Research On Digital Light-section Microscope

Surface roughness is one of the most commonly used parameters to describe the surfacemorphology in machining. It is an important indicator to assess a variety of parts’ surfacequality. For Laser texturing workpieces, to research and measure the surface roughness ofthe workpieces is an important research direction in the field of laser texturing process.Theresearch of the surface roughness measurements started from the1930s.In1936, the first surface roughness measuring instrument for workshop use has beendeveloped, which is a contact-type measuring instrument. Since then, as technologyadvances, much attention and research have been devoted to various measurement methodsbased on optics and electronics and a variety of non-contact surface roughness measurementinstruments were developed, such as light section microscope, interferometry microscope.However, the common shortage for this kind of instruments is that it works slowly becausethat they rely on manual readings and the data needs to be converted after reading. Inaddition, the work environment may not be suitable for measurement during productionprogress. With the increasing accuracy of CCD and development of computer visiontechnology, CCD can replace human to work on the bad working environment.Based on the analysis of the various existed measuring instruments, in this thesis wedesign the measurement system by using9J microscope based on light-section method,Daheng image CCD camera,capture card and the personal computer. The design is basedon digital image processing technology and light-section method measuring principle. Someresearches and creative proposals are achieved as following:(1) In this thesis, we firstly study the surface morphology of the laser texturingworkpieces. According to surface characteristics of the workpieces, we choose the light-section method to do surface roughness measurement.(2) Then we study the CCD knowledge. For the project’s need, we select theappropriate CCD and capture card. The CCD must have the appropriate accuracy.(3) We study the digital image processing techniques. Based on the image processingtechniques we complete the design.In this thesis, the system can measure automatically to acertain extent. This system greatly improve the measuring efficiency.