Development Of Engineering Prototype For Differential Interference Automatic Detection System

With the development of surface machining technology and 3D surface profile measurement technology,the precision of micro surface profile measurement is more and more demanding in the fi eld of precision machining.There are many techniques and methods of micro surface topography,the detection technology developed based on the optical interference principle has the advantages of non-contact,non-invasive,high precision and strong adaptability to the environment,also has a great development prospect and market prospect.However,most of these technologies are currently in the stage of laboratory research,few engineering and market,and the price is expensive.Therefore,it is of great significance to study the three-dimensional topography detection system with the high measurement accuracy.This paper is based on the principle of differential shearing interferometry,and the principle of polarization phase-shifting interference,using common optical path interference system for reference,a set of the engineering prototype of a differential interference 3D automatic detection system which has high measurement accuracy and stability is developed,the lateral resolution is 0.867 ?m and the vertical resolution is 0.508 nm.On the hardware aspect,in order to solve the problems that the previous system needs to adjust the light path manually and low hardware quality,according to the hardware structure of the system,the key hardware which affects the measurement precision of the system is upgraded,and the system measurement accuracy is improved;and automatic control system is added to realize the whole automation of the system by using software to control image acquisition,mechanical phase shifting and sample translation.Finally,the system can improve the detection precision and anti-jamming ability,and can make the system better adapt to the complex industrial conditions.Aiming at the problem th at the system stays in the laboratory research stage,the coaxial theory and three-dimensional modeling are put forward to improve the anti-jamming and stability of the system,and has developed the engineering prototype with high modularization and integr ation level,realized the transition from experimental system to the engineering and commercialization.On the software aspect,in order to solve the problems that previous experimental system can only measure the single point morphology and phase shifted manually,the new function of one-button automatic image acquisition and multi-point linear mosaic is developed by combining the new requirements of engineering: Using VC++ and QT development platform to achieve the mechanical automatic precision phase shift and automatic acquisition of images with the measurement system to improve the efficiency and accuracy;The linear multi-point mosaic function is realized,and the straight-line distance of the sample surface is increased,which is more in line with the engineering functional requirements,the minimum stitching error is 0.86%.In order to solve the problems that the previous experiment software has single functions and depend on the development platform,using VC++ language and QT development platform to improve the software system,realizes the phase extraction algorithm and the surface reconstruction algorithm,and all the seven functions of the automatic interference detection system are realized,and a user-friendly GUI is designed,and finally packaged into a separate executable file that handles data quickly and easily,can be applied on different computers.