US 5,805,289 AGranted

Portable measurement system using image and point measurement devices

AssigneeGeneral Electric Company

InventorsNelson Raymond Corby, Jr., Christopher Allen Nafis, Boris Yamrom

Life of this patent

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Abstract

Calibrated spatial reference devices (SRDs) of known dimensions having targets at known relative locations are attached to a large structure to be measured. A design device employs a digital camera to acquire digital images of `islands` of the structure including the SRDs and employs photogrammetry techniques to determine relative locations of `islands` within a large structure. A highly accurate coordinate measurement device provides absolute 3D measured locations of the targets used to convert the relative photogrammetry locations into absolute 3D locations. A monitor displays the digital images, measured 3D locations, photogrammetry locations in a superimposed manner to a user and a user interface allows the user to select objects to be measured. Image detection techniques are used to identify objects selected by a user and dimensions, and distances between selected objects are automatically calculated. A remote link allows remote users to interact with the device to view, select structures and measure dimensions. The device is also capable of storing any type of imagery, notes, voice annotations, and also capable of retrieving archived information. This allows a time-lapse playback of objects indicating wear or corrosion.

Claims8

Dependent claims

A design device for accurately measuring dimensions of a structure with high accuracy comprising:

a) at least one spatial reference device (SRD) attached to the structure, machined to highly accurate, known dimensions, having a plurality of reference nests each which receive a target, the nests also being visible on 2D digital images;
b) a digital camera for acquiring a plurality of high resolution 2D digital images each from an associated position and orientation, `pose`, with a field of view smaller than the entire structure, and encompassing at least one SRD;
c) a coordinate measurement machine (CMM) having a base fixed with respect to the structure, for measuring an absolute `pose`, of the digital camera for each acquired 2D image, and an absolute measured location of each of the targets, with reference to the CMM base;
d) a photogrammetry unit functionally coupled to the digital camera and the CMM, for receiving the 2D digital images and their associated poses, for determining relative 3D locations of selected structures based upon the 2D images and poses;
e) an transformation device functionally coupled to the CMM and the photogrammetry device for receiving the absolute 3D measured locations and the relative 3D photogrammetry locations, and for converting the relative 3D locations into absolute 3D photogrammetry locations;
f) a monitor for modifying the 2D digital images to be correctly viewed from a user-provided viewpoint, for displaying the modified 2D images with the absolute 3D photogrammetry, and 3D measured locations superimposed upon them in correct registration to a user as viewed from the given viewpoint;
g) a user interface coupled to the monitor, which receives user-selected input to the transformation device.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/888,795Filed 7 Jul 1997
Granted: 8 Sep 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G01C 11/02
Photogrammetry or videogrammetry, e.g. stereogrammetry; Photographic surveying: picture taking arrangements specially adapted for photogrammetry…
G01B 5/14
Measuring arrangements characterised by the use of mechanical techniques: for measuring distance or clearance between spaced objects or spaced…
G01B 11/002
Measuring arrangements characterised by the use of optical techniques: for measuring two or more coordinates
G01B 11/14
Measuring arrangements characterised by the use of optical techniques: for measuring distance or clearance between spaced objects or spaced apertures