in the field of 3D measurement in the industry.From the traditional mechanical measurement methods to optical three-dimensional measurement methods such as computer vision,three-dimensional measurement of objects is carried out.Compared with the traditional contact mechanical measurement,the optical three-dimensional measurement method makes the measurement result unaffected by the surface of the object,and the optical three-dimensional measurement method has a fast measurement speed,a simple structure,a moderate price,and an accurate precision.The higher the requirements of various aspects of industrial measurement,the wider the scope of application,and the wider application and development prospects in industrial manufacturing,defect detection,quality inspection,biomedicine,intelligent robots and other fields.The optical three-dimensional measurement methods is simple,the system is easy to set up and the precision is high,so in this thesis,this method is chosen.The installation structure of each device is designed by the selected measurement scheme,and the measurement range and estimated measurement accuracy of the system are obtained through calculation.The calibration of the measurement system is then performed on the image processing software platform using a dot calibration plate,including camera calibration,calibration of the light plane,and calibration of the motion displacement;Then using the gray center of gravity method to extract the center line of the laser light.Combined with the conversion relationship between the two-dimensional image coordinates and the three-dimensional coordinates determined by the calibration,the image of a series of surface light strips is analyzed and processed to complete the three-dimensional reconstruction of the surface of the object.The Z-coordinate image of the object is obtained from the surface three-dimensional reconstruction result,and the features on the image are analyzed.Click to get the desired height measurement.In this thesis,the height of the standard height block is measured.The measurement error range of the system is obtained and the measurement range of the system is verified by the measurement of the standard block.Finally,the surface of the target object is reconstructed in three dimensions to obtain the height values of the five feature positions,and the uncertainty is used for accuracy analysis.And perform error analysis on the measurement results.