scholarly journals Microscopic Three-Dimensional Measurement Based on Telecentric Stereo and Speckle Projection Methods

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3882 ◽  
Author(s):  
Kepeng Chen ◽  
Tielin Shi ◽  
Qiang Liu ◽  
Zirong Tang ◽  
Guanglan Liao
Keyword(s):  
Measurement Accuracy ◽  
Three Dimensional ◽  
Projection Methods ◽  
Reconstruction Procedure ◽  
Cylinder Arrays ◽  
Stereo Reconstruction ◽  
Three Dimensional Measurement ◽  
Binocular Stereo ◽  
3D Information ◽  
Microscopic Measurement

Three-dimensional (3D) measurement of microstructures has become increasingly important, and many microscopic measurement methods have been developed. For the dimension in several millimeters together with the accuracy at sub-pixel or sub-micron level, there is almost no effective measurement method now. Here we present a method combining the microscopic stereo measurement with the digital speckle projection. A microscopy experimental setup mainly composed of two telecentric cameras and an industrial projection module is established and a telecentric binocular stereo reconstruction procedure is carried out. The measurement accuracy has firstly been verified by performing 3D measurements of grid arrays at different locations and cylinder arrays with different height differences. Then two Mitutoyo step masters have been used for further verification. The experimental results show that the proposed method can obtain 3D information of the microstructure with a sub-pixel and even sub-micron measuring accuracy in millimeter scale.

Research and Realization of a New Algorithm for Stereo Matching Based on Binocular Vision

2013 ◽  
Vol 670 ◽  
pp. 202-207 ◽  
Author(s):  
Jun Ting Cheng ◽  
C. Zhao ◽  
W.L. Zhao ◽  
W.H. Wu
Keyword(s):  
Binocular Vision ◽  
Stereo Matching ◽  
Three Dimensional ◽  
Cnc Machining ◽  
Matching Algorithm ◽  
Evaluation Test ◽  
Three Dimensional Measurement ◽  
Binocular Stereo ◽  
Measuring Machine ◽  
3D Solid

In the development of a three-dimensional measurement system, binocular stereo matching is the most important and difficult. In the basis of introducing selective principles of matching algorithm, a new stereo matching algorithm for binocular vision is put forward that is named noncoded difference measuring distance. The algorithm effectively grapples with the problem of searching for the coincidence relation of raster and can efficiently and accurately obtain three-dimensional world coordinates of the entities. Experiment results show that this 3D measuring machine can effectively measure the 3D solid profile of free surface. During the evaluation test for accuracy, scan a standard plane. Fit all 3D points in one plane, and then the flatness value of this plane is obtained. The flatness value of the standard plane has been ultimately measured as: ± 0.0462mm, this measuring accuracy can completely satisfy the requirements of rapid prototyping or CNC machining, it as well as achieves the stated accuracy (± 0.05mm).

Applications of High-Precise Three-Dimensional Measurement System

2011 ◽  
Vol 222 ◽  
pp. 62-65 ◽  
Author(s):  
Takeshi Hashimoto ◽  
Mitsuo Kaneko ◽  
András Rövid ◽  
Hiroaki Ohta ◽  
Akira Fukuda ◽  
...  
Keyword(s):  
Global Warming ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Long Distance ◽  
Accuracy Measurement ◽  
Close Relationship ◽  
Three Dimensional Measurement ◽  
High Accuracy Measurement ◽  
Moving Speed

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.

scholarly journals HIGH THROUGHPUT SYSTEM FOR PLANT HEIGHT AND HYPERSPECTRAL MEASUREMENT

2018 ◽  
Vol XLII-3 ◽  
pp. 2365-2369
Author(s):  
H. Zhao ◽  
L. Xu ◽  
H. Jiang ◽  
S. Shi ◽  
D. Chen
Keyword(s):  
Physicochemical Properties ◽  
High Throughput ◽  
Stereo Vision ◽  
Three Dimensional ◽  
Working Hours ◽  
Field Of View ◽  
Geometrical Characteristics ◽  
Dimensional Measurement ◽  
Three Dimensional Measurement ◽  
3D Information

Hyperspectral and three-dimensional measurement can obtain the intrinsic physicochemical properties and external geometrical characteristics of objects, respectively. Currently, a variety of sensors are integrated into a system to collect spectral and morphological information in agriculture. However, previous experiments were usually performed with several commercial devices on a single platform. Inadequate registration and synchronization among instruments often resulted in mismatch between spectral and 3D information of the same target. And narrow field of view (FOV) extends the working hours in farms. Therefore, we propose a high throughput prototype that combines stereo vision and grating dispersion to simultaneously acquire hyperspectral and 3D information.

A High-Precision Binocular Measurement System

2013 ◽  
Vol 823 ◽  
pp. 402-405
Author(s):  
Yue Gang Fu ◽  
Fan Hao Jin
Keyword(s):  
Robot Navigation ◽  
Three Dimensional ◽  
Distant Object ◽  
Dimensional Measurement ◽  
Binocular Stereo Vision ◽  
Unique Measure ◽  
Three Dimensional Measurement ◽  
Binocular Stereo ◽  
Dimensional Measurements ◽  
Binocular Measurement

The system uses three-dimensional measurement of binocular vision theory, through optical, mechanical, computer and other aspects of the technology to measure the target without contact, and up to a certain precision. In the high-voltage area, high-altitude target,and the target which is not easy to touch, there is a unique measure advantage. Binocular stereo vision is based on the principle of parallax and using imaging devices from different locations to obtain two images of the measured object and obtain three dimensional geometric of target by positional deviation between corresponding points in computer image. Binocular stereo currently used in four areas: robot navigation, micro operating system parameter detection, three-dimensional measurements and virtual reality. In addition, the system not only to measure the length of the distant object, the system can also be used to measure the width, surface area, height and tilt angle. As the tip of an optical imaging technology this system has a broad application prospects in the future.

scholarly journals Improved High Dynamic Range for 3D Shape Measurement based on Saturation of the Coloured Fringe

2021 ◽  
Vol 29 (2) ◽  
Author(s):  
Shanyu Chua ◽  
Chee Chin Lim ◽  
Swee Kheng Eng ◽  
Yen Fook Chong ◽  
Chiun Tai Loh
Keyword(s):  
Measurement Errors ◽  
Dynamic Range ◽  
Three Dimensional ◽  
High Dynamic Range ◽  
Projection Methods ◽  
Phase Shifting ◽  
Reflective Property ◽  
High Dynamic ◽  
The Times ◽  
3D Information

Phase-shifting fringe projection methods have been developed for three-dimensional scanning (Zuo et al., 2018). However, the 3-Dimensional (3D) scanning of objects with a high dynamic reflectivity range based on structured light is a challenging task to achieve (Feng et al., 2018). The incorrect intensities captured will cause phase and measurement errors. Thus, this paper proposes a method that improves the current High Dynamic Range (HDR) (Jiang et al., 2016)) method to increase the dynamic range. The camera and projector have 3 channels, red, green, and blue, which can absorb and project these lights independently. This paper proposes a method that makes use of this by controlling the intensity of each projected for the camera. Each image can be split into 3 channels and provide 3 images which contain different intensities, then it will be used to compute the 3D information. In general, this is done by controlling the projection of red, green and blue (RGB) channel and apply the Jiang’s algorithm (Jiang et al., 2016). The results are compared and analysed with current HDR (Jiang’s method) and the regular three-step phase-shifting methods. From the experimental results, it has shown that our proposed method outperforms the current HDR and the regular three-step phase-shifting methods. Specifically, the proposed method manages to increase the dynamic range of the reflective property of objects. Additionally, our proposed method has also significantly reduced the times of 3D object measurements.

Three-Dimensional Measurement System Based on Line Laser

2013 ◽  
Vol 333-335 ◽  
pp. 32-36
Author(s):  
Le Wen Yu ◽  
Da Zhang ◽  
Yuan Sheng Zhang
Keyword(s):  
Mathematical Model ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Measurement Range ◽  
Laser Triangulation ◽  
Depth Information ◽  
Dimensional Measurement ◽  
Three Dimensional Measurement ◽  
On Line

This paper puts forward a three-dimensional measurement system based on line laser, describing its operating principle. Extracted the light stripes center by image processing technology, and establishing mathematical model, detecting the depth information by the method of laser triangulation, and reconstructed the three-dimensional form of object. The experimental results indicate that measurement accuracy less than ±0.03mm when the measurement range between 0mm to 10mm.

Study on 3-D Measurement Method in Shake Table Tests Using Image Processing Technique: 2nd Report - Measurement Accuracy in Actual Fracturing Test Using Full Scale Wooden House Model

2004 ◽  
Author(s):  
Satoshi Fujita ◽  
Osamu Furuya ◽  
Tadashi Mikoshiba
Keyword(s):  
Measurement System ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Shake Table ◽  
Shake Table Tests ◽  
Wooden House ◽  
Three Dimensional Measurement

This study has been examined about a three-dimensional measurement method that can measure a position and an attitude of test object without any contact. Fundamental hardware and software in measurement system has been constructed until now. Moreover, the fundamental dynamic measurement accuracy and effectiveness of the proposed measurement system has been confirmed from the several shake table tests. This paper describes the effectiveness of the proposed system for the measurement in fracturing test using real scale wooden house model.

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