Study On Key Techniques Of Surface Roughness Measurement

Surface roughness is an important index for evaluating machining qulity of kinds of mechanic parts which is used to describe parts micro-geomtry error.Many reserchers pay attention to measurement theroy,technology,method and instrument of surface roughness. Combined with the actual requirment and developing process of surface roughness measurement,some key technology such as roughness signal sampling,data filtering,and free-form surface roughness measurement were studied systematically in this dissetation.The main contents of this disstertation are following:In chapter 1,the background and significance of the research were discussed,and then the developing status of surface roughness measurement technology such as methods of roughness measurement,roughness signal filtering,speacial free-form roughness measuremnet were analyzed.The study contents of this dissertation were proposed based on forementioned work.In chapter 2,the basic requirments of surface roughness data sample were analyzed.Pizezoelectric sensor and inductive sensor applied in surface roughness measurement were introduced.Two kind of signal process circuits for above sensors were designed.According above research,a method of denoising surface roughness profile signal using self-adaptive filtering technology was researched.In chapter 3,2RC filter which was realized with analogy and digitalization was researched according surface roughness filtering.Digital 2RC filter based on zero-phase error was designed.Gaussian filter applied in roughness measurement was analyzed.The difference between 2RC filter and Gaussian filter was compared. The artificial immune system for Gaussian filter was set up.In chapter 4,the conception of free-form surface roughness measurement was proposed.The implementation plan of free-form surface roughness was designed based on Stewart platform.Virtual prototype was built.Kinematic analysis and simulation for virtual prototype based on Stewart platform was researched under ADAMS environment.In chapter 5, technology parameters,measuring software and hardware of surface roughness measurement based on PC were discussed.Caculation method for some key parameters were analyzed according national standards.Measurement indication error, indication repeatability and indication stability were discussed.Caculation method of special function parameters of Rk set was reserached according DIN4776.Finally,the chief work and innovations of this dissertation were summerized,the prospects and further research work were presented.