Measurement method and apparatus
AssigneeUnited States Pipe and Foundry Company
InventorKenneth J. Watts
Life of this patent
Estimating the term…
Abstract
An apparatus and method of measuring the inside surface of an object such as a pipe. The method includes capturing an image of the three dimensional interior pipe including an array of points of light projected by lasers from a mount positioned within the pipe, coplanar with the surface to be measured. The image is converted to a two dimensional array and analyzed to determine the dimensions of the interior surface of the pipe on the plane on which the points of light were projected.
Claims16
An apparatus for measuring an interior surface of a pipe, said pipe a longitudinal axis, comprising:
- an array of radial lasers comprising at least four lasers oriented radially with respect to the longitudinal axis of the pipe and disposed upon a mount adapted to be positioned axially within the pipe, wherein three of the radial lasers are positioned to project upon the interior surface of the pipe points of light consecutively spaced proximate to one another and the fourth laser is positioned to project a point of light substantially diametrically opposed thereto, forming a radial array of points of light;
- two parallel lasers disposed upon the mount oriented parallel to one another, the parallel lasers configured to project two points of light upon the interior surface of the pipe a predetermined distance apart, wherein the points of light projected by the radial lasers and parallel lasers are coplanar;
- a camera positioned to capture an image of the points of light projected by the radial laser array and the parallel lasers;
- and
- a processor configured to:
- convert length in the image to length along the interior surface of the pipe using the predetermined distance between the two parallel points;
- from the image, define a curve connecting the three consecutive points of the radial array;
- and
- determine a maximal distance between the curve and the fourth point of the radial array,
- wherein the maximal distance is the diameter of the pipe.
A method of measuring an interior surface of a pipe, said pipe having a longitudinal axis, comprising:
- projecting upon the interior surface of the pipe an array of at least four points of light radially spaced apart, forming a radial array of points of light, wherein three of the radial points are consecutively spaced proximate one another and the fourth point is substantially diametrically opposed thereto;
- projecting upon the interior surface of the pipe from parallel sources two points of light a predetermined distance apart;
- capturing an image of the radial array and the parallel points of light;
- converting length in the image to length along the interior surface of the pipe using the predetermined distance between the two parallel points;
- from the image, defining a curve connecting the three consecutive points of the radial array;
- and
- determining a maximal distance between the curve and the fourth point of the radial array,
- wherein the maximal distance is the diameter of the pipe.
Dependencies are inferred from the claim text.