Abstract: A machine vision system that can address a number of board, lineal, cant, and flitch inspection problems by incorporating all the sensors needed to address the surface feature detection problem, the three-dimensional shape detection problem, and the internal feature detection problem. To detect surface features, two color cameras are employed, one for imaging each of the major faces of a board, lineal, cant, or fitch. To address the three-dimensional shape detection problem, a high speed laser profiling device is employed. An x-ray scanning system is employed to detect internal features. The system is able to process material in a species-independent manner by using a histogram-based segmentation procedure for analyzing both the camera imagery and the x-ray imagery; and can detect small defects by removing the effects of large features from the histograms once they have been detected. The system also utilizes redundant information from the set of multiple sensors to improve system accuracy.
Type:
Grant
Filed:
August 16, 1996
Date of Patent:
September 28, 1999
Assignees:
Virginia Polytechnic & State University, The United States of America as represented by the Secretary of Agriculture
Inventors:
Richard W. Conners, David E. Kline, Phillip A. Araman, Xiangyu Xiao, Thomas H. Drayer
Abstract: Compositions having the general formula (Ca.sub.x Mg.sub.1-x)Zr.sub.4 (PO.sub.4).sub.6 where x is between 0.5 and 0.99 are produced by solid state and sol-gel processes. In a preferred embodiment, when x is between 0.5 and 0.8, the MgCZP materials have near-zero coefficients of thermal expansion. The MgCZPs of the present invention also show unusually low thermal conductivities, and are stable at high temperatures. Macrostructures formed from MgCZP are useful in a wide variety of high-temperature applications. In a preferred process, calcium, magnesium, and zirconium nitrate solutions have their pH adjusted to between 7 and 9 either before or after the addition of ammonium dihydrogen phosphate. After dehydration to a gel, and calcination at temperatures in excess of 850.degree. C. for approximately 16 hours, single phase crystalline MgCZP powders with particle sizes ranging from approximately 20 nm to 50 nm result. The MgCZP powders are then sintered at temperatures ranging from 1200.degree. C. to 1350.
Type:
Grant
Filed:
June 6, 1990
Date of Patent:
April 7, 1992
Assignees:
Center for Innovative Technology, Virginia Tech Intellectual Properties, Inc., Virginia Polytechnic and State University
Inventors:
Jesse Brown, Deidre Hirschfeld, Dean-Mo Liu, Yaping Yang, Tingkai Li, Robert E. Swanson, Steven Van Aken, Jin-Min Kim