Patent ID: 6675061
Filing Date: 2004-01-06
Classification: G05B

Abstract:
A numerically controlled curved surface machining unit equipped with three linear axes and, at least one rotary axis, including a simultaneous multiple-axis control NC machine, which is numerically controlled by a numerical control unit with a numerical control NURBS (non-uniform rational B-spline) interpolation function, comprising:means for reading tool control point vector data and tool axis vector data, calculated along a tool path on a workpiece coordinate system with defined curved shape by a host computer, as cutter location (CL) data and converting the CL data into a position vector of the three linear axes and a rotation angle on a machine coordinate system so as to operate the simultaneous multiple-axis control NC machine in accordance with the machine configuration of the NC machine; means for calculating knot vectors of a NURBS curve with the most suitable chord length on the basis of a position vector of the three linear axes and a rotation angle calculated on a machine coordinate system; means for calculating each NURBS curve of the three linear axes and one rotary axis using the knot vectors; means for converting the NURBS curve into NURBS interpolation NC data; means for converting the feed rate on the workpiece coordinate system into the feed rate per minute or feed rate per inverse time on the machine coordinate system; means for transmitting the obtained CL data to the NC control unit; means for removing or inserting CL data along the tool path in accordance with the machining accuracy of the curved surface, upon reading data as CL data; and means for reading a compensation value based on an individual difference of each tool from the NC control unit, upon reading data as CL data, and compensating the read CL data in accordance with the tool compensation value.