The influence of the assembly error of the plenoptic sensor on the wavefront detection

2021 ◽  
Author(s):  
Tao Jiang ◽  
Jianghui Zhang ◽  
Chao Mu ◽  
Xiaoxing Feng ◽  
Chunhong Qiao ◽  
...  
Keyword(s):  
Assembly Error ◽  
Wavefront Detection

scholarly journals A Novel Method for the Complex Tube System Reconstruction and Measurement

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2207
Author(s):  
Xiang Guo ◽  
Xin Su ◽  
Yingtao Yuan ◽  
Tao Suo ◽  
Yan Liu
Keyword(s):  
Neural Network ◽  
Minimum Distance ◽  
Technical Difficulty ◽  
Industry Structure ◽  
Tube System ◽  
Simulation Experiments ◽  
Pipe System ◽  
System Reconstruction ◽  
Novel Method ◽  
Assembly Error

Pipe structures are at the base of the entire industry. In the industry structure, heat and vibration are transmitted in each pipe. The minimum distance between each pipe is significant to the security. The assembly error and the deformation of the pipeline positions after multiple runs are significant problems. The reconstruction of the multi-pipe system is a critical technical difficulty in the complex tube system. In this paper, a new method for the multi-pipes structure inspection is presented. Images of the tube system are acquired from several positions. The photogrammetry technology calculates positions, and the necessary coordination of the structure is reconstructed. A convolution neural network is utilized to detect edges of tube-features. The new algorithm for tube identification and reconstruction is presented to extract the tube feature in the image and reconstruct the 3D parameters of all tubes in a multi-pipes structure. The accuracy of the algorithm is verified by simulation experiments. An actual engine of the aircraft is measured to verify the proposed method.

Post-assembly error-checking in subphthalocyanine based M3L2 metallosupramolecular capsules

2008 ◽  
pp. 6378 ◽  
Author(s):  
Christian G. Claessens ◽  
M. Jesús Vicente-Arana ◽  
Tomás Torres
Keyword(s):  
Error Checking ◽  
Assembly Error

scholarly journals Mechanism reliability and sensitivity analysis of landing gear under multiple failure modes

2021 ◽  
Vol 39 (1) ◽  
pp. 46-54
Author(s):  
Changcong Zhou ◽  
Mengyao Ji ◽  
Yishang Zhang ◽  
Fuchao Liu ◽  
Haodong Zhao
Keyword(s):  
Failure Probability ◽  
Failure Modes ◽  
Kriging Model ◽  
Landing Gear ◽  
Multiple Failure Modes ◽  
Analysis And Design ◽  
Extension System ◽  
Extension Mechanism ◽  
Assembly Error ◽  
Adaptive Kriging

For a certain type of aircraft landing gear retraction-extension mechanism, a multi-body dynamic simulation model is established, and the time-dependent curves of force and angle are obtained. Considering the random uncertainty of friction coefficient, assembly error, and the change of hinge wear under different retraction times, the reliability model is built including three failure modes of landing gear, i.e. blocking failure, positioning failure and accuracy failure. Based on the adaptive Kriging model, the reliability and sensitivity of retraction-extension system under the condition of single failure mode and multiple failure modes in series are analyzed, and the rule of reliability and sensitivity changing with the number of operations is given. The results show that the system failure probability of landing gear mechanism tends to decrease first and then increase when considering the given information of random factors, and the influences of random factors on the failure probability vary with the number of operations. This work provides a viable tool for the reliability analysis and design of landing gear mechanisms.

Error Analysis by Square 3 x 3 Machining Method for Five-Axis Machining Centers

2020 ◽  
Author(s):  
Shigehiko Sakamoto ◽  
Atsushi Yokoyama ◽  
Kazumasa Nakayasu ◽  
Toshihiro Suzuki ◽  
Shinji Koike
Keyword(s):  
International Standards ◽  
Test Method ◽  
Accuracy Evaluation ◽  
Alignment Error ◽  
Machined Surface ◽  
Machining Center ◽  
Alignment Errors ◽  
Assembly Error ◽  
Five Axis ◽  
Machined Surfaces

Abstract The establishment of international standards for 5-axis control machining centers has been supported by the high interest of each country. Internationally, various accuracy inspection methods have been proposed and widely discussed. Accuracy measuring devices for these purposes have also been proposed. In 2014, inspection methods for 5-axis machines were published in ISO 10791-6 and 10791-7. In this research, we propose a test method to process 9 square faces as a new accuracy evaluation method. We simulate the influence of assembly error by the proposed square 3 × 3 machining method on the machined surface. By processing 9 square faces with different tool angle on the same plane, it was possible to evaluate the influence of assembly errors in the 5-axis machining center on the machined surface. Nine surfaces machined by the square 3 × 3 processing method cause differences in surface height due to alignment errors. In addition, nine machined surfaces become all diagonal not parallelism. The alignment errors of the 5-axis machining center is identified by evaluating the orientation of the machined surfaces. Specifically, we propose a newly method to measure the height difference of nine surfaces. Then, the possibility of identifying the alignment error of the 5-axis machining center using the measurement results is shown.

Application of differential pentaprism scanning in wavefront detection

2014 ◽  
Vol 7 (6) ◽  
pp. 1003-1011
Author(s):  
汤兆鑫 TANG Zhao-xin ◽  
黄玮 HUANG Wei ◽  
许伟才 XU Wei-cai ◽  
刘立峰 LIU Li-feng ◽  
徐象如 XU Xiang-ru
Keyword(s):  
Wavefront Detection

Assembly Error Tolerance of Interferometer Plate in Mirau Interference-Microscope Objective

2019 ◽  
Vol 46 (9) ◽  
pp. 0904001
Author(s):  
胡捷 Jie Hu ◽  
袁群 Qun Yuan ◽  
于颢彪 Haobiao Yu ◽  
王帅 Shuai Wang ◽  
孙一峰 Yifeng Sun ◽  
...  
Keyword(s):  
Error Tolerance ◽  
Interference Microscope ◽  
Microscope Objective ◽  
Assembly Error

A linear model for the machine tool assembly error prediction considering roller guide error and gravity-induced deformation

2020 ◽  
Vol 234 (15) ◽  
pp. 2939-2950 ◽  
Author(s):  
Gaiyun He ◽  
Panpan Shi ◽  
Longzhen Guo ◽  
Bohui Ding
Keyword(s):  
Machine Tool ◽  
Error Model ◽  
Error Modeling ◽  
Propagation Model ◽  
Joint Surface ◽  
Analytical Relationship ◽  
Error Prediction ◽  
Linear Superposition ◽  
Roller Guide ◽  
Assembly Error

In assembly, error prediction and control according to the error state of the machine parts are the key links to ensuring the accuracy of the entire machine tool. In this study, an assembly error modeling method considering the error of the roller guide and gravity-induced deformation is proposed. First, based on the Hertz contact theory, a nonlinear error propagation model for the roller guide to the moving part is proposed. With this model, the analytical relationship between the straightness error of the guide rail and the errors of the moving part can be established. Then, after the linearization of the guide error model, a machine assembly error model considering the guide error is proposed. This model expresses the linear relationship between the error of the rolling joint surface and the error of the machine tool after the final assembly. Additionally, considering the influence of gravity deformation of structural parts, the gravity deformation is extracted by the finite element analysis method and added to the model by linear superposition. As a result, the model corresponds more with the practical assembly process. Finally, an assembly error prediction method of the precision horizontal machining center is presented, and a case is studied to demonstrate the validity of the proposed model and method.

Wavefront detection using curved nanoscale apertures

2019 ◽  
Vol 114 (18) ◽  
pp. 183103
Author(s):  
Charles Pelzman ◽  
Sang-Yeon Cho
Keyword(s):  
Wavefront Detection
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