A profile measurement method of large aspheric optical surface based on optimal stitching planning

2016 ◽  
Vol 45 ◽  
pp. 90-97 ◽  
Author(s):  
Shi-wei Ye ◽  
Ping Yang ◽  
Yun-feng Peng
Keyword(s):  
Measurement Method ◽  
Profile Measurement ◽  
Optical Surface

Wide Field of View Turbulence Profile Measurement Method

2018 ◽  
Vol 45 (8) ◽  
pp. 0804003
Author(s):  
方玉亮 Fang Yuliang ◽  
金振宇 Jin Zhenyu ◽  
刘忠 Liu Zhong ◽  
李正刚 Li Zhenggang
Keyword(s):  
Measurement Method ◽  
Field Of View ◽  
Profile Measurement ◽  
Wide Field ◽  
Wide Field Of View

Accurate profile measurement method for industrial stereo-vision systems

Sensor Review ◽  
2020 ◽  
Vol 40 (4) ◽  
pp. 445-453
Author(s):  
Yang Zhang ◽  
Wei Liu ◽  
Yongkang Lu ◽  
Xikang Cheng ◽  
Weiqi Luo ◽  
...  
Keyword(s):  
Stereo Vision ◽  
Measurement Method ◽  
Vision System ◽  
Practical Implication ◽  
Image Features ◽  
Reference Points ◽  
Profile Measurement ◽  
Surface Boundary ◽  
Content Type ◽  
Profile Reconstruction

Purpose Profile measurement with boundary information plays a vital role in the detection of quality in the assembly of aviation parts. The purpose of this paper is to improve the evaluation accuracy of the aerodynamic shapes of airplanes, the profiles of large-sized parts need to be measured accurately. Design/methodology/approach In this paper, an accurate profile measurement method based on boundary reference points is proposed for the industrial stereo-vision system. Based on the boundary-reference points, the authors established a priori constraint for extracting the boundary of the measured part. Combining with the image features of background and the measured part, an image-edge compensation model is established to extract the boundary of the measured part. The critical point of a laser stripe on the edge of the measured part is extracted corresponding to the boundary constraint. Finally, as per the principle of binocular vision, the profile of the measured part is reconstructed. Finding Laboratory experiments validate the measurement accuracy of the proposed method which is 0.33 mm. In the analysis of results between the measured data and the theoretical model, the measuring accuracy of the proposed method was found to be significantly higher than that of the other traditional methods. Practical implication An aviation part was measured in the part-assembly shop by the proposed method, which verified the feasibility and effectiveness of this method. The research can realize the measurement of smooth surface boundary which can solve existing profile reconstruction problems for aviation parts. Originality/value According to the two-dimensional contour constraint, critical points of the laser strip sequence at the edge of measured part are extracted and the accurate profile reconstruction with the boundary is realized.

Research on Tooth Profile Deviations Measurement Method Based on the Optical Image Measuring Instrument

2013 ◽  
Vol 712-715 ◽  
pp. 1979-1982 ◽  
Author(s):  
Qing Hai Wang ◽  
Feng Xia Zhao
Keyword(s):  
Mathematical Models ◽  
Measurement Method ◽  
Tooth Profile ◽  
Optical Image ◽  
New Method ◽  
Profile Measurement ◽  
Measuring Instrument ◽  
Profile Deviation ◽  
Form Deviation ◽  
Fitting Error

To resolve the problems of small module gear measurement with traditional methods, a new method for measuring the tooth profile deviations of small module gear using the optical image measuring instrument is put forward. According to the ISO 1328-1, the mathematical models of total profile deviation, profile form deviation and profile slope deviation are proposed. The involute profile measurement schemes are given. The results show that tooth profile coordinate values of small module gear can be measured automatically and effectively with the optical image measuring instrument, and the provided method has higher precision of getting measuring points and less fitting error of tooth profile.

Profile Measurement of Large Aspheric Optical Surface by Scanning Deflectometry with Rotatable Optical Devices - Error Analysis and Pre-Experiment-

2010 ◽  
Vol 447-448 ◽  
pp. 604-608 ◽  
Author(s):  
Mu Zheng Xiao ◽  
Satomi Jujo ◽  
Satoru Takahashi ◽  
Kiyoshi Takamasu
Keyword(s):  
Error Analysis ◽  
High Surface ◽  
Measuring Method ◽  
Optical Devices ◽  
Profile Measurement ◽  
Aspheric Surface ◽  
Optical Surface ◽  
Measuring Range ◽  
Angle Difference ◽  
Flat Mirror

Large aspheric mirrors with diameter over 300 millimeters with high surface accuracy are wildly used in many areas such as astronomical telescopes. Interferometers are widely used in profile measurement of optical flat and sphere. However, standard reference aspheric surface which is necessary for this method is difficult to make. Scanning defletometry based on ESAD (Extended Shear Angle Difference) is used to measure ultra-precise large near-flat and slight curved optical surface with the accuracy of sub-nanometer. However, it is not possible for it to measure aspheric surface because of the limitation of the measuring range of autocollimators. We proposed a new measuring method to scan the surface of a large aspheric optical surface using autocollimator with rotatable optical devices fixed on linear motion stage. To eliminate the influence of the pitching error of the scanning stage, we use two mirrors reflecting laser comes from autocollimator, which have the same effect with a pentaprism used in ESAD. To enlarge the measuring range of the autocollimator, we use a rotatable mirror to fit the changes of the slope of the mirror surface under measurement. The error analysis of the method is done. Measurement of an optical flat mirror and a sphere mirror with diameter of 50 mm and biggest slope of 6000 arc-second are done. The rotatable optical devices that we designed are proved effective on eliminating the pitching error of the moving stage.

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