Knife sensor apparatus for cutting sheet material

Abstract

A computer-controlled machine and variations thereof are disclosed for cutting shapes of material with a cutting tool, including a sensor for sensing or estimating a knife offset during cutting to provide feedback for reducing cut shape error caused by the knife being offset from its ideal position. An exemplary embodiment includes a proximity sensor, a knife, such as a reciprocating knife, and circuitry and/or computer readable instructions for separating the output signal of the proximity sensor into a tangent signal corresponding to the tangent offset and a normal signal corresponding to a normal offset. The reciprocating knife can include a temperature sensor which is positioned to measure the temperature of the reciprocating knife near the point of contact between the knife and the material being cut. The temperature sensor is preferably a non-contact temperature sensor such as an infrared thermometer which operates under the principle of measuring thermal radiation emitted from an object.

Dependencies are inferred from the claim text.