Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Oct 3:7:71.
doi: 10.1038/s41377-018-0072-3. eCollection 2018.

GOBO projection for 3D measurements at highest frame rates: a performance analysis

Affiliations

GOBO projection for 3D measurements at highest frame rates: a performance analysis

Stefan Heist et al. Light Sci Appl. .

Abstract

Aperiodic sinusoidal patterns that are cast by a GOBO (GOes Before Optics) projector are a powerful tool for optically measuring the surface topography of moving or deforming objects with very high speed and accuracy. We optimised the first experimental setup that we were able to measure inflating car airbags at frame rates of more than 50 kHz while achieving a 3D point standard deviation of ~500 µm. Here, we theoretically investigate the method of GOBO projection of aperiodic sinusoidal fringes. In a simulation-based performance analysis, we examine the parameters that influence the accuracy of the measurement result and identify an optimal pattern design that yields the highest measurement accuracy. We compare the results with those that were obtained via GOBO projection of phase-shifted sinusoidal fringes. Finally, we experimentally verify the theoretical findings. We show that the proposed technique has several advantages over conventional fringe projection techniques, as the easy-to-build and cost-effective GOBO projector can provide a high radiant flux, allows high frame rates, and can be used over a wide spectral range.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no conflict of interest.

Figures

Fig. 1
Fig. 1
Schematic illustration of a GOBO projection-based 3D sensor. Definitions of some of the variables that are listed in Table 1 by means of a a top view of the camera-projector-camera arrangement and b an exemplary GOBO wheel with aperiodic binary fringes
Fig. 2
Fig. 2. 3D point cloud completeness p and standard deviation σ3D when using varying GOBO wheel parameters to project aperiodic sinusoidal patterns (upper row) and phase-shifted sine-like patterns (lower row).
a, d p and σ3D as functions of randomly varied parameters c, σblur, n, ω, and e. b The minimum standard deviation σ3D, which is shown for each of the five parameters. c, e A camera image of the projection of the optimal GOBO pattern onto a plane. f The 3D point standard deviation σ3D as a function of the number of aperiodic sinusoidal patterns (solid lines) and phase-shifted sine-like patterns (dashed lines) that are used for reconstruction
Fig. 3
Fig. 3. Experimental investigation.
a A photograph of the sensor that is used. b, c The measured and e, f simulated dependency of the 3D point standard deviation σ3D and point cloud completeness p on the degree of projector defocusing, which is approximated by a Gaussian blur with standard deviation σblur, and the rotational speed ω of the GOBO wheel. d A detailed view of the GOBO wheel of the sensor that is shown in a. Undesired opaque spots, which may negatively affect the measurement accuracy, are clearly recognisable
Fig. 4
Fig. 4
High-speed 3D measurement of the impact of a 40-bar nitrogen jet on a 400×400mm2 pillow that is attached to a polystyrene plate. a Snapshots of the recorded process at five points in time. b Camera images of the GOBO-projected aperiodic sinusoidal fringes, which are recorded with a resolution of 512 × 408 px at a frame rate of 55.2 kHz. c Reconstructed point clouds at a 3D rate of 5.5 kHz (see also Supplementary Video S2)
Fig. 5
Fig. 5. Block diagram of the simulation framework.
According to the parameters c and n, a part of a GOBO wheel is generated (1). Based on the parameters σblur, ω, and e, subpatterns of the rotating GOBO wheel are determined (2). The subpatterns that are related to a pattern are projected onto a plane and the corresponding camera images are rendered (3). After computing the disparity map (4) and reconstructing the 3D point cloud (5), the standard deviation σ3D and completeness p are estimated

Similar articles

Cited by

References

    1. Schaffer M, Große M, Harendt B, Kowarschik R. Coherent two-beam interference fringe projection for highspeed three-dimensional shape measurements. Appl. Opt. 2013;52:2306–2311. doi: 10.1364/AO.52.002306. - DOI - PubMed
    1. Große M, Schaffer M, Harendt B, Kowarschik R. Fast data acquisition for three-dimensional shape measurement using fixed-pattern projection and temporal coding. Opt. Eng. 2011;50:100503. doi: 10.1117/1.3646100. - DOI
    1. Lutzke, P., Schaffer, M., Kühmstedt, P., Kowarschik, R. & Notni, G. Experimental comparison of phase-shifting fringe projection and statistical pattern projection for active triangulation systems. In Proceedings of SPIE 8788, Optical Measurement Systems for Industrial Inspection VIII. p. 878813 (SPIE, Munich, Germany, 2013).
    1. Pagès, J., Salvi, J., García, R. & Matabosch, C. Overview of coded light projection techniques for automatic 3D profiling. In Proceedings of 2003 IEEE International Conference on Robotics and Automation pp. 133–138 (IEEE, Taipei, Taiwan, China, 2003).
    1. Salvi J, Pagès J, Batlle J. Pattern codification strategies in structured light systems. Pattern Recognit. 2004;37:827–849. doi: 10.1016/j.patcog.2003.10.002. - DOI
  NODES
INTERN 1
Project 26
twitter 2
Verify 1