Westinghouse Electric Corporation

John M Beatty

Hassan J Ahmed

Ronald L Bannister

Ralph W Kugler

Nicola G Arlia

Lawrence J Zana

Robert L Frater

John C Lichauer

Edward C Borgoyn

The two sides of a flat panel are inspected in successive inspection stations each of which includes a camera having a linear array of CCD elements which generates an image line-by-line from a stripe of light reflected by one flat surface of the panel as the panel is conveyed through the inspection station. The signals representing images of the two faces of the panel are independently digitized and stored in separate pixel arrays of gray-scale values. The images are queued for filtering followed by processing by a single image processing board which generates a table of hits, identified as pixels having gray-scale values which breach preselected thresholds. Sections of the stored pixel array are transmitted sequentially to the image processing board which has a frame size smaller than the stored array, with the frame sized sections overlapping as required to confine the pixels processed to those inside the edges of the panel image. A microprocessor analyzes the hits identified by the image processing board and generates a reject signal if the density of hits exceeds a limit. The microprocessor also associates hits by proximity into blobs and rejects the panel if a weighted count of hits in any blob exceeds predetermined criteria.

Vision system for inspecting a part having a substantially flat

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 method and apparatus for inspecting cylindrically configured pellets for surface defects is disclosed. At least one axially extending linear portion of the peripheral surface of the pellet is optically sensed. A set of discrete digital values representative of the optically sensed linear portion of the pellet surface is generated and the set of digital values is compared to a predetermined standard. Groups of digital values representative of adjacent locations on the surface of the pellet having values greater or less than the predetermined standard are identified. The area of adjacent digital values having a value above the standard, and the area of adjacent digital values having a value below the standard are calculated and compared to a predetermined area. The pellet is rejected when the calculated area exceeds a predetermined area. During inspection, the pellet is moved axially through an inspection station by first and second horizontally positioned substantially parallel and longitudinally extending pellet support rolls. The rolls are spaced a distance from each other less than the diameter of a pellet to be transferred. The rolls are rotated upward and outward from each other and chain dogs are positioned between the spaced rolls for engaging a pellet and moving the pellet along between the spaced pellet support rolls.

Pellet inspection system

Turbine blade vibration detection apparatus having two or more extremely narrow beam radar sensors positioned to direct their radar signals towards predetermined blade row or rows. A blade identification circuit is provided for each blade row having an associated radar sensor for providing an output count indicative of which blade is being examined by a particular radar sensor. The gating of the blade count and radar sensor signals is governed by a computer which performs a frequency analysis of the radar signals and compares the result with predetermined threshold values.

Turbine blade vibration detection apparatus

A boiler feedpump turbine (BFPT) control system for controlling the rotating speed of a boiler feedpump turbine in a selected one of at least three control modes is disclosed. The boiler feedpump turbine is mechanically coupled to a boiler feedpump for governing the flow of feedwater pumped by the feedpump to a boiler. A boiler control turbine speed signal which represents the feedwater requirement of the boiler is provided to the BPFT control system from a conventional boiler feedwater control system. The flow of feedwater pumped by the feedpump is a function of the rotating speed of the boiler feedpump turbine which is controlled in a selected one of three modes in accordance with the adjustment of a speed set point. The three control modes include adjusting the speed set point in relation to a turbine speed demand signal generated within the BFPT control system only at values below the boiler control turbine speed signal, adjusting the speed set point in relation to the boiler control turbine speed signal, and overriding the adjustment of the speed set point by the boiler control turbine speed signal to permit adjustment of the speed set point by the turbine speed demand signal beyond the value of the boiler control turbine speed signal. Transfers between the control modes are performed automatically in response to a set of predetermined conditions and commands. The BFPT additionally provides for conducting an overspeed test which permits adjustment of the speed set point by the turbine speed demand signal in a predetermined range beyond a rated turbine speed value. This overspeed test function prohibits the speed set point from remaining above the rated turbine speed values at times when not conducting the overspeed test. The BFPT control system employs a closed-loop primary speed controller which calculates its turbine speed feedback signal from a selected one of two speed transducers. The other of the two speed transducers may be used if a malfunction is detected in the selected speed transducer. The BFPT control system further incorporates a degraded manual backup controller which assumes control responsibilities when a malfunction is detected which renders the primary controller inoperative.

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Murrysville, PA, United States of America

John M Beatty