Patent Document ID: 5523953
Application ID: 08301382
Patent Flag: 1

Claim One:
1. A machine tool having a plurality of components subject to thermal deformation, for machining a workpiece using a tool member in which said tool member and workpiece are moveable relative to each other, said machine tool comprising: a numerical controller for providing a drive signal to move said tool member relative to said workpiece along at least one axis of movement; thermosensors for sensing temperatures of at least some of said plurality of components; an inferring means for inferring thermal deformations of said components in the direction of said axis of movement, said inferring means including a plurality of neural networks having a number of neurons, each of said neural networks being adapted to receive temperature signals indicative of the sensed temperatures and to thereupon generate inferred values of thermal deformation of said components in the direction of said axis; and a correction value calculator, responsive to said inferred values of thermal deformation for providing a correction signal indicative of a correction value in the direction of said axis of movement; and wherein said numerical controller is operable to correct said drive signal by said correction signal to thereby correct any positioning error due to thermal deformation in the direction of said axis of movement.