Machine vision system for position sensing

US4891767A · kind A · utility

Assignee

• Combustion Engineering, Inc. · US

Inventors

• Peter W. Rzasa · Granville, US
• Matthew Allen · Enfield, US
• Carl H. Neuschaefer · Enfield, US
• Joseph E. Kowles · Glastonbury, US
• Thomas D. Williams · Shutesbury, US
• Frank C. Glazer · Wellesley, US

Key dates

• Filing date: Jun 2, 1988
• Grant date: Jan 2, 1990
• Expiry date: Jun 2, 2008

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B25J9/1692
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

The video image of the end effector (26) and work surface (32) in the vicinity of the end effector is converted into a series of continually generated digitized images (132), which are further processed to detect and track the relative motion between the end effector and the work surface. After calibration (126), whereby an index of coordinates and arm orientation is established for a known positioning of the end effector relative to a known reference feature (28a) on the work surface, the tracking (168) of the motion of the end effector is utilized to continually update the index (104) to indicate the actual coordinate and orientation of the end effector relative to the work surface. The updated index is displayed on a live video monitor (44), and can be used as input to the feedback circuit (94) of the manipulator control system. In another embodiment of the invention, a high resolution monitor (52) displays an image of substantially the entire work surface, and particularly the features of interest, in the nature of a work surface map, and superimposes thereon a visual indication of the location, orientation and movement of the end effector, using the updated index information.