3D-profilometry of moving objects with abrupt surface discontinuities by projection of two-frequency color-coded fringe patterns

2021 ◽  
Author(s):  
Jorge Luis Flores Nuñez ◽  
Oscar E. Castillo ◽  
J. Julia R. Alonso ◽  
Ariel Fernández ◽  
Yanely B. Machuca
Keyword(s):  
Moving Objects ◽  
3D Profilometry ◽  
Fringe Patterns ◽  
Surface Discontinuities

scholarly journals Reconstruction of Isolated Moving Objects by Motion-Induced Phase Shift Based on PSP

2021 ◽  
Vol 12 (1) ◽  
pp. 252
Author(s):  
Ke Wu ◽  
Min Li ◽  
Lei Lu ◽  
Jiangtao Xi
Keyword(s):  
Phase Shift ◽  
Fringe Pattern ◽  
Moving Objects ◽  
Object Motion ◽  
Moving Object ◽  
Phase Shifting ◽  
Phase Information ◽  
Object Reconstruction ◽  
Fringe Patterns

The reconstruction of moving objects based on phase shifting profilometry has attracted intensive interests. Most of the methods introduce the phase shift by projecting multiple fringe patterns, which is undesirable in moving object reconstruction as the errors caused by the motion will be intensified when the number of the fringe pattern is increased. This paper proposes the reconstruction of the isolated moving object by projecting two fringe patterns with different frequencies. The phase shift required by the phase shifting profilometry is generated by the object motion, and the model describing the motion-induced phase shift is presented. Then, the phase information in different frequencies is retrieved by analyzing the influence introduced by movement. Finally, the mismatch on the phase information between the two frequencies is compensated and the isolated moving object is reconstructed. Experiments are presented to verify the effectiveness of the proposed method.

scholarly journals Application of orthogonal fringe patterns in uniaxial microscopic 3D profilometry

OSA Continuum ◽  
2020 ◽  
Vol 3 (11) ◽  
pp. 3206
Author(s):  
Min Zhong ◽  
Ke Cheng ◽  
Feng Chen ◽  
Chao Xiao ◽  
Peng Duan ◽  
...  
Keyword(s):  
3D Profilometry ◽  
Fringe Patterns

scholarly journals Perfilometría 3D por proyección desenfocada de patrones binarios

2020 ◽  
Vol 1 (1) ◽  
pp. 18-24
Author(s):  
A. Silva ◽  
J. L. Flores ◽  
A. Muñoz ◽  
G. García-Torales
Keyword(s):  
Phase Shift ◽  
Linear Response ◽  
Moving Objects ◽  
Structured Light ◽  
Phase Error ◽  
Three Dimensional ◽  
Three Dimensional Reconstruction ◽  
El Sistema ◽  
Dimensional Reconstruction ◽  
Fringe Patterns

Las técnicas basadas en proyección de luz estructurada son ampliamente estudiadas y utilizadas en el área de perfilometría tridimensional, esto debido a la capacidad para obtener información completa de la superficie de objetos. Algunas de estas técnicas se basan en la proyección de patrones de intensidad sinusoidal y el uso de algoritmos de corrimiento de fase. En el caso de la reconstrucción tridimensional de objetos dinámicos en movimiento, uno de los desafíos es reducir el número de pasos o imágenes a ser proyectadas. Sin embargo, la precisión de estos sistemas se reduce conforme decrece el número de patrones (a un mínimo de tres). El sistema de proyección presenta una respuesta no lineal, lo cual introduce armónicos en los patrones adquiridos y en la recuperación de fase. En los últimos años, la proyección desenfocada de patrones binarios para generar patrones de franjas cuasi sinusoidales ha emergido como una alternativa para evitar el problema de no linealidad del proyector y, por ende, reducir el error en la fase. En este trabajo se presenta una revisión de distintos métodos propuestos en la literatura para generar patrones binarios, los cuales sintetizan patrones cuasi sinusoidales cuando son proyectados fuera de foco. Adicionalmente, analizamos el error de fase en función a la cantidad de desenfoque y el tamaño del periodo fundamental de las franjas. The techniques of structured light projection are widely studied in the area of three-dimensional profilometry, due to its ability to obtain information from the surface of an object. In particular, those based on the projection of a sequence of sinusoidal intensity patterns and the use of phase shift algorithms. In the case of three-dimensional reconstruction of dynamic or moving objects, one of the trends is to reduce the number of steps or patterns to be projected. However, the accuracy of these systems is reduced as the number of steps decreases (to a minimum of 3 steps). This is because the projection systems present a non-linear response, which translates into the introduction of harmonics in the acquired sinusoidal patterns, and therefore, error in the recovered phase. In the last years, the defocused projection of binary patterns has emerged as an alternative to avoid the projector’s non-linearity and generates quasi-sinusoidal fringe patterns to reduce the phase error. In this work, we review different techniques that have been proposed in the literature to generate binary patterns, which synthesize quasi-sinusoidal patterns when projected out of focus. In addition, we analyze the error in the phase as a function of the defocusing amount and the fringe pitch.

Humans can simultaneously attend to eight moving objects

2009 ◽  
Author(s):  
Piers D. Howe ◽  
Michael A. Cohen ◽  
Yair Pinto ◽  
Todd S. Horowitz
Keyword(s):  
Moving Objects

GPS and GSM Based Tracking System for Objects Moving over Wide Geographical Areas

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Fatima Ameen ◽  
Ziad Mohammed ◽  
Abdulrahman Siddiq
Keyword(s):  
Global Positioning System ◽  
Mobile Communications ◽  
Moving Objects ◽  
Tracking System ◽  
Geographical Area ◽  
Tracking Systems ◽  
Acceptable Result ◽  
Internet Service ◽  
Global Positioning ◽  
Tracking Objects

Tracking systems of moving objects provide a useful means to better control, manage and secure them. Tracking systems are used in different scales of applications such as indoors, outdoors and even used to track vehicles, ships and air planes moving over the globe. This paper presents the design and implementation of a system for tracking objects moving over a wide geographical area. The system depends on the Global Positioning System (GPS) and Global System for Mobile Communications (GSM) technologies without requiring the Internet service. The implemented system uses the freely available GPS service to determine the position of the moving objects. The tests of the implemented system in different regions and conditions show that the maximum uncertainty in the obtained positions is a circle with radius of about 16 m, which is an acceptable result for tracking the movement of objects in wide and open environments.

Real-Time Moving Objects Tracking for Distributed Smart Video Surveillances

2016 ◽  
Vol 11 (4) ◽  
pp. 324
Author(s):  
Nor Nadirah Abdul Aziz ◽  
Yasir Mohd Mustafah ◽  
Amelia Wong Azman ◽  
Amir Akramin Shafie ◽  
Muhammad Izad Yusoff ◽  
...  
Keyword(s):  
Real Time ◽  
Moving Objects ◽  
Objects Tracking

Stress Analysis of Tire Sections

1996 ◽  
Vol 24 (4) ◽  
pp. 349-366 ◽  
Author(s):  
T-M. Wang ◽  
I. M. Daniel ◽  
K. Huang
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Strain Analysis ◽  
Experimental Stress ◽  
Inflation Pressure ◽  
Substantial Agreement ◽  
Finite Element Stress Analysis ◽  
Strain Components ◽  
Fringe Patterns

Abstract An experimental stress-strain analysis by means of the Moiré method was conducted in the area of the tread and belt regions of tire sections. A special loading fixture was designed to support the tire section and load it in a manner simulating service loading and allowing for Moiré measurements. The specimen was loaded by imposing a uniform fixed deflection on the tread surface and increasing the internal pressure in steps. Moiré fringe patterns were recorded and analyzed to obtain strain components at various locations of interest. Maximum strains in the range of 1–7% were determined for an effective inflation pressure of 690 kPa (100 psi). These results were in substantial agreement with results obtained by a finite element stress analysis.

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