Research On Data Acquisition And Filter Methods Of Surface Roughness

The surface roughness of workpiece is the flatness and smoothness of machining marks on the surface, and it is a reflection of the microcosmic geometric errors on the surface of workpiece, and it is also an important indicator for assessing the surface machining quality of workpiece. The surface roughness exerts a great and tremendous influence on the mechanical workpiece and mechanical equipment. Therefore, the measurement and assessment of surface roughness is the area of research that has been a widespread concern.Regarding the surface roughness tester of SRM-1(D) produced by Union Glory as the research object, this thesis analyzed and studied the measurement of surface roughness in detail from the filter methods, data acquisition and implementation. With the above as base, the software used to calculate and evaluate the set of Rk function parameters of surface roughness was developed. In the surface roughness tester of SRM-1(D), a data acquisition board PCI-7422 was used to constitute the real-time data acquisition and transmission system which collected the data of the surface roughness tester and transmitted the data to PC, and this prominently enhanced the data acquisition capability and assessing function. The intelligent algorithms like self-adaptive denoising method and Gaussian digital approximation filtering method were truly applied in the filter of the measurement of surface roughness and improved the measuring accuracy and effectiveness of the tester. The calculating method and implementation of the set of Rk function parameters were discussed combining with DIN4776 standard, which satisfied the actual demand of the specific parameters'calculation of parts like cylinder liner. The introduction of self-adaptive denoising method and the research on digital implementation method of the traditional 2RC analog filter are the two innovations in this paper.This thesis was based on measuring technique and digital filtering technique, and the measurement of surface roughness was accomplished by using the powerful functions of a general-purpose computer. The implementation of the innovation, upgrading and multi-functional integration of the surface roughness tester of SRM-1(D) met the new national standards, and it possessed important practical significance.