Sensitivity Analysis in Ballbar Measurement of 3D Circular Interpolation Motion Equivalent to Cone-Frustum Cutting in Five-Axis Machining Centers

Abstract

This paper describes the testing method for five-axis machining centers using three-dimensional circular interpolation movement equivalent to the cone-frustum cutting. It is assumed in the simulation that a ball bar system is used as a measuring device that can freely moves in 3D space. The ratio of a measurement value by the ball bar and a real error of each axis is defined as a sensitivity coefficient of axis. The sensitivity coefficient of each axis was calculated changing the apex angle and the center location of virtual cone-frustum. The 3D circular movements are simulated, and the effect of the pitch errors of the axes of rotation was investigated by changing the sensitive direction of the ball bar. From the view point of sensitivity coefficient, it is pointed out that if the measurement is conducted by the ball bar which is parallel to the bottom of a cone-frustum whose center is set away from the center line of the axis of rotation, it is possible to measure the movement errors of five axes. は，ISO 規格で試験条件としている半頂角 15°と 45°の 2 種類の円すい台を想定 して，テーブル旋回形 5 軸 MC の測定を行うときに使用する NC データを詳細に分析した．そこでは，回転テー