The invention belongs to the technical field of ultra-precise work and complex parts manufacturing, which relates to a path generating method of a curved face
processing. The method is utilized on
a diamond ultra-precise
machine tool with three shafts, which comprises first, establishing a coordinate
system of a free curved
face model of a
processing surface of a workpiece, and establishing conversion relationship between the model coordinate
system and a
machine tool coordinate
system, second, conversing the model coordinate of a
processing point on the processed free curved face to a coordinate under the coordinate system of the
machine tool, third, solving and processing a normal vector of
cutting face of a cutter when the point is processed, fourth, projecting the normal vector of the point of the curved face on the
cutting face, and compensating a circular arc
radius of the cutter on the projection vector direction, and getting a coordinate of the arc center of the
cutting edge under the cutting edge coordinate system, traversing the processing point on the free curved face, at last generating a processing path. The limitation of processing the free curved face on the
machine tool with three shafts can be broken by adopting the path generating method which is provided by the invention, the invention can achieve ultra-sophisticated processing of the free curved face.