Method and apparatus for determining the straightness of tubes and bars

A method for automating the measurement of straightness of linear stock material, comprising:

• determining a centroid for each of at least three discrete perpendicular cross-sections of the linear stock material, said determined centroids defining a segment of the linear stock material;
• establishing a virtual longitudinal axis of the linear stock material between two of said determined centroids;
• for each remaining centroid, determining a measure of displacement from said virtual longitudinal axis;
• for each remaining centroid, determining a measure of angular orientation about said virtual longitudinal axis;
• utilizing each said determined measure of displacement and each said determined measure of angular orientation to identify a direction and magnitude of concavity in the linear stock material over said segment;
• and
• storing a representation of said identified direction and magnitude of concavity for said segment of the linear stock material.

A non-contact linear stock material straightness measurement system comprising:

• a plurality of spaced sensor modules, each sensor module configured to acquire data from of an external surface of a linear stock material in an associated cross-sectional plane;
• and
• a processing system operatively coupled to each of said sensor modules to receive data there from, said processing system configured with a software algorithm to calculate a location of a centroid of said linear stock material in each of said associated cross-sectional planes;
• wherein said processing system is further configured with a software algorithm to determine a direction and magnitude of concavity in said linear stock material over a segment defined by said centroids;
• and
• wherein said processing system stores the determined direction and magnitude of concavity for said segment of the linear stock material.