scholarly journals A Combined Measurement Method for Large-Size Aerospace Components

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4843
Author(s):  
Zhilong Zhou ◽  
Wei Liu ◽  
Qiong Wu ◽  
Yuxin Wang ◽  
Binchao Yu ◽  
...  

Automated and high-accuracy three-dimensional (3D) shape measurement is required in quality control of large-size components for the aerospace industry. To eliminate the contradiction between global measurement and local precision measurement control in 3D digitalization for the key local features of the large-size components, a combined measurement method is proposed, including a 3D scanner, a laser tracker, and an industrial robot used as an orienting device, to achieve high-accuracy measurement. As for improving the overall measurement accuracy, an accurate calibration method based on coordinate optimization of common points (COCP) and coordinate optimization of global control points (COGP) is proposed to determine the coordinate systems. Firstly, a coordinate optimization method of common points (COCP) is recommended. Then, a coordinate optimization method of global control points (COGP) based on the angular constraint is proposed for minimizing the measurement errors and improving the measurement accuracy of the position and orientation of the 3D scanner. Finally, a combined measurement system is established, and validation experiments are carried out in laboratory within a distance of 4 m. The calibration experiment results demonstrate that the max and mean errors of the coordinate transformation have been reduced from 0.037 and 0.022 mm to 0.021 and 0.0122 mm. Additionally, the measurement experiment results also show that the combined measurement system features high accuracy.

2010 ◽  
Vol 97-101 ◽  
pp. 4324-4327
Author(s):  
Yong Lu Zhu ◽  
Yin Biao Guo ◽  
Xiao Long Ke ◽  
Lu Shuang Chen

In this paper, the necessary instrument and control system called the “Large Size Four-axis Measurement System” which used for measuring large size aspheric surface have been designed and established. Then the development of semi-meridian measurement method on basis of large size four-axis detection system has been reported. The measurement paths were planed and the measurement program was performed on the IPC. The method can significantly reduced the align error caused by the aspheric center which is not coincidence with the rotation platform center. With the measurement system, an aspheric surface was successfully measured; whose radius of semi-meridian was 55 mm. The experimental results show that the developed methods are simple and rapid. The measurement accuracy can satisfy requirement of aspheric surface.


2011 ◽  
Vol 222 ◽  
pp. 62-65 ◽  
Author(s):  
Takeshi Hashimoto ◽  
Mitsuo Kaneko ◽  
András Rövid ◽  
Hiroaki Ohta ◽  
Akira Fukuda ◽  
...  

To reveal the influence of global warming on glaciers, highly accurate observations of glacier movement must continue every year. It is thought that there is a close relationship between glacier moving speed and global warming. Thus, there have been precise, detailed observations of the movement of the Perito Moreno glacier in Patagonia of the Argentine Republic over the past five years. The measurement method of using GPS and an optical measuring instrument is generally used to monitor glacier movement, but the measurement accuracy attained is not optimal because of the huge size of the glacier. The measurement system used for the Perito Moreno observations, however, could realize high accuracy measurement over long distance. The measurement system is based on the principle of stereo measurement using cameras. This paper describes the results of the Perito Moreno glacier observations of this year and considers the effectiveness of glacier observation using cameras.


2014 ◽  
Vol 609-610 ◽  
pp. 106-112 ◽  
Author(s):  
Hai Bin Pan ◽  
Jian Ning Ding ◽  
Bao Guo Cao ◽  
Guang Gui Cheng

Inspection and measurement for the sheet resistance and resistivity play a pivotal role in the semiconductor industry. In this study, a high-accuracy measurement system for sheet resistance of thin films was designed based on dual-measurement with four-point probe method. The measurement system was composed of a special switching circuit, a digital output module, Keithley 2400 SourceMeter, and a computer running LabVIEW. The special switching circuit designed based on the multiplexer played an important role in current probes and voltage probes automatic switching under the control of virtual instrumentation software LabVIEW and National instruments digital output module hardware NI 9401. Keithley 2400 SourceMeter controlled by LabVIEW was used for two-times high-precision voltage measurement. Van der Pauw correction factor were calculated based on the results of the two-times voltage measurement. Then the sheet resistance of thin films was calculated by LabVIEW softwares powerful computing. The experimental results show that the designed and developed system can meet the needs of fast on-line measurement of thin films sheet resistance with a wide range, and moreover, the accuracy of measurements and the level of automatization have been dramatically improved compared to the conventional measurement system.


2013 ◽  
Vol 392 ◽  
pp. 734-737
Author(s):  
Wan Ting Wang ◽  
Han Bing Liu

This paper introduces a new close-range photogrammetric bridge deflection non-contact measurement method that has high accuracy and efficiency, and can be conveniently used by engineers without help from professional surveyors. After a general theoretical description (analysis process and program development) of a photogrammetric bridge deflection measurement method, the system configuration is introduced and the application is verified through the laboratory and field tests.


Author(s):  
Satoshi Fujita ◽  
Osamu Furuya ◽  
Yasushi Niitsu

This study has been doing research and development of 3-dimensional measurement method using the image processing technique for the measurement of dynamic displacement in shake table test. This measurement system is a very convenient system because it can measure the three-dimensional dynamic displacement in shake table test in which the several makers are only attached to the surface of an experimental structure. The system therefore is the most suitable measurement system for an evaluation of complex 3-dimensional behavior of experimental model. Fundamental hardware and software for the measurement system have been constructed until now. The fundamental dynamic measurement accuracy and effectiveness of the measurement system have been also confirmed from several shake table tests. This paper describes the dynamic measurement accuracy in shake table test in with the experimental model has several rotational behaviors, and also summarizes the synthetic performance of the proposed measurement system.


2003 ◽  
Author(s):  
Satoshi Fujita ◽  
Osamu Furuya ◽  
Yasushi Niitsu ◽  
Tadashi Mikoshiba ◽  
Daisuke Nakano

This study has been doing research and development of 3-dimensional measurement method using an image processing technique for a measurement of dynamic displacement in shake table test. This measurement system is a very convenient system because it can measure the 3-D dynamic displacement in shake table test in which the several makers are only attached to the surface of an experimental structure. The system therefore is the most suitable measurement system for an evaluation of complex 3-dimensional behaviour of test model. Fundamental hardware and software for the measurement system has been constructed until now. The fundamental dynamic measurement accuracy and effectiveness of the measurement system has been also confirmed from several shake table tests. In this paper, the dynamic measurement accuracy in three measurement units on the assumption of practical use is described from the results of shake table tests in National Research Institute for Earth Science and Disaster Prevention using the collapse building and the inverted pendulum model.


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