PROCEDIMENTO DI CONTROLLO NUMERICO COMPUTERIZZATO PER LO SPOSTAMENTO DI UN ELEMENTO MOBILE LUNGO UN PERCORSO SU UNA SUPERFICIE A TRE DIMENSIONI

A CNC process for displacing a movable member along a path on an intricate surface in a three-dimensional coordinate system is disclosed in which the surface is divided into a plurality of elementary characteristic regions each individually definable as one of different geometrical categories such as toroidal, spherical, cylindrical and planar surfaces. The process comprises establishing a general equation for each of these categories and storing the established general equations into a memory unit for a computer. Data required to adapt each of the stored general equations to a corresponding one of the characteristic regions in the three-dimensional coordinate system are inputted into the computer to reduce the general equations to their respective specific equations in which no more than three coordinates are variable. A sequence of incremental two-dimensional positions defined in the system by first and second coordinates thereof are inputted into the computer to allow it to compute, for each position on the path, the value of the third coordinate from the first and second coordinates and the specific equations, thereby determining the path along which the member is moved.