Westinghouse Electric Corporation

Carnegie Mellon University

Shree K Nayar

Lee E Weiss

Arthur C Sanderson

Takeo Kanade

Katsushi Ikeuchi

David A Simon

The invention is an automated solder joint inspection system for determining the quality of a specular soldered joint through examination of the shape of the joint surface using a series of point light sources and the associated highlight reflections from the joint surface. The light from point light sources, which is directed toward the solder joint, is reflected in a pattern from the solder joint to an array of light responsive transducers from at least one location. Utilizing the intensity values from the light responsive transducer array, the surface orientation of the solder joint at a number of points is determined. The solder joint is evaluated in one of two ways. In one way, using known surface features of solder joints along with curve fitting techniques, a series of grid maps is mathematically interpreted to reconstruct the solder joint surface. A rule-based system, through comparison with acceptable solder joint surface features, evaluates and classifies the joint for an acceptability determination. In another way the surface orientation is used to generate an Extended Gaussian Image of the joint and the features of this are analyzed.

Solder joint inspection system and method

An photometric sampling apparatus for an object surface shape and reflectance extraction system includes an array of point light sources spaced apart from one another in an arcuate configuration about a common site at which an object is placed from inspection, an array of extended light sources spaced apart from one another in an arcuate configuration about and oriented in different directions toward the common site, and a viewing device for viewing the object from a single direction when placed at the common site in order to extract information corresponding to the image of the object viewed. The array of point light sources can be activated for emitting light therefrom along different orientation angles toward the object at the common site. The array of extended light sources are generated on the surface of a light-diffusing medium, such as a translucent globe, disposed between the array of point light sources and common site. Each extended source emits light from an area of points unlike each point source which emits light from a single point. A scanner device is connected to the point light sources for sequentially activating them to emit light therefrom. In response to the sequence of emitted light, the extended light sources are generated in a scanning fashion for producing a sequence of images of the object at the viewing device.

Surface shape and reflectance extraction system

The present invention pertains to a robotic vision system for identifying the location of objects. The robotic vision system includes a device for recording images, and n elements, where n.gtoreq.2 and is an integer. Each of the n elements is disposed at a predetermined position such that each of the n elements is in view of the recording device and reflections of objects from each of the n elements is received by the recording device. The robotic vision system also includes a device for determining the location of objects from the image received by the recording device. The recording device is connected to the determining device to provide the viewed image thereto.

Robotic vision system

The invention is an automated solder joint inspection system for determining the quality of a specular soldered joint through examination of the shape of the joint surface using a series of point light sources and the associated highlight reflections from the joint surface. The light from the point light sources, which is directed toward the solder joint, is reflected in a pattern from the solder joint to an array of light responsive transducers, such as a camera, at a fixed location. Utilizing the intensity values from the light responsive transducer array, a binary grid map is generated for the reflections from each point light source. Using known surface features of solder joints along with curve fitting techniques, a series of grid maps may be mathematically interpreted to reconstruct the solder joint surface. A rule-based system, through comparison with acceptable solder joint surface features, evaluates and classifies the joint for an acceptability determination.

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Pittsburgh, PA, United States of America

Shree K Nayar