Research On Ultra-precision Virtual Multi-Probe Scanning Measurement Method

With the concept of industrial 4.0 intelligent manufacturing,more and more industries have begun to develop advanced manufacturing technologies such as automation,high-precision and ultra-high precision,and smart manufacturing,flexible manufacturing,and extreme manufacturing are increasingly prosperous for precision and ultra-precision components.The demand is increasing,and this demand has accelerated the progress of machining technology to precision and ultra-precision.At present,AR,naked eye 3D and other technologies have entered people's daily lives,these are inseparable from the free-form lens processing and production,but also can not do without high-precision measurement.After the off-line inspection of the ultra-precision mold,it sometimes needs the machine to process again.In order to avoid introducing the setup error during the re-machining of the machine,the on-site measurement is generally adopted.This measurement can adapt to different measurement envi ronments and complete the measurement of various contour topographies.Even if the ultra-precision machine tool also has a certain degree of straightness error,these straightness errors in the scanning measurement process will affect the accuracy of the scanning measurement more or less.The general multi-head scanning measurement method can effectively separate the straightness error of the guide rail or the motion platform.However,the use of multiple probes introduces new errors.Therefore,the multiple probe scanning measurement method has certain limitations.In this paper,based on the high repeatability of the flexible hinge,a micro-motion platform with excellent repeatability is designed,and a probe is used to perform multi-probe scanning measurement—a virtual multi-probe scanning measurement method is used to improve the efficiency of the scanning measurement.Complete the high-precision reconstruction of the profile of the workpiece to be tested.The main research work of the dissertation includes:Firstly,a scanning method using a single probe to achieve multi-probe scanning measurement—a virtual multi-probe scanning measurement method—is proposed.Based on the characteristics of the flexible hinge mechanism,the core part of the measurement system — the micro-motion platform—is designed to be based on virtual multi-measurement.The principle of head scanning measurement selects the appropriate scanning platform and adapts the corresponding control system at the same time,and completes the construction of a virtual multi-probe scanning measurement system to study the reliability,innovation and practicality of the virtual multi-probe scanning measurement method.Secondly,the influence of the position and attitude of the non-contact probe on the measured value was theoretically analyzed,and the error of the sampling distance of the micro-motion platform,the positioning error of the scanning platform,the noise and thermal drift of the measured value,and the environment-vibration-to-virtual probe were analyzed.The effect of scanning measurement on reconstruction of contour accuracy was finally analyzed by the probability theory method(Monte Carlo method),and the influence of these influencing factors on the error of contour reconstruction was analyzed and the uncertainty was evaluated.Finally,experimental verification of the virtual multi-probe scanning measurement method was performed.The Taylor-Phoenix PGI 1240 profilometer and the measurement system of this article scan and measure optical molds that have been subjected to ultraprecision turning.By comparing the measurement results of the Taylor Hobson PGI 1240 profilometer,it is verified that the virtual multi-probe scanning measurement method is relatively simpler than single measurement.In terms of head scanning measurement,the measurement efficiency can be significantly improved,high-precision contour reconstruction can be realized more easily,and rail straightness error can be separated.