The State University of New York

Peisen S Huang

Fu-Pen Chiang

Imin Kao

Qingying Hu

A three dimensional surface contouring and ranging system ( ) based on a digital fringe projection ( ) and phase shifting technique is disclosed. In the system, three phase-shifted fringe patterns and an absolute phase mark pattern are used to determine the absolute phase map of the object ( ). The phase map is then converted to the absolute x, y, and z coordinates of the object surface by a transformation algorithm. A calibration procedure is used to determine accurate values of system parameters required by the transformation algorithm. The parameters are initially indirectly measured through experiments to determine their approximate values. A calibration plate is then measured by the system at various positions. An iteration algorithm is then used to estimate the system parameters.

Method and apparatus for three dimensional surface contouring and ranging using a digital video projection system

A novel three dimensional surface contouring method has been developed based on the fall-field fringe projection technique. A digital video projection system is used to project digitally created fringe patterns onto the object. The fringe pattern distorted by the geometry of the object surface is then captured by a high resolution CCD camera. To increase contouring resolution, purely software-based digital phase shifting technique is used, which eliminates the need for accurate positioning systems in the traditional phase shifting methods. The surface is reconstructed by applying the phase wrapping and unwrapping algorithms.

Method and apparatus for three dimensional surface contouring using a digital video projection system

An apparatus and method for semi-automatic focusing and assembling of a light beam modifier, such as a lens, relative to a light beam source to optimize the light beam characteristics at one or more locations along the beam path using one or more light beam analyzers ( ). A host computer compares the measurements and axially adjusts the light beam modifier. The apparatus may include two focusing stations ( ) for alternately focusing and assembling two light source assemblies, two beam splitters ( ) for splitting the light beam emitted from either focusing station into three components, and three light beam analyzers for measuring the beam characteristics at three locations. The apparatus may also include a video camera for automated or manual pointing of the laser beam, a semi-automatic glue dispensing system for fixing the light beam modifier relative to the light source and an automatic laser power-up circuit.

Computer based semi-automatic focusing and assembly apparatus and method

A laser measurement system for rapid calibration of machine tools includes a measurement enhancement device which enables an existing standard single degree of freedom laser interferometry system to simultaneously measure up to four additional degrees of freedom. The device includes a first beamsplitter which splits a laser beam of the existing system, and a measurement component which receives the split beam and senses at least one value for at least a second degree of freedom. The beamsplitter and measurement component are mounted in a compact housing which is configured for attachment to the existing system. The measurement component can employ a new type of compact angle measurement device according to the invention. The new angle measurement device is based on the internal reflection effect and requires only a single prism for each angular component to be measured.

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Coram, NY, United States of America

Peisen S Huang