Showing papers in "Optics and Lasers in Engineering in 1989"

TL;DR: In this paper, a sinusoidal grating structure is projected onto a diffuse three-dimensional surface, and the resulting deformed grating image is detected by a solid state array camera and processed by a microcomputer using interferometric phase measuring algorithms.

TL;DR: A no contact system based on laser scanning, which records 20 000 facial surface coordinates with a dynamic resolution of approximately 0·9mm in 30s, has been developed for the study of facial changes following facial reconstructive surgery.

TL;DR: In this paper, it was shown that simple integral relationships between the experimental data and the distribution of birefringence on the ray are valid, if rotation of the principal axes is moderate.

TL;DR: Electronic Speckle Pattern Interferometry (ESPI) is becoming a very common test and measurement tool among industrial users as discussed by the authors, and it has the potential to become the definitive tool for non-destructive testing.

TL;DR: In this paper, two measurements performed on rough surfaced objects are described, one on a mechanical component with a rather difficult accessible surface to be measured and the other on a convex surface of a ground lens.

TL;DR: In this paper, a high-precision image position sensing method for a position sensitive detector (PSD) with a kaleidoscopic mirror tunnel (KM-PSM) is introduced.

TL;DR: An approach for model-based shape inspection of large objects using active 3 -D vision is presented, based on the direct measurement of the time-of-flight of a laser pulse, and inspection software, including methods for comparison of the acquired shape information to a CAD model is described.

TL;DR: In this paper, an application of Digital Speckle Pattern Interference (DSPI) to the measurement of Poisson's ratio has been described, which provides several advantages over conventional holographic methods.

TL;DR: A dual aperture mask in a camera lens is used to transform a small commercially available CCD video camera into a ranging sensor and an active system using a projected laser beam provides a 360° range map which can be used to plan trajectories, either for robots or autonomous vehicles.

TL;DR: Moire interferometry utilizes high frequency gratings to contour displacement components with a sensitivity of the order of 0·5 μ as mentioned in this paper and is used for in-plane deformation measurement.

TL;DR: In this article, a theoretical and experimental investigation is made into the possibility of using a diffraction grating operating in total internal reflection (TIR) for studying the properties of light absorbing liquids.

TL;DR: In this article, a dual laser beam method was developed for the measurement of the thickness of a transient, wavy film, which is dependent only on reflections from the fluid surface; it does not require the surface covered by the film to be reflective nor does the fluid need to be translucent.

TL;DR: This software employs a pseudo-colour mapping technique which helps the operator to select the optimum threshold values and manual editing of the processed fringe pattern is possible to enable removal of unwanted kinks and to connect any discontinuities.

TL;DR: A CAD-integrated system using a CCD camera and a digital image processor for 3-D machine vision applications to industrial inspection of CAD-generated master objects is described.

TL;DR: In this article, the adoption and application of classical speckle metrological analysis techniques in particle image velocimetry (PIV) applications are described and an optical transform method for image analysis is outlined and the effect of the flow turbulence on the visibility of the resulting interference fringes demonstrated.

TL;DR: An optical filtering technique is used to improve the on-line quality characteristic of textile yarn and enables measurements to be made of the size of the main body of the yarn and the variation in hairiness along the length of the textile yarn.

TL;DR: In this article, the in-plane deformation/stress distribution has been studied for a typical bolted flange joint of a pressure vessel using two beam illumination DSPI, and the information obtained can be very useful in predicting the leakage behaviour of such joints employed in pressure vessels.

TL;DR: In this article, the bending of clamped defect-containing and defect-free circular plates, subjected to equal uniformly distributed loading, is investigated using the finite element method (FEM), and the results from the numerical computations are compared with those from a holographic experiment, based on comparative holographic moire interferometry (CHMI).

TL;DR: In this paper, the electronic correlation of speckle pattern to the measurement of surface displacement and strain is described, using a laser diode and line image sensors, and experimental results using a line image sensor are presented.

TL;DR: In this article, a small scale radar with a light beam modulated with a wavelength typical for radio waves is proposed for small scale ranging, which is a suitable means of scanning.

TL;DR: A theoretical discussion and experimental results show the efficiency of this method for subfringe evaluation, i.e. the measurement of displacements well below the mean speckle size.

TL;DR: In this article, the displacement at the apex, right ventricle, aortic and mitral valvular regions are significantly higher during I sound than that of II sound.

TL;DR: In this article, three-dimensional phase change-dependent parameter correlations, derived in previous work by modelling the heat transfer inside the workpiece processed with a focused beam, are combined with Gaussian beam propagation relationships for predicting the steady-state shape of the capillary and of the resolidified weld.

TL;DR: The fundamental basis of the laser tooling technique and its application in flexible automation is outlined and industrial applications of the tooling method are illustrated and possibilities for future systems are discussed.

TL;DR: In this paper, the role of the illuminating spot diameter on signal detection in laser Doppler vibrometry is emphasized and practical methods for beam expansion in reducing the spot size are described.

TL;DR: In real-time photogrammetry, and specifically when applied to machine vision, the solid state video cameras act as dynamic two-dimensional records of scences containing all the actual information for continuous gathering of three-dimensional object space data.

TL;DR: In this paper, the real conditions of a building are simulated and use is made of a pulsed laser in the experiments, and holographic interferograms corresponding to small pressure differences of air flow are presented and discussed.

TL;DR: In this paper, the deformation measured on the mock-up can be interpreted in the light of the particular geometry of the welded joint studied in order to minimise these effects.