Research On The Computer-aided Adjustment Method Of The Test Piece In Scanning Interferometry

Computer Aided Alignment(CAA)is a technique that uses a computer to solve the component misalignment and automatically adjusts the misalignment.It is faster and more accurate than the manual in the calibration of complicated precision instrument and equipment.According to the principle of this technique,this dissertation applies a method of computer-aided alignment based on interferometric measurement and sensitivity matrix.Based on the fundamental of computer aided alignment,the relationship between aberration and offset is analyzed.The aberrations and their characteri stics of the Zernike polynomial representation are described in detail.The sensitivity matrix and its solving method are expounded.The simulation results show that this mathod is suitble for the alignment.At the same time,the computer-aided alignment procedure based on the sensitivity matrix is listed.Then,a method of solving the sensitivity matrix based on the interferometric measurement is proposed according to the characteristics of the detection system.The feasibility of this method is verified by mathematical theory.Finally,the deviation of fitting region is analyzed,and the method of solving the problem is briefly described.The mathematical principle of dynamic scanning for detecting aspheric lens is introduced in detail.The method of surface reconstruction and scanning path planning are introduced.Finally,the ways and effects of computer aided alignment are discussed,and the deviation of the fitting area is analyzed further on the scan path.The software and hardware systems are described in detail,and the various parts of the function and workflow are expressed.In the experimental verification,the large-diameter aspheric lens is used as the test piece,and the adjustment effect is judged by the change of the Zernike coefficient.The factors that affect the adjustment accuracy are analyzed.Compared with the result tested by Taylor Hobson profilometer,the final aspheric surface test result has the same accuracy,which confirms the feasibility of the test method.