Abstract
As a base to improve the positioning accuracy by the real time compensation of the thermal elongation of ball-screw, it is important the improvement of the estimation accuracy on the thermal elongation of ball-screw. In this paper the improvement is carried out under two processes; namely, a process to improve the measurement accuracy of the elongation, in which it is eliminated the influences due to inertia force of table at the stroke ends and due to thermal elongation of the displacement measuring system during experiment, and another process to improve the estimation accuracy of the elongation, in which the longitudinal temperature distribution of the ball-screw is measured in detail at fifteen points by the optical telemeter system developed. It is clarified that the estimation accuracy of -2.50 - +2.58 μm is accomplished under several conditions less than 20m/min table speed.
