Numerical control system for highly dynamic processes

Abstract

A coarse interpolator is adapted for use in a numerical control system for performing path interpolation calculations for the control of highly dynamic processes. These processess have different path contour geometries wherein a vector having a length L connects in linear form a first point P1 to a second point P2. These points are located in three dimensional Cartesian space having axes X, Y, and Z, Length L has Cartesian components X, Y and Z and is subject to an angular rotation C about the z axis. The interpolator responds to a group of predetermined vector lengths, starting with the maximum length, in order to calculate the path elements L, X, Y, Z and C for the maximum length vector. A path error E is then determined for the path elements so calculated. The error E is then compared with a praedetemined maximum error value. If the error E does not exceed the maximum value, the calculated path elements are outputted. If the error E exceeds the maximum value, the path elements for the vector which has the length next shorter to the vector of maximum length are then calculated. These operations are repeated until the path elements calculated for a vector result in a path error which does not exceed the maximum value and these path elements can be outputted. The distance between the outputted path elements and the end point of the path contour is then determined and the coarse interpolator stops interpolating when the distance has a zero value.