The Investigation Of Handy Surface Roughness Measuring Instrument

Surface roughness is microcosmic geometry error of surface.It did lots of harms to the capability and using-life of machine or instrument.Now the technol-gy of surface roughness measure has made great development.More and more measuring methods such as comparative method,light-section,interferometer method etc.have put into widely use.But they often can't well combined their pr-cisions with cubage.So they were not much fit for the demanding of actual coditions in factories.The new GB had carried out and defined the surface roughnss based on the mean line which comes from Gaussian Filtering.A lot of instruments were digital filters were 2RC or zero-phase mean line filters,so they didn't fit the new GB.In the dissertation,some fundamental theories of surface roughness meas-rement such as the least squares mean line,2RC filtering mean line and the Gaus-sian filtering mean line were analyzed.Based on the approximation theory, Gaussian digital filter were designed that were not only had high accuracy but also had high computing efficiency.The Gaussian filter had been transformed to fit for the using in MCU.Meanwhile,its precision had been proved.In this research,the circuit system based on the Msp430f149 MCU was designed.The system was built up by several parts.Including power management part,LCD driver circuit, micro-printer driver circuit and analog signal transform circuit.In the developing process of surface roughness measuring instrument,a lot of new ICs had been adopted,some useful methods such as Portable-device design and Low-power system design have been used.System maintainability was progressed for using the method of the blocking designing method.When design finished,two tests have been done.One test used analog single generator to generate simulate roughness,the other tests used source roughness form it software design.On operation,this testing instrument is of the advantages of high testing precision, simple struct-ure,easily operation,small cubage, light weight and widely usage.