Design Of Pneumatic Sensor With Lager Measurement Range

Pneumatic measurement is nonlinearity,high sensitivity,high precision and not affected by the material and shape of workpiece,its has been widely used and developed in industrial production.However traditional back pressure pneumatic sensor has high precision(up to 1?m)and small measuring range(generally 0.05mm-0.2mm),which limits its application range,while the reflective pneumatic sensor has a measuring range of 1-4mm and low accuracy of ±0.2mm.The design is mainly aimed at on-line measurement of the thickness of thinparts,which is composed of a reflective pneumatic measurement and eddy current measurement,and completes the purpose of thickness measurement.The distance from the measured object to the surface is measured by reflective pneumatic measurement.The distance between the probe and the metal surface supporting the object is measured by eddy current measurement,the distance is from the lower surface of the object to the probe.Both measurements are non-contact and comparative.The difference between the two measured values is the thickness of the measured part.(1)According to the flow field structure of the reflective pneumatic sensor,the finite element model of the flow field is established by using the COMSOL.Added constraints and changed the structural parameters of flow field model.The pressure distribution diagram is obtained by simulation.The optimal values of structural parameters are obtained by analyzing the measurement curves of each structural parameter.The simulation results are verified by experiments.(2)The structure of the probe is designed by using the reflective pneumatic sensor with optimized structural parameters and the coil of eddy current probe.Design of precision moving structure of probe,roller and bracket.Combined mechanical zero complete measurement structure.The parameters selection of grating sensor,pressure transmitter and eddy current probe are discussed.(3)This paper analyzes the errors in the measurement,and discusses the causes of the errors and the methods to reduce the errors.Through error compensation and experimental results,the static accuracy of the instrument is 0.015 mm,the resolution is 1 ? m,and the range is 0.5-5 mm.In this thesis,the reflective pneumatic sensor simulation research,using computer simulation software flow field modeling analysis optimization reflective pneumatic sensor structure,through the experimental verification of the correctness of the simulation optimization,provides a research method for the design of fluid sensors.The design of the measurement system to measure the thickness of thin non-metallic materials has a good practical value,and provides design methods and ideas for the design of online measurement system.