Research On Surface Topography Reconstruction Technology Based On Optical Fiber Sensor

With the rapid development of industrial technology,new requirements have been put forward for the contour detection of the surface of processed parts,that is,to achieve real-time,fast,high-precision and intelligent detection of Parts' surface contour.With the rapid development of optical fiber laser transmission and optical fiber sensors,optical fiber sensing technology has been gradually applied to surface topography measurement.This paper takes the measurement and reconstruction of the surface profile of the part as the research object.A surface displacement measurement system based on fiber displacement sensor is designed and an experimental platform is built.It provides a new research method for measuring the surface profile of parts,which has important research significance and wide application value.Firstly,the paper expounds the background significance of the research and the development status of the surface profile measurement technology of parts.Based on the rapid development of fiber optic sensor technology,this paper explores the method of measuring the surface profile of parts by fiber optic displacement sensor.The paper has designed the surface profile measurement system of the parts,analyzed and tested the functions and parameters of each instrument,and programmed the upper computer program to realize the control of each device and data acquisition and display.Secondly,the paper introduces the working principle of reflective fiber displacement sensor.Based on this principle,the mathematical model and measurement principle of the surface topography measurement of the object are proposed.And analyzed the key issues in the measurement process.Presented several methods of line scan trajectory planning and data preprocessing.The B-spline surface fitting reconstruction algorithm and the triangulation principle of feature points on the scanning line are studied and the three-dimensional surface topography reconstruction scheme is given.Finally,an experimental platform was built according to the surface profile measurement system design.The feasibility of the measurement system was verified by the displacement experiment of the experimental platform,and the performance of the fiber sensor was tested.The repeatability error of the linear range of the front slope of the modulation characteristic curve is 0.57%.Next,the input and output functions of the fiber sensor are established in the linear interval of the front slope of the calibration displacement characteristic curve,and the appropriate scanning height is determined and scanned in the test area of the aluminum block surface.Through the experimental data analysis,the reconstructed step profile error is within 15 um,which indicates that the experimental platform can measure the surface profile of the object to a certain extent.