Deformation calculation device, deformation measurement device, and deformation calculation method

A deformation calculation method comprising:

• a deformation calculation obtaining a simply-calculated deformation of a measurement region by digital image correlation with use of
• one first image selected from a first image group composed of first images, of the measurement region, that are taken from mutually different relative positions during a first image-taking period and
• one second image selected from a second image group composed of second images, of the measurement region, that are taken from mutually different relative positions during a second image-taking period different from the first image-taking period;
• a viewpoint change elimination obtaining a provisional deformation by subtracting, from the simply-calculated deformation, an apparent strain that is back-calculated on an assumption that there is no deformation in the measurement region;
• and
• an outputting, as a deformation of the measurement region from the first image-taking period to the second image-taking period, a deformation resulting from averaging the provisional deformations obtained by applying the deformation calculation and the viewpoint change elimination through sequential selection of different ones of the first images from the first image group and sequential selection of different ones of the second images from the second image group.

A deformation measurement device comprising:

• an image-taking device which
• takes images of a measurement region from mutually different relative positions during a first image-taking period, to output a first image group composed of first images, and
• takes images of the measurement region from mutually different relative positions during a second image-taking period different from the first image-taking period, to output a second image group composed of second images;
• a distance measurement device which measures a change that is a change, in at least one direction, in a relative position between the image-taking device and the measurement region and that occurs between the first image-taking period and the second image-taking period;
• a deformation calculator which obtains a simply-calculated deformation of the measurement region by digital image correlation with use of one first image selected from the first image group and one second image selected from the second image group;
• a viewpoint change eliminator which obtains a provisional deformation by subtracting, from the simply-calculated deformation, an apparent strain that is back-calculated on an assumption that there is no deformation in the measurement region, by using information about the change in the relative position;
• and
• a uniting circuitry which outputs, as a deformation of the measurement region from the first image-taking period to the second image-taking period, a deformation resulting from averaging the provisional deformations obtained by applying the deformation calculator and the viewpoint change eliminator through sequential selection of different ones of the first images from the first image group and sequential selection of different ones of the second images from the second image group.

A deformation measurement device comprising:

• an image-taking device which
• takes images of a measurement region from mutually different relative positions during a first image-taking period, to output a first image group composed of first images, and
• takes images of the measurement region from mutually different relative positions during a second image-taking period different from the first image-taking period, to output a second image group composed of second images;
• an orientation measurement device which measures a change, in an orientation of the image-taking device, that occurs between the first image-taking period and the second image-taking period;
• a deformation calculator which obtains a simply-calculated deformation of the measurement region by digital image correlation with use of one first image selected from the first image group and one second image selected from the second image group;
• a viewpoint change eliminator which obtains a provisional deformation by subtracting, from the simply-calculated deformation, an apparent strain that is back-calculated on an assumption that there is no deformation in the measurement region, by using information about the change in the orientation;
• and
• a uniting circuitry which outputs, as a deformation of the measurement region from the first image-taking period to the second image-taking period, a deformation resulting from averaging the provisional deformations obtained by applying the deformation calculator and the viewpoint change eliminator through sequential selection of different ones of the first images from the first image group and sequential selection of different ones of the second images from the second image group.