Westinghouse Electric Corporation

United States of America As Represented by the Secretary of the Air Force

Lawrence J Zana

Gerald A Breakey

Hassan J Ahmed

Nicola G Arlia

John M Beatty

John C Lichauer

A system and a process for identifying three-dimensional coordinates and orientation to a robot. A pair of CCD video cameras are used to measure the position of a laser or other light source spot on the surface of a workpiece. The laser and cameras need not be fixed to each other, and the laser may be handheld. In operation, the light source provides a small spot of light centered on the location to be indicated to the robot. The spot of light is then located in the field of view of each of the cameras. Using the concept of stereo triangulation, the three-dimensional coordinates of the spot are calculated by a microcomputer. These coordinates are then transformed into a form which is recognizable by the robot. The spot of light from the object can also be generated by an emitter (such as an LED or Laser diode) which is fixed on the workpiece and stimulated by an energy source.

Method and apparatus for identifying three-dimensional coordinates and

A camera system for simultaneously recording separate near-infrared and visible light images is disclosed having a visible light source for illuminating a given area with visible white light, indicia generating means for directing an image of a wavelength of light longer than wavelengths of light of the visible white light upon the given area, a first electronic camera for recording an image of the visible light but not the longer wavelength of light and a second electronic camera for recording an image of the longer wavelength of light but not the visible light, and a single cold mirror common to the two cameras for directing the two light images to their respective cameras.

Optical system for obtaining separate and simultaneous near-infrared and

A non-contact surface flaw detection system for workpieces such as nuclear fuel pellets transports the pellets continuously along an illuminated path while rotating them. A line scan camera records a series of line scans for the pellets and the resulting values of pellet reflectivity are digitized. Pixel values are compared to thresholds defined adaptively by averaging and/or using a video finite impulse response filter, to generate a binary map of 'good' and 'bad' pixels, that also defines the edges of the pellet in the map. A processor counts and associates bad pixels to logically define and assess blobs of bad pixels. The processor checks for coincidence of the edge pixels with a nominal edge line that best fits the edge, for finding edge flaws. The pellets assessed in this manner are selected or rejected. Camera sensor elements are normalized for gain and offset. Shifting of the pixel data cancels skew produced in scanning moving pellets. Convolution filters cancel isolated bad pixels and enhance contrast at the edge. For processing adjacent areas, the pixel image of the pellets can be tiled, flaws bridging the tile boundaries being assessed as a single blob. The apparatus is preferably arranged for parallel pipeline processing for sidewall and edge defects and can be embodied in a series of modular VME boards.

Non-contact flaw detection for cylindrical nuclear fuel pellets

A control processor in a robotic system treats optically sensed locations along the seam path ahead of the tool, which are classified in relation to elapsed distances and identified in 3-D coordinates and 3-axes tool orientation, to apply in real time and under feedforward a control signal representing the error between anticipated tool position and anticipated sensed location on the path. In the process, the anticipated sensed location is obtained by interpolation between actually sensed locations. A taught path is recovered from the robot. The control processor operation is also based on elapsed distances and related to actual tool position provided by the robot.

Automatic seam tracker and real time error cumulative control system for

A signal converter adapted for use in a nuclear fuel tube inspection system that inspects the inner diameter and outer diameter of the tubes by comparing their actual diameters to the corresponding nominal values and uses that comparison to reject or pass each fuel tube. The signal converter receives signals corresponding to the inner and outer diameters, adds those signals to inverted reference signals corresponding to the nominal values for the inner and outer diameters, shifts the difference signals by an appropriate level, and amplifies the difference signals. The amplified difference signals can be applied to an analog to digital converter and then supplied to a microprocessor for processing. The signal converter increases the resolution of the inspection system without reducing the range of signal levels that it can process.

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Hampton Township, PA, United States of America

Lawrence J Zana