Dr. Cecil F. Hess Profile

Dr. Cecil F. Hess

President at MetroLaser Inc

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Author

Publications (19)

Proceedings Article | 18 April 2023 Paper

Non-destructive damage detection using laser Doppler vibrometry and machine learning statistical techniques

Dave Dimas, Caden Ziegler, Cecil Hess, Jian Gao, James Trolinger

Proceedings Volume 12487, 124870O (2023) https://doi.org/10.1117/12.2657633

KEYWORDS: Data modeling, Machine learning, Education and training, Digital image correlation, Manufacturing, Vibrometry, Vibration, Metals, Doppler effect, Additive manufacturing

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Due to its ability to manufacture a single, complex part that either (1) could not have been built with traditional manufacturing or (2) would require the assembly of several sub-components, the use of Metal Additive Manufacturing (MAM) has increased over 300% in just the last 5 years1,2. Even with the advancements in the technology of Metal Additive Manufacturing, the final as-built mechanical properties continue to possess variability that make it difficult for designers and engineers to utilize them effectively, especially on mission critical parts. The final material properties of an MAM part are process and operator-dependent and the MAM process is more complex than traditional metal manufacturing techniques. The ability to non-destructively validate the quality of an MAM part is critical as the utilization of metal these parts increases. This paper describes ongoing research that focuses on techniques that can predict if a given part meets customer requirements and is free from hidden defects, flaws, non-visible geometric fluctuations, and variations in mechanical properties that are critical to the design/analysis process and mission certification. The techniques use Laser Doppler Vibrometry to detect the frequency response spectrum for a given part then process that data with non-p-value statistical techniques (Machine Learning) to develop models that can be “trained” to detect a variety of quality issues. Machine Learning models work best when data from many samples with different unacceptable end-states are available and used to train and develop the models. These end-states could be the result of a variety of unacceptable variations in the MAM process, quality of the precursor powdered metal, quality of the millions of micro-welds that make up the MAM build process, size and number of inclusions and micro flaws in the material as well as residual stresses in the part. In this study, our goals were to (1) use a large enough number of parts to ensure the validity of the machine learning model and (2) focus on geometric defects and the effects of residual stresses. For these initial investigations, we utilized Off-The-Shelf parts to increase statistical reliability, improve our ability to train our Machine Learning Model and refine our experimental protocol while keeping costs within the budget for the research. In the second phase of this research, we will use MAM parts.

Proceedings Article | 3 October 2022 Presentation + Paper

A new optical diagnostics tools for grading additive manufactured parts

James Trolinger, Jian Gao, Cecil Hess, Amit Lal

Proceedings Volume 12223, 122230J (2022) https://doi.org/10.1117/12.2633560

KEYWORDS: Composites, Additive manufacturing, Inspection, Finite element methods, Signal processing, Optics manufacturing, Optical diagnostics, Laser spectroscopy, Amplitude modulation, Nondestructive evaluation

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Proceedings Article | 7 September 2018 Paper

An airborne, scanning, digital holography system

James Trolinger, Colin Dankwart, Ali Ziaee, Cecil Hess

Proceedings Volume 10834, 1083411 (2018) https://doi.org/10.1117/12.2319333

KEYWORDS: Digital holography, Holograms, Particles, 3D image reconstruction, Holography, Crystals, Image resolution, Clouds, 3D image processing, Image processing

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SPIE Journal Paper | 26 February 2018

Pulsed spatial phase-shifting digital shearography based on a micropolarizer camera

Vyacheslav Aranchuk, Amit Lal, Cecil Hess, James Davis Trolinger, Eddie Scott

OE, Vol. 57, Issue 02, 024109, (February 2018) https://doi.org/10.1117/12.10.1117/1.OE.57.2.024109

KEYWORDS: Shearography, Cameras, Phase shifts, Polarization, Imaging systems, Pulsed laser operation, Charge-coupled devices, Interferometers, Sensors, Wavefronts

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Proceedings Article | 6 September 2017 Presentation + Paper

Simultaneous measurements of density field and wavefront distortions in high speed flows

Jacob George, Thomas Jenkins, James Trolinger, Cecil Hess, Benjamin Buckner

Proceedings Volume 10410, 1041006 (2017) https://doi.org/10.1117/12.2275883

KEYWORDS: Wavefront distortions, Wavefronts, Rayleigh scattering, Wavefront sensors, Optical sensors, Aerodynamics, Distortion

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Proceedings Article | 28 August 2016 Paper

Digital holographic interferometry for characterizing deformable mirrors in aero-optics

James Trolinger, Cecil Hess, Payam Razavi, Cosme Furlong

Proceedings Volume 9960, 99600Q (2016) https://doi.org/10.1117/12.2238593

KEYWORDS: Digital holography, Digital cameras, Cameras, Deformable mirrors, Actuators, Wavefronts, Laser Doppler velocimetry, Mirrors, Holographic interferometry, Temporal resolution

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SPIE Journal Paper | 1 October 2006

Multi-beam laser Doppler vibrometer for landmine detection

Vyacheslav Aranchuk, Amit Lal, Cecil Hess, James Sabatier

OE, Vol. 45, Issue 10, 104302, (October 2006) https://doi.org/10.1117/12.10.1117/1.2358975

KEYWORDS: Land mines, Doppler effect, Mining, Image segmentation, Speckle, Spatial resolution, Laser Doppler velocimetry, Sensors, Signal processing, Photodetectors

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Proceedings Article | 18 May 2006 Paper

Speckle noise in a continuously scanning multibeam laser Doppler vibrometer for acoustic landmine detection

Vyacheslav Aranchuk, Amit Lal, Cecil Hess, James Sabatier, Richard Burgett, Ina Aranchuk, William Mayo

Proceedings Volume 6217, 621716 (2006) https://doi.org/10.1117/12.668783

KEYWORDS: Laser Doppler velocimetry, Speckle, Spiral phase plates, Signal to noise ratio, Doppler effect, Wavelets, Land mines, Interference (communication), Fermium, Frequency modulation

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Proceedings Article | 17 May 2006 Paper

Advanced LDV instruments for buried landmine detection

Amit Lal, Slava Aranchuk, Valentina Doushkina, Ernesto Hurtado, Cecil Hess, Jim Kilpatrick, Drew L'Esperance, Nan Luo, Vladimir Markov, Jim Sabatier, Eddie Scott

Proceedings Volume 6217, 621715 (2006) https://doi.org/10.1117/12.668927

KEYWORDS: Land mines, Laser Doppler velocimetry, Spatial resolution, Sensors, Doppler effect, Cameras, Interferometry, Phase shifts, Imaging systems, Photography

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Proceedings Article | 10 June 2005 Paper

Whole-field digital vibrometer system for buried landmine detection

Amit Lal, Cecil Hess, Eddie Scott, Michael Dang, Robert Nichols

Proceedings Volume 5794, (2005) https://doi.org/10.1117/12.604048

KEYWORDS: Land mines, Speckle, Phase shifts, Wavefronts, Spatial resolution, Interferometry, Pulsed laser operation, Interferometers, Phase interferometry, Beam splitters

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Proceedings Article | 10 June 2005 Paper

Multi-beam laser Doppler vibrometry for acoustic landmine detection using airborne and mechanically coupled vibration

Vyacheslav Aranchuk, James Sabatier, Amit Lal, Cecil Hess, Richard Burgett, Michael O'Neill

Proceedings Volume 5794, (2005) https://doi.org/10.1117/12.603512

KEYWORDS: Doppler effect, Laser Doppler velocimetry, Land mines, Interference (communication), Image segmentation, Sensors, Acoustics, Vibrometry, Airborne laser technology, Photodetectors

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Proceedings Article | 21 September 2004 Paper

Acoustic sensor for landmine detection using a continuously scanning multibeam LDV

Vyacheslav Aranchuk, Amit Lal, Hansheng Zhang, Cecil Hess, James Sabatier

Proceedings Volume 5415, (2004) https://doi.org/10.1117/12.541562

KEYWORDS: Laser Doppler velocimetry, Land mines, Mining, Sensors, Image segmentation, Mirrors, Acoustics, Velocity measurements, Photography, Diffractive optical elements

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Proceedings Article | 11 September 2003 Paper

Multiple-beam LDV system for buried landmine detection

Amit Lal, Hansheng Zhang, Vyacheslav Aranchuk, Ernesto Hurtado, Cecil Hess, Richard Burgett, James Sabatier

Proceedings Volume 5089, (2003) https://doi.org/10.1117/12.487154

KEYWORDS: Land mines, Mining, Laser Doppler velocimetry, Speckle, Clocks, Ferroelectric materials, Electronics, Sensors, Data acquisition, Diffractive optical elements

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Proceedings Article | 11 September 2003 Paper

Mobile mounted laser Doppler vibrometer array for acoustic landmine detection

Richard Burgett, Marshall Bradley, Michael Duncan, Jason Melton, Amit Lal, Vyacheslav Aranchuk, Cecil Hess, James Sabatier, Ning Xiang

Proceedings Volume 5089, (2003) https://doi.org/10.1117/12.487186

KEYWORDS: Laser Doppler velocimetry, Mining, Acoustics, Land mines, Doppler effect, Electronics, Head, Data acquisition, Control systems, Sensors

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Proceedings Article | 13 August 2002 Paper

Whole-field laser vibrometer for buried land mine detection

Amit Lal, Cecil Hess, Hansheng Zhang, Ernesto Hurtado, Vyacheslav Aranchuk, Vladimir Markov, William Mayo

Proceedings Volume 4742, (2002) https://doi.org/10.1117/12.479135

KEYWORDS: Land mines, Target detection, Magnesium, Doppler effect, Digital signal processing, Performance modeling, Computer simulations, Speckle

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Proceedings Article | 19 June 2002 Paper

Reverse engineering by fringe projection

Jan Burke, Thorsten Bothe, Wolfgang Osten, Cecil Hess

Proceedings Volume 4778, (2002) https://doi.org/10.1117/12.473547

KEYWORDS: Fringe analysis, Calibration, Cameras, Phase measurement, Computer aided design, Projection systems, Data modeling, Solid modeling, Reverse modeling, Reverse engineering

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Proceedings Article | 18 March 1994 Paper

Practical applications in UV Raman line imaging of water vapor

Peter DeBarber, Cecil Hess, Robert Pitz, Sastri Nandula, Thomas Brown, P. Skaggs

Proceedings Volume 2122, (1994) https://doi.org/10.1117/12.171303

KEYWORDS: Raman spectroscopy, Calibration, Luminescence, Cameras, Ultraviolet radiation, Spectroscopy, Raman scattering, Spatial resolution, Charge-coupled devices, Laser scattering

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Proceedings Article | 2 December 1993 Paper

Temperature sensitivity of the two-photon photodissociation fluorescence spectrum of water vapor in a hydrogen-air burner

Peter DeBarber, Cecil Hess, Robert Pitz, Warren Cole

Proceedings Volume 2005, (1993) https://doi.org/10.1117/12.163704

KEYWORDS: Luminescence, Temperature metrology, Photons, Diagnostics, Error analysis, Absorption, Pulsed laser operation, Excimer lasers, Spectroscopy, Mechanical engineering

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Proceedings Article | 1 October 1990 Paper

Holographic diagnostics of breakup phenomena of impinging jets for liquid rocket motor applications

Cecil Hess, James Trolinger, David Weber, Craig Wood, Gary Samuelsen, Blake Stapper

Proceedings Volume 1375, (1990) https://doi.org/10.1117/12.35054

KEYWORDS: Liquids, Holograms, Holography, Combustion, Photography, Rockets, Diagnostics, Pulsed laser operation, Light scattering, Spherical lenses

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Showing 5 of 19 publications

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