Research On Key Technology Of Self-rotating Line Structured Light 3D Measurement

The advancement of science and technology is inseparable from the cooperation of high-precision tools and instruments.Some devices may not meet the production standards during manufacturing,also some equipment may wear out and deform after using for a period of time.In order to use these devices better and more safely,they need to be measured.The line structured light three-dimensional measurement technology has the advantages of non-contact and high accuracy,and has a wide range of applications in various fields.Therefore,the research on the line structured light measurement technology is also particularly important.The current scanning method of line structured light measurement has some limitations when measuring the inner wall of inconvenient moving objects.This paper proposes a self-rotating line structured light threedimensional measurement system,which can realize the measurement of inconvenient moving objects through the movement of the line structured light measurement device.At the same time,since it can be rotated at a large angle,the measurement range is increased.The main contents of this paper are as follows:1.By comparing the current common line structured light three-dimensional measurement and scanning methods,a self-rotating line structured light threedimensional measurement method is proposed.This method has a simple and intuitive structure and is easy to build a self-rotating line structured light three-dimensional measurement device.The combination of the optical profile measuring device and the turntable can realize large-angle rotation scanning.2.Research on line structured light measurement technology,including camera calibration,light strip centerline extraction and laser plane calibration,and realize line structured light profile measurement.By comparing the common methods for extracting the center line of laser light strips,the Steger method with higher accuracy is selected to extract the center line.The calibration of the optical plane is achieved through the checkerboard plane target,and the original laser plane calibration method is improved.Take two shots of the camera calibration image and the corresponding image with the laser light bar to ensure that the laser light bar does not interfere with the camera calibration.Finally,the linear structured light profile measurement experiment is carried out.Through the measurement of thickness and height,the measurement error is within0.5%.3.Combining the line structured light measuring device with the turntable,the conversion relationship of the measurement data from the line structured light profile measuring instrument coordinate system to the turntable coordinate system is established based on the self-rotating line structured light three-dimensional measuring system.A method based on multi-plane constraints is proposed to calibrate the position parameters of the rotation center.By measuring plane targets at different positions,the parameter that makes the point cloud flatness the best after coordinate conversion is the calibration result of the rotation center.The problem of the inconvenience of obtaining the position parameter of the rotation center accurately through the installation position is solved,and the error caused by the rotation to the measurement is reduced.4.According to the research content in the article,two self-rotating linear structured light three-dimensional measurement devices are built to measure different objects,and large-angle scanning measurement is realized.The measurement errors are within 0.7%and 0.5%,respectively.The feasibility and practicability of the self-rotating linear structured light measurement system are verified.