REALTIME CURVE INTERPOLATORS

The amount of geometric information that must be transferred between a CAD system and a computerized numerical control system creates a conflict between part precision on the one hand and fedrate fidelity and communications load on the other. This is the motivation for the development of new curve interpolation algorithms for CNC. The interpolation depends on the method of curve representation, i.e. the use of an implicit or a parametric form. Accordingly, the paper presents two realtime interpolation algorithms and compares them with existing CAD interpolators. With the new interpolators, the amount of geometric information transferred from the CAD system to the CNC system is reduced by orders of magnitude. Moreover, the contour errors caused by the new interpolators are much smaller than those caused by conventional CAD interpolators.