3-D measurement of cutting tool wear

The method of measuring the three dimensional profile of a contoured object relative to a reference plane comprising the steps of:

• projecting stripes of light having uniform slope and spacing onto the surface of the object and the reference plane at a first angle to illuminate the object as well as the plane, wherein the stripes of light on the reference plane viewed from a second angle are straight and uniform;
• sensing an image of the stripes from the second angle whereby the image comprises unconnected line segments due to noise,
• constructing from the unconnected line segments complete lines extending across the object and the reference plane whereby in the image the lines of the object are locally displaced as a function of the distance from the reference plane;
• calculating straight reference lines in the object that are extensions of the completed lines on the reference plane;
• and
• measuring the displacement of the completed lines in the object from the straight calculated reference lines to extract profile information.

A method of measuring wear of a cutting tool having a worn portion and an unworn planar portion, comprising the steps of:

• projecting a striped pattern of light onto the surface of the cutting tool at a first angle to illuminate each of the worn and unworn planar portions with multiple common stripes of light, wherein the stripes of light viewed from the first angle are straight and uniform and the stripes of light on the unworn planar portion viewed from a second angle are straight and uniform;
• sensing an image of the surface of the cutting tool from the second angle, the sensed image comprising image lines, each of which corresponds to a respective strip of light on the surface of the cutting tool, each image line having a first line portion corresponding to a respective one of the stripes of light on the unworn planar portion of the tool and a second line portion extending from the first line portion corresponding to said respective one of the stripes of light on the worn portion of the tool;
• calculating a straight line extension of each first line portion of the image lines into the worn portion;
• and
• measuring an offset distance of the straight line extension and the second line portions as a measure of depth of wear.