Research On Measuring Instrument Of Surface Roughness Based On Virtual Instrument

In the field of machining, the roughness of surface exerts a tremendous influence to the function of surface of the part. It contributes to improving product quality to control the roughness of surface, guarantee the serviceability of the products, lengthen the service life. So, it is very necessary to measure the roughness of surface and evaluate parameters. Contact measuring instruments is most widely used in engineering surface measurement apresent, But this apparatus has some shortcomings such as small measurement range, low precision, few parameters and inconvenient operation and so on,it already could not satisfy the need to develop. Therefore, the development of a new instrument that own characteristics of large range, high precision and multi- parameters is imperatived. The measuring instrument of surface roughness based on the virtual instrument design the running program of roughness surface parameter according to the defines, the procedure can measure the parameters of surface roughness while applying to the real instrument evaluates parameters, it can change the parameter type through changing the procedure according to the need which have facilitated user greatly. It not only can solve the problem which the traditional instrument exists at present, but also has some merits such as quick survey speed, high automaticity, good man-machine contact surface etc. It will have the bigger market potential and the application value Because of cheap price and strong versatility.In this paper,the important role of surface roughness survey and the insufficiency of the traditional instruments is analyzed,a new measuring instrument of surface roughness based on the virtual instrument is designed. The main research contents are as follow:(1)The overall structure of surface roughness measuring instrument is designed according to the characteristic of this instrument which Including software system design, hardware system design and its connection design etc.(2)DAQ is the main part of hardware system design which contains sensor, electric charge amplifier,computer interface technology anddata acquisition card.(3)This paper provides the definition and algorithm of R_a,R_p,R_v,R_z,R_t,R_q,R_sk,R_ku,R_Δq etc.and compiles software control procedure of parameters of surface roughness with Graph programming language and analyzes the result of running.(4)The result which is surveyed by this instrument compare to other measuring instrument and determin the feasibility of this instrument surveyed. This paper has analyzed the measuring error origin from several aspects, and how to eliminated or compensates these errors to make the simple introduction.