scholarly journals Accurate and Robust Surface Measurement Using Optimal Structured Light Tracking Method

2010 ◽  
Vol E93-D (2) ◽  
pp. 293-299 ◽  
Author(s):  
Shi WANG ◽  
Hyongsuk KIM ◽  
Chun-Shin LIN ◽  
Hongxin CHEN
Keyword(s):  
Structured Light ◽  
Surface Measurement ◽  
Tracking Method

A New Three-Dimensional Profilometer for Surface Profile Measurement Using Digital Fringe Projection and Phase Shifting

2005 ◽  
Vol 295-296 ◽  
pp. 471-476
Author(s):  
Liang Chia Chen ◽  
S.H. Tsai ◽  
Kuang Chao Fan
Keyword(s):  
High Speed ◽  
Structured Light ◽  
Three Dimensional ◽  
Surface Profile ◽  
Phase Shifting ◽  
Fringe Projection ◽  
Surface Measurement ◽  
Profile Measurement ◽  
Digital Fringe Projection ◽  
Fringe Patterns

The development of a three-dimensional surface profilometer using digital fringe projection technology and phase-shifting principle is presented. Accurate and high-speed three-dimensional profile measurement plays a key role in determining the success of process automation and productivity. By integrating a digital micromirror device (DMD) with the developed system, exclusive advantages in projecting flexible and accurate structured-light patterns onto the object surface to be measured can be obtained. Furthermore, the developed system consists of a specially designed micro-projecting optical unit for generating flexibly optimal structured-light to accommodate requirements in terms of measurement range and resolution. Its wide angle image detection design also improves measurement resolution for detecting deformed fringe patterns. This resolves the problem in capturing effective deformed fringe patterns for phase shifting, especially when a coaxial optical layout of a stereomicroscope is employed. Experimental results verified that the maximum error was within a reasonable range of the measured depth. The developed system and the method can provide a useful and effective tool for 3D full field surface measurement ranging from µm up to cm scale.

Influence of Coating Spray on Surface Measurement Using 3D Optical Scanning Systems

2019 ◽  
Author(s):  
Yuhang Yang ◽  
Siyuan Chen ◽  
Letao Wang ◽  
Jingying He ◽  
Shang-Ming Wang ◽  
...  
Keyword(s):  
Structured Light ◽  
Spray Coating ◽  
Surface Measurement ◽  
Scanning System ◽  
3D Measurement ◽  
Optical Scanning ◽  
Wide Range ◽  
Structured Light Scanning ◽  
3D Measurement System ◽  
Scanning Systems

Abstract High-resolution 3D measurement is crucial for a wide range of applications in manufacturing. With the recent development of optical technologies, the performance of many 3D scanning systems has entered the practical range for object digitizing, reverse engineering, quality control, and many other manufacturing applications. In order to extend the measurement capability to reflective or transparent surfaces, a common practice for reducing the unwanted reflection and refraction is to coat the surfaces with micro-particle spray. There is, however, limited discussion about the influence of coating spray on the resulted measurement precision of 3D optical scanning systems, and due to lack of standardized procedure for spray coating, the variability caused by different operators in surface measurement remains to be examined. This paper investigates the 3D data acquisition of spray-coated surfaces with a structured-light scanning system through experiments and statistical analysis. Both surface roughness and spatial statistics are used to quantitatively evaluate the characteristics of the 3D measurement system. Gauge R&R study is conducted to determine measurement repeatability and reproducibility. The results demonstrate that both the number of spray pass and the skill of the individual operator can significantly affect the performance of the structured-light scanning system. Other pertinent suggestions for the operation of 3D optical scanning systems with spray coating are also provided.

Three-Dimensional Inner Surface Inspection System Based on Circle-Structured Light

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Zhu Ye ◽  
Wang Lianpo ◽  
Gu Yonggang ◽  
Bi Songlin ◽  
Zhai Chao ◽  
...  
Keyword(s):  
Structured Light ◽  
Three Dimensional ◽  
Ccd Camera ◽  
Absolute Error ◽  
Surface Measurement ◽  
Laser Triangulation ◽  
Inspection System ◽  
Surface Inspection ◽  
Laser Plane ◽  
Inner Surface

A three-dimensional (3D) inner surface inspection system is developed in this research based on circle-structured light, which is an improved laser triangulation method. A conical reflector is used to reflect the laser and generate radial laser plane that is called circle-structured light, and a CCD camera is used to capture the light stripe on the inner surface. Then, the 3D coordinates of points on the light stripe are calculated through laser triangulation algorithm. Compared with existing inner surface measurement systems, this research takes assembly errors and refraction distortion into consideration and proposes a laser plane mathematical model with four degrees-of-freedom along with corresponding flexible laser plane calibration technique based on binocular vision that is easy to operate. The proposed inspection system calibrated by proposed algorithm performs well in diameter measurement experiment, in which the absolute error is superior to 3 μm, and defect detecting experiment, in which the defect resolution is superior to 0.02 mm. Moreover, the system also performs well in straightness and roundness evaluation. Experiments indicate that this system is applicable in inner surface measurement and inspection, and the calibration method is accurate and easy to operate.

scholarly journals Fourier-Transform-Based Surface Measurement and Reconstruction of Human Face Using the Projection of Monochromatic Structured Light

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2529
Author(s):  
Bingquan Chen ◽  
Hongsheng Li ◽  
Jun Yue ◽  
Peng Shi
Keyword(s):  
Fourier Transform ◽  
Structured Light ◽  
Surface Measurement ◽  
Human Face ◽  
Image Processing Algorithm ◽  
Optical Filtering ◽  
Linearly Polarized ◽  
Potential Applications ◽  
Filtering Technique ◽  
The Fourier Transform

This work presents a new approach of surface measurement of human face via the combination of the projection of monochromatic structured light, the optical filtering technique, the polarization technique and the Fourier-transform-based image-processing algorithm. The theoretical analyses and experimental results carried out in this study showed that the monochromatic feature of projected fringe pattern generated using our designed laser-beam-based optical system ensures the use of optical filtering technique for removing the effect of background illumination; the linearly-polarized characteristic makes it possible to employ a polarizer for eliminating the noised signal contributed by multiply-scattered photons; and the high-contrast sinusoidal fringes of the projected structured light provide the condition for accurate reconstruction using one-shot measurement based on Fourier transform profilometry. The proposed method with the portable and stable optical setup may have potential applications of indoor medical scan of human face and outdoor facial recognition without strict requirements of a dark environment and a stable object being observed.

Sphere-Based Geometrical Calibration Method for Structured Light Surface Measurement Systems

2012 ◽  
Vol 571 ◽  
pp. 433-438 ◽  
Author(s):  
Jules Douet ◽  
Jing Xu ◽  
Ken Chen
Keyword(s):  
Structured Light ◽  
Calibration Method ◽  
Ease Of Use ◽  
Translation Method ◽  
Surface Measurement ◽  
Measurement Systems ◽  
Light System ◽  
Light Surface ◽  
Calibration Time ◽  
Structured Light System

This paper proposes a sphere-based calibration method for the structured light system with unconstrained one projector & one camera, regardless of pattern codification. A 1-pose example of such a method is also proposed and tested. In comparison with a traditional plane translation method of 15 poses, we note an increase in the consistency of more than 10% while the calibration time shrinks to 6% and the calibration accessory is reduced to the size of a flash-light. This method suits well for applications where mobility, speed and ease-of-use are important criteria.

Sign in / Sign up

Export Citation Format

Share Document